Stoichiometry

Page 1

2552 RUMTL Chiang Mai

Stoichiometry

By Chollada Kulwat

Chemistry for Engineers

Stoichiometry

4 !" "# $# %& ภภภภภภ! ภ"#

4.1

)* +,-. !" "# $# %& !" "# $# %& (Stoichiometry) 1 ภD : ภŕ¸

Metron = ภ*#C

Stoicheion = % 3A

ภภภ!ภ" # " ภภ$ " % % &' () $ %" & '

" %* " " # " ( ) ภ* +( ( " % % &' & ,- . ภ/ ! ภ# ภภภ.! * ) 0 " +( )ภ1 " )/ )* 0 1#ภ" 3 4 (Hypothesis) ) " 2 ! ( " " ( .! & / " 3 !4()3 ภภ( - . .! 0 5 !4()3 ภภ(

6 3 ! 4() $) ) " %* %( ) ภ%/ ) 2 ! 4() 3 ภภ( 9:; (Theory) %7 3 ŕ¸

6 .!

6 %* ( ) ภ%/ ) !4()3 ภภ( - 8 " & ภ+( 4 # ) %( )

6 %* 83 ภ1 ภ; (Law)

132

Chemistry for Engineers

Stoichiometry

%7 # 3 ก 1 ก1 - %ก " 3 & 2 ! $ ( -) -9 - . ( -)( %" 4()5 - . ( ,ก %* 3 ก 4() $ + ,-. #"/ก. 0 " # " 1 ก " ก2 0 2 0 ! %" ก " ก $

4.2

ก; . *E (Law of Mass Conservation)

"%"2 ' 5 ) %* ก1 * * ( . .1774) ) " "# ก (8 " $ 1 ก 3 ) ก ก ! " $ 1 1" 3 ) ก

%" # # ก@ 2 N2 28 ก % 0 ก ก%/ก@ 2 H2 6 ก % # 4()ก@ 2 NH3 34 ก %

" ก# ก ( ก (N2 + H2) = 28 + 6 = 34 ก %

= 34 ก %

" - % ก ( ก (NH3) # * ก ก N 2 + 3H 2 → 2 NH 3

" %* ) N2 1 + (2 ×14 = 28 ก % ) " ก%/ H2 3 + (3 ×2 ×1 = 6 ก % ) = 28+6 = 34 ก %

" 5 J% K' NH3 2 + = 2(14+(3×1)) = 34 ก %

(% %* " ก# ก ( ก = " - % ก ( ก 3#*-+G . 4.1 0 *0 30 " 20 ก % 4 ก()" 4MMN 4 4() %ก #- ! /"# .! ก (ก@ 2 H2 2 ก % 3 ก (ก@ 2 O2 16 ก % *0 - . # 2 ก % 3 ( -) -9 "# ก ก ( ก * 4 ก1 " " ก# ก ( ก = " *0 = 20 ก %

" - % ก ( ก = " ก@ 2 H2+ " ก@ 2 O2 + " *0 ! - . = 2 + 16 + 2 = 20 ก %

3 -9 "# " ก# ก ( ก # ก%/ " - % ก ( ก 2 ! 4

ก1 "

133

Chemistry for Engineers

4.3

Stoichiometry

ภ;"#C"G* ). (Law of Definite Proportions) +3 2M ' 5 ) %* ภ1 * * " ! 18 ) " "# 4 " 5 ภ/ภ!6 1 / * * 2 / /ภ! $ ภ* $ 1 4 ภภ2 ภ7

# *0 # ภ/()" & , H O 2 ! 33 4()- " & # 2H 2 + O 2 → 2H 2O CuSO 4 .5H 2O → CuSO 4 + 5H 2 O NaOH + HCl → NaCl + H 2O

4 #"# 3 ()" " & (ภ9 3 /"# % #" +( " H:O *0 3 # 1:8

" H = 1 , O = 16 (% %* H:O *0 = 2:16 = 1:8 3#*-+G . 4.2 .! 5 C 30 " 1.2 g ภภ"# ) ) ภ2 3 30 " 3.2 g ภ0 ภ( ภ%/ C 30 " * .! -) ภ( CO2 - ( .! 0 CO2 ! ภ(3 ภภ0 ภ- ภ%/ ภ( ภ. /"# CO2 ! ภ( * 30 " 2.2 g C # 0.6 g 3 ( -) -9 "# ' ภ/ CO2 4 ภ1 %( #" !

.! 5 C ภ% #" +( " C:O CO2 = 1.2 : 3.2 = 3 : 8 .! - 0 ภภ%/ ภ( ภ.

" ภ2 3 CO2 = 2.2 T 0.6 = 1.6 % #" +( " C:O CO2 = 0.6 : 1.6 = 3 : 8

3 -9 "# % #" +( " C:O CO2 # ! 4 #"# 3 CO2 +( " & (ภ9 2 ! 4 ภ1 %( #" !

4.4

ภ;"#C"G* $ A)0! (Law of Multiple Proportions) 3 -' ( % 5 ) %* ภ1 * * ( . .1803) ) " "#

134

Chemistry for Engineers

Stoichiometry

0 5 2 5 ภภ/ภ!2 ภภ1 6 #" " 5 1 : ภ! " * ภ51 / 3 !ภ2 " 3 " # N2 " ภ%/ O2 4() NO, NO2, N2O, N2O3 N2O5 $) -) " N ภ/ %* 5 ( # ! " O %* 5 .! / /ภ% 3 4() %" ) 8 3 . 4.1 "

M"C. *E,-. O O " Pภ- 5 Q C RภC1 ภภ* 3#*,-. N ภ# O *E * 3#*$-C ภ# *E * $-C ภ# R T - *E,-. N ). N O N O 14 16 14 16 14 32 14 32 28 16 14 8 28 48 14 24 28 80 14 40

NO NO2 N2O N2O3 N2O5

" O NO : NO2 : N2O : N2O3 : N2O5 = 16 : 32 : 8 : 24 : 40 = 2 : 4 : 1 : 3 : 5

3 -9 4()"# .! " N ! " O ! "

%" ( ภ%/ N ภ/ # 8 3 / /ภ% 4() %" # !0 ( "# ภ"

%" N2 ภ%/ O2 4 ภ1 %( #" -, 3#*-+G . 4.3 ภ42(' ภ0 $% ( ( ! 1 ภ/()" ภ0 $% 50% +( " ( ! 2 ภ/()" ภ0 $% 40% +( " 3 ( -) -9 3 "# %" - # * 4 ภ1 %( #" -, ภ42(' ภ0 $% (- ! ภ/()" S 50 - #" " O 50 - #" " ภ42(' ภ0 $% ( ! 2 ภ/()" S 40 - #" " O 60 - #" " $) -)& , S & , ! ) 50 - #" " " ! S ภ42(' ภ0 $% ( ! 2 S 40 - #" " 3 O = 60 - #" "

135

Chemistry for Engineers

Stoichiometry

60 × 50 = 75 - #" " 40

" O ก42(' %* 2 ( 2 ! # "

%" ( ก%/ " ! S 30 " 50 - #" " .! 0 /ก% % #" 3 4() # ก%/ 50:75 = 2:3 2 ! % #" 30 " %" ) 8 4 ก1 %( #" -, M UVก #C 4.1 1. O ก CE-.R$T -" # " A ก; . *E,-." 1P3 -.)* )A " .OCR W $ RX: ก. , -J ! 3 ) 0 ก ก% . ก 5 .! -) ) 0 ก ก% . ก "/ , ก@ 2 ! ก (3 ก ก . ก "/ , 4 # -) ก $# % 2. 1 ก 0 MEP, - 0E3G-Y Z 1.M"C.O R [ *G R W Y 3 ก;"#C"G* ). $) ก42(' ก0 $% ( ! 2 S 50 - #" " 3 O =

ก ! ก ( * .

CuO + H 2 → Cu + H 2 O

J + CuO = 41.538 ก %

= 82.279 ก %

- ( %" + CaCl2 E#.R\ J + = 37.538 ก %

- ( %" + CaCl2 = 86.779 ก %

O ก * R) P &" Pก- ]#EY^C&,-.R E[กQ C _ . $ *G Pก- C *+R E[ก 63.4% bC+ *E R ET-R W ก/ Pc# c / R E[ก 11.0 ก # R\ * ก# ก/ Pc# 5.0 ก # E#.1 ก Rก C e ก + " 0 !& 1PYC " Pก- ]#EY^C&ก ก # R ET-R E[ก T-ก/ Pc# ก ก # c ก CE-. ZR W Y 3 ก;"#C"G* ). % 3A A MEP % 3A B / e ก + ก# YC R W " Pก- C R$ +.Q CRC +* bC+ , - 0E1 ก ก CE-.C#. Z *E OQ 3- R 3 (ก # ) ) #Z. *E,-. C (ก # ) A B 1 3 4 4.5 2 5 6 7.5 3 15 6 18.0 กG- R\

3.

4.

136

Chemistry for Engineers

4 5

20 30

6 4

Stoichiometry 18.0 12.0

ภ. 1.)/ *!-#3 "G* bC+ *E,-. A:B / e ภ+ $-C ภ# ,. c OQ A MEP B -+G .EP 10 ภ# 1PYC C ภภ# % % &' " 0 %\ # ภ- ภ" -' # ภ- " ) ) + +2 (O3) / ภภ" -'- ) & , # 8 # - 0 3 ภ# ภ. ภ)ภ" & # 8 ภ! $# - .*

# 8ภ9 ) % % &' %* *

4.5

9:; -P3- ,-.C E3#

3 -' ( % 5 ) %* 1 * ] . .1808 .! ) & / ภ1 # 8 # ภ1 " ภ1 %( #" ! 1 ภ# ""# 1. # ภ/()" ,J 9ภ8 ภ"# 2 ! 3 /# ภ-) 9ภ4 ภ4 #4() 2. & , ( ( "ภ% #

/% - . ภ% ,ภภ3. & , # (ภ% #

/% # ภ% 4. 3 4 # \- 4 3 0 -) ภ( * - #4 #4() 5. ภ/ ภ( * 4()()" ภ"

%" & , # (ภ% 30 "

& , # (ภ% ! "

%"ภ% %* 4 ()" % #" ! %" ) 8 6. + ภ, ภ/ ( ( "ภ% #

/% - . ภ% ,ภภภ# 3 ภ+ ภ, ภ/ .! 8 ^33,/% 1 ( % ! 4 # 3 / # # , - 1 4 #3 # " ' 2 ! /"# ภ/()" 9ภ+ " sub-atomic particle , - 2 4 #3 # Isotope 2 ! & , ( ( "ภ% ! 4 +2+ ภ% 3 " # ภ% ) 4 4 #3 # " ' Mk ภ' " ' 1 ( % $ 0 & / ภ1 " ภ1 %( #" ! (% *

137

Chemistry for Engineers

Stoichiometry

1. ภ& / ภ. " ) 1 ( % ) 4 ภ!5 " ภ# - % ภ# ภ% 30 " 4 #4() \- - . ภ( * - # 3 ภ!ภ% .! ภ( ภ2. ภ& / ภ. * ) 1 ( % ) 2, 5 ภ! % #" +(

" & , ! " ภ% ภ/ %* ! .! & , # (ภ% " ภ% ภ/ 3 " ภ% ()" % #" 30 " ! .! 3 ภ& , ( ( "ภ% /% - . ภ% " # ภ% % #" +( " & , ! " ภ% ภ/3 !()"

4.6

*E-P3- (Atomic mass)

( 9ภภ(% %* " ภ9 #

# ) ภ()" ภ!3 /, lภ% m # 4 # ("ภ( % 3 (" & !3 - " & , # 8 +( ภ/ /ภ%/ " & , 6 +( / /ภ%/ " & , 6 +( / /3 ภ" !& , %* 8 0 ภ( ภ%/ " & , 6 ( % /"# H & , ! / ! ,( 3 -) ) H & , 6 ภ0 - ("# H 1 " 1 - #" 6 (1 amu) (amu # 3 ภatomic mass unit, 1 amu # # ภ%/ 1.66Ă—10-24 ภ% ) 3 ภภ! H "

%"ภ%/ O *0 ( % - " % % &' " O H 4() (% *

" O 8 =

" H 1 $) %*

6 "# *0 ภ(3 ภO 1 0 ภภ%/ H 1 3 4()"#

" O1

= 8 = " ภ2 3

" H 2

# 3 '4()"# H " ภ%/ O ()" % #" 30 " = 2 : 1 3 4()"#

1 - ( 2

" O1 8 =

" H 2 1

138

Chemistry for Engineers

" O1

=1

Stoichiometry

8

1 [ " H 2 ] [1] 2 2

" O1

= 8 Ă— 2 = 16 = " O

" H 2

()" " & ภ- # * 0 -)( % - " & , .! 84() ภ- & , $ )"# 3 4 #4() # !$ ภ) #" & ภภ9 .* 6 ภ- # " & , !$ ภ) ! * 3 -9 "# $) " ( ( % 3 4() "# %* 1

" & ,

" & , = 1 [ " ภ2 3 1 ] 16 # .! 3 ภ%ภ) " o ! ,ภ4 +2+ ภ2 3 ! # &

6 # %ภMk ภ' ) o O-16 6 (% %* 6 "

# = 1.00272 # 6 Mk ภ' 3 0 -) %/ .! -) 6 ( "ภ% %ภ" '3 4() ) C-12 2 ! 4 +2+ ! 1

ภ! ,( & '/ 6 +( ภ0 - ( -) " C-12, 1 12 # ภ%/ 1 - #" 6

" & ,

" & , %* 1

=

1 [ " C-12, 1 ] 12

; " / < # ภ%/ ; " 1 / < # 4 " / T " / / / ภ-) /"# & , %* 8 1 - %ภภ! # " & ,

6 T 4 # - #" " 1 / T " ! )3 & , %* 8 1

T - #" amu, g (1 amu = 1.66Ă—10-24 g) 139

Chemistry for Engineers

Stoichiometry

4.6.1 ภ)/ *! *E-P3 0 " 4()- " & * #ภ%/ %ภ) !ภ0 - ( -) # - 0 " 3 ภภ/ /ภ%/& ,4r+( 3 - . & , C-12 - 0 " 3 ภภ- 0 " " o ! 4 +2+ 4.6.2 ภ)/ *! *E-P3- 1 ภภR + R + ภ# H T- C 3 + 33 0 " / /ภ%/ H - . C-12 +( - . 33 / /ภ%/& , .! 8 ! / " )"ภ94() !ภ# " ) ) 4.6.3 ภ)/ *! *E-P3- 1 ภe ภ+ R) ,-.% 3A 0 - %/ภ!& , # 8 %* # 2 ( * 4 ภ( ภ"

%"4() ภ/ 1 ( ภ%!"84 4()(% *

#

& , A + & , B + ............... & , Al + & , O & , Mn + & N

ภ/ AXBY........................ ภ/ Al2O3 ภ/ Mn3N2

ภ!3 - " & , 3 ) / ภ. " & , ! 0 ภ( ภ% . " & , (& ,- ! . ภ/ ! ภ( * ) ภ! ภ(5 J% K' ภ/ ( ( " # %* ภ0 " " & , 33 0 " 3 ภภ+( ภ-)$ ภ) )" )+ ) #" - . 33 0 " +( ) # 8 +( 4 # ) ภ(% *

WA M A x = Ă— WB M B y WA , WB MA , MB x,y

= " & , A B 0 (%/ ! 0 ภ( ภ% = " & , A B 0 (%/ = 30 " & , A B ภ/ 140

Chemistry for Engineers

Stoichiometry

x 3 - 4()3 ภภ/ # %* (% %* ภ0 " " 3 ) / y ภ/ ! ภ( * x 2 Al + O 2 → Al 2 O 3 ; = y 3 x 3 A + B → A 3B ; = y 1 x 1 Cr + Cl 2 → CrCl 3 ; = y 3 (% ภ# " ภ3 ภ3 )ภ%/ ภ/ ! ภ(3 ภ& , 2 ( )" % $ )ภ%/ ภ/ ! ภ(3 ภ& , ภภ"# 2 (4()()" #

3#*-+G .RQG

ภ/ A2B4C7

& , A + & , B + & , C

.! ) ภ3 - " & , ( ภ9 0 & , %* 4 /ภ%/& ,2 ! / "

# )"

"# / " & , A 3 - " & , C ภ9 0 4()+( / % #" -"# & , A ภ%/ C (% * WA M A 2 = Ă— WC M C 7

A2B4C7 0 - %/ A ภ%/ C # ภ%/ .! / " A (WA) C (WC) ! 0 ภ( ภ% / " A ภ9- " C 4() 0 ( "ภ% .! ) ภ- " & , B ภ9 /ภ%/& , A # ( "ภ% +( ) WA M A 2 = Ă— WB M B 4 ภ3 ภ3 ) 0 " " )" - %ภภ(% ภ# " * % $ ) 0 " + + ภ, ภ/ - . 0 " 30 " *0 5 ภ! # ภ/4() +( ! ภ/ ! *0 5 ภ%* %ภภA + nH 2 O → A.nH 2 O MEP)/ *!bC+OQ "03 141

Chemistry for Engineers

Stoichiometry

WA M 1 = A Ă— WH 2 O M H 2 O n WA , WH 2 O

. " A H2O 0 (%/ 5 ŕ¸

MA ,MH2O

. + ภ, A H2O 0 (%/

n . 30 " *0 5 ภ(% ภ# " 33 )- 30 " *0 5 ภ- . - " + ภ, - . " & ,/ & , .! /30 " *0 5 ภ# # 4 ภ9 " % % &' (% ภ# " 3 ) 0 " " 4() o ภ!& , # 8 " ภ% )"4() ภ/ ( ( " # %* $) 4() ภ/ ภภ"# 1 (3 )4 #4() ( ) 0 " 3 ภภ) # & , A + & , B A2B + AB3 ภ(% ภ# "3 ) 0 " " 4 #4() 4.6.4 ภ)/ *!-P3- RkE +1 ภY-b]b )/ *!YC 1 ภ"03 3G-Y Z M=

M ∑ % A

∑ %A = (%A ) + (%A 1

100

2

) + .............

100

= =

" o ! 4 +2+ summation (5 " )

= =

) & 4 +2+ # %"

" 4 +2+ # %" ($) +3 '4 #ภ0 - (

" -) 33 ) " 4())

( ภ0 " " o ! 4 +2+ -)( .!

)" 3#*-+G . 4.4 " Na = 23 3 - "#

142

!

Stoichiometry

Chemistry for Engineers

ภ. Na 1 - %ภภ!ภ%

. Na 5 - %ภภ!ภ%

ภ. Na 1 - %ŕ¸

= = = = =

. Na 5 - %ŕ¸

" Na Ă— 1.66 Ă—10-24 g 23 Ă—1.66 Ă—10-24 g 38.18 Ă—10-24 g Ans 5 Ă— 38.18 Ă—10-24 g 190.9 Ă—10-24 g Ans

" ! ( & , " o ! 4 +2+ & & & , # 84 #4() 4 +2+ ( " (% %" # # 4

3#*-+G . 4.5 & & , Si 3 isotope . Si-28, Si-29, Si-30 # 92.21%, 4.70%, 3.09% 0 (%/ " isotope %*

# # ภ%/ 27.977, 28.976 29.974 amu 3 0 " - " o ! Si

" o ! Si 1

=

C#. #Z *E-P3- RkE +,-. Si

= 28.086

(92.21Ă— 27.977) + ( 4.70 Ă— 28.976) + (3.09 Ă— 29.974 ) 100 = 28.086 amu 3-

^33,/% $- # " & , # 8()" " & Mass spectrograph 2 ! " & ! ) % .! . " %* ) )" & 0 " %* ภ# ) 3#*-+G . 4.6 .! 0 + - X 1.4 ภ% 5 3 " ( ภ%/ ภ2 3 0.6 ภ% $) ภ42(' * + ภ, X2O3 " X # # 4 # *

X + O2 → X 2O3 143

Stoichiometry

Chemistry for Engineers

Wx M x 2 = Ă— WO M O 3 1.4 M x 2 = Ă— 0.6 16 3 1.4 Ă— 3 Ă—16 = 56 Mx = 0.6 Ă— 2 *E-P3- ,-.bE P X = 56

3-

M UVภ#C 4.2 1. 2 (Ca) 1 - %ภภ!ภ% $) " Ca = 40 (6.64Ă—10-23 ภ% ) 2. & , A 2 " 3 # & ,4 + 3 5 3 0 " "

" 1 & , A (105, 1.74Ă—10-22 ภ% ) 3. $) 0 NiCl2 1.296 ภ% 0 -) + - Ni ภ%/ภ@ 2 ()" " & ภ4MMN " + - Ni !4() = 0.587 ภ% $) " = 35.453 # " + - Ni # ( (58.7) ( ภ. NiCl 2 → Ni + Cl 2 ) 4. ภ/ (- ! ภ/()" 3 & , & , ภ. Z Y 4 # / "

#" & , ! 3 ภ2 3 ภ/ * /"# Z2YO4 3 ภภ" -' ภ1"# Z = 32.39% , Y = 22.54% O = 45.07% 3 - " Z Y $) - ภ" O 16.00( " Z=23 , " Y=32) ( ภ. Z 2 YO 4 → 2Z + Y + 4O ) 5. $) 14 ภ% X 0 ภ( ภ%/ 16 ภ% ภ2 3 & , X " # ( $) ภ42(' X XO (14) ( ภ. 2X + O 2 → 2XO )

4.7

*Eb REภAE

ภ3G .ภ# 1

ภ-+G .Y

144

Chemistry for Engineers

Stoichiometry

"4 "ภ5" T " / / / ภ-) /"# " %* 1 + ภ, - %ภภ! # " & , 6 T 4 # - #" " 1 4 "ภ5" T " ! )3 %* 8 1 + ภ, T - #" amu, g (1 amu = 1.66Ă—10-24 g) 4.7.1 * % ภ*Eb REภAE 0 " 4()- " & * #ภ%/ %ภ) !ภ0 - ( -) # - 0 " 3 ภภ/ /ภ%/& ,4r+( 3 - . & , C-12 - 0 " 3 ภ"

- 0 " 3 ภ+ - 0 " 3 ภภ- - . 0 " ()" " & .! 8 4.7.2 ภ)/ *! *Eb REภAE1 ภภR + R + ภ# H T- C

" 1 + ภ, =

" + ภ, Ă— 1.66 Ă—10-24 ภ%

" + ภ,

=

" 1 + ภ,

" H 1

=

" 1 + ภ,

" C 1

- . 33 0 " +( ภ/ /ภ%/& , .! 8 ! / " )"ภ94() 4.7.3 ภ)/ *! *Eb REภAE1 ภ*E-P3$) / ภ/ / " & , # 8 ภ/ 3 -

" + ภ, 4()

" + ภ, = 5 " " & , ภ/ %* # " + ภ, C6H12O6 = " (6C + 12H + 6O) 4.7.4

ภ)/ *! *Eb REภAE1 ภb E 145

Chemistry for Engineers

Stoichiometry

+( % " % % &' -"# + " ! STP 30 " + ภ, (% * W V N n= = = M 22.4 6.02 Ă—10 23 .! / " (W) + (n) - . ! STP (V) - . 30 " + ภ, (N) # ( # - ! 3 - " + ภ, 4() 3 4()ภ# "$ ( ภ! "ภ%/ + # 4 4.7.5 ภ)/ *! *Eb REภAE1 ภe ภ+ R) +( % ภ" % % &' -"# + " + ภ, 3 - " + ภ, 4() ภ3 ภ* % $ 0 " *0 5 ภ+ ภ, +( % ภ4() 4.7.6 ภ)/ *! *Eb REภAEC *+* % -T m ภ3 ภ3 0 " " + ภ, ()" " & ภ# 8(% !ภ# " )" % $ 0 " " + ภ, +( % ภ1 ภ@ +( % /% ภM (3,( . ภ9 ! ( 3,( (. ( ! ! * ) )

3#*-+G . 4.7 ภ0 - ( " H = 1, S = 32, O = 16 3 - ภ. " + ภ, H2SO4 . " H2SO4 1 + ภ, . " H2SO4 10 + ภ, ภ. " + ภ, H2SO4 = (2 Ă—1) + 32 + (4 Ă—16) = 2 + 32 + 64 = 98 3- . " H2SO4 1 + ภ, = " + ภ, H2SO4 Ă—1.66 Ă—10-24 g = 98 Ă—1.66 Ă—10-24 g = 162.68Ă—10-24 g 3- . " H2SO4 10 + ภ, = 10 Ă—98Ă—1.66 Ă—10-24 g = 1626.8Ă—10-24 g 3-

4.8

ภ)/ *!Rภ+*ภ# b E

+ - #" ! )"%( # - ! +( ภ0 - ( -) l (8 1 + ภ/()" ,J 6.02 Ă— 1023 ,J 6.02 Ă— 1023 . +"ภ+( (Avogadroƒs number)

146

Chemistry for Engineers

Stoichiometry

E-.X_ภ: 3 ,#Z 3- 3G-Y Z 1. " Na = 23 $) Na - %ภ23 g 3 Na ภ!

Na - %ภ23Ă—1.66Ă—10-24 g 3 Na = 1

Na - %ภ23

(% %* Na 23 g 3 Na = 2.

23 23 Ă—1.66 Ă—10 −24

1 23 −24 = 6.02 Ă—10 1.66 Ă—10

g 3 Na =

" Al = 27 $) Al - %ภ27 g 3 Al ภ!

Al - %ภ27Ă—1.66Ă—10-24 g 3 Al = 1 Al - %ภ27

g 3 Al =

(% %* Al 27 g 3 Al =

27 27 Ă—1.66 Ă—10 −24

1 23 −24 = 6.02 Ă—10 1.66 Ă—10

3.

" + ภ, H2SO4 = 98 $) H2SO4 98 g 3 H2SO4 ภ!+ ภ, H2SO4 - %ภ98Ă—1.66Ă—10-24 g 3 H2SO4 = 1 + ภ, 98 g 3 H2SO4 = + ภ, H2SO4 - %ภ98 −24 98 Ă—1.66 Ă—10 1 23 (% %* H2SO4 98 g 3 H2SO4 = + ภ, = 6.02 Ă— 10 1.66 Ă—10 −24

4.

" + ภ, C12H22O11 = 342 $) C12H22O11 342 g 3 C12H22O11 ภ!+ ภ, C12H22O11 - %ภ342Ă—1.66Ă—10-24 g 3 C12H22O11 = 1 + ภ,

342 + ภ, 342 Ă—1.66 Ă—10 −24 1 23 (% %* C12H22O11 342 g 3 C12H22O11 = −24 = 6.02 Ă—10 + ภ, 1.66 Ă—10

C12H22O11 - %ภ342 g 3 C12H22O11 =

3 ภ1 T 4 3 -9 "# $) %! " lภ% m +( -) %" " %* # ภ%/

%" " - . " + ภ, )" 3 30 " ,J = 6.02Ă—1023 ,J

147

Chemistry for Engineers

ภ/ 1

+

- $

1

Stoichiometry

+ + ภ,

%ภ" ' (- #" * .! ) ภ,J 30 " 6.02Ă—1023 ,J *"# l+ m # ( "ภ%/ 0 "# l+- m 2 ! ) ภ30 " 12 * .! ภ0 - ( 1 + = 6.02Ă—1023 ,J )" 30 " ,J % " % % &'ภ%/ " ()" (% %* l+ m 3 4 % % &'ภ%/ " ()" 1 + = 6.02Ă—1023 ,J ( , + ภ, , 4 „ „ T 4 # * ภ%/ , -J , " (% T 4 # * ภ%/ $ 1 + = M g (M = " - . " + ภ, - . " 4 „ „ T 4 # * ภ%/ , -J , " (% T 4 # * ภ%/ $ 1 + = 22.4 dm3 ! STP T * ภ%/ , -J , " (% ) STP T * ภ%/ $ ) ภ@

4.9

PRD ,-.b E

/# ( ,J . + + ภ, , + + 4 ภภ0 - ( J + +3 ' 33 / ภ-)+( "# + J ( # HCl 1 + + ภ, , He 1 + , NH4+ 1 + 4 - . 33 / ภ+ +( 4 #/ ภJ 2 ! ภ*3 ) /"# + J ( #

148

Stoichiometry

Chemistry for Engineers

ภ@ 2 ภ2 3 1 +( %!" & , ภ2 3 1 3 4 ('4 1 + -)( 3 ภ%*

+ + +

- $ - $ - $

1 1 1

+ + ภ, + 8 4 ภJ + 4

4.9.1 )* "# $# %& P *G .b Eภ# *E,-." - %ภ%!"84 (% * 1 + + ภ, - %ภ= 1 + - %ภ= - %ภ- %=ภ# 1 HCl+ 4 1 + Na

" + ภ, (- #" ภ% )

" (- #" ภ% )

" 4 = 36.5 (- # ภ%" ภ% )

1

+ - %ภ=

23

ภ%

NH4+ 1

+ - %ภ=

18

ภ%

J " 6 ภ@ . J " ! , -J 0OC " (% 1 / ภ- . 760 mm ) %\ %ภ' STP 4.9.2 )* "# $# %& P *G .b Eภ# 3 ,-.Mภo" ภ0 - (4")(% * ภ@ ,ภ(30 " 1 + 3 22.4 ! STP - . # + ภ@ ,ภ(3 # ภ%/ 22.4 ! STP 4 #"# ภ@ %* 3 + ภ, ( 9ภ- . ( -\# 1 + 3 22.4 %* *

# He(g)

1

+ = 22.4

! STP

O3(g)

1

+ = 22.4

! STP

C4H10(g) 1

+ = 22.4

! STP

+R 3A # + # ภ%/ 22.4 )4() o ภ@ ! STP # %* 3 )ภ%/ - " 9 - . J " , -J " (% .! 8 4 #4() 4.9.3 )* "# $# %& P *G . 1/ * b E, 1/ * - AD ), *E MEP 3 149

Chemistry for Engineers

n=

Stoichiometry

W V N = = M 22.4 6.02 Ă—10 23

.! n

=

30 " +

N

=

30 " ,J ( , + ภ, , 4 )

W

=

" (- #" ภ% )

M

=

" - . " + ภ, - . " 4

V

=

ภ@ (- #" ! STP)

4.10 E#ภ:!P # *mY ,-.b1 +&Rภ+*ภ# b E +3 ' ! / 33 , 4()(% * ภ. ภ0 - ( # 8 -) )"$ "# ( 30 " - . 30 " + ภ,

ภ! ,( ภ3 -) 0 / / +( )- %ภn = N ! +

ภ3 30 "

ภ! + + ภ, ภ3 30 " + ภ, ภ. $ ภ! "ภ%/ " % % &' -"# n, W, V, N ( - ! +( ภ0 - ( %" %" - ! -) )"

%" ! - . # ภ0 - ( " )"$ "# ภ!+ ภ,

%" # # H2SO4 5 ภ% ภ!+ ภ!+ ภ, ภ0 " -) ) " % % &'

n=

W V N = = M 22.4 6.02 Ă—10 23

. $ ภ! "ภ%/& , ภ/ +( ภ0 - ( ภ/ -) )"$ "# & ,

# 8 ภ!+ ภ!ภ% ภ!

ภ0 " % ) " % % &'

n=

W N = M 6.02 Ă—10 23

150

Chemistry for Engineers

Stoichiometry

3#*-+G . 4.8 ภ@ 2 ภ2 3 1.5 + 3 ภ!+ ภ, - %ภภ!ภ% ภ! (ภ0 - ( " O = 16) 1 ภ@ 2 ภ2 3 1 + 6.02Ă—1023 + ภ, ภ@ 2 ภ2 3 1.5 + 1.5Ă—6.02Ă—1023 + ภ, = 9.03Ă—1023 + ภ, ภ@ 2 ภ2 3 1 + - %ภ2Ă—16 = 32 ภ%

ภ@ 2 ภ2 3 1.5 + - %ภ1.5Ă—32 = 48 ภ%

ภ@ 2 ภ2 3 1 + 22.4 ! STP ภ@ 2 ภ2 3 1.5 + 1.5Ă—22.4 = 33.6 ! ATP 2

N 6.02 Ă—10 23 N = n Ă— 6.02 Ă—10 23

n=

N = 1.5 Ă— 6.02 Ă—10 23 = 9.03 Ă—10 23 molecule Ans

W M W = nĂ—M n =

W = 1.5 Ă— (2 Ă—16) = 48 g V n= 22.4 V = n Ă— 22.4

Ans

V = 1.5 Ă— 22.4 = 33.6 litre at STP

151

Ans

! STP

3- 3-

3-

Chemistry for Engineers

Stoichiometry

M UVภ#C 4.3 1. 3 ) %! - 9ภ- %ภภ!ภ% .! -) - 9ภ0.384Ă—1023 (3.56 ภ% ) 2. ภ@ 2 C4H10 1 dm3 ! , -J " (% 6 " ภ!ภ% (2.6 ภ% ) 3. .! 0 .* (- ! - %ภ100 ภ% " -' /"# 0.2 #" ) #" +( *0 - %ภ.* * #ภ! (6Ă—1016 ) 4. ภ/ (NH4)2HPO4 79.2 ภ% & ,4r+( 3 ' ภ/ภ!+ (5.4 + ) 5. / ( ภ@ 2 # 4 * ( (3 30 " + ภ, ) ! ,( ( ( " & () ภ. 1 ภ% H2 . 2 ภ% N2 . 3 ภ% NH3 . 4 ภ% O2 ( / ) .) 6.

"# X Y 0 -) ภ( ภ/ 2 ( ! Y2X3 Y2X $) 0.05 +

Y2X3 - %ภ9 ภ% 0.10 + Y2X - %ภ10 ภ% " X Y

# 0 (%/ # ( (40 , 30) 7. ภ/ (- ! .! 0 -) 4 ภ"# 5 cm3 4 *- %ภ20.85 # H2 25 cm3 2 ! "%( ! , -J " (% ( "ภ% 3 0 " " + ภ, %* (208.5)

4.11 ภ)/ *!bC+OQ "03 R) MEP" ภR) 4.11.1 "03 R) = * (Chemical formula) : ภ,# %\ %ภ' & , ! * .! ( ' ภ/ /# 3 J . 1. # # (Empirical formula) 2. + ภ, (Molecular formula) 3. + ) (Structural formula) 4.11.1.1 "03 -+G ..G + (Empirical formula) $/ ภ$ ! # 8 (% * 1.1 %* ภ/()" & , 4 /) 1.2 % #" # !0 30 " & , ! ' ภ/ %* 1.3 % #" # !0 30 " + & , ! ' ภ/ %* 1.4 % #" # !0 " ภ% & , ! ' ภ/ %* 1.5 ' 29 '+( " & , ' ภ/ 4.11.1.2 "03 b REภAE (Molecular formula) $/ ภ$ ! # 8 (% * 152

Chemistry for Engineers

2.1 2.2 2.3 2.4 2.5

Stoichiometry

%* 1 + ภ, ภ/()" & , 4 /) # ภ!

%* 1 + + ภ, ภ/()" & , # 8 # ภ!+

" + ภ, ภ! / " & , # 8 ! ' ภ/ ' 29 '+( " & , ' ภ/ # # E#ภภO ภ"03 b REภAE 1. ) /& , ! ' ภ/ %* 2. - % #" +( " # & , ! ' ภ/ %* 3. - % #" +( 30 " + # & , ! ' ภ/ %* 4. - # # 5. ) / " + ภ, %* (+3 ' 3/ ภ+( - . / ภ+( ) ) 6. ) ( # # ) n = " + ภ, .! / # n ภ9 # n ) 4 " 9/ ภ93 / + ภ, 7. ภ- + ภ, ภ@ 2 +( +3 '/ ภภ@ 2 ! ) 0 ภภ% ( ภ@ 2 !4()3 ภภ-) )ภ1 +"ภ+( +( )- %ภ"# -#3 "G* bC+ 3 = -#3 "G* bC+b REภAE

4.11.1.3 "03 b) ." . (Structural formula) $/ ภ$ ! # 8 (% * - . ภ%/ + ภ, ) 2.1 T 2.5 & , ! ' ภ/ %* # 3%( ภ% # 4 3#*-+G . # ภ( *0 ) (Acetic acid) + ภ, ภ( *0 ) . C2H4O2 # # ภ( *0 ) . CH2O + ) ภ( *0 ) . CH3COOH ( + ) # # ) - .

153

Chemistry for Engineers

Stoichiometry

3#*-+G . 4.9 ภ/ & , Ca X " + ภ, 160 Ca - %ภ25% 3 - + ภ, ภ/ * (ภ0 - ( " Ca = 40, X = 60) % #" +( " Ca : X = 25 : 75 25 75 % #" +( 30 " + Ca : X = : 40 60 = 0.625 : 1.25 =1: 2 (% %* # # * . CaX2 ( # # )n = = (CaX2)n [40+(2Ă—60)]n = (40+120)n = n = (% %* + ภ, * . (CaX2)1 =

" + ภ, 160 160 160 1 CaX2

4.11.1.4 ภqC X + ภ0 " - %* / %* - % #" +( 30 " + ภ)" /"# %ภ/"# %( 3 0 / ภ4 # /"# 3 ^( # 4 ภ^( * 3 0 -) 0 / ( .! 4 4() (% %* .! / 3 " )- %ภ(% * 1. $) < .2 -) ^( 2. $) > .8 -) ^( * 3. $) # -"# .2 $ .8 -) ^( # 0 -) 30 " 9 4()+( %" ! ) ! ,( % #" ,( %* - ( - 30 " 9 ! ) ! ,( ) 3.1 .! -)4() 30 " 9 - . 4() 2 ! < .2 - . > .8 )"3 ^(

154

Chemistry for Engineers

Stoichiometry

M UVภ#C 4.4 1. ภ/ ! ภ@ 2 (- ! ภ/()" C 75%, H 25% +( " "%( "

- # ! STP 4() 0.7143 g/dm3 3 - + ภ, (ภ0 - ( " C = 12, H = 1) +3 ' ) *4 #4()ภ0 - ( " + ภ, * +( #ภ0 - ( "

" ( - # ! STP -) 2 ! " - # " % % &' -"# " ภ%/ ) /- "# 22.4 dm3 ! STP (- . 1 + ) " # 4 %! . /"# 1 + - %ภ# 4 ภ93 4() " + ภ, %* 2. .! -) " ) ภ%/ภ@ 22 ! 4r4( (' & , X 2 ! 60 cm3 ภ"# 4()4 & , X 30 cm3 ภ@ 24r+( 3 90 cm3 3 - 4r4( (' & , X (ภ0 - ( " H = 1) ภ0 - ( 4r4( (' & , X . XaHb ภ! ภ( * . X H → X + H 3. & , 2.5 g 5 ภภ( ภ42(' 2.949 g 3 - # # ภ42(' * (ภ0 - ( " U = 238, O = 16) 4.11.1.5 ภ)/ *! *ER W -+EP1 ภ"03 E#ภO ภ)/ *! 1. - " ภ/ 1 + - " & , ! ' ภ/ %* 1 + 2. / -) " ภ/ %* 100 a

b

∆

2

2

3#*-+G . 4.10 3 - ' 29 '+( " O H2SO4 (ภ0 - ( " H = 1, S = 32, O = 16) " + ภ,

" O 1 + % & , O

H2SO4 = 2(1) + 32 + 4(16) = 98 = 4(16) = 64 g

" O 1+ = Ă— 100

" + ภ, H 2 SO 4 64 Ă—100 = = 65.31% 98 155

Chemistry for Engineers

(% %* H2SO4 ภ/()" O

= 65.31%

Stoichiometry 3-

M UVภ#C 4.5 3 - ' 29 '+( " *0 Na2CO3 .10H2O (ภ0 - ( " Na = 23, C = 12, O = 16, H = 1)

4.12 " ภR) (Chemical equation) ภ( -) ) 34()+( ภ* (Chemical equation) # ภ!ภ@ 24r+( 3 (H2) (4M4() H2 0 ภภ%/ O2 ภ! ภ( * . *0 (H2O) ภ! ( ภ* 4() 2H 2 + O 2 → 2 H 2 O # .! - + ภ*"# l 0 ภภ%/m # ภ"# l 0 -) ภ(m ! # 2) ภ) %* ) 2 ! ภ"# $ (reactant) ! ภ( " ภภ"# %" & ' (product) %" ! #- ) ( * / Q (coefficient) +( # ! 1 3 4 # ภ0 ภ%/4") (% %* ภ* 3 - $ ภ,# %\ %ภ'- . ! ) ภ! ภ( * .! 3 ภภ4 # ภ) - #- . 0 (8 (% %* 30 " & , # ( ! # %* () ภ3 # ภ% ภ"# ภ5"#" (balanced equation) $) / %* %* ) 5 J% K' 3 ภ%* ) ! % 4 #(, * ภ# 3 ภ%* 3 (, ภ+( # # % & ‹ ! 0 -) ,ภ( ! # # () ภ30 " # ภ% ภ# % & ‹- ) ภ! 4 # # ! ( # 2H2O - $ *0 2 + ภ, #" 3H2O - $ *0 3 + ภ, ) 3#*-+G . 5.3 ภ(, ภภภ5 4- ) (CH4)

#" ภ/ ! 0 %\ ! # ภ@ 2& .! $ ภ5 4- ) ภ3 -)ภ@ 2 '/ 4( ภ42(' (CO2) 4 *0 (H2O) (% %* ภ%* ) ! % 4 #4()(, 3

CH 4 + O 2 → CO 2 + H 2 O 156

Chemistry for Engineers

Stoichiometry

ภ(, ภ%* ) -) . ภ(, & , ! # ( ( "ภ% # () ภภ# ! * . C H 2 ! / o %* ) CH4 #" 5 J% K' / C CO2 H / H2O 3 (, 30 " C ภ# )" ()" ภ(, H -) % ภ"# CH4 1 + ภ, C 1 CO2 C 1 % & ‹ %* 3 # ภ% . 1 # CH4 H 4 ! *0 ! ภ( * H 2 $) -) % & ‹ *0 2 3 4() H %* () ภ# ภ% (% *

CH 4 + O 2 → CO 2 + 2 H 2 O

( ภ!(, / #" )

ภ!4() O 4 # # ภ% %* ) +( 5 J% K' O " 4 %" 2 ! ภภ"# O %*

) # 2 %" (% %* 3 ) # 2 % & ‹- ) O2 ! %* )

CH 4 + 2 O 2 → CO 2 + 2 H 2 O

( ภ!(, # / ')

0 4.1 1 ภ" ภCAEME *,-. e ภ+ ภR\ Y R ภR, + D $,-.b REภAE / O R [ *G 1/ * -P3- Aภ-P3- / e ภ+ +#.). R G RC bC+ # *Y + / O " ภCAEME * RE,"# P" % sR W RE, 1/ * -+ "AC

ภ(, ภ+( " & ) ) 3%( ภ(, // 5 ( $ ภ(trial and error) %* * ) " & (, # ( # ภ% 4 +( %/ # % & ‹ " 30 " & * )4()( ภ%/ ภ#" -\#

157

Chemistry for Engineers

Stoichiometry

$ ภJ ! # ภ%ภ( 4") " 9/ +( ) (g), (l), (s) (aq) $ ! ภ@ - " 9 *0 0 (%/ (% %* ภ!(, ) ) .! # / '3 (% *

CH 4 ( g) + 2 O 2 ( g) → CO 2 (g) + 2 H 2 O(g) ภ( J " / # ภ0 ภ/ ภ# , -J - . " (% %ภ%\ %ภ' %* 8 4") ) / - . ) # ภ# .! - ∆ ภ%/ ภ!

) ) " )

0 4.2 0 M"C.)* M3ภ3G .,-.3#*RE, ภ/ ภ# C EG .,-.% 3AO "03 ภ# 3#*RE,"# P" % s -+0G "03 O "#.Rภ3*G 1/ * -P3- ,-.% 3AM3GEPQ CO "03 )G R G ภ# \E)0!,-.)G "# P" % ภs # 3#*RE,ภ/ ภ# C EG .,-.% 3AO "03 # Z

M UVภ#C 4.6 1.CAE" ภ3G-Y Z

_Na(s) + _ H 2 O(l) → _NaOH(aq) + _H 2 (g) _C 2 H 4 (g) + _ O 2 (g) → _CO 2 (g) + _H 2 O(g) _Al(s) + _ HCl(aq) → _AlCl 3 (aq) + _H 2 (g) 4.12.1 E#ภO ภR, + " ภR) 1. ) ภ3 ภภ( ! ภ( * 3

158

Chemistry for Engineers

Stoichiometry

2. ! ) 0 ภภ% ( %* ) ) 4") () 2) ภ4") ภ+( -) -%" ภ*4 % !4()3 ภภ(5 J% K') %* ) → - # - . 5 J% K' (Reactant) (Product) 3. (, ภ+( - %" - ) %\ %ภ'- . .! 0 -)30 " # & , 5 J% K' # ภ%/ %* )

4. .! -) ภ" - ! * ( $ - . J " ! ภ! " ) ()" $) 9 3 # (s) 4") ) 8 %* $) - " 3 # (l) 4") ) 8 %* $) ภ@ 3 # (g) 4") ) 8 %* $) ! *0 %" 0 3 # (aq) 4") ) 8 %* ภ3 0 -) / ! # 4 * . 1. ( 0 ภภ% ( ภ( * - % 3 ภภ2. 30 " + ! 0 ภภ% ( 30 " + ! ภ( * 3. 30 " ,J ! 0 ภภ% ( 30 " ,J ! ภ( * 4. " ! 0 ภภ% ( " ! ภ( * 5. $) ภภS : 3 / ()" 3#*-+G . 4.11 ภภ3 ภภ# # 2 J . ) ภภ(combination reaction) ) ภภ" (decomposition reaction)

159

Chemistry for Engineers

Stoichiometry

0 4.3 ภR\ bE PM ภR R] + -P3- M ภR R] + / e ภ+ ภ# b REภAE O2 1 ภ- ภXRภCR W ,-.M,[.Y--- ภ)T- MgO

2Mg(s) + O 2 (g) → 2MgO (s)

0 4.4 ภ"E +3#*,-.b]RC + R-Y]C& (Sodium azide NaN3) OQ O cA.E D#+O c+ 3& R T -c0ภ1AC Pภ+O "D *P R P" NaN3 1P"E +3#*O Mภo"Y b3R1 N2 -+G . *CR [* MEP / O c.A E ,+ +3#*--ภ160

Chemistry for Engineers

Stoichiometry

2NaN 3 (s) → 2Na(s) + 3N 2 (g) 4.12.2 ก )/ *!1 ก" ก R) ก 0 " - " % % &' # 8 ! ก ! " ) ก%/ ก %* # +

" ! ก@ 2 30 " ,J $3 0 " - ! 3 ก ก - ! 2 ! / )" ก 0 " 3 ก ก 3 ก ! " ) ก%/ ก 1 ก - . - ก 33 ก ! " ) ก%/ # 8 2 ( - . กก"# ก94() 2 ! # ก 3 .* 6 ก 0 " ) ก% # ก # ก% /) 9ก ) ( 4.12.2.1 ก )/ *! Rก +*, -.ก# 1 " ก +3 ' 33 ก0 - ( ก -) - . 4 #ก0 - (ก94() 2 ! $) 4 #ก0 - ( -) %* ก ) ก ก# ) %* (, ก )"3 0 4 0 " +( %!" 8 4 +3 '3 ก0 - ( ( - ! -) ( ( ( ") )"$

.! 8 ! - . ก 0 " ) % ก ! "ก%/+ #" -\#3 3 o !+3 '$ !ก0 - ( -) )" 0 30 " + / % #" ก% .! # +

" - 3 0 " ! ! ) ก 4() 3 -9 4()"# ก /30 " + ) (3 ก ก (% %* ก !$ ก ) ! (, )" 3 3 $ 0 0 " 4() # $ ก ) , - %ก ก K' %!" 8 4 0 - %/ก 0 " 3 ก ก 4()(% * 1. ก -)$ ก ) ( 0 -)(, ) 2. 3 o !+3 '$ !+3 'ก0 - ( -) 0 30 " + 3 ก ก

/ % #" ก% 3. # + " - 3 0 " ! ! ) ก 4() ก3 ก3 0 " +( ก / % #" + )" % $ 3 4()3 กก / /%\\% 4 ' 3#*-+G . 4.12 5 + 2 (KClO3) # ( 3 3 %" -)+ 2 4 (' (KCl) 4() ก@ ก2 3 (O2) 22.4 ! STP

161

Chemistry for Engineers

Stoichiometry

ก ( ก 4()(% * : 2KClO 3 (s) → 2KCl(s) + 3O 2 ก@ 2 ก2 3 22.4 ! STP = 1 + 3 ก ก 4() O2 3 + ) ) KClO3 = 2 + 4() O2 1 + ) ) KClO3 = 2 × 1 = 2 + 3

KClO3 1 + " = 39 + 35.5 + 3(16) = 122.5 ก %

(% %* ) )+ 2 (KClO3) = 2 ×122.5 = 81.6 ก % 3- 3

3#*-+G . 4.13 .! 5 ' " (II) ก42('3 - (4() ก@ ก2 3 11.2 ก/ ก' (2

! , -J " (% 6 ก ก (% * 2HgO(s) → 2Hg(l) + O 2 (g)

" ' " (II) ก42(' ! ) # 4 (ก % ) %" !+3 '$ . HgO %" !+3 'ก0 - ( -) . O2 + HgO 2 3 ก ก = 1 + HgO = 2 + O2 + O 2 1  W HgO = 2 V O     2 M  22.4  W = ? ก % , M = 216.6 , V = 11.2 dm3 W 11.2 ∴ = 2× → W = 216.6 g 216.6 22.4 (% %* ) ) HgO 216.6 ก %

3- M UVก #C 4.7 1. *0 % ก (C8H18) .! $ ก 5 4- ) # / ' .! ' % #" +( + ! 0 ก ( ก% C8H18 : O2 = 1 : 12.5 $) ) O2 4 67.2 ! STP *0 % ก $ ก 5 4- )4 ก !ก % (27.36 ก % ) 2. .! 5 ก 2 '/ (MgCO3) 3 %" ก 2 ก42(' (MgO) '/ 4( ก42(' (CO2) $) 5 -"# MgCO3 MgO = 8.00 ก % .! 0 4 5 3 %" # / ' ก "# 4()ก@ 2 CO2 1.12 dm3 ! STP 5 *ก# 5 MgO #ก !ก % (3.8 ก % ) 162

Chemistry for Engineers

Stoichiometry

3 ก ) ก 5 *0 % *0 % 5 dm3 3 )

( (C2H5)4Pb 4 cm3

( " - # 1.66 ก % /cm3 ก ! ) ( (% * 4C 2 H 5Cl + 4NaPb → (C 2 H 5 )4 Pb + 4NaCl + 3Pb $) ) ก *0 % 100 dm3 3 ) ) 4 (' (C2H5Cl) ก !ก % .!

( -) ( (106.1 ก % ) 4.12.2.2 ก )/ *!1 ก 1 " ก M3Gก/ C" 3#Z.3 O 2 Q C ก ! ก %* ก ! " ) ก%/ 1 ก #+3 'ก0 - ( %* ) ! ) 0 " -) 2 ( 3 ,# กก"# ก ก ! ก ! " ) ก%/ 1 ก ก0 - ( %* ) -) ( ( " ก !+3 'ก0 - ( %* ) -) 2 ( 33 /# 2 J . ก. $ ก3 1 (1 $ 2 6 $ 3 ) ก ก 1 - % 3 ก ก ( ก / '3 4 # ( - . # ก *3 (6 $ 6 ( ก72 3 1 !*3 %" & '

. ก $ ก3 1 (1 $ 2 6 1 ก ก - % 3 ก ก ( ก / ' 6 1 /0=ก(61 2 ก (- ! 3 - . # (61 2 3 " 0 %\

กก"# ก"# ก3 1 (limiting reagent) (6*3 %" & '

ก 0 " 3 ,# ก ! * ) 3 3 ก ก ก# "# ( )- ( - % 3 ก %* 3 0 ! )- (4 0 " 5 J% K'

) ก 3.

" A ก !ก0 - ( %* ) -) 2 ( 0 " 4()(% * ,#Z M ก 0 " ก# "# ( )- (4 ,#Z "-. 0 ! )- (4 0 " 5 J% K' !+3 '$ +( 0 30 " + / /ก% 2 ! .! # + " - 3 0 " ! ! ) ก 4() 3#*-+G . 4.14 .! 5 + - (Ag) 4.32 ก % ก%/5 2% M ' (S) 0.64 ก % & , ( - . 3 ก ก - . ก ! ก %

3 ก+3 ' ก 4() 2Ag (s) + S (s) Ag2S (s) 3 ก ก ) Ag 2×108 ก % (2 + ) ) ) S = 32 ก % (1 + ) 32 × 4.32 ก %

$) ) Ag 4.32 ก %

) ) S = 2 × 108 163

Chemistry for Engineers

(% %* Ag 4.32 ก % 0 ก ( ก%/ S 4 # & , ( - . - % 3 ก ก ( ก / '

= 0.64

Stoichiometry ก %

3-

3#*-+G . 4.15 ก 5 Freon 2 ! ) *0 ) 9 (% ( ก 3CCl 4 + 2SbF3 → 3CCl 2 F2 + 2SbCl 3 .! ) CCl4 30.3 ก % 5 ก%/ SbF3 17.9 ก % 3 4() Freon (CCl2F2) ก !ก %

ก0 - ( " + ก, CCl4 = 154 , SbF3 = 179 , CCl2F2 = 121 ก. 12.92 . 18.15 . 22.4 . 24.2 +3 'ก0 - ( %* ) -) 2 ( . CCl4 SbF3 (% %* 3 ) 3 ก# "# ( )- ( )"3 0 4 0 " - CCl2F2 (Freon) ก - "# ( )- ( 3 ก ก ) SbF3 2×179 ก % (2 + ) ) ) CCl4 = 3×154 ก % (3 + ) 3 × 154 × 17.9 $) ) SbF3 17.9 ก %

) ) CCl4 = = 23.1 ก %

2 × 179 $) ) SbF3 17.9 ก % 3 ) ) CCl4 23.1 ก % # CCl4 30.3 ก % ( "# - . SbF3 )- ( -) 0 4 0 " - CCl2F2 0 " CCl2F2 + CCl 2 F2 3 3 ก ก = + SbF3 2

3 1 + CCl2F2 = + SbF3 2

 W1  3 W   CCl 2 F2 =  2 SbF3 2  M2   M1  W1 = ? ก % , M1 = 121 , W2 = 17.9 ก % , M2 = 179 W 3 17.9 ∴ 1 = × → W1 = 18.15 g 121 2 179 (% %* 3 Freon 4() 18.15 ก %

164

3-

Chemistry for Engineers

Stoichiometry

ก 0 " ! ก ! " ) ก%/ %* ) 2 ( $) . ก ) ก0 - ( 5 ( 3 4() 0 / !4 #$ ก ) 2 ! %ก3 # 0 / %* - (()" # ก ! ) CCl4 0 " - CCl2F2 3 4() 0 / # .! !5 ( # 0 / ก , , ()"

M UVก #C 4.8 1. 3 กก " -' ก / X /"# ก /()" ก0 $% 40 ' 29 '+( " ! - . ก %* ก2 3 (% %* $) )ก0 $% ก2 3 # 10 ก % 0 ก ก% 3 4() X # กก !ก % (16.67 ก % ) 2. .! 0 ก # 4 * -)(, )" 3 ) ) CaCl2 ก !ก % 3 3 4() AgCl 10.0 ก %

AgCl + Ca(NO3)2 (3.87 ก % ) CaCl2 + AgNO3 3. 3 ก ก Zn (s) + H2SO4 (aq) ZnSO4 (aq) + H2 (g) 3 ) ) * % ก - %กก !ก % ก H2 6.9 dm3 ! STP ( " Zn = 65.4 ) (20.1 ก % ) 4. 3 ก ก !ก0 - ( -) (M . + - ! " = 30) 2 MCln + n H2SO4 M2(SO4)n + 2n HCl (g) /"# $) ) ก / 4 (' (MCln) - %ก 3.44 ก % 0 ก 3 4()ก@ 24r+( 3 4 ('- %ก 2.92 ก % # n 3 # ( (n = 4) 4.12.2.3 ก )/ *! Rก +*, -.ก# " ก กก*G 1 " ก %ก ก (% ก # " *3 ก ( # .! ก% 4 +( %* # ก " ก%

%* # 2 %* # * 4 ก * ก3 ก3 (, ก # ก )" % ) 0 -) ก %* - ( - # %* (, // # .! ()" +( - ! 0 - ) ! .! ก ) ()" ก% - % 3 ก !(, ก // # .! )" 3 3 0 30 " + !+3 '$ !+3 ' ก0 - ( -) 2 ! # # ก / % #" ก% .! # + " - )"3 0 " ! ! ) ก 4() ก 0 " ! ก ! " ) ก%/ ก กก"# 1 ก ก. ก ( ก ! ก ( * # ก -)$ ก ) . 0 ก %* - ( %* -)(, // # .!

165

Chemistry for Engineers

Stoichiometry

. 3 ก ก !(, // # .! 0 30 " + !+3 '$ !ก0 - ( -) / % #" ก% .! # + " - 3 0 " ! !+3 '$ 4() ก ก !" # . ก 0 30 " + ก, ! ก ( ก # .! ก% -) # ก% ก # "4()"# l !3 )(, ก // # .! . ! ) - , ก ก ( ก // # .! 2 ! .! 0 %* -) 30 " # ก% ก93 4() ก !(, // # .! m

3#*-+G . 4.16 3 ก ก

2C(s) + O 2 (g) → 2CO(g) LL(1)

Fe 2 O 3 (s) + 3CO(g) → 2Fe(s) + 3CO 2 (g)LL(2) 3 ) ) '/ ก !ก + ก % 4 ( "2' Fe2O3 100 ก + ก %

.! 3 ก ก ! ก ! " ) 2 ก !+3 '$ . C !+3 'ก0 - ( -) . Fe2O3 # ก (% %* 3 ) (, ก -) # .! ก# )"3 3 0 " - ! ! ) ก 3 ก ก (1) (2) 3 -9 4()"# CO # %* ก (1) (2) ( "# ! 0 -) ก ( ก # .! ก% 4 (% %* 3 0 ก -)(, // # .! +( 0 30 " + ก, CO -) # ก% (1) × 3 : 6C + 3O 2 → 6COLLL(3)

(2) × 2 : 2Fe 2 O 3 + 6CO → 4Fe + 6CO 2 LLL(4) ก (3) (4) CO # ก% 3 (, // # .! + C 6 6 3 ก (3),(4); = 1 + C = + Fe2 O3 + Fe 2 O 3 2 2  W1  6 W   C =  2 Fe 2 O 3 2  M2   M1  W1 = ? ก + ก % , M1 = 12 , W2 = 100 ก + ก % , M2 = 160 W 6 100 ∴ 1 = × → W1 = 22.5 kg 12 2 160 (% %* ) ) '/ 22.5 ก + ก %

M UVก #C 4.9

166

3-

Chemistry for Engineers

1.

Stoichiometry

3 0 " " KMnO4 ! ) ) 0 - %/ 0 ก ก%/ก ( HCl ! 30 " ก .! -)4() Cl2 ( !3 0 ก ก%/ก@ 2 H2 !4()3 ก Mg 10 ก % 0 ก ก%/ H2SO4 ! 3. 3 ! ก (26.3 ก % ) ก ! ก ! " ) . 2KMnO 4 + 16HCl → 2KCl + 2MnCl 2 + 8H 2 O + 5Cl 2 LL(1)

Cl 2 + H 2 → 2HCl LL(2) Mg + H 2 SO 4 → MgSO 4 + H 2 LL(3)

2.

ก KMnO4 3 4() ก 2 %* (% * MnO 2 + 4KOH + O 2 → K 2 MnO 4 + 2H 2 OLL(1)

3K 2 MnO 4 + 4CO 2 + 2H 2 O → 2KMnO 4 + 4KHCO 3 + MnO 2 LL(2) $) ) ก KMnO4 100 ก % 3 ) )ก@ 2 O2 ก !ก % (30.4 ก % )

4.13 ก$ ก%& 'ก T- ก$ก ! ก( ) ( " % % &' -"# ก@ ! 0 ก ( ก% ก@ ! ก (3 ก ก , -J " (% ( "ก% l % #" -"# ก@ ! 0 ก ( ก% ก@ 2 ! 4() 3 ก ก ! , -J " (% ( "ก% 3 4() 30 " 9 %" ) 8 m # % #" N2 : H2 : NH3 = 1 : 3 : 2 2 ! %" # !0 ( "# 4 ก1 ก ' , 2ก

4.14 ก$ ก T- ! ) ก ) ( " % % &' -"# ก%/30 " ,J ก@ J ) " (% , -J ( "ก% lJ ) , -J " (% ( "ก% ก@ ,ก ( ! # ก% # 3 30 " ,J 30 " + # ก% m

167

Chemistry for Engineers

Stoichiometry

* % " ภ@ ,ภ(4 #"# 3 + ภ, ( -\# - . 9ภภ9 ! J " , -J " (% ( "ภ% # ภ% 3 ) 30 " + ภ, - . 30 " + # ภ%

# ! STP $) ภ@ SO2

1 N + ภ, ภ@ 2 CH4 1 ภ9 ) N + ภ, # ( "ภ% ภ1 +"ภ+( ( $ " % % &' ภ%/ + ภ, - . + 2 ! ภ4()(% * V âˆ? N or V âˆ? n

4.15 ภP+Aภ3&ภ;- b*ภbC ภ# " ภR) ภ1 +"ภ+( $ ! ภ@ ! 0 ภ( ภ% -) 30 " + ภ, 4() ภ9 $ ! 30 " + ภ, ! 0 ภ( ภ% -) 4() # ( "ภ% ภ. $) ภ!(, )" $ ! 30 " + ! 0 ภ( ภ% -) 4() % %" ! ( 30 " + ภ, # ( ภ@ %* 8()" # N 2 (g) + 3H 2 (g) → 2NH 3 (g)

1 mole

3 mole

2 mole

1 cm 3

3 cm 3

2 cm 3

5 J ( 4()(% *

168

Chemistry for Engineers

Stoichiometry

. $) ภ@ ! 0 ภ( ภ% ภ@ ! ภ(3 ภภ2 ! 4() 0 -) # !0 )" $ ! -) + ภ, - . + 0 4 ภ! (, )"4() # A(g) + B(g) → C(g)

20 cm 3

30 cm 3

20 cm 3

2 cm 3

3 cm 3

2 cm 3

2 mole

3 mole

2 mole

ภ2A + 3B 2C +, ภ1 ภ' , 2ภภ1 +"ภ+( )4() o ภ%/ ! # $ ภ@ #J ) , -J " (% ( "ภ% # %*

3#*-+G . 4.17 J ) , -J " (% # - ! ภ@ r 1 dm3 ภ/4 ()" r 2.4 x 1022

J ) J " ( "ภ% * 30 " + ภ, 4r+( 3 ภ@ 1 dm3 3 ภ!+ ภ, ภ. 2.4 x 1011 . 1.2 x 1022 . 2.4 x 1022 . 2.4 x 1044 ภ1 +"ภ+( ภ@ # 8J ) , -J " (% ( "ภ% .! # ภ% # 3 30 " + ภ, # ภ% ()" .! ภ@ He 1 dm3

He 2.4 x 1022 (+ ภ, ) ภ@ H2 1 dm3 3 H2 2.4 x 1022 + ภ, -----------------( ) 3#*-+G . 4.18 "( /- ! / 3, ภ@ ภ2 3 "%( " ภ@ , -J " (% 4") ภ2 3 ภ-) - ( )" # ภ@ ) 4 -) , -J " (% ( "%( " " 3 ภ! # ภ2 3

169

Stoichiometry

Chemistry for Engineers

ก. # ก%

.

1 2

. 2 #

.

1 4

ก1 +"ก +( ก@ # 8J ) , -J " (% ( "ก% .! # ก% # 3 30 " + # ก% ()" = + CH4 + O2

 W1  W   O 2 =  2 CH 4  M1   M2  W1 = ? , M1 = 32 , W2 = ? , M2 = 16 W W W 1 ∴ 1 = 2 → 2 = 32 16 W1 2

" CH4 (W2) 3

1 # " O2 (W1)--------------------------------( ) 2

M UVก #C 4.10 1. 3 ก ก # 4 * 2X2Y3(g) + 5Z2(g) 3Z3Y2(g) + ZX4(g) ก@ ! 5 J% K'3 กก " 30 cm3 X2Y3 100 cm3 Z2 ก ! cm3 ! , -J " (% ( "ก% ก. 40 . 45 . 55 . 60 2. .! 0 ก@ A 0 ก ก%/ ก@ B 4() ก@ C ( ( " +( 5 ก ( (% * 3 R 3 (cm3) 3 R ET- (cm3) ) #Z. 3 * E#.Rก C e ก + (cm3) A B A B 1 40 60 20 60 2 100 350 50 250 $) ก "%( ก@ 0 ! , -J " (% ( "ก% ก. 3 ก ( ก ! ก ( * . $) ) B 150 cm3 0 ก ก%/ A 30 " ก ก 3 4() ก@ C ก ! cm3 170

Chemistry for Engineers

Stoichiometry

4.16 ภ)/ *!Rภ+*ภ# " EPE + % (solution) : 5 .* ( " ! ภ/()" 3 "/" (solvent) 0=ภ"/" (solute) 0 "/" ภภ3 "/" #"/ 0=ภ"/" 0 / ภ# - " - " ! ภภ"# 3 3%("# %" 0 ! ) ภ"# 3 %"$ ภ0 "/" ภภ3 "/" #"/ 0=ภ"/" 0 /ภ# - " 9 , - "- ภ@ ! $ ( "ภ%/ 3 %" 0 ! $ # 3 ภ3 %"$ ภ# NaCl *0 *0 $ - " # ( "ภ%/ (% %* *0 3

%" 0 ! NaCl 9 2 ! $ # 3 ภ3 %"$ ภ(- ! 8 33 $ 9 - " - . ภ@ ภ94() 33 %" $ ภภภ"# 1 (ภ94() #3 ) %" 0 ( ( "ภ% 4.16.1 G*+,-.)* R, , +( %!" 8 4 3 ภ0 - ( %"$ ภ- . %" 0 # HCl 0.1 + / , C6H12O6 0.02 + /ภ+ ภ% ) - #" " ) ) ! )ภ% ภ4() ภ# ภ. + ' (Molar ; M) - . + / - . mol/dm3 - $ 30 " + %"$ ภ1 # HCl 0.1 + / - $ 1 HCl 0.1 + + / - #" " ) ) ! * ภ%/ , -J $) , -J ! " ) ) 3 ! 4 ()" . + (Molal ; m) - . + /ภ+ ภ% - . mol/kg - $ 30 " + %"$ ภ1 ภ+ ภ%

# HCl 0.1 + /ภ+ ภ% - $ *0 1 ภ+ ภ% HCl # 0.1 + . ) - . ' 29 ' (%) /# ภ3 J .

171

Chemistry for Engineers

Stoichiometry

1. ) +( " # " - . ) +( " - $ " 100 - #" *0 - %ภ# HCl 30%+( " - $ 100 ภ% HCl # 30 ภ%

2. ) +( # - . ) +( - $ 100 - #" # HCl 30%+( - $ 100 cm3 HCl # 30 cm3 3. ) +( " # - $ " 100 - #" # HCl 30%+( " / - $ 100 cm3 HCl # 30 ภ%

) +( " - #" " ) ) !4 # * ภ%/ , -J # ) +( ) +( " # - #" " ) ) ! * ภ%/ , -J ภ3 ภ* % - #" " ) ) .! 8 ภ# - #" #" ) #" +( " - . +( (ppm) - $ " 1 ) - #" *0 - %ภ- . 1 ) - #" # Hg 2 #" ) #" +( " - $ 1 ) ภ% Hg 2 ภ%

/ ภ33 ภ0 - (- #" " ) ) / / # $) %"$ ภ) # %" 0 ภภ"# 3. 3 $) %"$ ภภ# %" 0 ) ภ"# ) ) )

4.16.2 ภ1/ * b E,-." O " EPE + o - #" + / $) / " ) ) 3 - 30 " + 4()(% * Ă— " ) ) 30 " + = 1000 VC n = 1000 V = cm3 , C = mol/l .! 3 30 " + #" ภ%/30 " + # # 8 !5# )" 3 4()

172

Chemistry for Engineers

n=

Stoichiometry

W V N VC = = 23 = M 22.4 6.02 Ă— 10 1000

M UVภ#C 4.11 1. 3 0 " 30 " + NH3 # 4 * ภ. NH3 0.1 mol/l , 200 cm3 . NH3 3.4%w/v , 200 cm3 2. ภ2 4 (' ) ) 0.5 mol/l 30 " 500 cm3 3 4 ('4 #ภ!+ ภ. 0.25 . 0.50 . 1.00 . 17.75 4.16.3 PRD ,-.ภ)/ *!Rภ+*ภ# " EPE + /# ภ3 J ภ. ภ+( - 3 ภ9 - " ภ@ %" 0 ! -

- 3 ภภ3. 3 - 3 ภภ5 - " ) ) ) ()" ภ% . ภ! - #" " ) ) - ! % -) mol/l - ! mol/l -) % . ภ0 " ภ! "ภ%/ ŕ¸

4.17 ภR3 + " EPE +1 ภ,-.M,[. ,-.R E* Mภo" +( 0 9 - " - . ภ@ 30 " - ! # *0 - . %" 0 ! -

#" -\#3 ) %! *0 - %ภ! ) ภ)" 0 4 *0 .! 3 ภ" $ 9 ( - " , ภ@ ) # ภ%/ " (% %* l30 " + / , & ‹ # # ภ%/ 30 " + n ( ) = n ( ) W VC = M 1000

173

Chemistry for Engineers

Stoichiometry

3 ภ3 -9 4()"# %" # 3 ( . W, V C 2 ! ภ0 " +3 '3 ภ0 - ( -) 2 %" # ภ0 - ( W, V 0 " - C 0 - %/ W 33 ภ0 - ( -) ) # $) - "3 ภ0 - ( -) ) ! -) " ภ# +( ()" " - # W = Ă— " - # ภภ@ 2ภ9 # ( "ภ% 33 ภ0 - ( ! STP -) $3 ! ภ@ 2 -) " ภ# - . 3 0 " +( ) V VC = 22.4 1000 M UVภ#C 4.12 1. $) ( (II) 4 # 3.31 ภ% ) ภ( (II) 4 ! "

) ) 0.4 mol/l 3 4() ภ! cm3 (M = 331) 2. $) ภr ' 23.75 cm3 ()" / 2 300 cm3 !4()3 " ) ) # ( " - # ภr ' = 0.8 g/cm3 , " - # / 2 = 0.9 g/cm3 , " + ภ, ภr ' = 46 3. $) ) ภ+2 ( 4 (NaNO3) 100 cm3 +( -) !4() +2 ( 4 0.023 ภ% 1 cm3 3 0 4() # 4

4.18 ภR3 + " EPE +bC+ภ/ O R1T-1 . .! *0 (- . %" 0 ) 4 3 0 -) " ) ) ! #30 " + 4 # ! (% %* ภ0 " 3 (- %ภ30 " + ภ# *0 = 30 " + - % *0 C1 V1 = C 2 V2 M UVภ#C 4.13 1.

HCl ) ) 0.2 mol/l # 500 cm3 $) ) ภภ( HCl -) ) ) 0.03 mol/l 30 " 100 cm3 3 ) )ภ( HCl 0.2 mol/l ภ! cm3 2. NaCl ) ) 0.2 mol/l 30 " 300 cm3 0 *0 3 1 ) ภ/"# *0 - %ภภ% NaCl 300 cm3 ) ) 0.2 mol/l *0 - %ภภ% NaCl 300 cm3 ! 3. 3 )" # # 4

174

Chemistry for Engineers

3.

Stoichiometry

$) ) ภ0 H2SO4 ) ) 1 mol/l 30 " 50 cm3 3 ภ) ) 4 mol/l 3 ) ภ*0 30 " ภ! cm3 5 ภ%/ ภ( *

4.19 ภR3 + " EPE +bC+ภ\" " EPE + E +)* R, , R, C *+ภ# .! 0 ( ( "ภ% ! " ) ) # 8ภ% 5 ภ% 3 4() - # ! " ) ) ภ# 3 ภ(

ภ0 " % - %ภ!"# l30 " + ภ# - % 5 ภ% 3 ) # ภ% m n (ภ# 5 ) = n (- % 5 ) V1C1 + V2 C 2 + LLL = VC - . VC = V1C1 + V2 C 2 + LLL M UVภ#C 4.14 1. 3 ) 0 ภ( HCl 0.5 mol/l ภ! 5 ภ%/ ภ( HCl 0.1 mol/l ภ! 3 3 4() ภ( HCl 0.2 mol/l 2 2. $) ) ภ3 ภ( HNO3 1 mol/l -) 14 +( ภภ( HNO3 15 mol/l 4 ภ( HNO3 2 mol/l 30 " 1250 cm3 3 ) )ภ( HNO3 15 mol/l 30 " ภ!

4.20 ภR E + G*+)* R, , ,-." EPE + #" -\#3 ภ! 3 ภ- #" ) // # 8 -) + / - . 33 ! + / -) ) ภ0 " ภ! "ภ%/ภ! - #" " ) ) #" -\# ) ) ) ภ! "ภ%/ "

- # 33 , ภ0 " ภ! - #" 4()(% * dx mol/l = 10 M 3 d = " - # (g/cm ) , x = % , M = " + ภ, * % *! 1. ภ! %w/v mol/l 4 # ) ) " - # (% %* x mol/l = 10 M 2. ภ! %w/w mol/l , d = " - # 3. ภ! %v/v mol/l , d = " - # ( %"$ ภ) 175

Chemistry for Engineers

Stoichiometry

M UVภ#C 4.15 1. *0 ) (- ! " - # 1.13 g/cm3 /,"# ภ( 2 ภ(CH3COOH) # 8%w/w *0 ) * " ) ) ภ( 2 ภ( ภ! mol/l 2. *0 ) ภ( *0 ) (CH3COOH) # 5%v/v $) ( " ) ) mol/l 3 # # ( 3. ภ( - ! ภ"# ) )ภ(( " (HNO3) 0.1 mol/l 30 " 450 cm3 # -) /% ภ#ภ(( " (ภ(4 ภ) ! ( ภ4")(% * 70%(wt/vol) HNO3 density 1.4 g/cm3 3 ! " ) ) ! ) ภ4() # 4

4.21 ภ)/ *!" EPE +1 ภe ภ+ R) )- %ภภ0 ( "ภ%/ภ0 " 3 ภภ+( 3 o %" !+3 ' $ %" !ภ0 - ( ) -) 0 30 " + / % #" ภ% - % 3 ภ# 30 " + 3 - 0 / ! ) ภ4() 3#*-+G . 4.19 $) 0 0.55 dm3 0.01 mol/dm3 Na2CO3 ภ( HCl 0.1 mol/dm3 30 " 0.2 dm3 3 ภ( ภ(% * Na 2 CO 3 + 2HCl → 2NaCl + H 2 O + CO 2 4()ภ@ 2 CO2 ภ( * ภ!+ .! 3 ภ%* ) 2 ( . Na2CO3 ภ%/ HCl %* ภ3 ) - ภ# "# ( ) - ( )"3 0 ! )- (4 0 " 30 " + CO2 0 - %/ Na2CO3 n = VC (% %* + Na2CO3 = 0.55 x 0.01 = 0.055 + 0 - %/ HCl n = VC (% %* + HCl = 0.2 x 0.1 = 0.02 + 3 ภภ) HCl 2 + ) ) Na2CO3 = 1 + $) ) HCl 0.02 + ) ) Na2CO3 = 1Ă—0.02 = 0.01 + 176

Chemistry for Engineers

Stoichiometry

# Na2CO3 0.055 + (% %* Na2CO3 3 - . # HCl )- ( 3 0 HCl 4 - CO2 3 ภภ) HCl 2 + 4() CO2 = 1 + $) ) HCl 0.02 + 4() CO2 = 1Ă—0.02 = 0.01 + 0.01 + 3- (% %* 4() ภ@ CO2

M UVภ#C 4.16 1.

NaOH ) ) 0.5 mol/l #30 " - ! 2 ! 30 " !3 0 ภ( ภ%/ HCl ) ) 0.2 mol/l 30 " 100 cm3 $) ) ภNaOH ) ) 0.1 mol/l +( 3 ภ! #3 4() # ภ! ,( ภ! cm3 2. .! 0 ภ# 4 * -)(, BaCl2 (aq) + AgNO3 (aq)

Ba(NO3)2 (aq) + AgCl (s)

3 ) ) BaCl2 0. 5 mol/l # ( 3 3 4() ภAgCl ภ( * 71.75 ภ%

ภ0 - ( " + ภ, AgCl = 143. 5

177

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