Workbook
Derek McMonagle
Contents Unit1 Working like a scientist..............................................................................4 Unit2 Transport across cells................................................................................ 13 Unit3 Transport inhumans................................................................................ 17 Unit4 Transport in plant s................................................................................... 24 Unit5 Staticelec tricity........................................................................................ 28 Unit6 Current elec tricity..................................................................................... 32 Unit7Magnetism................................................................................................ 43 Unit8 Chemical bonding, formulae andequations.......................................... 51 Unit 9 Sensitivity and coordination.................................................................... 63 Unit 10 Acids and alkalis 72 Unit 11 Embr yo development and birth control..................................................89 3
10 Acids and alkalis
10.1 Acids and alkalis
1 Statewhether each of the following statement sisTRUEor FALSE.
a) Citrus fruits , like oranges and lemons , containacids.
b) Household chemicals may containacids or alkalis.
c) Calcium hydroxide is a weak acid.
d) Acids are hazardous but alkalis are not.
e) Acids are agroup ofchemicalswithsimilarproper ties.
f) Sulfuric acid is a common laboratory reagent.
2 Somepeopletake vitamin and mineral supplement saspart of their diet.The following labelshows the ingredient s in such a supplement.
SupplementFacts
Sugars
VitaminA (aspalmitate,betacarotene)
VitaminC (asascorbicacid)
VitaminD-3 (ascholecalciferol)
VitaminE (asd-alphatocopherolacetate)
VitaminK (asmenatetrenone)
Thiamin (VitaminB-1)(asthiaminemononitrate)
Riboflavin (VitaminB-2)
Niacin (asniacinamide)
VitaminB-6 (aspyridoxineHCl)
Folate (asfolicacid)
VitaminB-12 (asmethylcobalamin)
Biotin
PantothenicAcid (ascalciumpantothenate)
Calcium (asgluconate,citrate)
Iron (asgluconate)
Magnesium (asgluconate,oxide)
Selenium (asselenomethione)
Copper (asgluconate)
Chromium (aschromiumaminoacidchelate)
Potassium (asgluconate,citrate)
Fruitand VegetablePowder
PlantDerivedMineralPowder
GlucosamineSulfateHCl
MSM (methylsulfonylmethane)
ChondroitinSulfate
AminoAcidComplex
alanine,arginine,asparticacid,cystine, glutamicacid,glycine,histidine,isoleucine, leucine,lysine,methionine,phenylalanine, proline,serine,threonine,tyrosineandvaline.
Choline (ascholinebitartrate)
Inositol
Dimethyglycine
Bioflavonoids
GrapeSeedExtract*** Co-enzymeQ10
Boron (sodiumborate)
*PercentDaily Valuebasedona2,000caloriediet.
†Daily Valuenotestablished.
***Standardisedplantextract.
OTHERINGREDIENTS: Maltodextrin,citricacid,naturalflavourandcolour,xanthangum,CitriSweet® (inulin,fructose, citruspellextract),stevia.
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(asgluconate) 2mg 100mcg 1mg 200mcg 100mg 13% 143% 50% 167% 3% † † † † † † † † † † † † † 500mg 300mg 125mg 100mg 25mg 25mg 25mg 20mg 15mg 5mg 3mg 1mg 125mg
Zinc
Calories 30 TotalCarbohydrate 7g 1g 7500IU 1000mg 750IU 200IU 30mcg 30mg 30mg 40mg 30mg 400mcg 500mcg 600mcg 150mg 50mg 1mg 20mg 2% 2% † 150% 1667% 187% 667% 38% 2000% 1765% 200% 1500% 100% 8333% 200% 1500% 5% 6% 5%
Amount PerServing
%Daily Value* Amount PerServing %Daily Value*
ServingsPerContainer:30
ServingSize:13.9g/2scoops
a) Make a list of the dif ferent acids contained in the supplement.
b) Which of these acidsis another name for vitamin C?
c) Which of theseacidsdoes thebody use to buildproteins?
d) Which of these acids is found in citrus fruits?
10.2 Identifying acids
1 Complete the following sentences
a) Acid comes from a Latin word that means .
b) Our food contains many acidswhich are safe to eat.
c) An isa subs tance that is dif ferent colour s in acids and alkalis.
d) In the laborator y litmus maybe dipped into a solution to test if it is an acid or an alkali
e) H2 SO 4 isthe chemicalformula for acid.
2 a) Complete the followingtable.
Hydrochloric acid Blue litmus paper
Nitric acid Phenolphthalein
Sulfuric acid
Methyl orange
Ethanoic acid phenolphthalein
Citric acid
Methyl orange
Phosphoric acid Blue litmus paper
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Acid IndicatorInitial colour of indicator Final colour in acid
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10 Acids and alkalis (cont.)
b) Which of these indicators cannotbe used to detec t an acid? Explain your answer
c) Doany ofthese indicator sprovideinformationabout the s trengthofanacid? Explain your ans wer.
3 a) Which gas isneeded by plant s for photosynthesis?
b) Name the acid formed by this gas in solution.
c) State threeprocesses which result in theproduc tion of this gas.
d) Name the reagent used to detec t this gas.
e) Describeapositive test for this gas.
10.3 Strength of anacid
1 a) What does thepH scalemeasure?
b) On this scalewhat range of values indicatesasolutionisacidic?
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c) Which indicator gives information about thepH value of asolution?
d) Explain why using this indicator maybe more useful than usingblue litmus paper.
e) Complete the followingtable.
a) Predic ta likelypH value for each of the followingacids by consideringwhether they are strong acids or weak acids.
i) Sulfuric acid
ii) Carbonic acid
iii) Lactic acid(in milk)
iv) Nitric acid
b) Leaves of theplant Aloe vera are used to treatburnson theskin.The juice they contain hasapH value of 6.1.
i) Is Aloe vera juice best describedas:a strongacid,a weak acid orneutral?
ii) Predic t the colour produced when a few drops of univer sal indicator are added to this juice.
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pH value of solutionColour of universal indicator in the solution 7 2 5 6 4 [5]
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10 Acids and alkalis (cont.)
2 a) Predic ta likelypH value for each of the following alkalis by considering whether they are strong alkalis or weak alkalis.
i) Sodium hydroxide
ii) Aqueous ammonia
iii) Toothpas te
iv) Antacid tablet s
b) Sodium hydrogencarbonateis used to treatbee stings .It hasapH value of 8.3.
i) Is sodium hydrogencarbonate best describedas:a strong alkali, a weak alkali or neutral?
ii) Predic t the colour produced when a few drops of univer sal indicator are added to sodium hydrogencarbonatesolution.
10.6Makinganacid– alkali indicator
1 a) Fromwhat is litmus indicatorobtained?
b) Give one example of each of the following that might provide an acid –alkali indicator.
i) A flower
ii) A vegetable
c) What essential proper ty must an acid –alkali indicator have?
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2 a) Name the piece of apparatus picturedwhichis used in preparing an acid –alkali indicator and describe it s func tion.
b) i) Why is ethanoladded to theplantmaterial?
ii) Why isethanol preferred towater?
c) i) How is the plant ex trac t separated from the plantmaterial?
ii) Describe an alternativemethod of separation that could be used.
iii) Comparethe twomethods of separation interms of speed and effectiveness .
10.7 Acid –alkali reactions
1 a) What type of reaction takes place when an acid react s with an alkali?
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10 Acids and alkalis (cont.)
d) How coulda sample of pure lithium chloridebe made?
4 Give the name of the salt formed in aneutralisation reaction involving the following pair s of acidand base.
a) Magnesium hydroxide and nitric acid
b) Copper(II) oxide and sulfuric acid
c) Aqueous ammonia and nitric acid
d) Potassium hydroxide and hydrochloric acid
e) Zinc oxide and nitric acid
f) Calcium hydroxide and hydrochloric acid
10.9 Neutralisation reac tions in everydaylife
1 The following diagram shows details of anold-fashioned fire ex tinguisher.
glassbottle
sodium hydrogencarbonate solution
metallic container
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knob
sulfuricacid
a) What neutralisation reac tiontakes place when the ex tinguisherisac tivated?
b) Explain how the fire ex tinguisher work s.
2 Some insec ts have stings whichcausepain and irritation to theskin.
a) The sting of a waspis alkaline
i) What type of subs tanceisneeded to neutralise the sting?
ii) Sugges ta suitable subs tancebearing in mind that the substance itself shouldnotdamage the skin.
b) The sting of abeeisacidic.
i) What type of substance is needed to neutralise the sting?
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10 Acids and alkalis (cont.)
ii) Sugges ta suitable subs tancebearing in mind that the substance itself shouldnotdamage the skin
10.10 Ammonium compounds
1 State whether each of the following statements about ammonia isTRUEor FALSE.
a) Ammonia isa pungent gas.
b) Ammonia is palegreen in colour.
c) Ammonia gas turns damp red litmus paper blue.
d) Ammonia isdenser than air.
e) Ammonia is insoluble in water.
f) Ammonia is used in fire ex tinguishers.
2 a) Writea word equation for the reac tion of ammonium nitrate andcalcium hydroxide.
b) Complete the following diagram by adding the labels .
collectingtube
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