Higher Chemistry Unit 1 Section 1 Reaction Rates Multiple Choice Questions This is designed to be used by teachers to help students develop skills in

Higher Higher ChemistryChemistry

Unit 1Section 1 Reaction RatesMultiple Choice Questions

This is designed to be used by teachers to help students develop skills in answering multiple choice questions.

Douglas Racey, Waid Academy, Anstruther, Fife, Scotland

Higher Chemistry Higher Chemistry Unit 1 - Section 1 Reaction RatesUnit 1 - Section 1 Reaction RatesMultiple Choice QuestionsMultiple Choice Questions

1.1. Excess marble chips (calcium Excess marble chips (calcium carbonate) carbonate) were added to 25cmwere added to 25cm33 of hydrochloric of hydrochloric acid, acid, concentration 2 mol lconcentration 2 mol l-1-1. Which . Which measurement, measurement, taken at regular intervals and plotted taken at regular intervals and plotted against against time, would give the graph shown?time, would give the graph shown?

A.A. temperaturetemperatureB.B. volume of gas producedvolume of gas producedC.C. pH of solution pH of solution D.D. mass of the beaker and contentsmass of the beaker and contentsAnswer D.


2.2. The same reaction was carried out at four The same reaction was carried out at four different temperatures and the times taken different temperatures and the times taken for the reaction recorded.for the reaction recorded.Temperature /Temperature /ooCC 2020 3030 4040 5050Time / sTime / s 6060 3030 1414 5 5The results show thatThe results show thatA.A. a small rise in temperature results in a a small rise in temperature results in a large increase in reaction large increase in reaction rate rateB.B. the activation energy increases with the activation energy increases with increasing temperatureincreasing temperatureC.C. the rate of the reaction is directly the rate of the reaction is directly proportional to the proportional to the temperature temperatureD.D. the reaction is endothermic the reaction is endothermic

Answer A.


3.3.

In area XIn area XA.A. molecules always form an activated molecules always form an activated complexcomplexB.B. no molecules have the energy to form an no molecules have the energy to form an activated complexactivated complexC.C. collisions between molecules are always collisions between molecules are always successful in forming successful in forming products productsD.D. all molecules have the energy to form an all molecules have the energy to form an activated complexactivated complexAnswer

D.


4.4. Excess zinc was added to 100cmExcess zinc was added to 100cm33 of of hydrochloric acid, hydrochloric acid, concentration 1 mol lconcentration 1 mol l-1-1 Graph I Graph I refers to this reaction.refers to this reaction.

Graph II could be forGraph II could be forA.A. excess zinc reacting with 100cm excess zinc reacting with 100cm33 hydrochloric acid, hydrochloric acid, concentration 2 mol lconcentration 2 mol l-1-1

B.B. excess zinc reacting with 100cm excess zinc reacting with 100cm33 of sulphuric acid, of sulphuric acid, concentration 1 mol lconcentration 1 mol l-1-1

C.C. excess zinc reacting with 100cm excess zinc reacting with 100cm3 3 of ethanoic acid, of ethanoic acid, concentration 1 mol lconcentration 1 mol l-1-1

D.D. excess magnesium reacting with 100cm excess magnesium reacting with 100cm33 of of hydrochloric acid, hydrochloric acid, concentration 1 mol l concentration 1 mol l-1-1

Answer D.


5.5. When copper carbonate reacts with excess When copper carbonate reacts with excess acid, acid, carbon dioxide is produced. carbon dioxide is produced. The curves shown were obtained The curves shown were obtained under different conditions.under different conditions.

The change The change PP to to QQ could be brought about by could be brought about by

A. increasing the concentration of the acidA. increasing the concentration of the acidB. decreasing the mass of copper B. decreasing the mass of copper carbonatecarbonateC. decreasing the particle size of the C. decreasing the particle size of the copper carbonatecopper carbonateD. adding a catalystD. adding a catalystAnswer B.


6.6.The continuous use of large extractor The continuous use of large extractor fans greatly reduces the possibility of fans greatly reduces the possibility of an explosion in a flour mill becausean explosion in a flour mill because A. A. a build up in the concentration of a build up in the concentration of oxygen oxygen is preventedis preventedB. B. local temperature rises a prevented local temperature rises a prevented by the by the movement of airmovement of airC. C. particles of flour suspended in the air particles of flour suspended in the air are are removedremovedD. D. the slow accumulation of carbon the slow accumulation of carbon monoxide ismonoxide is preventedprevented

Answer C.


7. A small increase in temperature 7. A small increase in temperature results in aresults in a

large increase in reaction rate .large increase in reaction rate .

The The mainmain reason for this is that reason for this is that

A. A. more collisions are taking placemore collisions are taking place

B. B. the enthalpy change is loweredthe enthalpy change is lowered

C. C. the activation energy is loweredthe activation energy is lowered

D. D. many more particles have energy many more particles have energy greatergreater

than the activation energy.than the activation energy.Answer D.


8. 8. The graph shown below shows The graph shown below shows the variation of concentration of a the variation of concentration of a reactant with time as a reaction reactant with time as a reaction proceeds.proceeds.

The average reaction rate, in The average reaction rate, in mol lmol l-1-1 s s-1-1, during the first 20s is, during the first 20s isA. A. 0.00250.0025B. B. 0.00360.0036C. C. 0.00750.0075D. D. 0.00900.0090

Answer C.


9. 9. Which of the following is Which of the following is notnot a a correct statement about the effect correct statement about the effect of a catalyst?of a catalyst?

The catalystThe catalystA. A. lowers the energy which molecules lowers the energy which molecules need for need for successful collisionsuccessful collision

B. B. provides an alternative route to the provides an alternative route to the productsproducts

C. C. forms weak bonds with reacting forms weak bonds with reacting moleculesmolecules

D. D. provides energy so that more provides energy so that more molecules havemolecules have

successful collisionssuccessful collisions..Answer D.


10. For any chemical reaction, the 10. For any chemical reaction, the temperature is a measure oftemperature is a measure of

A. A. tthe average kinetic energy of the he average kinetic energy of the moleculesmolecules

which reactwhich react

B. B. the average kinetic energy of all the the average kinetic energy of all the moleculesmolecules

C. C. the activation energythe activation energy

D. D. tthe minimum kinetic energy required he minimum kinetic energy required before before

reaction occursreaction occursAnswer B.

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Higher Chemistry Unit 1 Section 1 Reaction Rates Multiple Choice Questions This is designed to be used by teachers to help students develop skills in