# Worksheet: Reaction Rate Measurements

In this worksheet, we will practice finding the rate of a reaction by plotting the masses or concentrations of reactants or products.

Q1:

Which of the following is not a viable unit for a reaction rate?

• Akg/s
• Bt/d
• CM/min
• Dh/s
• Eg/s

Q2:

The rate of a reaction can be determined by measuring changes in the physical properties of the reaction mixture. Which of the following parameters is not typically monitored to obtain a measure of reaction rate?

• ATemperature
• BVolume
• CColor
• DCloudiness
• EMass

Q3:

What is the formula for calculating the rate of a reaction from the reaction time and the amount of product formed?

• A
• B
• C
• D
• E

Q4:

Shown in the diagram is the experimental apparatus used to identify the end-point of a reaction from changes in turbidity. The average reaction rate is determined by measuring the time taken for the cross to be obscured by the product suspension. When monitoring changes in turbidity, the cross must be viewed from directly above. How does this approach help to ensure that the experiment is repeatable?

• AThe cross is not viewed through glass, which would reduce its visibility by refracting light.
• BThe cross is not viewed through glass, which would reduce its visibility by adhering to the solid product.
• CThe cross is viewed through a constant depth of liquid.
• DThe cross is viewed over the largest possible area.
• EThe cross is viewed through a minimum depth of liquid.

Q5:

In a rate of reaction experiment between lumps of calcium carbonate and hydrochloric acid, what method or methods could you use to speed up the rate of reaction?

 Method A B C D E Use larger lumps of calcium carbonate Heat up the acid Cool down the acid Add a catalyst Use a pestle and a mortar on the calcium carbonate
• AB
• BA, B, and D
• CD
• DB, D, and E
• EB and D

Q6:

Sodium hypochlorite decomposes in light according to the equation shown. The rate of this photochemical reaction can be controlled by varying the intensity of light.

Which of the following is not an appropriate method of measuring this rate of reaction?

• AMeasuring the amount of oxygen produced over time
• BCounting the bubbles of oxygen produced over time
• CWeighing the mass of the solution over time
• DIncreasing the intensity of light over time

Q7:

In a rate of reaction experiment between marble chips and hydrochloric acid, which of the following methods could you use to slow down the rate of reaction?

 Method A B C D E Using powdered marble Gently shaking the reaction vessel Cooling down the acid Using larger marble chips Adding a catalyst
• AB and D
• BC and D
• CB and E
• DA and C
• EC and E

Q8:

In the following experiment, different temperatures of dilute acid are tested to see the effect of heat on the rate of reaction. Which of the following variables is not a control variable?

 Variables A B C D E F Volume of HCl Temperature of HCl Temperature of NaSO223 Volume of NaSO223 Concentration of HCl Concentration of NaSO223
• AB
• BE
• CA
• DC
• EF

Q9:

For which of the following reactions would the apparatus in the diagram be unsuitable for measuring the rate of reaction? • A
• B
• C
• D
• E

Q10:

When excess hydrochloric acid reacts with calcium carbonate, carbon dioxide is produced. Apart from measuring the change in mass of the calcium carbonate, which of the following could be measured to determine the rate?

• AThe intensity of light emitted over time
• BThe temperature of the reaction mixture over time
• CThe volume of gas produced over time
• DThe turbidity of the solution over time
• EThe color of the solution over time

Q11:

The diagram shows an experiment before and after the chemical reaction in the equation takes place. Which of the following observations matches an increase in temperature of one or both of the reactants? • AThe cross is obscured by the solid sulfur after more time.
• BThe cross is obscured by the solid sulfur after less time.
• CThe cross is obscured by the solid sulfur after a similar time.

Q12:

In the following experiment, if the rubber bung used in the conical flask were loose, what would the effect be? • AHydrochloric acid could be lost; therefore, the level of water in the measuring cylinder may be lower than it should be.
• BHydrochloric acid could travel through the glass tubing; therefore, the level of water in the measuring cylinder may be higher than it should be.
• C could be lost; therefore, the level of water in the measuring cylinder may be higher than it should be.
• D could be lost; therefore, the level of water in the measuring cylinder may be lower than it should be.
• EAir could enter the experiment; therefore, the level of water in the measuring cylinder may be lower than it should be.

Q13:

Which of the following would the arrangement of apparatus in the diagram be used to measure? • AThe volume of gas given off in a reaction
• BThe effectiveness of a catalyst
• CChanges in turbidity in the conical flask
• DThe temperature change of a reaction
• EDifferences in surface area

Q14:

In the following experiment, different-sized marble chips are tested to see the effect of surface area on the rate of reaction. Which of the following variables should be kept constant?

 Variables A B C D E Volume of HCl Temperature of HCl Mass of marble chips Size and shape of marble chips Concentration of HCl
• AA, B, C, and E
• BC and D
• CA, B, and E
• DB, C, D, and E
• EA, B, C, D, and E