Rates of Reaction

Which factors increase the rate of a reaction.

• increasing temperature
• increasing concentration
• increasing surface area
• all of these

Increase in temperature of the reactants can do one of the following

• Slow collision frequency
• Allow less effective collision between the particles
• Neutralise the reaction
• increase collision between the particles thus increasing the rate.

How does a catalyst work in speeding up a reaction?

• By lowering the activation energy

• by giving them more energy

• by making them more available

Which graph shows the effect of increasing temperature on the rate of reaction of calcium carbonate with dilute hydrochloric acid?

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• 
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What type of reaction is this?

• Endothermic
• Exothermic

The graph shows how the total volume of a gas given off from a reaction changes with time. In which time interval is least gas given off? 

• A
• B
• C
• D

In an experiment, a 2 g lump of zinc and 2 g of powdered zinc are added separately to equal volumes of dilute sulphuric acid. The solid line on the graph shows the volume of gas given off when the 2 g lump is used. Which dotted line is obtained when the zinc is powdered? 

• A
• B
• C
• D

A solution of hydrogen peroxide releases oxygen slowly at room temperature.
 hydrogen peroxide → water + oxygen
 The diagrams show the effect of adding blood to the solution. What could be the reason for the observed change? 

• Blood contains an enzyme. 
• Blood contains water. 
• The hydrogen peroxide becomes more concentrated. 
• The hydrogen peroxide is neutralised by blood. 

A student investigated the rate of reaction of calcium carbonate with dilute hydrochloric acid. Every minute, the student recorded the total volume of carbon dioxide produced, until some time after the reaction was complete.
Which graph shows the correct results? 

• A
• B
• C
• D

The following graph shows two different reaction pathways for the same overall reaction at the same temperature. Which pathway is slower and why?

• Red, because the activation energy is larger
• Blue, because the activation energy is lower
• both reaction progress at the same rate