Rate of reactions

What criteria must be met for reactant collisions to result in a successful product?

• The reactants must collide with each other

• The reactants must collide with enough energy and be in the right positions

• The reactants must have enough energy to form the activated complex

The collisions which bring about a chemical reaction are called: 

• Consistent collisions
•  Normal collisions 
• Effective collisions 
• None of the above

More collisions correspond to a: 

• Faster reaction rate  
• Slower reaction rate
• Constant reaction rate 
• None of the above

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.

Why does a higher temperature increase the rate of a reaction?

• it increases both the frequency and energy of particle collisions
• it only increases the frequency of particle collisions
• it only increases the energy of particle collisions
• it reduces the activation energy of the reaction

How could we make this reaction happen more quickly?

• Decrease the concentration of the acid

• crush the chalk to increase the surface area

• Put the test tube in an ice bath

Which has more surface area?

• Large chunks of chalk

• Cube of sugar

• Powdered sugar

• Small chunks of sugar

A temperature increase causes the particles ......

• to slow down

• move faster

• collide higher

• in the right order

How does a catalyst work in speeding up a reaction?

• By lowering the activation energy or reaction

• by giving them more energy

• by making them more available