Rates Of Reaction

Question 1

What is the rate of a reaction?

Answer 1

How quickly reactants are used up or products are produced

Question 2

What is the unit for rate of reaction in a reaction involving a change in mass?

Answer 2

g/s

Question 3

What is the unit for rate of reaction in a reaction involving a change in volume?

Answer 3

Cm3/s

Question 4

How can you measure the rate of a reaction that produces a gas?

Answer 4

Measure change in mass using a balance
Measure volume of gas produced using a syringe or upside down measuring cylinder

Question 5

What is a precipitate?

Answer 5

An insoluble solid in a solution

Question 6

How can you measure the rate of a reaction that produces a precipitate?

Answer 6

Measure how long it takes for a cross to disappear

Question 7

What is the activation energy?

Answer 7

The minimum amount of energy colliding particles need to have before a reaction will take place

Question 8

What effect does increasing concentration have on the rate of a reaction?

Answer 8

Increases

Question 9

Why does increasing concentration have this effect?

Answer 9

More reactant particles in the same volume lead to more frequent collisions

Question 10

What effect does increasing pressure have on the rate of reaction?

Answer 10

Increases

Question 11

Why does increasing pressure have this effect?

Answer 11

Less space between particles means more frequent collisions

Question 12

What effect does increasing surface area have on the rate of a reaction?

Answer 12

Increases

Question 13

Why does an increasing surface area have this effect?

Answer 13

More reactant particles are exposed and able to collide, leading to more frequent collisions

Question 14

What effect does increasing temp have on the rate of reaction?

Answer 14

Increases

Question 15

Why does increasing temp have this effect?

Answer 15

Particles move faster, leading to more frequent collisions- particles have the same activation energy, so more collisions result in a reaction

Question 16

What is a catalyst?

Answer 16

Speeds up the rate of reaction without being used up

Question 17

How do catalysts increase the rate of reaction?

Answer 17

Lower the activation energy of the reaction, so more collisions result in a reaction

Question 18

Silver chloride is an insoluble salt that can be made into the following reaction. Suggest how the rate of this reaction could be measured
AgNo3(Aq) + NaCl(aq) =
NaNo3(aq) + AgCl(s)

Answer 18

One way of measuring the rate of a reaction is to look at the rate of production of silver chloride precipitate. This could be measured by placing the beaker with the reacting solution on a piece of white paper with a black cross printed on it, and measuring the time taken for the cross to disappear.