the rate and extent of chemical change

Question 1

Mean rate of reaction formula

Answer 1

Mean rate of reaction = quantity of reactant used / time taken

Mean rate of reaction = quantities of product formed / time taken

Question 2

Measurement of quantity of product/reactant

Answer 2

Mass- grams
Volume - cm*3

Question 3

Factors affecting the rate of chemical reactions

Answer 3

Concentration of reactant in solution
Pressure of reacting gases
Surface area of solid reactants
Temperature
Presence of catalyst

Question 4

Increasing the temperature 

Answer 4

When temperature is increased the particles Move faster
they move faster so they collide, more frequently, and more energy is provided to them, so more of the collisions will have enough energy to make a reaction happen

Question 5

Increasing the concentration or pressure

Answer 5

If a solution is more concentrated, it means that more particles are knocking into the same volume of solvent
pressure of gas is increased. This means that the same about particles occupy a smaller space so the collisions are more frequent.

Question 6

Increasing the surface area

Answer 6

If a reactant is solid, then breaking it up into small pieces with increase the surface area to volume ratio
This would mean that the same volume of the solid the particles around, it would have more area to work on, so there would be more frequent collisions 

Question 7

Using a catalyst

Answer 7

This is a substance that speeds up a reaction without being used up in the reaction itself, so it does not take part in the overall reactions equation

Question 8

Collision theory

Answer 8

Reacting collide with each other, and with sufficient energy
The minimum amount of energy that particles must have to react is called activation energy

Question 9

Reversible reactions

Answer 9

A+B reverse C+D

Question 10

Energy changes

Answer 10

If a reversible reaction is endothermic in one direction, it is exothermic in the other direction to the same amount of energy transferred in both cases

Question 11

Equilibrium

Answer 11

If a system is at equilibrium, and change is made to any of the conditions, then the system responds to counteract the change
The effects of changing conditions on the system at equilibrium can be predicted, using a chatelier principle 

Question 12

Temperature at equilibrium is increased

Answer 12

The amount of product increases of an endothermic reaction
The amount of product at decreases for an exothermic reaction

Question 13

Temperature of a system at equilibrium is decreased

Answer 13

Amount of product at equilibrium decreases for an endothermic reaction
Amount of product is increased for an exothermic reactions

Question 14

For gaseous reactions at equilibrium

Answer 14

an increase in pressure causes the equilibrium position to shift towards the side with the smaller number of molecules as shown by the symbol equation for that reaction

a decrease in pressure causes the equilibrium position to shift towards the side with the larger number of molecules as shown by the symbol equation for that reaction