Quantitive Chemistry

Question 1

Calculate the MR of H2 S04

Answer 1

2+32+4×16 = 98

Question 2

How would you calculate percentage by mass of an element in a compound?

Answer 2

Percentage mass brackets, total MR of the element /MR of the compound) times 100

Question 3

What is the law of the conservation of mass?

Answer 3

The total mass or reactants is equal to the total mass of the products

Question 4

When does the law of conservation of mass appear to be violated?

Answer 4

When one of the reactants or products is a gas?

Question 5

Give the equation that links mass moles and MR

Answer 5

mass =mr moles

Question 6

How many particles in one mole

Answer 6

6.02 x 10 to the power of 23

Question 7

Unit of concentration

Answer 7

Mol/dm3

Question 8

What’s the equation to calculate moles, when given concentration and volume?

Answer 8

Moles equals concentration times volume

Question 9

What does a high concentration mean?

Answer 9

A large number of solute particles per unit volume

Question 10

What is the equation to calculate yield

Answer 10

Yield =actual mass divided by theoretical mass x100

Question 11

Give three reasons why might yield not be 100%

Answer 11

An incomplete reaction. Some products might be lost side reaction.

Question 12

Give the equation to calculate atom economy

Answer 12

Ask economy equals Mr of useful product /total MR of reactants) x100

Question 13

Apart from atom economy, what are the factors are important in choosing a reaction pathway

Answer 13

Yield environmental impact of reactants or products rate of reactions

Question 14

What volume does one mole of gas occupy

Answer 14

24dm 3

Question 15

Give the equation that calculates the volume of gas, when given the number of moles

Answer 15

Volume (dm3) =moles x24