Calculations

Question 1

What is the formula for calculating the rate of reaction?

Answer 1

rate=Δquantity/Δtime

Question 2

What is the formula for calculating heat energy?

Answer 2

Eh= cmΔT

Question 3

If n=cV, how would you work out V?

Answer 3

V=n/c

Question 4

What is meant by the term ‘atom economy’?

Answer 4

The atom economy of a reaction is a measure of how many reactant atoms form a desired product.

Question 5

What is the formula used to calculate the percentage yield of a reaction?

Answer 5

%yield=(actual yield/ theoretical yield)*100

Question 6

What is the formula used to calculate the atom economy?

Answer 6

%atom economy= (mass desired product[s]/ total mass reactants)*100

Question 7

How is the Gram Formula Mass of a molecule or compound calculated?

Answer 7

The RAM of the element[s] in a molecule/compound are added together in order to obtain the GFM of a compound

Question 8

What is the specific heat capacity of water?

Answer 8

4.18

Question 9

What is meant by the term ‘molar mass’?

Answer 9

The mass of one mole of a compound in grams

Question 10

Find the percentage of oxygen in Ca(OH)₂

Answer 10

O=16, Ca=40, H=1
(2x16) /74 =32 /74 *100%
=43.2%

Question 11

Calculate the percentage by mass of C in CH₄

Answer 11

12/16*100%

=75%