Moler Formulas

Question 1

Finding moles

Answer 1

Moles = mass / Mr
Moles = c * v

Question 2

Finding Gas volume

Answer 2

V = moles * 24

Question 3

Finding yield

Answer 3

Yield = actual yield / theoretical yield * 100

Question 4

Finding the mass

Answer 4

Mass = moles * Mr

Question 5

How many cm3 in a dm3

Answer 5

1000

Question 6

How much volume does 1 mole of gas take up

Answer 6

24dm3

Question 7

Finding atom economy

Answer 7

= (formula mass of desired product / formula mass of reactants)* 100

Question 8

Finding the concentration

Answer 8

Concentration = mass of solute / volume of solvent
Concentration = moles / vol

Question 9

Finding Molecules

Answer 9

Avogadro’s number * moles

Question 10

what is concentration and volume measured in

Answer 10

concentration = mol/dm3
volume = dm3

Question 11

how do you calculate the relative formula mass/ Mr

Answer 11

steps in bullet points
Example Q1) Calculate the Mr of HCl

1. look at you’re element’s on the periodic table
2. add up the big number’s
3. that’s you’re answer

Question 12

Finding the concentration in a titration

Answer 12

c = n/v
some times they ask you to work out the concentration
in g/dm3 and to do this you use the formula

c (g/dm3) = c (mol/dm3) * Mr

Question 13

The process to do a titration calculation

Answer 13

steps
1) write on each reactant
c=
n=
v=
2) fill in the blanks and turn all volumes into dm3 like this

c= c= 0.1 mol / dm3
n= n=
v= 0.017 dm3 v= 0.025 dm3

3) calculate right n by using the formula
n = c * v

4) now that you have n/moles do the ratios for the moles/n, so remember that if the ratios are 2 HCl and 1 NaOH you multiply NaOH by 2. And if the ratios are HCl and NaOH
you don’t do anything with the moles/n because they don’t have any number’s

5) calculate c on the left by using the formula

c = n / v