Question

You have a sample of 35.2g of MgSO4. How many moles of MgSO4 are in the sample? Show all your work

Answer 1

General Stoichiometry

We must understand the relationship between moles, molar mass and mass to be able to solve questions with them:

`n=(m)/(M)`

• 
  `n` = moles
• 
  `m` = mass
• 
  `M` = molar mass

Solving the Question

We're given:

• 
  `m` = 35.2 g
• 
  `M` = sum of Mg, S and O4: 120.368 g/mol (taken from Chemspider)

Apply the formula:

`n=(m)/(M)`

`n=(35.2)/(120.368)\\\\n=0.292\hspace{4}mol`

Answer

0.292 mol