Question

how many moles of MgSO4 are in 2.07g of MgSO4

Answer 1

The first thing to do is to work out how what the mass of one mole of MgSO4 is...I don't have a periodic table with me so you'll have to look up the exact values but it will be something like

(Mg) g/mol + 32 g/mol + 4x16 g/mol = XY g/mol for MgSO4

That's the molar mass.

Then you can just divide the mass of the substance by it's molar mass to get number of moles:

So: \[\frac{ 2.07g }{ XYg/mol}=N^{o} moles\]

Answer 2

thank you