How many moles is this?

Question

A student weighed out 1.066 g of KHP. How many moles was that?

Answer 1

Potassium hydrogen phthalate, KHC8H4O4, has mol. wt. = 204.22

1.066gKHP x 1molKHP/204.22gKHP = 5.220 x 10^-3 mole to four significant figures

Answer 2

Before i start i will like to say what KHP is.  Potassium hydrogen phthalate , and its a colorless ionic salt which is soluble in water.

And its molecular formula is (KHC8H4O4).

      Solution

Using mole concept, you calculate the relative molecular mass(RMM) from the above formula. Which is 204.

now converting mass to mole you  say

given mass of the substance in (g) divide by mass of i mole of substance in g\mol.

which is 1.066g/204g\mol   =0.0052mol.  because both grams cancel out.

GOOD LUCK