Question

How many moles of H3PO4 are there in 658 grams of H3PO4?

Answer 1

97.995181 would be the correct answer

Answer 2

Answer : There are 6.71 moles of H₃PO₄.

Explanation:

The mole of a substance is calculated as

$mole = \frac{Mass(g)}{MolarMass}$

Let us find the molar mass of H₃PO₄.

Molar mass of H₃PO₄ = 3 x atomic mass of H + atomic mass of P + 4x atomic mass of O

From the periodic table, we have

Atomic mass of H = 1.008 g/mol

Atomic mass of P = 30.973 g/mol

Atomic mass of O = 15.999 g/mol

Molar mass of H₃PO₄ = $3 \times 1.008 + 30.973 + 4 \times 15.999 = 97.993 g/mol$

Molar mass of H₃PO₄ is 97.993 g/mol

The mass of H₃PO₄ is given as 658 g.

The moles can be calculated as,

$moles = \frac{658g}{98g/mol} = 6.71 mol$

There are 6.71 mol in the given amount of H₃PO₄