Question

How many grams of strontium (Sr, 87.62 g/mol) are in 2.92 moles of strontium?

Answer 1

mass= number of mole *Molar mass
mass =2.92 mol*87.62 g/mol≈256 g

Answer 2

Answer :The correct answer for mass of Sr is 255.85 g.

Mole :

It can defined as the amount of substance that contains as many entities as present 12 g of Carbon-12 .

In 1 mole of any atom , molecule or ions is equal to its atomic mass , molecular mass or ionic mass respectively .

Mass , molar mass ( or atomic mass or ionic mass ) and mole can be related as :

`Mole(mol) = ( given mass (g))/(molar mass ((g)/(mol)))`

Given :

Molar mass of Strontium = 87.62
`(g)/(mol)`

Mole of Strontium = 2.92 mol

Plugging these values in Mole formula :

`2.92 mol = (mass of Sr )/(87.62 (g)/(mol))`

Multiplying both side by 87.62
`(g)/(mol)`

`2.92 mol * 87.62 (g)/(mol)= (mass of Sr )/(87.62 (g)/(mol)) * 87.62 (g)/(mol)`

Mass of Sr = 255.85 g