Question

Sarah has a sample of 34g of sodium (Na) and she want to convert her sample into moles. How many moles does she calculate?

Answer 1

Answer :

Moles = mass/molar mass = 34/23 = 1.47

Answer 2

Sarah has a sample of 34g of sodium element and she wants to convert her sample into moles.

To find : how many moles does she calculate ?

solution : number of moles of an element = given mass/atomic mass

here given of sodium sample = 34g

atomic mass of sodium element = 23g/mol

so no of moles of sodium sample = 34/23 = 1.478 mol

Therefore she calculates 1.478 (approx) moles in 34g of sodium sample.

[ note :

1. no of moles of a compound = given mass of compound/molar mass of the compound
2. no of moles = given volume/22.4L
3. no of moles = given no of atoms/Avogadro's number]