Calculate the number of moles in 8.00 g of He

2 moles

Explanation:

Mole:

Mole is the unit of amount in chemistry. It is SI unit and represented by "mol".

Example:

one mole of hydrogen has a mass of 1.008 g and contain 6.022 * 10∧23 atoms.

Steps to find the number of moles:

1. If the number of grams are given then to find out the moles first of all we will find the molar mass of given chemical substance.

For example:

If the given chemical substance is NaOH then its molecular weight is determine through following way:

atomic mass of Na = 1*22.989 g/mol

+

atomic mass of oxygen = 1*16 g/mol

+

atomic mass of hydrogen = 1 * 1.008 g/mol

molecular mass of NaOH = 39.97 or 40 g/mol

2. when the molar mass and grams are known then number of moles are determine through following formula:

number of moles = mass in gram / molar mass (g/mol)

Given dа ta:

Now we will put the values in formula,

number of moles = 8.00g/4 g/mol

number of moles = 2 mol