How many atoms of hydrogen are in 2.50g of water

1.67 * 10²³ atoms of hydrogen present in 2.5 g of water.

Explanation:

Given dа ta:

Mass of water = 2.5 g

Number of hydrogen atoms=?

Solution:

First of all we will calculate the molar mass of water.

Molar mass of H₂O = 16 + 1 * 2 = 18 g/mol

The number of atoms will be determine through the Avogadro number.

The number 6.022*10²³ is called Avogadro number and it is the number of atoms or molecules in one gram of atoms of an element or one gram molecules of a compound.

First of all we will calculate the number of moles of water in 2.5 g.

Number of moles = mass / molar mass

Number of moles = 2.5 g / 18 g/mol

Number of moles = 0.139 mol

The number of molecules of water in 10 g.

0.139 * 6.022*10²³ = 0.837 * 10²³molecules

one water molecule contain two hydrogen atoms. For 0.837*10²³ molecules,

0.837*10²³ * 2 = 1.67 * 10²³ atoms