Question

calculate the the number of moles in 36g of water

Answer 1

1 mole of water (H₂O) = 18 gms
Given mass of water = 36g
Therefore , No.of moles = 36/18 = 2 moles.

Answer 2

Given,

Amount of water = 36 grams

To find,

The number of moles in 36g of water.

Solution,

We can simply solve this numerical problem by using the following process:

The atomic mass of hydrogen = 1 gram

The atomic mass of oxygen = 16 gram

Now,

The total atomic mass of a water molecule

= 2(Atomic mass of hydrogen) + Atomic mass of oxygen

= 2(1 gram) + 16 grams

= 18 grams

As per stoichiometry;

The total mass of 1 mole of any compound is called its molar mass and is equal to the total atomic mass of the same compound.

Now,

18 grams of water molecules = 1 mole of water molecules

=> 36 grams of water molecules = 2 x 1, that is, 2 moles of water molecules

Hence, the number of moles in 36g of water is equal to 2.