Question

Calculate the molar mass of Mohr's salt ( Fe = 56, S = 32, N = 14, H = 1, O = 16 )

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Answer 1

Given:

The molar mass of a few elements (Fe = 56, S = 32, N = 14, H = 1, O = 16).

To Find:

The molar mass of Mohr's salt.

Solution:

1. The molar mass of Mohr's salt is to be calculated.

2. The chemical formula of Mohr's salt is (NH₄)₂Fe(SO₄)₂·6H₂O. (Where N = Nitrogen, H = Hydrogen, Fe = Iron, S = sulfur, O = Oxygen).

3. The molecular weights of H, N, O, S, Fe are 1, 14, 16, 32, 56 respectively.

4. On substituting the weights in the chemical formula the weight of mohr's salt is obtained,

=> Molar mass of Mohr's salt = ( 14 + 4)x 2 + 56 + ( 32 + 64) x 2 + 6 x (16+2),

=> 36 + 56 + 192 + 108,

=> 300 + 92,

=> 392 g/mol.

Therefore, the molar mass of Mohr's salt is 392 g/mol.