Question

Calculate the molar mass of Potassium dichromate (K2Cr2O7).

Answer 1

Calculate the molar mass of Potassium dichromate :
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Potassium Dichromate -- K2Cr2O7

Molar mass is the mass of 1 mole of substances in grams.

Let us first find out Molecular mass of K2Cr2O7
Atomic mass of K=39u
Atomic mass of Cr=52u
Atomic mass of O=16u

Molecular mass of K2Cr2O7 is the sum of all the atomic masses of the elements present in the compound.

=2x39+2x52+7x16
=78+104+112
=294 Unified mass.

∴Molar mass of K2Cr2O7 is 294g

Answer 2

Molecular Mass of KMnO4 = Atomic mass of potassium + atomic mass of manganese + 4 (atomic mass of oxygen)

1(39u) + 1(55u) + 4(16u) = 39u + 55u + 64u = 158u