Question

What is the empirical formula of a compound composed of 21.5 g potassium (K) and 4.40 g oxygen (O) K20 Insert subscripts as needed.

Answer 1

Answer:

Given mass of potassium, K=21.5 g, molar mass of K=39.0983 g/mol.

Moles of K=mass/molar mass=21.5 g/39.0983 g/mol=0.549 mol K.

And also given mass of O=4.40 g

Molar mass of O=16 g/mol.

Therefore moles of O=4.40g/16 g/mol=0.275 mol O.

Therefore the mole ratio between K:O=0.549 : 0.275=2:1.

The emperical formula of a compound=K₂O.

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