Question

m(Mg) - 5г
2Mg + O2 = 2MgO
m(O2) - ?

Answer 1

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Answer 2

2Mg + O₂ = 2MgO

n(Mg) = m ÷ M = 5г ÷ 24г\моль = 0.2 моль

n(Mg) = n(O₂) = 0.2 моль ÷ 2 = 0.1 моль

m(O₂) = n × M  = 0.1 моль × 32г\моль = 3.2г