Ответ:

дано

m(ppa Na2O) = 300 g

w(прим ) = 20%

m(ppa HNO3) = 250 g

W(HNO3) = 40%

η(NaNO3) =90%

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m пр(NaNO3)-?

m(Na2O) = 300 - (300*20%/ 100%) = 240 g

M(Na2O) = 62 g/mol

n(Na2O) = m/M = 240  / 62 = 3.87 mol

m(HNO3) = 250*40% / 100% = 25 g

M(HNO3) = 63 g/mol

n(HNO3) =25 / 63 = 0.4 mol

n(Na2O) > n(HNO3)

Na2O+2HNO3-->2NaNO3+H2O

2n(HNO3) = 2n(NaNO3) = 0.4 mol

M(NaNO3) = 85 g/mol

m теор (NaNO3) = 0.4* 85 = 34 g

m пр (NaNO3) = 34 * 90% / 100% = 30.6 g

ответ 30.6 г

Объяснение: