1)
дано
m(MgO) = 200 g
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n(MgO)-?
N(MgO)-?
M(MgO) = 40 g/mol
n(MgO) = m/M = 200 / 40 = 5 mol
N(MgO) = n(MgO)*N(A) = 5*6.02*10^23 = 30.1*10^23 молекул
2)
дано
m(H3PO4) =294 g
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N(H3PO4) -?
M(H3PO4) = 98 g/mol
N(H3PO4) = m/M*N(A) = 294 / 98 * 6.02*10^23 = 18.06*10^23 молекул
3)
дано
n(Cl2O) = 5 mol
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V(Cl2O) -?
V(CL2O) = n*Vm = 5*22.4 = 112 L