1)
дано
m(AL) = 27 g
m(Al2S3)-?
2Al+3S-->AL2S3
M(Al) = 27 g/mol
n(AL) = m(AL) / M(Al) = 27 / 27 =1 mol
2n(Al) = n(AL2S3)
n(Al2S3) = 1 / 2 = 0.5 mol
M(Al2S3) = 150 g/mol
m(Al2S3) = n*M =0.5 / 150 = 75 g
ответ 75 г
2)
дано
m(NaBr) = 68 g
m(Br2) =?
2Na+Br2-->2NaBr
M(NaBr) = 103 g/mol
n(NaBr) = m/M = 68 / 103 = 0.66 mol
n(Br2) = 2n(NaBr)
n(Br2) = 0.66 / 2 = 0.33 mol
M(Br2) = 80*2 = 160 g/mol
m(Br) = n*M = 0.33 *160 = 52.8 g
ответ 52.8 г
3)
дано
m(Mg3P2) = 110 g/mol
m(Mg)-?
2P+3Mg-->Mg3P2
M(Mg3P2) = 134 g/mol
n(Mg3P2) = m/M = 110 / 134 = 0.82 mol
n(Mg3P2) = 3n(Mg)
n(Mg) = 3*0.82 = 2.46 mol
M(Mg) = 24 g/mol
m(Mg) = n*M = 2.46 * 24 = 59.04 g
ответ 59.04 г
1)
дано
m(AL) = 27 g
m(Al2S3)-?
2Al+3S-->AL2S3
M(Al) = 27 g/mol
n(AL) = m(AL) / M(Al) = 27 / 27 =1 mol
2n(Al) = n(AL2S3)
n(Al2S3) = 1 / 2 = 0.5 mol
M(Al2S3) = 150 g/mol
m(Al2S3) = n*M =0.5 / 150 = 75 g
ответ 75 г
2)
дано
m(NaBr) = 68 g
m(Br2) =?
2Na+Br2-->2NaBr
M(NaBr) = 103 g/mol
n(NaBr) = m/M = 68 / 103 = 0.66 mol
n(Br2) = 2n(NaBr)
n(Br2) = 0.66 / 2 = 0.33 mol
M(Br2) = 80*2 = 160 g/mol
m(Br) = n*M = 0.33 *160 = 52.8 g
ответ 52.8 г
3)
дано
m(Mg3P2) = 110 g/mol
m(Mg)-?
2P+3Mg-->Mg3P2
M(Mg3P2) = 134 g/mol
n(Mg3P2) = m/M = 110 / 134 = 0.82 mol
n(Mg3P2) = 3n(Mg)
n(Mg) = 3*0.82 = 2.46 mol
M(Mg) = 24 g/mol
m(Mg) = n*M = 2.46 * 24 = 59.04 g
ответ 59.04 г
дано
m(CxHy) = 8.4 g
m(CO2) = 26.4 g
m(H2O) = 10.8 g
D(возд) = 2.9
CxHY-?
M(CxHy) = D(возд)*29 = 2.9 * 29 = 84 g/mol
n(C) = n(CO2) = m(CO2) / M(CO2) = 26.4 / 44 = 0.6 mol
n(H) = 2n(H2O) = 2(m(H2O) / M(H2O)) = 2*10.8 / 18 = 1.2 mol
n(C) : n(H) = 0.6 : 1.2 = 6 :12
C6H12
ответ C6H12