1. 2Na + 2H2O = 2NaOH + H2
2. 2K + 2H2O = 2KOH + H2
3. Ca + 2H2O = Ca(OH)2 + H2
4. 2Al + 6H2O = 2Al(OH)3 + 3H2
5. 2KNO3 = 2KNO2 + O2
6. CuO + H2 = Cu + H2O (в данном случае коэффициенты не нужны).
7. 4NO2 + O2 + 2H2O = 4HNO3
8. NH4NO2 = N2 + 2H2O
9. 2Al + 3H2SO4 = Al2(SO4)3 + 3H2
10. CaO + 2HCl = CaCl2 + H2O
1) C+O2=CO2
2) CO2+2NaOH=Na2CO3+H2O
3) CaSO4+Na2CO3=CaCO3+Na2SO4
1. ковалентная неполярная
2. ковалентная полярная
3. водородная
4. ковалентная неполярная
1)
дано
m(H2SO4) = 4 g
m(Zn) = 2.6 g
V(практ H2) = 0.7 L
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φ-?
M(H2SO4) = 98 g/mol
n(H2SO4) = m/M= 4/ 98 =0.0408 mol
M(Zn)= 65 g/mol
n(Zn) = m/M = 2.6 / 65 = 0.0400 mol
n(H2SO4) > n(Zn)
Zn+H2SO4 -->ZnSO4+H2
n(Zn) = n(H2) = 0.04 mol
V(H2) = n(H2) * Vm = 0.04*22.4 = 0.896 L
φ = V(практ) / V(теор) * 100% = 0.7 / 0.896 * 100% = 78.13%
ответ 78.13%
2)
дано
m(CO2) = 0.88 g
m(ppaNaOH) = 10 g
W(NaOH)= 30%
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m(Na2CO3)-?
m(ppa NaOH)= 10*30%/100% = 3 g
M(NaOH) = 40 g/mol
n(NaOH) = m/M = 3/40 = 0.075 mol
M(CO2) = 44 g/mol
n(CO2) = m/M = 0.88 / 44 = 0.02 mol
n(NaOH) > n(CO2)
2NaOH+CO2-->Na2CO3+H2O M(Na2CO3) = 106 g/mol
n(CO2) = n(Na2CO3) = 0.02 mol
m(Na2CO3) = n*M = 0.02 * 106 = 2.12 g
ответ 2.12 г
