В14
дано
m(H2SO4)=4.2 kg
m(NaOH)=2 kg
--------------------
n(K2SO4)-?
M(H2SO4)=98 kg/kmol
n(H2SO4)=m/M=4.2/98 = 0.043 mol
M(NaOH)=40 kg/kmol
n(NaOH)=m/M= 2/40=0.05 mol
n(H2SO4) 4.2 Х
H2SO4+2NaOH-->Na2SO4+2H2O M(K2SO4)=174 kg/kmol
98 174
Х=4.2*174/98=7.46кг
ответ 7.46 кг
B15
дано
m(MgCO3)=7 g
m(HCL)=10 g
----------------
V(CO2)-?
M(MgCO3)=84 g/mol
n(MgCO3) = m/M=7/84 = 0.08 mol
M(HCL)=36.5 g/mol
n(HCL)=m/M=10/36.5 = 0.27 mol
n(MgCO3)
MgCO3+2HCL-->MgCL2+H2O+CO2↑
n(MgCO3)=n(CO2)=0.08 mol
V(CO2)=n*Vm=0.08*22.4 = 1.792 L
ответ 1.792 л
В16
дано
W(O)=36.36%
------------------------
CnH2n+1COOH-?
M(CnH2n+1COOH)= 14n+46
36.36% = 16*2 / (14n+46)*100%
509.04n+1672.56=3200
n=3
C3H7COOH - пропановая кислота
ответ C3H7COOH