Question

Помогите с примерами.
m(H2)= 10г
m(H20) -?

m(NAOH) = 120г
w(NAOH) = 10%
m(Cu(OH)2) -?

m(CaCo3) = 250г
w(CaCo3) = 80%
V(CO2) -?

Answer 1

Ответ:

1)

дано

m(H2)= 10г

найти

m(H20) -?

2H2+O2-->2H2O

M(H2) = 2 g/mol

n(H2) = m/M = 10 / 2 = 5 mol

2n(H2) = 2n(H2O) = 5 mol

M(H2O) = 18 g/mol

m(H2O) = n*M = 5 * 18 = 90 g

ответ 90 г

2)

дано

m(ppa NAOH) = 120г

w(NAOH) = 10%

---------------------

m(Cu(OH)2) -?

m(NaOH) = 120 * 10% / 100% = 12 g

2NaOH+CuCL2-->Cu(OH)2+2NaCL

M(NaOH) = 40 g/mol

n(NaOH) = m/M = 12 / 40 = 0.3 mol

2n(NaOH) = n(Cu(OH)2

n(Cu(OH)2) = 0.3 / 2 = 0.15 mol

M(Cu(OH)2) = 98 g/mol

m(Cu(OH)2) = n*M = 0.15 * 98  = 14.7 g

ответ 14.7 г

3)

дано

m(рра CaCО3) = 250г

w(CaCО3) = 80%

---------------------

V(CO2) -?

m(CaCO3) = 250 * 80% / 100% = 200 g

CaCO3-->CaO+CO2

M(CaCO3) = 100 g/mol

n(CaCO3) =m/M = 200 / 100 = 2 mol

n(CaCO3) = n(CO2)

V(CO2) = n*Vm = 2* 22.4 = 44.8 L

ответ 44.8 л

Объяснение: