Giải thích các bước giải:

 Câu 1:

`a)` $n_{MgO}$ `=` $\dfrac{45,9}{40}$ `=1,1475(mol)`

`b)` $n_{K_3PO_4}$ `=` $\dfrac{37,72}{40}$ `=0,17(mol)`

`c)` $n_{Cu(NO_3)_2}$ `=` $\dfrac{56,4}{188}$ `=0,3(mol)`

`d)` $n_{Al_2O_3}$ `=` $\dfrac{20,4}{102}$ `=0,2(mol)`

Câu 2:

`a)` $m_{Na_3PO_4}$ `=0,35.164=57,4 (g``/``mol``)`

`b)` $m_{ZnCl_2}$ `=0,4.136 =54,4 (g``/``mol``)`

`c)` $m_{Na_3PO_4}$ `=0,35.164=57,4 (g``/``mol``)`

`d)` $m_{Ba(OH)_2}$ `=1,2.171 =205,2 (g``/``mol``)`

Câu 3:

`a)` $n_{NaOH}$ `=` $\dfrac{12}{40}$ `=0,3(mol)`

`b)` $n_{CaCl_2}$ `=` $\dfrac{33}{111}$ `=0,29(mol)`

`c)` $n_{CO_2}$ `=` $\dfrac{1,2.10^{23}}{6,02.10^{23}}$ `=0,2(mol)`

`d)` $n_{H_2SO_4}$ `=` $\dfrac{1,2.10^{23}}{6,02.10^{23}}$ `=0,8(mol)`

Câu 4:

`a)` $m_{FeSO_4}$ `=0,3.152=45,6 (g``/``mol``)`

`b)` $n_{Zn(NO_3)_2}$ `=` $\dfrac{1,8.10^{23}}{6,02.10^{23}}$ `=0,3(mol)`

`⇔` $m_{Zn(NO_3)_2}$ `=0,3.189=56,7 (g``/``mol``)`

`c)` $n_{CuSO_4}$ `=` $\dfrac{1,5.10^{23}}{6,02.10^{23}}$ `=0,25(mol)`

`⇔` $m_{CuSO_4}$ `=0,25.160=40 (g``/``mol``)`

`d)` $n_{KOH}$ `=` $\dfrac{3,6.10^{23}}{6,02.10^{23}}$ `=0,3(mol)`

`⇔` $m_{KOH}$ `=0,6.56=33,6 (g``/``mol``)`

Đáp án:

 câu 1:

a,nMgO=45,9/40=1,1475mol

b,nK3PO4=37,72/212=0,178mol

c,nCu(NO3)2=56,4/188=0,3mol

d,nAl2O3=20,4/102=0,2mol

câu 2:

a,mNa3PO4=0,35.141=49,35g

b,mZnCl3=0,4.171,5=68,6g

c,mBa(OH)2=1,2.171=203,2g

câu 3

a,nNaOH=12/40=0,3mol

b,nCaCl2=33/111=0,3mol

c,nCO2=1,2.10mux23/0,6.10 mũ 23=2mol

d,nH2SO4=4,8.10 mũ 23/0,6.10 mũ 23=1,1475mol

câu 4

a,mFeSO4=0,3.152=45,6g

b,nCuSO4=1,5.10 MŨ 23/0,6.10 MŨ 23=2,5MOL

mCuSO4=2,5.160=400g

c,nZn(NO3)3=3mol

mZn(NO3)3=3.251=753g

d,mKOH=6.48 =288g

Giải thích các bước giải: