* Đề 5:
1)
a, 3Fe+ 2O2 (t*)= Fe3O4
3:2:1
b, AlCl3+ 3NaOH= Al(OH)3+ 3NaCl
1:3:1:3
c, BaO+ 2HCl= BaCl2+ H2O
1:2:1:1
d, Fe2O3+ 6HNO3= 2Fe(NO3)3+ 3H2O
1:6:2:3
2)
Áp dụng QTHT, ta có:
a, Zn(OH)2
b, Al(NO3)3
c, MgCl2
3)
a, 1,8.10^23= 0,3 mol NaCl
=> mNaCl= 0,3.58,5= 17,55g
b, nCO2= 11,2/22,4= 0,5 mol
=> mCO2= 0,5.44= 22g
c, m= 0,2.32+ 0,4.28= 17,6g
4)
Na2CO3 có:
%Na= 23.2.100:106= 43,4%
%C= 12.100:106= 11,32%
%O= 100-43,4-11,32= 45,28%
5)
a, K2O+ H2O= 2KOH
mK2O+ mH2O= mKOH
b, mKOH= 9,4+1,8= 11,2g
