Đáp án:
Câu 1:
a,
nZn=6,565=0,1(mol)nZn=6,565=0,1(mol)
nO2=11,222,4=0,5(mol)nO2=11,222,4=0,5(mol)
2Zn+O2to→2ZnO2Zn+O2→to2ZnO
⇒O2⇒O2 dư.
nO2pứ=12nZn=0,05(mol)nO2pứ=12nZn=0,05(mol)
⇒nO2dư=0,5−0,05=0,45(mol)⇒nO2dư=0,5−0,05=0,45(mol)
⇒mdư=0,45.32=14,4g⇒mdư=0,45.32=14,4g
b,
nZnO=nZn=0,1(mol)nZnO=nZn=0,1(mol)
⇒mZnO=0,1.81=8,1g⇒mZnO=0,1.81=8,1g
Câu 2:
a, 2Mg+O2to→2MgO2Mg+O2→to2MgO
b,
nMg=2,424=0,1(mol)nMg=2,424=0,1(mol)
nO2=9.10236.1023=1,5(mol)nO2=9.10236.1023=1,5(mol)
⇒O2⇒O2 dư.
nO2dư=1,5−12nMg=1,45(mol)nO2dư=1,5−12nMg=1,45(mol)
⇒mdư=1,45.32=46,4g⇒mdư=1,45.32=46,4g
c,
nMgO=nMg=0,1(mol)nMgO=nMg=0,1(mol)
⇒mMgO=0,1.40=4g