Câu 39: $A$
$n_{(NH_4)_2SO_4}=0,05(mol)$
Bảo toàn N: $n_{NH_3\uparrow}=2n_{(NH_4)_2SO_4}=0,1(mol)$
$\Rightarrow V_{NH_3}=0,1.22,4=2,24l$
Câu 40: $B$
$n_{Cu}=\dfrac{9,6}{64}=0,15(mol)$
Bảo toàn e:
$2n_{Cu}=3n_{NO}$
$\Rightarrow n_{NO}=0,1(mol)$
$\Rightarrow V_{NO}=0,1.22,4=2,24l$
Câu 41: $A$
$n_{NO}=\dfrac{3,584}{22,4}=0,16(mol)$
$\Rightarrow n_{NO_3^-\text{muối KL}}=n_e=3n_{NO}=0,48(mol)$
$\Rightarrow m_{\text{muối}}=0,48.62+9,94=39,7g$
