Câu 1:

$\rm n_{CH_3OH}=\dfrac{6,4}{32}=0,2\ (mol)$

Phản ứng xảy ra:

$\rm CH_3OH+Na\to CH_3ONa+\dfrac{1}{2}H_2$

Theo phương trình:

$\rm n_{H_2}=\dfrac{1}{2}n_{CH_3OH}=0,1\ (mol)$

$\rm V_{H_2}=0,1×24,79=2,479\ (L)$

Câu 2:

$\rm n_{Ag}=\dfrac{5,4}{108}=0,05\ (mol)$

Phản ứng xảy ra:

$\rm CH_3CHO+2[Ag(NH_3)_2]OH\to CH_3COONH_4+3NH_3+2Ag+H_2O$

Theo phương trình:

$\rm n_{CH_3CHO}=\dfrac{1}{2}n_{Ag}=0,025\ (mol)$

$\rm m_{CH_3CHO}=0,025×44=1,1\ (g)$