$\rm a)\ CH_3COOH+Na\to CH_3COONa+\dfrac{1}{2}H_2\\b)\ 2CH_3COOH+N_2O\to 2CH_3COONa+H_2O\\c)\ CH_3COOH+NaOH\to CH_3COONa+H_2O\\d)\ CH_3COOH+NaHCO_3\to CH_3COONa+CO_2+H_2O$

$\rm n_{KMnO_4}=\dfrac{0,3}{158}\ (mol)\\2KMnO_4\xrightarrow{t^°}K_2MnO_4+MnO_2+O_2\\n_{O_2}=\dfrac{1}{2}n_{KMnO_4}=\dfrac{3}{790}\ (mol)\\m_{O_2}=\dfrac{3×32}{790}=0,12\ (g)$

$\rm a)\\C_2H_4+Br_2\to C_2H_4Br_2\\b)\\n_{Br_2}=n_{C_2H_4}=n_{C_2H_4Br_2}=0,05\ (mol)\\m_{C_2H_4Br_2}=0,05×188=9,4\ (g)\\c)\\C_{M\ Br_2}=\dfrac{0,05}{0,5}=0,1\ (M)$