Đáp án + Giải thích các bước giải:

`-` PTHH:

`(COOH)_2 + 2Na \to (COONa)_2 + H_2`

`(COOH)_2 + 2NaOH \to (COONa)_2 + 2H_2O`

`(COOH)_2 + CaCO_3 \to (COO)_2Ca + CO_2↑ + H_2O`

`(COOH)_2+CH_3OH +C_2H_5OH`$\buildrel{{H_2SO_4(đ),t^o}}\over\rightleftharpoons$`CH_3OOC-COOC_2H_5 + 2H_2O`

`(COOH)_2 + 2CH_3OH`  $\buildrel{{H_2SO_4(đ),t^o}}\over\rightleftharpoons$ `CH_3OOC-COOCH_3 + 2H_2O`

`(COOH)_2 + 2C_2H_5OH` $\buildrel{{H_2SO_4(đ),t^o}}\over\rightleftharpoons$ `C_2H_5OOC-COOC_2H_5 + 2H_2O`

`(COOH)_2 + CH_3OH`  $\buildrel{{H_2SO_4(đ),t^o}}\over\rightleftharpoons$ `CH_3OOC-COOH + H_2O`

`(COOH)_2 + C_2H_5OH` $\buildrel{{H_2SO_4(đ),t^o}}\over\rightleftharpoons$ `C_2H_5OOC-COOH + H_2O`