中和作用既計算*v* 請各位高手幫忙

要睇邊個放得最多熱, 就要知佢地既number of moles of H+ & OH-:

H+ + OH- --> H2O
愈多mole reacted, more heat is given out.

A. number of moles of OH- = 2(25/1000) = 0.05 mol
number of moles of H+ = 2(25/1000) = 0.05 mol
so, 0.05 mol is reacted for A

B. number of moles of OH- = (25/1000) = 0.025 mol
number of moles of H+ = 2(1)(10/1000) = 0.02 mol
****因為H2SO4 is dibasic acid, H+ 要乘2
so, OH- is in excess, 0.02 mol is reacted for B

C. number of moles of OH- = 2(50/1000) = 0.1 mol
number of moles of H+ = 2(50/1000) = 0.1 mol
so, 0.1 mol is reacted for C

D. number of moles of OH- = (50/1000) = 0.05 mol
number of moles of H+ = 2(2)(25/1000) = 0.1 mol
****因為H2SO4 is dibasic acid, H+ 要乘2
so, H+ is in excess, 0.05 mol is reacted for D



overall, C reacted the most, C 會放出最多熱能

其實唔使計ga bo,
只要比較邊個reaction produces最多H2O 就得ga la.

同埋要注意 佢地ge concentration. 2M 同埋 1M, 2M 比 1M 多一倍acid ions.
仲有 H2SO4 同 HCl ge分別, H2SO4 一個molecule有2個H+ ion 但係HCl 只有1個
所以 一個H2SO4 可以同NaOH react 2次, 出2 個水.
但係HCl 只可以同NaOH react 1次, 出1 個水

經過比較, 就可以得出 C) react得最多, 所以放出ge熱就最多la.