Re: [化學] 99台聯大A1 19 20

[water0bearer (霖)]

※ 引述《asd789456123 (123)》之銘言：
: 19.How many mmoles of HCL must be added to 100ml of a 0.10M solution of
:    methylamine(pKb=3.36)to give a buffer having a PH of 10?
:    (A)8.1   (B)18.7   (C)20.0   (D)41.5   (E)12.7
:    Ans:(A)8.1

pOH = pKb + log[HA]/[A-]
4 = 3.36 + log[HA]/[A-]
log[HA]/[A-] = 0.64
[HA]/[A-] = 4.2(懶的按計算機，自己估計的)

CH3NH2 + HCl ---> CH3NH3+ + Cl-

0.1*100 = 10mmole 原來CH3NH2的量

設加入Xmmole
X / (10-X) = 4.2
X差不多=8.1

: 20.Of energy, work, enthalpy, and heat, how many are stable functions?
        ^^^^^^        ^^^^^^^^這兩個                   ^state吧!?
:    (A)0   (B)1   (C)2   (D)3   (E)4
:     Ans:(C)2
:    請問是哪兩個呢? 感激不盡

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