Properties of the Equilibrium Constant · 平衡常数的性质
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| equilibrium constant/ˌiːkwɪˈlɪbrɪəm ˈkɒnstənt/ | 平衡常数 | píng héng cháng shù |
Rules for reshaping K
- Flip a reaction and its constant flips too.
- Double it, and the constant gets squared.
- Combine reactions, and their constants multiply.
- A few tidy rules let you build any K from known ones.
重塑 K 的规则
- 翻转一个反应,它的常数也翻转。
- 把它加倍,常数就被平方。
- 组合反应,它们的常数相乘。
- 几条整洁的规则让你从已知的 K 搭出任意 K。
Reverse the reaction
- Reverse a reaction and the equilibrium constant 平衡常数 becomes its reciprocal, $1/K$.
- What was product-favoured becomes reactant-favoured.
- The balance simply flips.
逆转反应
- 逆转一个反应,平衡常数变成它的倒数 $1/K$。
- 原本偏向产物的变成偏向反应物。
- 平衡就这样翻转。
A reaction has $K = 5$. What is $K$ for the reverse reaction? (as a decimal) · 某反应具有 $K = 5$。其逆反应的 $K$ 是什么？（作为小数）
Reversing gives $1/K = 1/5 = 0.2$. · 反转后得到 $1/K = 1/5 = 0.2$。
Reversing a reaction replaces $K$ with its ____. · 反转反应会用____替换$K$。
The reverse reaction's constant is $1/K$. · 逆反应的常数是$1/K$。
Multiply the coefficients
- Multiply a reaction by $n$ and $K$ becomes $K^n$.
- Double it gives $K^2$; halve it gives $\sqrt{K}$.
- The power matches the scaling factor.
把系数相乘
- 把一个反应乘以 $n$,$K$ 变成 $K^n$。
- 加倍给出 $K^2$;减半给出 $\sqrt{K}$。
- 次方与缩放因子相匹配。
A reaction has $K = 3$. If you double every coefficient, the new $K$ is...? · 一个反应的$K = 3$为...。若将每个系数加倍，新的$K$是...？
Doubling gives $K^2 = 3^2 = 9$. · 加倍后得到$K^2 = 3^2 = 9$。
If you halve all the coefficients of a reaction, its $K$ becomes... · 若将反应的系数减半，其$K$变为...
Scaling by $\tfrac{1}{2}$ raises $K$ to the power $\tfrac{1}{2}$. · 按$\tfrac{1}{2}$缩放会将$K$提升至$\tfrac{1}{2}$次幂。
Add reactions
- Add two reactions and multiply their $K$ values.
- $K_{total} = K_1 \times K_2$.
- This mirrors Hess's law, but with multiplication instead of addition.
把反应相加
- 把两个反应相加,把它们的 $K$ 值相乘。
- $K_{total} = K_1 \times K_2$。
- 这与赫斯定律相仿,只不过是相乘而非相加。
When two reactions are added, their equilibrium constants are... · 当两个反应相加时，它们的平衡常数是...
$K_{total} = K_1 \times K_2$ when reactions add. · 反应相加时$K_{total} = K_1 \times K_2$...
A reaction has $K = 4$. What is $K$ for the reverse reaction?
- Reversing gives the reciprocal.
- $K_{reverse} = 1/4 = 0.25$.
某反应 $K = 4$。逆反应的 $K$ 是多少?
- 逆转给出倒数。
- $K_{reverse} = 1/4 = 0.25$。
How K changes when you rewrite · 重写方程式时 K 如何变化
Rewriting an equation changes K in a predictable way. · 重写方程式会以可预测的方式改变 K。
Pure solids and liquids are included in the $K$ expression. · 纯固体和液体包含在$K$表达式中。
Only gases and aqueous species appear in $K$. · 只有气体和水溶液物种出现在 $K$ 中。
The three operations are different: reversing inverts $K$ ($1/K$), scaling by $n$ raises $K$ to the $n$, and adding reactions multiplies their $K$ values. Do not mix them up. And pure solids and liquids never appear in $K$.
三种操作各不相同:逆转把 $K$ 取倒数($1/K$),乘以 $n$ 把 $K$ 升到 $n$ 次方,相加反应把它们的 $K$ 相乘。别混淆。而且纯固体和液体从不出现在 $K$ 中。
Reshaping a reaction reshapes its equilibrium constant: reversing gives $1/K$, multiplying the equation by $n$ gives $K^n$, and adding reactions multiplies their $K$ values. It parallels Hess's law, except $K$ multiplies where $\Delta H$ adds.
重塑一个反应就重塑它的平衡常数:逆转给出 $1/K$,把方程乘以 $n$ 给出 $K^n$,把反应相加则把它们的 $K$ 相乘。它与赫斯定律相仿,只是 $K$ 相乘而 $\Delta H$ 相加。