Molecular Structure of Acids and Bases · 酸碱的分子结构
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| oxoacid/ˈɒksəʊsɪd/ | 含氧酸 | hán yǎng suān |
What makes an acid strong
- Two acids can look alike but differ wildly in strength.
- The secret is hidden in their bonds and atoms.
- A weaker or more polar bond to hydrogen lets the proton leave.
- A stable leftover ion also helps the proton go.
是什么让酸变强
- 两种酸看起来可能很像,强弱却天差地别。
- 秘密藏在它们的键和原子里。
- 与氢之间更弱或更极性的键让质子离开。
- 一个稳定的剩余离子也帮助质子离去。
Bond strength and polarity
- A weaker bond to hydrogen releases the proton more easily.
- A more polar bond also loosens the $\text{H}^+$.
- Both make the acid stronger.
键的强弱与极性
- 与氢之间更弱的键更容易释放质子。
- 更极性的键也松开 $\text{H}^+$。
- 两者都使酸更强。
A weaker bond to hydrogen makes an acid... · 较弱的氢键使酸……
A weaker H bond releases the proton more easily. · 较弱的H键更容易释放质子。
A more polar bond to hydrogen helps release the proton. · 极性的氢键有助于释放质子。
Polarity loosens the $\text{H}^+$, aiding ionization. · 极性削弱了$\text{H}^+$，促进电离。
A stable conjugate base
- The more stable the conjugate base, the stronger the acid.
- Spreading the negative charge out stabilizes it.
- A contented leftover ion means the proton leaves willingly.
稳定的共轭碱
- 共轭碱越稳定,酸越强。
- 把负电荷分散开会使它稳定。
- 一个满意的剩余离子意味着质子乐意离开。
A more stable conjugate base means a stronger acid. · 更稳定的共轭碱意味着更强的酸。
A stable conjugate base lets the proton leave more readily. · 稳定的共轭碱使质子更容易离去。
Spreading out the negative charge makes the conjugate base more . · 分散负电荷使共轭碱更。
A spread-out charge is more stable, so the acid is stronger. · 分散的电荷更稳定，因此酸性更强。
Two useful trends
- Binary acids (H-X): stronger down a group, as the H-X bond weakens.
- An oxoacid 含氧酸 grows stronger with more oxygen atoms.
- These trends predict relative strengths quickly.
两条有用的规律
- 二元酸(H-X):沿一族向下越强,因为 H-X 键变弱。
- 含氧酸随氧原子越多而越强。
- 这些规律能快速预测相对强弱。
Which is the stronger binary acid? · 哪个是更强的二元酸？
The weaker H-I bond makes HI stronger than HF. · 较弱的H-I键使HI比HF更强。
Adding more oxygen atoms to an oxoacid generally makes it... · 增加含氧酸中的氧原子通常使其……
More oxygens stabilize the conjugate base, strengthening the acid. · 更多氧原子稳定了共轭碱，从而增强了酸性。
Why is $\text{HI}$ a stronger acid than $\text{HF}$?
- The H-I bond is weaker than the H-F bond.
- So $\text{HI}$ releases its proton more easily, making it stronger.
为什么 $\text{HI}$ 比 $\text{HF}$ 是更强的酸?
- H-I 键比 H-F 键弱。
- 所以 $\text{HI}$ 更容易释放它的质子,使它更强。
What makes an acid strong? · 什么使酸变强？
Sort each comparison by which structural feature gives the stronger acid. · 根据哪种结构特征使酸更强，对每组比较进行排序。
Down a group, binary-acid strength increases because the H-X bond weakens (bond strength matters more than electronegativity here). More oxygens on an oxoacid pull electron density away, stabilizing the conjugate base and strengthening the acid. A more stable conjugate base always means a stronger acid.
沿一族向下,二元酸的强度增大,因为 H-X 键变弱(这里键的强弱比电负性更重要)。含氧酸上更多的氧把电子密度拉走,使共轭碱稳定并加强酸。更稳定的共轭碱总意味着更强的酸。
An acid is stronger when its bond to hydrogen is weaker or more polar, and when its conjugate base is more stable. Two trends follow: binary acids strengthen down a group (weaker H-X bond), and an oxoacid strengthens with more oxygen atoms.
当酸与氢之间的键更弱或更极性、且它的共轭碱更稳定时,酸更强。由此得出两条规律:二元酸沿一族向下增强(H-X 键更弱),而含氧酸随氧原子越多而增强。