Oxides
Vocabulary
| English | Chinese | Pinyin |
|---|---|---|
| oxide | 氧化物 | yǎng huà wù |
| metal oxides | 金属氧化物 | jīn shǔ yǎng huà wù |
| basic oxide | 碱性氧化物 | jiǎn xìng yǎng huà wù |
| acidic oxide | 酸性氧化物 | suān xìng yǎng huà wù |
| amphoteric | 两性 | liǎng xìng |
Acidic, basic or neither
- When an element reacts with oxygen it forms an oxide 氧化物 — and oxides behave very differently.
- Whether an oxide is acidic or basic depends on the element.
Explore
Oxide type lab
Classify oxides by how they behave with acids and bases.
Practice
Metal oxides are usually:
Metal oxides tend to be basic.
Practice
Non-metal oxides are usually:
Non-metal oxides tend to be acidic.
Metal and non-metal oxides 金属氧化物
- Metal oxides are usually basic (many dissolve to form alkalis).
- Non-metal oxides are usually acidic (many dissolve to form acids).
The pH scale: below 7 is acidic, 7 is neutral, above 7 is alkaline
Practice
A basic oxide reacts with an acid to form a salt and water.
Basic oxides neutralise acids.
Practice
Carbon dioxide is a non-metal oxide, so it is ______.
Non-metal oxides are acidic.
Acidic and basic oxides 碱性氧化物
- A basic oxide (e.g. magnesium oxide) reacts with acids to form a salt and water.
- An acidic oxide 酸性氧化物 (e.g. carbon dioxide, sulfur dioxide) reacts with alkalis.
Practice
An amphoteric oxide reacts with:
Amphoteric oxides react with both.
Amphoteric 两性 oxides
- A few oxides are amphoteric — they react with both acids and alkalis.
- Examples include aluminium oxide and zinc oxide.
Example
Worked example. Magnesium (a metal) burns to form magnesium oxide, a basic oxide. Carbon (a non-metal) burns to form carbon dioxide, an acidic oxide. Metal vs non-metal predicts the oxide's nature.
You've got it
Key idea
- metal oxides are usually basic; non-metal oxides are usually acidic
- a basic oxide reacts with acids; an acidic oxide reacts with alkalis
- amphoteric oxides (e.g. aluminium oxide) react with both