Extracting metals: carbon can reduce suitable metal oxides
| English | 中文 | Pinyin |
|---|---|---|
| native metal | 自然金属 | zì rán jīn shǔ |
| metal extraction | 金属提取 | jīn shǔ tí qǔ |
What would explain this observation?
- Gold can occur as the metal itself, but many useful metals occur in compounds. Extraction must separate the metal chemically from the other elements.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Very unreactive metals such as gold can be found native, as the metal. Most metals are found as compounds. Metals less reactive than carbon can be extracted from their oxides by reduction using carbon. The oxide loses oxygen and produces metal; carbon gains oxygen. Metals above carbon require another route in this GCSE account, including electrolysis where suitable.
- native metal 自然金属: A metal occurring naturally in its elemental form; metal extraction 金属提取: Obtaining a metal from a naturally occurring source or compound.
Which oxide is suitable for the stated carbon-reduction rule?
For 2CuO + C → 2Cu + CO₂, copper oxide is reduced and carbon oxidised in oxygen terms. Carbon cannot be assumed to reduce every metal oxide under useful extraction conditions. Aluminium is more reactive than carbon and its extraction uses electrolysis, not simply this copper-oxide route. Detailed blast-furnace process recall is not required by this section’s stated limits.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- For 2CuO + C → 2Cu + CO₂, copper oxide is reduced and carbon oxidised in oxygen terms. Carbon cannot be assumed to reduce every metal oxide under useful extraction conditions. Aluminium is more reactive than carbon and its extraction uses electrolysis, not simply this copper-oxide route. Detailed blast-furnace process recall is not required by this section’s stated limits.
- When given an extraction description, locate the feed compound, reducing substance, desired metal and by-products. Evaluate supplied energy, cost, purity or waste data against a stated purpose rather than inventing industrial details. Any actual heated-oxide school work uses the approved small-scale method and technician-selected substances; industrial extraction is a reference case, not a school construction task.
Which two habits make the investigation or model in this case more defensible?
When given an extraction description, locate the feed compound, reducing substance, desired metal and by-products. Evaluate supplied energy, cost, purity or waste data against a stated purpose rather than inventing industrial details. Any actual heated-oxide school work uses the approved small-scale method and technician-selected substances; industrial extraction is a reference case, not a school construction task.
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: a supplied ore model contains 4% recoverable metal by mass. A 250 kg batch therefore contains 0.04×250=10 kg recoverable metal before processing losses. If 8 kg is obtained, recovery is 80%. This ore-content calculation supports a supplied process comparison but does not imply that every carbon reduction has the same yield or ore composition.
A supplied ore contains 5% recoverable metal. Find that metal mass in 360 kg ore before losses. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A supplied ore contains 5% recoverable metal. Find that metal mass in 360 kg ore before losses.
The result is 18 kg. Known: a supplied ore model contains 4% recoverable metal by mass. A 250 kg batch therefore contains 0.04×250=10 kg recoverable metal before processing losses. If 8 kg is obtained, recovery is 80%. This ore-content calculation supports a supplied process comparison but does not imply that every carbon reduction has the same yield or ore composition.
Check the conclusion and its limits
- Native means occurring as the elemental metal, not merely being dug from a mine. Oxygen loss identifies oxide reduction; lower ore mass alone does not. A process may be chemically possible while poor economically or environmentally under supplied conditions.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Carbon is a suitable reducing route for every metal oxide. This claim is false: Native means occurring as the elemental metal, not merely being dug from a mine. Oxygen loss identifies oxide reduction; lower ore mass alone does not. A process may be chemically possible while poor economically or environmentally under supplied conditions.
Extracting metals: carbon can reduce suitable metal oxides: For 2CuO + C → 2Cu + CO₂, copper oxide is reduced and carbon oxidised in oxygen terms. Carbon cannot be assumed to reduce every metal oxide under useful extraction conditions. Aluminium is more reactive than carbon and its extraction uses electrolysis, not simply this copper-oxide route. Detailed blast-furnace process recall is not required by this section’s stated limits.
Carbon is a suitable reducing route for every metal oxide.
Native means occurring as the elemental metal, not merely being dug from a mine. Oxygen loss identifies oxide reduction; lower ore mass alone does not. A process may be chemically possible while poor economically or environmentally under supplied conditions.
A metal occurring naturally in its elemental form: write the technical term.
native metal means A metal occurring naturally in its elemental form.