Acids with metals: choose the salt and hydrogen products
| English | 中文 | Pinyin |
|---|---|---|
| iron(II) salt | 亚铁盐 | yà tiě yán |
| acid–metal reaction | 酸与金属反应 | suān yǔ jīn shǔ fǎn yìng |
What would explain this observation?
- Magnesium in dilute hydrochloric acid produces bubbles and a dissolved salt. Hydrogen is the gas, while chloride from the acid contributes to the salt identity.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Some metals react with acids to make a salt and hydrogen. In this source recall scope use magnesium, zinc and iron with dilute hydrochloric or sulfuric acid. Hydrochloric acid gives chlorides and sulfuric acid gives sulfates. Mg + 2HCl → MgCl₂ + H₂ and Zn + H₂SO₄ → ZnSO₄ + H₂ are balanced examples. Iron with dilute acid forms iron(II) salts 亚铁盐 in the stated school account.
- acid–metal reaction 酸与金属反应: A suitable metal reacting with acid to produce a salt and hydrogen; iron(II) salt: A salt containing Fe²⁺ ions.
Which products are expected from zinc and dilute sulfuric acid?
The metal must be suitable relative to hydrogen. Copper does not normally release hydrogen from these dilute acids. Do not extend this acid–metal pattern to nitric acid or concentrated acid reactions, which are outside the stated scope and can produce different outcomes. With a metal oxide, the usual products are salt and water instead of hydrogen.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- The metal must be suitable relative to hydrogen. Copper does not normally release hydrogen from these dilute acids. Do not extend this acid–metal pattern to nitric acid or concentrated acid reactions, which are outside the stated scope and can produce different outcomes. With a metal oxide, the usual products are salt and water instead of hydrogen.
- Use teacher-approved dilute acid and selected small metal samples with eye protection and no nearby ignition source. Record bubbles and metal disappearance. A permitted small collected hydrogen sample gives a squeaky pop with the teacher-approved lit-splint test; do not apply a flame to the generating vessel or a large gas accumulation. Temperature, surface area and acid concentration affect the observed rate.
Which two habits make the investigation or model in this case more defensible?
Use teacher-approved dilute acid and selected small metal samples with eye protection and no nearby ignition source. Record bubbles and metal disappearance. A permitted small collected hydrogen sample gives a squeaky pop with the teacher-approved lit-splint test; do not apply a flame to the generating vessel or a large gas accumulation. Temperature, surface area and acid concentration affect the observed rate.
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: Fe + 2HCl → FeCl₂ + H₂ balances one Fe, two Cl and two H atoms on each side. Four represented iron atoms require eight HCl molecules and form four H₂ molecules. This counting exercise uses equation particle ratios without requiring the Higher-only electron explanation of this reaction.
In Fe + 2HCl → FeCl₂ + H₂, how many HCl molecules react with six represented Fe atoms? Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
In Fe + 2HCl → FeCl₂ + H₂, how many HCl molecules react with six represented Fe atoms?
The result is 12 molecules. Known: Fe + 2HCl → FeCl₂ + H₂ balances one Fe, two Cl and two H atoms on each side. Four represented iron atoms require eight HCl molecules and form four H₂ molecules. This counting exercise uses equation particle ratios without requiring the Higher-only electron explanation of this reaction.
Check the conclusion and its limits
- Not every acid–solid reaction releases hydrogen. Carbonates release carbon dioxide, while many bases produce water. Salt formulae need correct ion charges. Common-tier product prediction remains separate from the embedded Higher-only electron redox interpretation.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
A metal oxide and acid necessarily produce hydrogen gas. This claim is false: Not every acid–solid reaction releases hydrogen. Carbonates release carbon dioxide, while many bases produce water. Salt formulae need correct ion charges. Common-tier product prediction remains separate from the embedded Higher-only electron redox interpretation.
Acids with metals: choose the salt and hydrogen products: The metal must be suitable relative to hydrogen. Copper does not normally release hydrogen from these dilute acids. Do not extend this acid–metal pattern to nitric acid or concentrated acid reactions, which are outside the stated scope and can produce different outcomes. With a metal oxide, the usual products are salt and water instead of hydrogen.
A metal oxide and acid necessarily produce hydrogen gas.
Not every acid–solid reaction releases hydrogen. Carbonates release carbon dioxide, while many bases produce water. Salt formulae need correct ion charges. Common-tier product prediction remains separate from the embedded Higher-only electron redox interpretation.
A suitable metal reacting with acid to produce a salt and hydrogen: write the technical term.
acid–metal reaction means A suitable metal reacting with acid to produce a salt and hydrogen.