AQA · Chemistry · 8462
GCSE Chemistry: Mass changes when a reactant or product is a gas
Quantitative chemistry · AQA GCSE Chemistry (8462), specification point 4.3.1.3. Cards are generated from the exam board's own specification for "Mass changes when a reactant or product is a gas", and every card links back to the page it came from. Specification © AQA — used with attribution.
9 flashcards · Free to study · No account needed
Study this deck
Preparing your cards…
All questions and answers
Read through the full deck, or practise recalling each answer above.
Why can a chemical reaction appear to change mass in a non-enclosed system?
Show answer
A reactant or product is a gas whose mass has not been taken into account.
Why does the mass of the oxide exceed the mass of the metal when a metal reacts with oxygen?
Show answer
Oxygen gas from the air combines with the metal, so its mass is added to the solid product.
Why does the solid appear to lose mass during the thermal decomposition of a metal carbonate?
Show answer
Carbon dioxide gas is produced and escapes into the atmosphere, leaving only the metal oxide as solid.
Thermal decomposition of a metal carbonate gives a metal oxide and ?.
Show answer
carbon dioxide
What is the only solid product of the thermal decomposition of a metal carbonate?
Show answer
The metal oxide.
Which model is used to explain observed mass changes in non-enclosed reactions?
Show answer
The particle model — gas particles leave or enter the system, carrying mass with them.
In the particle model, why does a solid gain mass when a metal burns in air?
Show answer
Oxygen particles from the air bond to the metal particles, so more particles make up the solid product.
When a metal reacts with oxygen, the mass of the oxide produced is ? than the mass of the metal.
Show answer
greater
Would the mass of a metal carbonate decomposing in a sealed container appear to change?
Show answer
No — in an enclosed system the carbon dioxide cannot escape, so total mass is conserved.
Want to create your own cards? Create a free account. AI generation uses credits.