Answer:
The correct answers are C and D.
Using a more concentrated HCl solution and Crushing the CaCO₃ into a fine powder makes the reaction to occur at a faster rate.
<u>Explanation:</u>
CaCO₃(s) + 2HCl(aq) → CaCl₂(aq) + H₂O(aq) + CO₂(g)
When calcium carbonate reacts with hydrochloric acid, it gives out carbon-dioxide in the form of bubbles and there is a formation of calcium chloride in aqueous medium.
The rate of the reaction can be increased by
- Using a more concentrated HCl solution
- Crushing the CaCO₃ into a fine powder
When concentrated acid is used instead of dilute acid then the reaction will occur at a faster rate.
When CaCO₃ is crushed into a fine powder then the surface area will increases thereby increasing the rate of the reaction.
Burning gas is a chemical change and evaporation of gas is physical change.
If the level of acid in a lake increased, then the number of fish that live there will be decreased because highly acidic lakes will not have enough food for the fish to survive. Acidic level increases , then availability of food for fish decreases as some food will be contaminated so if the fish won't got enough food for their survival then their number of fish decreases.
I’m not very good at this subject, however I have a idea of what it could be but if wrong My apologies “ Placed wires “.
Have a blessed day and God bless.
