C8.7 - Energy and reversible reactions Flashcards
Energy cannot be created or destroyed in a chemical reaction.
What must the amount of energy transferred to the surroundings when the reaction goes in 1 direction in a reversible reaction be?
The amount of energy transferred to the surroundings when the reaction goes in 1 direction in a reversible reaction must be exactly the same as the energy transferred back in when the reaction goes in the opposite direction
Why do blue copper(II) sulfate crystals contain water?
Blue copper(II) sulfate crystals contain water as part of the lattice formed when the copper(II) sulfate crystallised
Blue copper(II) sulfate crystals contain water as part of the lattice formed when the copper(II) sulfate crystallised. What is the copper(II) sulfate?
The copper(II) sulfate is hydrated
Hydrated
Hydrated describes a substance that contains water in its crystals
Blue copper(II) sulfate crystals contain water as part of the lattice formed when the copper(II) sulfate crystallised. The copper(II) sulfate is hydrated. What does heating the copper(II) sulfate do?
Heating the copper(II) sulfate drives off the water from the crystals
Blue copper(II) sulfate crystals contain water as part of the lattice formed when the copper(II) sulfate crystallised.
The copper(II) sulfate is hydrated.
Heating the copper(II) sulfate drives off the water from the crystals, producing white anhydrous copper(II) sulfate.
What reaction is this?
This is an endothermic reaction
Anhydrous
Anhydrous describes a substance that does not contain water
What happens when you add water to anhydrous copper(II) sulfate?
When you add water to anhydrous copper(II) sulfate, hydrated copper(II) sulfate is formed
When you add water to anhydrous copper(II) sulfate, hydrated copper(II) sulfate is formed.
What is a useful test for the presence of water?
A useful test for the presence of water is the colour change in the reaction, from white to blue
What reaction is adding water to anhydrous copper(II) sulfate?
Adding water to anhydrous copper(II) sulfate is an exothermic reaction
Adding water to anhydrous copper(II) sulfate is exothermic.
If you add water dropwise to anhydrous copper(II) sulfate powder, what may you see?
If you add water dropwise to anhydrous copper(II) sulfate powder, you may see steam rising
What can you soak filter paper in?
You can soak filter paper in cobalt(II) chloride solution
You can soak filter paper in cobalt(II) chloride solution and allow it to dry in an oven.
What is the blue paper that is produced?
The blue paper that is produced is called cobalt(II) chloride paper
You can soak filter paper in cobalt(II) chloride solution and allow it to dry in an oven.
The blue paper that is produced is called cobalt(II) chloride paper.
What happens to the paper when water is added to it?
The cobalt(II) chloride paper turns pale pink when water is added to it
Why can blue cobalt(II) chloride paper be used as an indicator for the presence of water?
Blue cobalt(II) chloride paper can be used as an indicator for the presence of water, because it turns pale pink when water is added to it
Blue copper(II) sulfate crystals contain water as part of the lattice formed when the copper(II) sulfate crystallised. The copper(II) sulfate is hydrated. Heating the copper(II) sulfate drives off the water from the crystals, producing what?
Heating the copper(II) sulfate drives off the water from the crystals, producing white anhydrous copper(II) sulfate
You can soak filter paper in cobalt(II) chloride solution and allow it to what?
You can:
- Soak filter paper in cobalt(II) chloride solution
- Allow it to dry in an oven
