Chemical Changes

Question 1

How do you calculate overall energy change

Answer 1

Overall energy change =
energy to break bonds - energy released forming new ones

Question 2

Metal + Acid —>

Answer 2

Salt + Hydrogen

Question 3

Metal Oxide (base) / Metal Hydroxide (alkali) + Acid —>

Answer 3

Salt + Water

Question 4

Metal Carbonate + Acid —>

Answer 4

Salt + Water + Carbon Dioxide

Question 5

(Reactive) Metal + Water —>

Answer 5

Metal Hydroxide + Hydrogen

Question 6

What is a strong acid?

Answer 6

An acid which fully dissociates (splits up into ions) in solution, releasing many Hydrogen ions.

Question 7

What is a weak acid and what type of reaction is it?

Answer 7

An acid which does NOT fully dissociate in solution. This is a reversible reaction

Question 8

Why do strong acids react faster than weak acids of the same concentration?

Answer 8

Reactions of acids depend on hydrogen ions reacting with things. Strong acids produce a greater concentration of hydrogen ions so theres a faster rate of reaction.

Question 9

3 weak acids

Answer 9

Citric acid
Ethanoic acid
Carbonic acid

Question 10

What happens at the cathode (in aqueous electrolysis)

Answer 10

Hydrogen is always discharged unless the metal ion is less reactive (least reactive is discharged)