Chemical changes

Question 1

Give the general equation for a neutralisation reaction.

Answer 1

acid + alkali = salt + water

Question 2

What type of ions do acids / alkalis release when dissolved in water?

Answer 2

Acids form positive hydrogen ions (H+) and alkalis form negative hydroxide ions (OH-).

Question 3

What is the product of the reaction between H+ and OH- ions?

Answer 3

H2O (water)

Question 4

The alkali lithium hydroxide reacts with hydrochloric acid.

a) What kind of reaction is this?
b) A salt is formed. What is the other product of this reaction.

Answer 4

a) This is a neutralisation reaction.

b) H2O

Question 5

What is meant by the strength of an acid?

Answer 5

The strength of an acid tells you about the proportion of acid particles that will dissociate to produce H+ ions in solution.
Strong acids ionise completely in water, whereas weak acids only partially ionise in water.

Question 6

What is meant by the dissociation of acids?

Answer 6

I generally don’t know I’ll fill out this card later

Question 7

Give an 3 examples of strong acids.

Answer 7

Sulfuric (H2SO4)
Hydrochloric (HCL)
Nitric (HNO3)

Question 8

Give 2 examples of weak acids.

Answer 8

Citric (C6H8O7)

Carbonic (H2CO3)

Question 9

How do acids and alkalis neutralise each other?

Answer 9

Dissolved H+ and OH- ions combine to form H2O, which is neutral.

Question 10

State the equation for change in H+ concentration.

Answer 10

Factor H+ ion concentration changes by = 10^-x

x= difference in PH.

Question 11

A student added acid to an alkaline solution. The PH of the solution changed from 9-7.

Answer 11

Difference in PH = 7-9=-2
Factor H+ ion concentration changes by = 10^-(-2)
= 10^2
=100