pH Scale, Neutralisation & Salts

Question 1

What does an aqueous solution mean?

Answer 1

Something dissolved in water.

Question 2

What is a base and what do they produce?
Keywords: Neutralise, salt and water

Answer 2

A substance that reacts with an acid to neutralise it.
Bases produce salt and water.

Question 3

True or false: Metal oxides are acids.

Answer 3

False. Metal oxides are bases.

Question 4

True or false: Non-metals produce oxides which are alkaline.

Answer 4

False. Non-metal oxides are acidic.

Question 5

Most metal oxides can _____________, producing _________ solutions.

Answer 5

dissolve in water
acidic

Question 6

What is an acid?
Keywords: pH and hydrogen ions

Answer 6

A corrosive substance with a pH less than seven. Has a high concentration of hydrogen ions.

Question 7

What is an alkali?

Answer 7

A base that can dissolve in water.

Question 8

Acids produce an _______ ____when dissolved in water.

Alkali produce an _______ ____when dissolved in water.

Answer 8

excess of hydrogen ions
excess of hydroxide ions

Question 9

The higher the concentration of H+ ions in an acidic solution, the _______ the pH.

Answer 9

lower

Question 10

The more concentrated the solution of an acid, the _______ its pH will be.

Answer 10

lower

Question 11

What is the difference between a strong and weak acid?

Answer 11

A strong acid completely disassociates into hydrogen ions while a weak acid only partially disassociates.

Question 12

What is neutralisation?

Answer 12

A chemical reaction when an acid and base react with each other quantitatively.

Question 13

Is neutralisation endothermic or exothermic?

Answer 13

Exothermic.

Question 14

How can pure, dry crystals of zinc chloride be made?

Answer 14

Can be produced by crystallisation, then filtration to remove excess solution, then drying in the oven.

Question 15

What is the equation for a neutralisation reaction between an acid and metal?

Answer 15

Acid + metal → salt + hydrogen

Question 16

What is the equation for a neutralisation reaction between an acid and alkali?

Answer 16

Acid + alkali → salt + water

Question 17

What is the equation for a neutralisation reaction between an acid and carbonate?

Answer 17

Acid + carbonate → salt + water + carbon dioxide

Question 18

The neutralisation reactions of acids with metals are _______ reactions.

Answer 18

redox

Question 19

What are the two steps to naming salts?
1.
2.

Answer 19

1.Base, acid or metal carbonate
2. Acid.

Question 20

How do you make a soluble salt from
an acid and insoluble reactant
(metal, metal oxide, metal hydroxide or carbonate)?

1. Add ________________________ to acid in a beaker with a __________.
2. Then _____ to mix.
3. Continue adding powder until in _________ to ensure all of the acid _____________.
4. __________ the mixture to __________________ so the filtrate now only contains a ________________.
5. Heat the solution in an ___________________ over a water bath so it is now _____________.
6. Leave the saturated solution to ____________ at ________________________.

Answer 20

powdered insoluble reactant
spatula

stir

excess
has reacted

Filter
remove excess solid
salt and water

evaporating dish
saturated

crystalise
room temperature

Question 21

Why do chemists usually make salts by reacting a metal oxide or a metal carbonate with an acid instead of a metal with an acid?

Answer 21

Because the reaction between metals and acids produces flammable hydrogen.