Formulae And Acids

Question 1

How do atoms on the left make ions?

Answer 1

Lose electrons to form positive ions (cations)

Question 2

How do atoms on the right make ions?

Answer 2

Gain electros to form negative ions (anions)

Question 3

What are polyatomic ions?

Answer 3

Ions which contains atoms of more than one element.

Question 4

How are chemical formulas produced?

Answer 4

Combing ions which are negative and positive.

Question 5

What do covalent compounds not contain?

Answer 5

Don’t contain ions. Most covalent compounds exist as molecules with a small number of atoms. E.g. H2O

Question 6

What are example of diatomic atoms?

Answer 6

Diatoic atoms have two atoms joined together.
E.g. O2, CL2, Br2, I2, F2, N2, H2

Question 7

What are the 4 state symbols in chemical equations?

Answer 7

Gaseous (g)
Liquid (l)
Solid (s)
Aqueous (aq)

Question 8

What is the definition of an acid?

Answer 8

An acid is described as a proton donor.
All contain hydrogen because when added to water , the acid releases hydrogen into the solution in the form of H+ ions.

Question 9

What is a strong acid?

Answer 9

Releases all its hydrogen atoms into solution as H+ ions and completely dissociates in aqueous solution.
Has high concentration of H+ ions

Question 10

What is a weak acid?

Answer 10

Only releases a small proportion of its available hydrogen atoms into a solution as H+ ions and is partially dissociates in aqueous solution.
Has low concentration of H+ ions

Question 11

What is a base?

Answer 11

Is a proton acceptor.

Question 12

What are some common bases?

Answer 12

Metal oxides, hydroxides , metal carbonates, ammonia and compounds.

Question 13

What is an alkali?

Answer 13

A soluble base that releases OH- ions in a solution.

Question 14

What are examples of alkalis?

Answer 14

Sodium hydroxide, potassium hydroxide and aqueous ammonia/ammonium hydroxide.

Question 15

What is a salt?

Answer 15

A chemical compund formed when the H+ ions from an acid has been replaced by a metal ion or another positive ion

Question 16

What does an acid + alkali make?

Answer 16

Salt + water
Its a neutralisation reaction

Question 17

What is the general ionic equation for the reaction between acid + alkali?

Answer 17

H+ (aq) + OH- (aq) -> H2O (l)

Question 18

What does a acid and a base make?

Answer 18

Salt + water
Its a neutralisation reaction.

Question 19

What is the general ionic equation for the reaction between an acid and a base?

Answer 19

H+ (aq) + OH- (aq) -> H2O (l)

Question 20

What can be observed when an acid and base react with each other?

Answer 20

Solid disappears

Question 21

What does and acid + carbonate make?

Answer 21

Salt + water + carbon dioxide

Question 22

What is the general ionic equation for when an acid reacts with a carbonate?

Answer 22

H+ (aq) + CO3 2- (aq) -> CO2 (g)+ H2O (l)

Question 23

What can be observed when an acid reacts with a carbonate?

Answer 23

Solid disappears
Bubbles

Question 24

What does an acid + metal make? (Remember MASH)

Answer 24

Salt + hydrogen

Question 25

What is the general ionic equation for an acid + metal?

Answer 25

H+ (aq) + metal (s) -> metal ion (aq) + H2 (g)
E.g. 2H+ (aq) + Mg ( s) -> Mg2+ (aq) + H2 (g)

Question 26

What can be observed when an acid reacts with a metal?

Answer 26

Metal disappears
Bubbling.

Question 27

How are ammonium salts formed?

Answer 27

When acids are neutralised by aqueous ammonia.
Ammonium salts contain ammonium ion (NH4+)
In reaction, the ammonium accepts the proton from acid to form ammonium salt.
The only product in this reaction is ammonium salt.

Question 28

What are ammonium salts used for?

Answer 28

Fertilisers