Acids

Question 1

What do you acids form in water

Answer 1

H+ ions

Question 2

What does higher concentration of H+ ions in an acidic solution mean

Answer 2

The more acidic the solution is (lower it’s pH)

Question 3

What is an alkali

Answer 3

A base that is soluble in water

Question 4

What is an acid

Answer 4

A substance with a pH of less than 7

Question 5

What do you alkalis form in water

Answer 5

OH- ions (hydroxide ions)

Question 6

What does a higher concentration of OH- ions in an alkaline solution mean

Answer 6

The more alkaline the solution (The higher the pH)

Question 7

What colour do acids, alkalis and neutral solutions go in litmus

Answer 7

Acids=Red
Alkaline= Blue
Neutral=Purple

Question 8

What colour do acids, alkalis and neutral solutions go in Methyl orange

Answer 8

Acids =Red
alkaline =yellow
neutral = yellow

Question 9

What colour do acids, alkalis and neutral solutions go in phenolphthalein

Answer 9

Acids = colourless
alkaline = pink
neutral = colourless

Question 10

How does the concentration of hydrogen ions effect the pH of the solution

Answer 10

As hydrogen ion concentration in a solution increases by a factor of 10 the pH of the solution decreases by 1

Question 11

What is the reaction between an acid and a base called

Answer 11

Neutralisation

Question 12

Acid + base = ?

Answer 12

salt + water

Question 13

What happens when an acid neutralises a bass (or vice versa)

Answer 13

The products are neutral (they have a pH of 7)

At pH 7 the concentration of hydrogen ions is equal to the concentration of hydroxide ions.

Question 14

What is a strong acid

Answer 14

They ionise almost completely in the water
(a large portion of the acid molecules dissociate to release H+ ions)
They tend to have low pHs

Question 15

What are weak acids

Answer 15

They do not fully ionise in a solution (only a small proportion of the acid molecules disassociate to release H+ ions)
There pHs are around 2 - 6

Question 16

Acid + metal oxide = ?

Answer 16

Salt + water

(2HCl + CuO = CuCl2 + H2O) copper chloride

Question 17

Acid + metal hydroxide = ?

Answer 17

Salt + water

(HCL + NaOH = NaCl + H2O)sodium chloride

Question 18

Acid + metal = ?

Answer 18

Salt + hydrogen

(2HCl + Mg = MgCl2 + H2) magnesium chloride

Question 19

Acid + Metal carbonate = ?

Answer 19

Salt + water + carbon dioxide

(2HCl + Na2CO3 = 2Na + H2O + CO2) sodium chloride

Question 20

How do you test for hydrogen

Answer 20

Using a lighted splint
Hydrogen makes the ‘squeaky pop’ with a lighted splint
The noise comes from hydrogen burning with the oxygen in the air to form water

Question 21

How do you test carbon dioxide

Answer 21

By bubbling it through lime water

Is the gas is carbon dioxide, the limewater will turn cloudy