3.2.2 Group 2 Knowledge

Question 1

Does reactivity increase or decrease down group 2?

Answer 1

increases

Question 2

group 2 metal + water => ?

Answer 2

metal hydroxide + hydrogen

Question 3

Mg(s) + 2H₂O(l) ⇒ ?

Answer 3

Mg(OH)₂(aq) + H₂(g)

Question 4

Mg(s) + H₂O(g) ⇒

Answer 4

MgO + H₂(g)

Question 5

why does Mg react different with liquid water or steam?

Answer 5

steam has more energy that ignites Mg

Question 6

what are the observations when Mg reacts with steam?

Answer 6

white solid produced, bright white light

Question 7

what is the equation for the use of Mg for the extraction of Titanium from Titanium Tetrachloride

Answer 7

TiCl₄ + 2Mg ⇒ 2MgCl₂ + Ti

Question 8

what is the role of Mg in this reaction: TiCl₄ + 2Mg ⇒ 2MgCl₂ + Ti?

Answer 8

reducing agent

Question 9

does the solubility of group 2 hydroxides increase or decrease down the group?

Answer 9

increases

Question 10

how soluble is Mg(OH)₂?

Answer 10

sparingly soluble

Question 11

how soluble is Ca(OH)₂?

Answer 11

sparingly soluble

Question 12

how soluble is Sr(OH)₂?

Answer 12

more soluble

Question 13

how soluble is Ba(OH)₂?

Answer 13

completely dissolves

Question 14

how do you test for Mg²⁺ and OH⁻ ions?

Answer 14

if Mg²⁺ ions are added to a solution containing OH⁻ ions (and vice versa) a white precipitate (Mg(OH)₂) forms

Question 15

what is the precipitate formed when Mg²⁺ ions are added to a solution containing OH⁻ ions?

Answer 15

Mg(OH)₂, a white solid almost insoluble in water

Question 16

what is the ionic equation for the reaction between Mg²⁺ ions and OH⁻ ions?

Answer 16

Mg²⁺(aq) + 2OH⁻(aq) ⇒ Mg(OH)₂(s)

Question 17

how do you test for Mg²⁺ ions?

Answer 17

add Na(OH)(aq) or any other OH⁻ containing compound

Question 18

how do you test for OH⁻ ions?

Answer 18

add Mg(NO₃)₂(aq) or any other Mg²⁺ containing compound

Question 19

what is a use of Mg(OH)₂?

Answer 19

indigestion relief (often called ‘milk of magnesia’)

Question 20

does the solubility of the group 2 sulphates increase or decrease down the group?

Answer 20

decreases

Question 21

describe the solubility of MgSO₄

Answer 21

completely dissolves

Question 22

describe the solubility of CaSO₄

Answer 22

fairly soluble

Question 23

describe the solubility of SrSO₄

Answer 23

sparingly soluble

Question 24

describe the solubility of BaSO₄

Answer 24

insoluble

Question 25

how do you test for Ba²⁺ and SO₄²⁻ ions?

Answer 25

if Ba²⁺ ions are added to a solution containing SO₄²⁻ ions (and vice versa) a white precipitate (BaSO₄) forms

Question 26

what is the precipitate that forms when Ba²⁺ ions are added to a solution containing SO₄²⁻ ions?

Answer 26

BaSO₄, a white solid that is insoluble in water

Question 27

give the ionic equation for the reaction between Ba²⁺ and SO₄²⁻ ions

Answer 27

Ba²⁺(aq) + SO₄²⁻(aq) ⇒ BaSO₄(s)

Question 28

how do you test for Ba²⁺ ions?

Answer 28

add H₂SO₄(aq)

Question 29

how do you test for SO₄²⁻ ions?

Answer 29

add BaCl₂

Question 30

what is a use of barium sulphate?

Answer 30

‘Barium meal’ - it is radiopaque allowing stomach and intestines to show up on x-rays