Year 9 term 2

Question 1

properties of alkali metals

Answer 1

• Low density, density increases going down the group
• MP and BP decrease going down the group
• MP and BP are low for metals.
• Form hydroxides in water
• Good conductors
• Shiny but tarnish quickly
• Very reactive

Question 2

Halogens are very —- non-metals

Answer 2

Reactive

Question 3

Properties of halogens

Answer 3

• MP and BP are high, increase going down the group
• More dense going down the group
• Darker colour as you go down
• Poisonous vapour, bromine is corrosive to skin

Question 4

% of oxygen in the air

Answer 4

21%

Question 5

% of nitrogen in the air

Answer 5

78%

Question 6

% of argon in the air

Answer 6

0.9%

Question 7

% of CO2 in the air

Answer 7

0.04%

Question 8

A use for oxygen

Answer 8

To respire aerobically

Question 9

A use of nitrogen

Answer 9

• Ammonia
• Crisps
• Fertilizer

Question 10

A use for CO2

Answer 10

• Photosynthesis
• extinguishing fires
• Dry ice

Question 11

A use for argon

Answer 11

Light bulbs

Question 12

Outline an experiment to show the percentage oxygen in the air

Answer 12

1. 2 syringes are connected by a tube, fill the passage way with copper fillings.
2. Pull the first syringe back to measure volume of air in both tubes(should be 100cm^3)
3. Heat the fillings
4. Push the air through the syringes so it passes over the fillings
5. Continue action for a period of time, then measure the final volume of air.
6. Subtract the beginning value from the end value
7. As copper oxide formed, the answer is the volume of oxygen in the air.

Question 13

Group 1 all form —— ions

Answer 13

Positive or colourless

both are correct answers

Question 14

What is observed in a reaction of sodium with water?

Answer 14

• Effervescence
• a trail in the water
• Sodium floats on the water
• Sodium melts into a ball
• If tested with indicator, alkali solution forms.

Question 15

Francium and astatine are ——-

Answer 15

radioactive

Question 16

Group 1 metals

What is the trail in the water that sodium leaves upon reaction?

Answer 16

Sodium hydroxide

Question 17

predicted properties of francium

Answer 17

• very soft
• Room temperature MP
• Very dense
• Violent with water

Question 18

Observations of Mg burning in pure oxygen?

Answer 18

• Effervesence
• (insoluble) white powder

Question 19

Chemical and physical

Observations of Sulphur burning with oxygen?

Answer 19

• Blue flame
• Colourless gas(SO2)
• Soluble gas

Question 20

Observations of hydrogen heated with oxygen

Answer 20

• H2O forms
• Explosive

Question 21

Properties fo a metal oxide

Answer 21

• Ionic compond
• Basic oxide(makes salt with acidic)
• Insoluble with water(those few that are form OH+)

Question 22

Properties of a non-metal oxide?

Answer 22

• Covalent compounds
• Acidic oxides
• Soluble in water, make H+ ions

Question 23

A simple thermal decomposition we can do in school to form CO2?

Answer 23

CuCO3——>CuO+CO2

can also be done with calcium carbonate

Question 24

What is galvanizing of iron?

Answer 24

Coating it with Zinc so that it is is prevented from rusting as zinc is more reactive, even if the layer is scratched oxygen will still react with it in preference to Iron. A combination of barrier and sacrificial anode protection methods.

Question 25

Outline a method to identify the place of a metal in the reactivity series?

Answer 25

1. Place the metal in cold water-if it reacts then it's above Mg. 2. If not, then place the metal in HCl acid or SO4 acid, if there is still no reaction, warm the acid carefully, if it reacts then it is above Hydrogen in the reactivity series 3. If not, the the metal is probably below hydrogen in the reactivity series.

Question 26

In reactivity series which react vigrously and what is made?

Answer 26

K, Na, Li, and Ca. Form hydroxide and hydrogen with water.

Question 27

Metals below calcium in reactivity series? | in water

Answer 27

Slow in water, some only react with cold water. (Zn and Fe)

Question 28

Metals in the reactivity react with acids only if they are above -----

Answer 28

Hydrogen

Question 29

In MASH what is usually seen>

Answer 29

- Metal dissappears - Effervesence as it dissapears

Question 30

If zinv and magnesium both give off effervesence in an acid, how do we now see which is more reactive?

Answer 30

Place them in water and see how they react

Question 31

Common displacement reaction of copper sulphate.

Answer 31

With magnesium solid- BLue solution becomes colourless and red copper solid is formed as displaced so magnesium more reactive

Question 32

Mnemonic for reactivity series?

Answer 32

PLEASE STOP SENDING LIONS,CATS, MONKEYS, AND CUTE ZEBRAS TO HOT COUNTRIES.(SIGNED Glamrocks)

Question 33

2 ways a displacement reaction can occur

Answer 33

- more reactive metal and... - lesser reactive metal oxide - lesser reactive metal salt sol.

Question 34

wast CO2 in electro

Answer 34

rodes becomme smaller

Question 35

coke in electro

Answer 35

heat

Question 36

use of CO2

Answer 36

carbonating drinks / in drinks soluble (in water) / reacts with water 1 M3 1 M4 fire extinguishers / putting out fires denser than air / does not support combustion

Question 37

iii) Explain why the lamp stops working after the teacher stops heating the lead(II) bromide.

Answer 37

ions stop moving / ions not free to move OR electrons stop moving (through wires)

Question 38

The waste gases escaping from the electrolysis cell contain carbon dioxide. Describe how the carbon dioxide is formed.

Answer 38

oxygen from anode

Question 39

What happens to the ions in magnesium chloride during melting? (

Answer 39

ions mobile

Question 40

State how these ionic half-equations show that equal volumes of the two gases should be collected.

Answer 40

same no. of e- means same no. of mol

Question 41

bubble chlorine into a solution of potassium iodide

Answer 41

black percipitate

Question 42

Suggest why a small amount of dilute acid is added to the water before it is electrolysed.

Answer 42

conduct electricity