Matals

Question 1

Name 5 physical properties of metals

Answer 1

Solids at room temp.
Lustrous
Malleable and ductile
Sonorous
High melting point + High density
Good conductors of electricity and heat.

Question 2

What are the 4 metal properties
( metal +acid —>………)

Answer 2

1. Metal + acid —> salt + hydrogen
2. Metal + oxygen —> metal oxide
3. Metal + water —> metal hydroxide + hydrogen
4. Metal + oxygen —> metal oxide + hydrogen

Question 3

Name 5 physical properties of non-metals

Answer 3

1. Solids and gases at room temperature(bromine is a liquid )
2. Poor thermal conductor
3. Poor conductor of electricity(except graphite )
4. Low melting point and low density
5. Brittle + not malleable

Question 4

Name 3 uses of Aluminium

Answer 4

Aircraft + cars (low density )
Overhead electrical cables (ductile + good conductor if electricity )
Food containers (resistant to corrosion )

Question 5

What are the uses of Zinc

Answer 5

• alloy in bronze /brass
• sacrificial protection
• galvanizes iron -protective coating to prevent rusting
• batteries

Question 6

What is the use if copper

Answer 6

• for electrical wires (good electrical conductors + ductile )

Question 7

What is an alloy

Answer 7

A mixture of two or more metals or a metal and non-metal .

Question 8

Why are alloys more suitable for use than pure metals

Answer 8

• they are harder + stronger and can resist rusting with air +water

Question 9

What is brass made from?
And it’s 2 special properties ?
And it’s 2 uses ?

Answer 9

Brass
Copper and zinc
Stringer + more resistant from rusting
Electrical fittings + car radiators

Question 10

What is stainless steel made from?
What is its special property ?
What are its 3 uses ?

Answer 10

(CINC) Chromium , Iron , Nickel , Carbon
Resistant to corrosion
Kitchen sinks , cutlery , surgical instruments

Question 11

Why are alloys stronger ?

Answer 11

They are stronger because of the irregularity if the different atoms sizes +structure which stops the layers from sliding over each other making them stronger

Question 12

Why is aluminum seemingly unreactive despite its high place in the reactivity series.

Answer 12

Because aluminum makes an unreactive layer of aluminum oxide . Which is unreactive

Question 13

What is the reactivity series

Answer 13

Potassium
Sodium
Calcium
Magnesium
Aluminum
Carbon
Zinc
Iron
Hydrogen
Copper
Silver
Gold

Question 14

What are the products if water + cold water and metal + steam

Answer 14

Metal + cold water —> metal hydroxide + hydrogen
Metal + steam —> metal oxide + hydrogen

Question 15

What can displace hydrogen from its acid. What does hydrogen do

Answer 15

Everything above hydrogen can displace in its acid + hydrogen cannot reduce its oxides

Question 16

What is the reaction if a metal and oxygen

Answer 16

Metal + oxygen —> metal oxide

Question 17

What is the reaction with dilute acids .

Answer 17

Metal + acid, the hydrogen atom is displaced forming a salt + hydrogen. If the metals is above H+ in the R.S

Question 18

Metals above carbon …

Answer 18

Their oxides cannot be reduced by carbon

Question 19

Which metals cannot react with dilute HCL + why?

Answer 19

Copper , Silver , Gold cannot react with dilute HCL because it is too unreactive.

Question 20

In displacement reactions what do metals compete for

Answer 20

Oxygen or anions

Question 21

What is oxidation ?
What is reduction?(In terms of electrons )
What will the more reactive metal do to a less reactive one ?
What will an highly reactive metal do when it has the O2 or anion?
How is a reaction made faster ?

Answer 21

• Oxidation is the loss of electrons
• Reduction is the gain of electrons
• A more reactive metal will displace the less reactive and gain the anion or oxygen
• no reaction
  The further apart the reactivity of the metals the faster the reaction

Question 22

What is rusting ?
What is its chemical name ?
What are the conditions required for rusting to occur ?

Answer 22

The corrosion of iron or steel via oxidation to firm rust.
Hydrated iron (III) oxide via Oxidation
Water + air containing oxygen

Question 23

What is the equation for the rusting iron?

Answer 23

Iron + water + oxygen —> hydrated iron (III) oxide .
4Fe (s) + 2H2O(l) + 3O2(g) —> 2Fe2O3.H2O(s)

Question 24

What are the 2 ways if preventing rust + their explanations

Answer 24

Barrier method - where a metal is coated with a material to prevent being in contact with water and air (panting , greasing , plastic coating)
Sacrificial method- When a more reactive cats and less reactive metal and reacts with air and water preventing contact to the conditions , they lose electrons in preference to iron.

Question 25

What is galvanizing + what method is it

Answer 25

Galvanization is the protection of iron and steel objects by coating them with a layer of zinc .
The barrier method is due to the zinc layer preventing exposure to air + water & sacrificial protection because it is more reactive than iron and prefers to be corroded in favor of Iron ?

Question 26

What is the ore for aluminum oxide ?
What is is then dissolved in and for what purpose?
What the half equations at each electrode ?
Why do graphite electrodes replaced ?
Why is cryolite used?

Answer 26

• Bauxite
• Aluminium (III) Oxide (alumina)is dissolved in cryolite that lowers the melting point (industrially preferred )
• at Cathode = Al3+ + 3e- —> Al
• at anode = 2O2- —> O2+ 4e-
• cryolite reduces the melting point/ operating point of Aluminium oxide + increases conductivity.
• At the Carbon anode the carbon and the oxygen frequently react producing CO2 , causing the anode to thin therefore the need of being periodically replaced

Question 27

Which metals of the R.S can be extracted through electrolysis ?
How are metals between carbon and hydrogen extracted ?
And under hydrogen ?

Answer 27

• Metals before carbon —>potassium , sodium , Aluminium , Magnesium , Calcium .
• reduced by carbon —> iron, zinc , lead
• already pure—> silver , gold , copper

Question 28

What is the ore for metal?
What does the burning if coke provide ?
What are the raw materials added ?
What are the waste products ?
Name the process and their equations and what type of reaction it is ?
Use of slag ?

Answer 28

Haematite (Fe2O3)
Coke provides reacts with oxygen creases higher temps in the blast furnace +
Limestone , iron , coke , hot air (oxygen )
Nitrogen , carbon monoxide , carbon dioxide
Slag is at the bottom and pure iron beneath it and tapped off.
Slag is used for cement + roads

C + O2 —> CO2 (exothermic)
CO2 + C —> 2CO
3CO + Fe2O3 —> 2Fe + 3CO2( reduction)
CaCO3(heat) —> CaO + CO2(thermal decomposition)(lime broken down )
CaO + SiO2 —> CaSiO3 (acid -base Neutralisation )(slag )