Metals

Question 1

what is the chemical formula for limestone

Answer 1

CaCO3

Question 2

what is the balanced equation for the thermal decomposition of limestone into quicklime and carbon dioxide

Answer 2

calcium carbonate heat = calcium oxide + carbon dioxide

Question 3

What would you see when sulphur burns with oxygen

Answer 3

it burns with a very nice blue flame

Question 4

What is the symbol equation for when sulphur burns with oxygen

Answer 4

S(s) + O2(g) ——> SO2(g)

Question 5

what type of oxide is so2

Answer 5

sulphur dioxide

Question 6

what is meant by the term amphoteric

Answer 6

It is a substance that can act as either an acid or a base

Question 7

what type of oxide is Mg0

Answer 7

Magnesium oxide

Question 8

define an ore

Answer 8

Ores are naturally occurring rocks that contain metal or metal compounds in sufficient amounts to make it worthwhile extracting them.

Question 9

what do you see when potassium reacts with water

Answer 9

A fire

Question 10

lithium is less reactive than potassium, how would your observations differ

Answer 10

lithium floats and fizzes

Question 11

Calcium reacts with water with lots of fizzing and turns universal indicator blue. what does this show ?

Answer 11

That its an alkali

Question 12

under what condition does magnesium react with water?

Answer 12

At high temperatures

Question 13

when magnesium is added to copper sulphate

Answer 13

the copper sulphate will turn colourless to a magnesium sulphate solution and form a reddish brown copper powder.

Question 14

What is the word equation for copper sulfate and magnesium

Answer 14

Copper II sulfate (aq) + Magnesium(s) –> Magnesium sulfate (aq) + Copper (s)

Question 15

what is the balanced symbol equation for iron and carbon

Answer 15

2FE203 + 3C > 4Fe + 3CO2

Question 16

Why is pure iron soft

Answer 16

This is because the atoms of pure iron are arranged in a standard manner

Question 17

What is an alloy

Answer 17

a metal made by combining two or more metallic elements

Question 18

Why Is Steel Better Than Iron?

Answer 18

Steel is better than iron because it is durable, strong, stable and it is also environmentally friendly

Question 19

What is meant by a shape memory alloy

Answer 19

a shape-memory alloy is an alloy that remembers its original shape: returning to the pre-deformed shape when heated

Question 20

What Are the Uses of Smart Alloys?

Answer 20

smart alloys are used in aircrafts to reduce the aircraft’s engine noise

Question 21

2 properties of transition metals

Answer 21

they form coloured compounds

they are good conductors of heat and electricity

Question 22

Why are new ways of mining copper being developed

Answer 22

because We are running out of ores rich in copper.

Question 23

why is aluminium extraction very expensive

Answer 23

because of the amount of electricity used up in the extraction process.

Question 24

what is the test for the presence of oxygen

Answer 24

rags

Question 25

define oxidation and reduction in terms of oxygen

Answer 25

Oxidation is gain of oxygen.

Reduction is loss of oxygen.

Question 26

what is necessary for iron to rust

Answer 26

Iron must react with oxygen