Topic 5 - Separate Chemistry 1 (Unfinished)

Question 1

Where do transition metals sit on the periodic table?

Answer 1

In the middle

Question 2

Give some common examples of transition metals

Answer 2

Iron, copper, zinc, gold, silver, mercury, titanium

Question 3

Give some properties of transition metals

Answer 3

Relatively hard, strong and shiny

Malleable and conduct heat and electricity

High densities and high melting points (exception of Hg)

Question 4

Are transition metals good catalysts?

Answer 4

Yes - for example iron is used in the Haber process for making ammonia

Vanadium pentoxide (V205) is used for making sulfuric acid in the Contact process

Question 5

Transition metal compounds are usually colourless

True or false?

Answer 5

False - the compounds of transition metals are colourful

For example, iron ions (Fe 2+) are usually light green, and others (Fe 3+) are orange/brown

Question 6

What are alloys?

Answer 6

Alloys are a mixture of two or more metals

Question 7

What is an advantage of using alloys rather than pure metals?

Answer 7

Alloys are harder than pure metals

Question 8

Why are alloys stronger than pure metals?

Answer 8

Pure metals are malleable (easily shaped) because they have a regular arrangement of identical atoms. These layers can easily slide over each other. This means that some metals are not strong enough for certain uses

Different elements have different sized atoms. E.g. when carbon is added to iron, the smaller carbon atoms will make it harder for the layers to slide as there is no regular arrangement, making them much harder

Question 9

Why are pure metals sometimes not suitable for certain uses?

Answer 9

E.g. iron can corrode fairly quickly, but steel is less likely to rust, making it more suitable

Steel is harder than iron, and is also stronger as long as carbon content does not exceed 1%

Question 10

Give two other examples of alloys in everyday life

Answer 10

Copper + Tin = Bronze - bronze is harder than copper. it is used to make medals, decorative ornaments and statues

Copper + Zinc = Brass - brass is more malleable than bronze and is used in situations where lower friction is required, such as in water taps and door fittings

Question 11

What type of reaction if the rusting of iron?

Answer 11

A redox reaction

Question 12

Give three ways that you can prevent iron from rusting

Answer 12

1. Oiling or greasing can be used when moving parts are involved, like on bike chains
2. Galvanisation
3. Sacrifical protection

Question 13

What is galvanisation?

Answer 13

An example of sacrificial protection, where a coat of zinc is put onto an iron object