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Topic 2 Element, compounds and mixtures

Last updated about 2 months ago
14 questions
1

write the method

1

write the method

1

write the method

1

write the method

1

Which of the mixtures P, Q, R or S contains an undissolved solid?

2

Pure dry crystals of magnesium nitrate can be obtained from magnesium nitrate solution by crystallisation.
These steps describe the method, but the steps are in the wrong order.
A allow the solution to cool to room temperature
B heat the solution to evaporate some of the water
C pour the mixture of crystals and solution through filter paper
D put the crystals in a warm place to dry
E dip a glass rod into the solution to see if crystals form
Write a letter in each box to show the correct order.
One has been done for you.
_ E _ _ _

5
Rock salt is a mixture of salt and sand. Crystals of pure salt can be obtained from rock salt by using the method below. Use words from the box to complete the sentences. You may use each word once, more than once or not at all.

Grind the rock salt into a fine powder.
Add the powder to hot water and stir to __________ the salt.
Filter the mixture. The salt __________ passes through the filter paper leaving behind the sand.
Boil the filtrate to __________ some of the water.
Leave the saturated solution to cool so that __________of salt form.
Finally, __________ the cold mixture to separate the crystals from the remaining solution.
This is a description of how the orange colouring can be extracted from rose petals.
Ɣ crush the petals using a pestle and mortar
Ɣ add the crushed petals to some ethanol in a beaker
Ɣ heat to about 60oC and stir to produce an orange solution
Ɣ separate the orange solution from the petals
1

Suggest why ethanol is used instead of water

1

Ethanol is a flammable liquid. Suggest how it could be heated safely.

1

How could the orange solution be separated from the petals?

2

see the image

6
Use words from the box to complete the sentences. Each word may be used once, more than once or not at all.


In Step 1, the mixture of salt and sand is placed in a __________ containing __________ and stirred with a __________
In Step 2, the mixture from Step 1 is poured through a __________ into a __________
In Step 3, the liquid is transferred to a basin to allow the__________
1

What should be placed in A before the mixture from Step 1 is poured through it?

1

What is the solid removed in Step 2?