find the relative formula mass (Mr) of water. ( H20)
Answer
18
24
36
72
Question 2
Question
calculate the percentage of nitrogen in NH3.
Answer
82.4
78
34.6
Question 3
Question
The moles of an element = mass of that element/ the relative atomic mass of that element. Sarah has 48 grams of magnesium, she believes she has two moles, is she right?
Answer
True
False
Question 4
Question
What are the advantages of hard water?
Answer
Prevention of heart disease.
it makes you feel happy
it contains minerals which may be good for your health.
Question 5
Question
If I add soap to water and it easily forms a lather, is it hard or soft water?
Answer
Hard water
Soft water
Question 6
Question
Which compounds are dissolved into temporary hard water?
Answer
Magnesium hydrogen carbonate and Calcium hydrogen carbonate.
Magnesium sulfate and calcium sulfate.
Question 7
Question
when boiling temporary hard water, what is the product it forms?
Answer
rust
limescale
nasty worms
Question 8
Question
Name the disadvantages of hard water.
Answer
more soap is needed to form a suitable lather.
It is bad for your eyes
it produces scum which is difficult to clean
Hard water cannot be used for industrial processes like dying materials.