find the relative formula mass (Mr) of water. ( H20)
Responda
18
24
36
72
Questão 2
Questão
calculate the percentage of nitrogen in NH3.
Responda
82.4
78
34.6
Questão 3
Questão
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?
Responda
True
False
Questão 4
Questão
What are the advantages of hard water?
Responda
Prevention of heart disease.
it makes you feel happy
it contains minerals which may be good for your health.
Questão 5
Questão
If I add soap to water and it easily forms a lather, is it hard or soft water?
Responda
Hard water
Soft water
Questão 6
Questão
Which compounds are dissolved into temporary hard water?
Responda
Magnesium hydrogen carbonate and Calcium hydrogen carbonate.
Magnesium sulfate and calcium sulfate.
Questão 7
Questão
when boiling temporary hard water, what is the product it forms?
Responda
rust
limescale
nasty worms
Questão 8
Questão
Name the disadvantages of hard water.
Responda
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.