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