Preparing Salts

Question 1

What is method 1?

Answer 1

• use a measuring cylinder to measure 25cm^3 of sulphuric acid
• pour the acid into a beaker
• set up Bunsen burner, tripod and gauze and heat the acid gently- do not let it boil
• turn off the Bunsen burner
• remove the beaker from the gauze and put on the heat-proof mat
• add magnesium and wait for it to stop reacting
• continue to add magnesium until no more will react
• filter off excess metal, collecting the filtrate in a evaporating basin
• heat the evaporating basin, do not boil until crystals appear on the edge
• leave the evaporating basin to cool and allow crystals to form
• filter out the crystals and dry on paper towel

Question 2

Method 1:Why is it important that you put the Bunsen burner out before you start adding the magnesium to the acid?

Answer 2

You’re producing hydrogen gas and it’s flammable

Question 3

Method 1:Why did you heat up the sulphuric acid?

Answer 3

To speed up the rate of the reaction

Question 4

Method 1:What two observations indicated that the magnesium had finished reacting?

Answer 4

It stopped fizzing, stopped producing hydrogen(no more bubbles), magnesium doesn’t dissolve