Suggest what might happen to the experiment if you used a lot more magnesium and acid, so that more than 100cm^3 of hydrogen gas was formed. what could be done to reduce the risk of an accident if more than 100cm^3 of hydrogen was produced?

Wear eye protection throughout. Ensure that there are no naked flames.

Magnesium ribbon, Mg(s) – see CLEAPSS Hazcard HC59a. The magnesium ribbon should be clean and free from obvious corrosion or oxidation. Clean if necessary by rubbing lengths of the ribbon with fine sandpaper to remove the layer of oxidation.

Hydrochloric acid, HCl(aq) – see CLEAPSS Hazcard HC47a and CLEAPSS Recipe Book RB043. The hydrochloric acid should be about 1M for a reasonable rate of reaction. Each experiment run will need 50 cm3. Though low hazard, eye protection is necessary as you may get a spray as tiny bubbles burst.

Hydrogen gas, H2(g) (EXTREMELY FLAMMABLE) – see CLEAPSS Hazcard HC048. Ensure that all naked flames are extinguished, and that there are no other sources of ignition available to students.

Procedure

Measure 50 cm3 of 1M hydrochloric acid using one of the measuring cylinders. Pour the acid into the 100 cm3 conical flask.

Set up the apparatus as shown in the diagram. Half fill the trough or bowl with water.

Fill the other measuring cylinder with water, and make sure that it stays filled with water when you turn it upside down.

Explanation:

Hydrogen gas (extremely flammable) is generated in the experiment. Students should not have access to any source of ignition.

the mantle

explanation:

earth is divided into three layers: the crust or the outermost layer on which we live; the underlying, middle layer - the mantle - and the core (the innermost layer of earth).