Researching Chemistry

Question 1

Key Scientific Apparatus

Answer 1

Beaker
Conical Flask
Measuring Cylinder
Evaporation Basin
Test Tube
Dropper
Funnel
Burette
Pipette
Delivery Tube
Thermometer

Question 2

Discuss when to use a Bunsen burner, heating mantle or water bath

Answer 2

Use a heating mantle when chemicals are flammable.

Water baths and heating mantles can be used to keep chemicals at a constant temperature.

Question 3

Discuss when to use a beaker, measuring cylinder or pipette

Answer 3

Beakers are used for rough measurements.

Measuring cylinders are more accurate but pipettes are used when accuracy is key (eg, for a titration).

Question 4

Describe how to make a standard solution

Answer 4

In exams, a common 3 mark question requires you to describe how a standard solution is made.

Accurately weigh the mass of the solute and add to a beaker.
Add a little distilled water to the beaker until the solute dissolves.
This solution is then added to a volumetric flask.
The beaker in then rinsed with more distilled water and the rinsing added to the volumetric flask (this can be repeated).
Distilled water is then added to the volumetric flask up to the mark.

Question 5

Describe distillation

Answer 5

Distillation is a technique used to separate two liquids in a solution.

The solution is heated up and the liquid with the lower boiling point is evaporated off.

It is then passed through a condenser where it condenses back to a liquid.

Question 6

Discuss methods of improving an experiment

Answer 6

Method of heating - water bath, heating mantle or Bunsen burner
Ways of removing inaccuracies
Methods of stopping heat being lost to surroundings - heat shield
Equipment that is used - especially when measuring (measuring cylinder or pipette)
Repeating to ensure reliable results

Question 7

State the meaning of the symbol: ±

Answer 7

± is the measure of uncertainty of results, for example when reading scales there is a degree of uncertainty (or inaccuracy) of the readings.