Manipulative skills

Manipulative skills in chemistry internal assessment

Manipulative skills are assessed summatively. This means that one overall mark will be given. The skills

assessed should cover most of the two-year course, and the mark given should reflect the student’s general

ability near the end of the course. This mark is not an average nor does it relate to a given investigation. It is

important therefore that the scheme of work sets the students a variety of tasks and that they carry out a

range of different techniques. The examples below are suggestions to aid assessment of manipulative skills

and are not considered to be a prescribed list.

Note: No supporting evidence is required for moderation of manipulative skills.

Aspect 1: Following instructions

The student:

• reads/listens to instructions before asking for help

• only starts the investigation after having read/listened to all the instructions

• is able to follow a sequence of several written or verbal instructions with little

assistance.

Aspect 2: Carrying out techniques

Measuring volume

The student:

• uses a suitable cylinder/pipette/burette size

• does not overfill cylinder/pipette/burette

• places his/her eyes at the height of the meniscus.

Measuring mass

The student:

• handles the balance appropriately when transporting it

• adjusts the balance to zero before starting

• uses a suitable container for the substance to be measured.

Measuring temperature

The student:

• leaves his/her thermometer in a safe place when it is not in use

• refrains from touching the sides of the container with the thermometer when

measuring the temperature of a liquid

• leaves the thermometer in the liquid when measuring the temperature of that liquid.

(Vacuum) filtering

The student:

• folds/places the filter paper correctly

• uses equipment/filter paper of adequate size

• adds a reasonable amount of liquid to the funnel.

Making solutions

The student:

• uses a funnel to add the solid to the volumetric flask

• washes the container containing the solid several times and adds the water to the

volumetric flask

• carefully adds water to the mark.

Titration

The student:

• makes one trial before taking measurements

• takes at least three measurements

• takes care towards the end of the titration.

Assembling equipment

The student:

• ensures that different parts are clamped safely together without forcing the glass

• uses anti-bumping granules for boiling liquid

• chooses the correct size/shape of flasks

• places the thermometer at an adequate height

• connects the cooling water adequately.

Collection of gas

The student:

• takes care that the assembly is airtight

• takes care that the equipment does not contain air before starting.

Setting up electrical circuits

The student:

• connects up a circuit without help

• connects the ammeter in series and the voltmeter in parallel

• connects the positive side of the ammeter/voltmeter to the positive side of the power

supply

• uses a suitable scale.

Aspect 3: Working safely

The student:

• always wears safety clothing appropriate to the task, such as eye protection, lab

coats and gloves

• pays proper attention to written or verbal safety instructions and hazard symbols

• lights and uses the Bunsen burner safely

• places flammable substances far away from flames

• takes care, when heating, that the test tube does not point at other students

• takes care that the test-tube holders are not in the flame

• ensures that solutions are not heated to complete dryness

• places hot equipment on heat mats

• uses the fume cupboard for all poisonous volatile liquids

• washes his/her hands after using toxic substances in the laboratory

• takes care not to mix spatulas for different chemicals, or caps off different bottles

• leaves glassware on solid surfaces and ensures that glassware cannot be knocked or

roll off the surface

• reports when equipment has been broken

• avoids wasting chemicals

• cleans spilled chemicals or broken glassware immediately

• washes and tidies up the equipment after use

• disposes of chemicals in a suitable manner

• shows awareness of the impact of chemicals on the environment.