Practical skills 1: safety
Practical skills 2: Planning
Practical skills 3: Results
Practical skills 4: data analysis
Practical skills 5: Improvements
100

The use of which apparatus requires hair to be tied and goggles to be worn? 

The Bunsen burner.

100

Which apparatus can be used to quickly and simply measure a volume, but is less accurate than a burette?

The measuring cylinder.

100

What is the name given to the type of data that can be measured?

Quantitative data.

100

What is most commonly used to record observations in chemistry?

A table

100
A student uses a beaker to measure 30 cm3 of a solution. How could the precision and accuracy of his measurement be improved?

Use a measuring cylinder or a burette instead.

200

What is the name given to any chemical substance capable of causing harm to a person or the environment?

A chemical hazard

200

What is the name given to the variable you manipulate or vary in an experimental study to explore its effects?

The independent variable.

200

Give an example of qualitative data.

A colour change, the formation of a precipitate, smell...

200

On which axis of a graph, should the values of the independent variable be located?

The x-axis.

200

During titration, the end-point is usually identified through a change in colour. This is however a source of human error, why?

Because each individual perceives colour slightly differently, which affects the outcome of the experiment. 

300

Which hazard symbol is represented by red triangle/diamond surrounding a skull?


Toxic/poison hazard.

300

If you want to estimate the concentration of a NaOH solution, using a solution of H2SO4 of known concentration, what type of experiment would you carry out? 

A titration.

300

What can be done to spot and discard anomalous readings?

Taking repeated measurements.

300

In a graph, what is an ''outlier''?

It is a data point that doesn't fit the pattern shown by the other points on the graph.

300

In exam, when asked about ways to improve an experiment what can be a standard answer?

Repeat the experiment AND calculate the mean.

400

What should you be careful about when collecting a gas in a sealed container?

The container used for the collection of gas must be big enough for the amount of product that will be released, otherwise it may burst and damage the equipment.

400

What is the difference between precision and accuracy?

Precisions: how close to each other are repeated measurements.

Accuracy: how close a measurement is to the real value.

400

When carrying out a titration, what is the name given to the very first trial (1st titration), which aims to estimate the end-point?

The rough titration.

400

In exam, what should you do if you are asked to draw a ''line of best fit'' and the data points on your graph are not perfectly aligned?

A freehand continuous curve must be drawn. Never just connect the points like a ''dot-to-dot''.

400

In general, at least how many times should an experiment be repeated? and how many different values of independent variable should be investigated?

The experiment should be repeated at least 3 times (or 3 readings), and 5 different values of independent variable should be investigated at least.

500

If you spill a strong corrosive substance on a surface it is advised to neutralize it first with sodium bicarbonate; however, if the spill is on your skin, it is advised to wash it thoroughly with water. Why?

Because acid-base reactions are typically exothermic, which would increase the damage done to your skin.

500

Which apparatus uses vacuum to quickly carry out a filtration? 

the Büchner  Flask (+ Büchner funnel)

500

When taking readings from an apparatus filled with liquid, you must take the measurement from the bottom of the curve of the liquid. What is it called?

The meniscus.


500

What is the formula to calculate the slope of a graph?

slope = rise/run = (Y2 - Y1)/(X2 - X1)

500

A student is asked to use a mass balance to measure the mass of NaHCO3 contained in a stoppered container, as it will be used in an experiment. How should the student proceed?

First measure the mass of the container with NaHCO3 still inside.

Then measure the mass of the empty container.

Finally calculate the difference between the 2 masses, to know the mass of NaHCO3 used.