Practical techniques

A student was provided with only a thermometer, a stopwatch and a beaker. What could the student measure?

• 30oC

• 20 seconds

• 20.5 ml

• 24g

• W

• X

• Y

• Z

Which of the following is true about chromatography?

• baseline is drawn by ink

• chromatography is used to separate a mixture of a liquid and a solid

• retention time = distance moved by solvent : distance moved by compound

• baseline is drawn by a pencil

Which is the best way to separate a mixture of water and sand?

• evaporation

• filtration

• distillation

• condensation

Which of the following is necessary to separate a substance from a solution by crystallization?

• the solution is colorful

• the solution is staturated

• the solution is extremely dilute

• the temperature is 0oC

Which method is used to separte a mixture of water and ethanol?

• crystallisation

• simple distillation

• fractional distillation

• filtration

Which apparatuses are usually used to measure a liquid volume?

• 
• 
• 
• 

During a reaction, the following changes take place: the temperature rises; a gas is given off. Which apparatuses are required to measure the rate of this reaction?

• thermometer

• gas syringe

• stopclock

• balance

• a homogeneous mixture

• a heterogeneous mixture

The diagram shows a chromatography of four substances. Which substance has an Rf value of approximately 0.32?

• A

• B

• C

• D