Experimental Chemistry – Quiz 1

 The diagram shows a simple laboratory apparatus for the preparation and collection of dry gas.

What is the gas?

Q2: A mixture containing equal volumes of two liquids that mix completely but do not react together is placed in the apparatus shown and heated until the thermometer first shows a steady reading. At which position will there be the highest proportion of the liquid with the higher boiling point?

Q3: During a titration experiment, an acid is transferred into a burette.
The diagrams show part of the burette at the start of the titration and at the end-point.

What is the volume of acid used during the titration?

Q4: When calcium carbonate is added to dilute hydrochloric acid, carbon dioxide gas is released.
Three sets of apparatus are shown.

Which sets of apparatus are suitable, together with a stop-watch, for following the rate of this
reaction?

Q5: Chromatography can be used to separate and identify dyes present in a mixture.
Which statement is correct?

Q6: Petroleum (crude oil) is separated into useful fractions by fractional distillation. The positions at which fractions X and Y are collected from the fractionating column are shown.

Which statement is correct?

Q5: Aqueous zinc chloride is tested with various reagents.
Which observation is correct?

Q8. A drop of liquid bromine is placed in the bottom of a gas jar. Brown fumes of bromine vapour slowly spread through the covered gas jar.
Why does this happen?

Q9. Copper(II) sulfate crystals are separated from sand using the four processes listed below.  In which order are these processes used?

Q10. The diagrams show an experiment with aqueous ammonium chloride.

A gas, Y, is produced and the litmus paper changes colour.  What are solution X and gas Y?

Q11. A student tested a solution by adding aqueous sodium hydroxide. A precipitate was not seen because the reagent was added too quickly.  

What could not have been present in the solution?

Q12: The concentration of aqueous sodium carbonate can be found by reaction with hydrochloric acid
of known concentration. The indicator methyl orange is used.

Which items of equipment are needed?

Q13: The diagrams show three stages, 1, 2 and 3, used in the preparation of a salt.

Which row correctly shows the solubilities both of the reactants and of the salt formed in this
preparation?

Q14: Which is a pure compound?

Q15: The diagram shows some of the changes of state.