Chemistry Quiz

Why should concentrated nitric acid be stored in a brown bottle?

• Because it is volatile.

• Because it is flammable.

• Because it would decompose under sunlight.

• Because it would react with oxygen in the air.

7.80 g of copper(II) sulphate crystals (CuSO4•5H2O) were dissolved to make 250.0 cm3 of solution. What is the molarity of the solution?

(Relative atomic masses: H = 1.0, O = 16.0, S = 32.1, Cu = 63.5)

• 0.125 mol dm-3

• 0.200 mol dm-3

• 1.250 mol dm-3

• 2.000 mol dm-3

A solution of sample X contains 4.81 × 10-4 mol dm-3 of hydrogen ions. What is the pH of the sample?

• 1.32

• 2.32

• 3.32

• 4.32

Which of the following liquids is miscible with water?

• Bromine

• Carbon disulphide

• Cyclohexane

• Ethanol

Which of the following hydroxides can dissolve in excess dilute sodium hydroxide solution?

• Copper(II) hydroxide

• Magnesium hydroxide

• Iron(III) hydroxide

• Zinc hydroxide

Which of the following pairs of solutions would NOT give a precipitate when mixed?

• K2CO3(aq) and MgCl2(aq)

• H2SO4(aq) and Ba(OH)2(aq)

• NH3(aq) and Pb(NO3)2(aq)

• Na2SO4(aq) and HCl(aq)

25.0 cm3 of water are mixed with 70.0 cm3 of 0.500 mol dm-3 nitric acid. What is the concentration of the diluted acid?

• 0.250 mol dm-3

• 0.368 mol dm-3

• 0.500 mol dm-3

• 0.679 mol dm-3

Consider the equation for the complete combustion of hexane

Which of the following combinations is correct?

w x y z

• 2 19 12 14

• 1 9 6 6

• 2 16 10 12

• 1 13 6 7

The structure of polystyrene is shown in the left:

What is the molecular mass of a polymer chain of polystyrene that made up of 7 000 repeating units?

• 520 000

• 455 000

• 546 000

• 728 000

Which of the following chemical species does NOT exist?

• OF2

• PCl3

• NCl5

• PCl5