Chem Study Camp Revision Quiz

‘Particles moving very slowly from an area of higher concentration to an area of lower concentration.’ Which process is being described?

• a liquid being frozen

• a solid melting

• a substance diffusing through a liquid

• a substance diffusing through the air

A student mixes 25 cm³ samples of dilute hydrochloric acid with different volumes of aqueous sodium hydroxide. In each case, the student measures the change in temperature to test if the reaction is exothermic. Which piece of apparatus is not needed?

• burette

• clock

• pipette

• thermometer

A sample contains a mixture of powdered limestone (calcium carbonate), sugar and wax. What is the correct way to obtain a pure sample of sugar?

• Dissolve the mixture in dilute hydrochloric acid, filter and wash the residue.

• Dissolve the mixture in hexane, filter and evaporate the filtrate.

• Dissolve the mixture in water, filter and evaporate the filtrate.

• Dissolve the mixture in water, filter and wash the residue.

The table shows information about four different particles. What are the values of W, X, Y, and Z?

• W = 11, X = 10, Y = 10,

  Z = 8

• W = 11, X = 11, Y = 8,

  Z = 10

• W = 12, X = 10, Y = 8,

  Z = 10

• W = 12, X = 11, Y = 10,

  Z = 8

In which ionic compound do the metal ion and the non-metal ion have the same electronic structure?

• CaO

• KBr

• MgO

• NaCl

The structure of methanal is shown. Which diagram shows the arrangement of outer shell electrons in a molecule of methanal?

• 
• 
• 
• 

Iron is a metal. Its structure consists of a giant lattice of positive ions in a ‘sea of electrons’. Which statements about solid iron are correct?

1. Iron conducts electricity because the electrons are free to move.

2. Iron conducts heat because the positive ions are free to move.

3. Iron has a high melting point due to the strong covalent bonds.

4. Iron is malleable because the layers of ions can slide over one another.

• 1 and 3

• 1 and 4

• 1 only

• 2, 3 and 4

Which sample contains the greatest number of molecules?

• 4 g of hydrogen

• 18 g of water

• 24 dm³ of oxygen

• 66 g of carbon dioxide

Sodium carbonate solution reacts with dilute hydrochloric acid. The equation for the reaction is shown.

Na₂CO₃(aq) + 2HCl(aq) → 2NaCl(aq) + CO₂(g) + H₂O(l)

Excess sodium carbonate is added to 10.0 cm³ of 0.10 mol/dm³ hydrochloric acid. Which volume of carbon dioxide gas is made?

• 12 cm³

• 24 cm³

• 12 000 cm³

• 24 000 cm³

Which experiment is the most exothermic?

• initial temperature 20°C, final temperature 5°C

• initial temperature 20°C, final temperature 32°C

• initial temperature 25°C, final temperature 12°C

• initial temperature 25°C, final temperature 34°C