NOVEMBER 2023-CJEMISRTY

• A

• B

• C

• D

Which substance is a pure compound?

• air

• brass

• ethanol

• petroleum

The Group I element potassium forms an ionic bond with the Group VII element fluorine.

Which two ions are produced?

• K⁺ and F⁺

• K⁺ and F^-

• K^- and F^-

• K^- and F⁺

• A

• B

• C

• D

Fluorine, F₂, is in the same group of the Periodic Table as chlorine, Cl₂.

Which diagram represents the arrangement of the outer-shell electrons in a molecule of fluorine?

• 
• 
• 
• 

Which use of graphite depends on the layers of carbon atoms being able to slide over each

other?

• cutting tools

• electrodes

• jewellery

• lubricant

Which equations are balanced?

• 1 and 2

• 1 and 4

• 2 and 3

• 3 and 4

The equation for the combustion of methane is shown.

CH₄ + 2O₂ → CO₂ + 2H₂O

Which mass of methane produces 36 g of water?

• 16 g

• 18 g

• 32 g

• 64 g

• A

• B

• C

• D

Which statement about a hydrogen-oxygen fuel cell in a car is correct?

• The fuel cell produces heat, which powers the car.

• The fuel cell is supplied with hydrogen directly from the air.

• The only emission from the fuel cell is nitrogen gas, which is non-polluting.

• The fuel cell produces electricity, which powers an electric motor.