IGCSE - C6 - Chemical reactions

What are the common symbols used in chemical equations to represent solid, liquid, gas, and aqueous solutions?

• (b)

• (s), (l), (g), (aq)

• (c)

• (a)

What type of reaction is

4Fe+3O₂​→2Fe_2​O₃​

• Synthesis

• Single replacement

• Double replacement

• Combustion

The number in front of a compound or element is a 

• Subscript
• Coefficient
• Superscript
• Charge

Identify the reaction: 2Al + Fe₂O₃ -----> Al₂O₃ + 2Fe

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

• Combustion

Balance the following equation:

__ KOH + __ HBr → __ KBr + __ H₂O

• 8, 8, 2, 2

• 1, 1, 1, 1

• 4, 2, 2, 4

• 2, 2, 2, 2

Balance the equation.

__ N₂ + __ H₂ → __ NH₃

_{The number are shown in order from left to right for the blanks.}

• 2, 3, 1

• 2, 1, 3

• 3, 1, 2

• 1, 3, 2

Balance the following equation:

__ Al(OH)₃ + __ HBr → __ AlBr₃ + __ H₂O

_{The number are shown in order from left to right to be inserted the blanks.}

• 1, 1, 3, 3

• 1, 3, 1, 3

• 3, 1, 3, 1

• 3, 3, 1, 1

The number of atoms of  N (nitrogen) in 3N₂O₅ is

• 2
• 5
• 6
• 15

Which of these is a chemical reaction?

• Boiling water
• Melting aluminum
• Crushing a piece of chalk
• Cooking an egg

Which of these is NOT a chemical reaction?

• Two liquids mix to give a new color
• Two gases react to make a liquid
• A liquid and a solid mix to make a gas
• Melting gold coins