Adv Chem 2023 Sem 2 review

In the equation,          2Mg + O₂ ---> 2MgO, which are the reactants?

• Mg and O
• MgO
• Mg and MgO
• O and MgO

Balance this equation, Ca + H₂O --> CaO + H₂

• Ca + 2H₂O --> CaO + 2H₂
• 2Ca + H₂O --> CaO + H₂
• Its balanced as it is
• Cannot be balanced

What type of chemical reaction is this one?
Al(OH)₃ --> Al2O3  + H2O

• Decomposition
• Combustion
• Synthesis
• Single Replacement 

What type of chemical reaction is this one?
CUO + CO2 --> CuCO3

• Decomposition
• Combustion
• Synthesis
• Single Replacement 

What type of chemical reaction is this one?
Ca + MgCl2 --> CaCl2 + Mg

• Decomposition
• Combustion
• Synthesis
• Single Replacement 

What is a coefficient?

• The small number on the right of the chemical symbol.
• The large number to the left of a formula.

What coefficients are needed to correctly balance the equation?
_Bi   +   _O₂   >   _Bi₂O₃

• 3,2,3
• 2,3,2
• 4,3,2
• none of these

Why must chemical equations be balanced?

• So that the equation doesn't explode

• The reaction won't happen until it is balanced

• Based on the Law of Conservation of Matter, matter cannot be created or destroyed.

• Based on the Law of Conservation of Energy, energy cannot be created or destroyed.e

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.

• Coefficient
• reactant
• subscript
• product 

How many atoms of hydrogen (H), sulfur (S), and oxygen (O) are there in sulfuric acid (H₂SO₄)?

• H-6, S-4, O-4
• H-1, S-2, O-8
• H-2, S-1, O-4
• H-2, S-4, O-4