Chemical Reactions Quiz

Which of the following represents a synthesis reaction?

• H₂+O₂→H₂O

• CaCO₃→CaO+CO₂

• NaCl+AgNO₃→NaNO₃+AgCl

• Zn+HCl→ZnCl₂+H₂

Identify the product(s) of the decomposition reaction: 2H₂O₂→?

• H₂O+O₂

• H₂O₂

• H₂+O₂

• H₂O

What is the charge of an atom that has lost two electrons?

• -2

• +2

• 0

• -1

If a non-metal has a valency of -1, what does this imply about its electron configuration?

• It has gained 1 electron

• It has lost 1 electron

• It has gained 2 electrons

• It has lost 2 electrons

Balance the following chemical equation: C₃H₈+O₂→CO₂+H₂O

• C₃H₈+5O₂→3CO₂+4H₂O

• C₃H₈+4O₂→3CO₂+5H₂O

• C₃H₈+6O₂→4CO₂+4H₂O

• C₃H₈+5O₂→4CO₂+3H₂O

According to the law of conservation of mass, which of the following must be true for a balanced chemical equation?

• The total mass of reactants must equal the total mass of products

• The number of molecules must be the same on both sides

• The number of electrons must be equal on both sides

• The number of atoms of each element must be the same on both sides

Using the criss-cross method, what is the correct chemical formula for a compound formed between magnesium (Mg) and chlorine (Cl)?

• MgCl

• MgCl₂

• Mg₂Cl

• Mg₂Cl₂

Write a balanced chemical equation with state symbols for the reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl) to form water (H₂O) and sodium chloride (NaCl).

• NaOH(aq)+HCl(aq)→NaCl(s)+H₂O(l)

• NaOH(aq)+HCl(aq)→NaCl(aq)+H₂O(l)

• NaOH(s)+HCl(l)→NaCl(aq)+H₂O(g)

• NaOH(aq)+HCl(aq)→NaCl(s)+H₂O(g)

If an atom has an atomic number of 15 and a mass number of 31, how many neutrons does it have?

• 31

• 16

• 15

• 14

Which type of reaction is represented by the following equation: Zn(s)+CuSO₄(aq)→ZnSO₄(aq)+Cu(s)?

• Synthesis

• Decomposition

• Single displacement

• Double displacement