Pick out
Compound + element ⟶ compound type of combination reaction

(a)

PCl₅ ⟶ PCl₃ + Cl₂

(b)

Mg + O₂ ⟶ 2MgO

(c)

PCl₃ + Cl₂ ⟶ PCl₅

(d)

2Na + Cl₂ ⟶ 2NaCl

Pick out a chemical reaction which is not feasible

(a)

2NaCI ⟶ 2Na + Cl₂

(b)

2NaCI + F ⟶ 2NaF + Cl₂

(c)

2NaF + Cl₂ ⟶ 2NaCI + F

(d)

NaOH + HCI ⟶ NaCl + H₂O

Pick out the metal that displaces hydrogen from hydrochloric acid.

(a)

Zinc

(b)

Silver

(c)

Copper

(d)

Gold

Which among the following is not a balanced equation?

(a)

Fe + Cl₂ ⟶ FeCl₃

(b)

Zn + S ➝ ZnS

(c)

CaCO₃ ➝ CaO + CO

(d)

Fe + CuSO₄ ⟶ FeSO₄ + Cu

Acids have pH

(a)

less than 7

(b)

greater than 7

(c)

equal to 7

(d)

less than 14

What is activation energy?

Define concentration

What is balanced chemical reaction?

What is acid rain?

What are called thermolysis reactions?

Explain the types of double displacement reactions with examples.

How does pH play an important role in everyday life?

What is a chemical equilibrium? What are its characteristics?

A solid compound ‘A’ decomposes on heating into ‘B’ and a gas ‘C’. On passing the gas ‘C’ through water, it becomes acidic. Identify A, B and C.

Can a nickel spatula be used to stir copper sulphate solution? Justify your answer.

The hydroxide ion concentration of a solution is 1 × 10^–11M. What is the pH of the solution?