Question

Q15- Consider reaction: P(s) + O₂(g) → P₄O₁₀(s). Moles of O₂(g) needed to balance equation will be
A) 1
B) 3
C) 5
D) 7


Q16- Consider reaction: Na(s) + O₂(g) → Na₂O. Moles of oxygen needed to balance equation are
A) 1
B) 2
C) 3
D) 4

Answer 1

Answer:

15.C).5

16.B).2

hope it helps

Answer 2

15. The correct option is C 5.

• The given reaction is -

P(s) + O₂(g) → P₄O₁₀(s).

• To balance the reaction we need 4 moles of phosphorus and 5 moles of oxygen and these reactants react to form 1 mole of phosphorus pentoxide.
• Thus the balanced reaction is-

4P(s) + 5O₂(g) → P₄O₁₀(s).

• So, 5 moles of oxygen needed to balance equation.

16.The correct option is A 1.

• The given reaction is -

Na(s) + O₂(g) → Na₂O.

• To balance the reaction we need 4 moles of sodium and 1 mole of oxygen and these reactants react to form 2 moles of sodium superoxide.
• Thus the balanced reaction is-

4Na(s) + O₂(g) → 2Na₂O.

• So, 1 mole of oxygen needed to balance equation.