Question

Which of the following is a correctly balanced equation?

1) 0 P4 + 6 H₂ → 4 PH3
2) P4 + 6 H₂ → 4 PH3
3) 2 P4 + 6 H₂ → 8 PH3
4) 4 P4 + 6 H₂ → 4 PH3
5) P4 + 3 H₂ → PH3

Answer 1

Option 2: P4 + 6 H2 → 4 PH3 is the correctly balanced equation, satisfying the law of conservation of matter with an equal number of phosphorus and hydrogen atoms on both sides.

Step-by-step explanation:

The student asked which of the following is a correctly balanced chemical equation for the reaction of phosphorus (P4) with hydrogen gas (H2) to produce phosphine (PH3):

1. 0 P4 + 6 H2 → 4 PH3
2. P4 + 6 H2 → 4 PH3
3. 2 P4 + 6 H2 → 8 PH3
4. 4 P4 + 6 H2 → 4 PH3
5. P4 + 3 H2 → PH3

The correct answer is Option 2: P4 + 6 H2 → 4 PH3. When balancing chemical equations, the law of conservation of matter must be satisfied, which means there must be the same number of each type of atom on both sides of the equation. In this case, each side of the equation has 4 phosphorus atoms and 12 hydrogen atoms, making the equation balanced.