1. According to the reaction Ca3P2 + 6H2O → 3Ca(OH)2 + 2PH3, how many moles of phosphine are formed from 1 mole of calcium phosphide?
A.
1 mole
B.
2 moles
C.
3 moles
D.
6 moles
Correct Answer:
2 moles
Explanation:
The balanced equation shows that 1 mole of Ca3P2 produces 2 moles of PH3.
2. How many moles of water are required to react completely with 1 mole of Ca3P2 in the preparation of phosphine?
A.
2 moles
B.
3 moles
C.
6 moles
D.
9 moles
Correct Answer:
6 moles
Explanation:
From Ca3P2 + 6H2O → 3Ca(OH)2 + 2PH3, 1 mole of Ca3P2 requires 6 moles of water.
3. What is the mole ratio of Ca3P2 to PH3 in the reaction Ca3P2 + 6H2O → 3Ca(OH)2 + 2PH3?
A.
1:1
B.
1:2
C.
2:1
D.
3:2
Correct Answer:
1:2
Explanation:
The coefficients show that 1 mole of Ca3P2 produces 2 moles of PH3, giving a ratio of 1:2.
4. How many moles of calcium hydroxide are formed when 2 moles of Ca3P2 react completely with water?
A.
2 moles
B.
3 moles
C.
6 moles
D.
12 moles
Correct Answer:
6 moles
Explanation:
One mole of Ca3P2 forms 3 moles of Ca(OH)2. Therefore, 2 moles form 2 × 3 = 6 moles.
5. How many moles of Ca3P2 are needed to produce 4 moles of PH3?
A.
1 mole
B.
2 moles
C.
3 moles
D.
4 moles
Correct Answer:
2 moles
Explanation:
The reaction produces 2 moles of PH3 from 1 mole of Ca3P2. Thus, 4 moles of PH3 require 2 moles of Ca3P2.
6. Using the equation Ca3P2 + 6H2O → 3Ca(OH)2 + 2PH3, how many moles of PH3 are formed from 3 moles of Ca3P2?
A.
2 moles
B.
3 moles
C.
6 moles
D.
9 moles
Correct Answer:
6 moles
Explanation:
Each mole of Ca3P2 produces 2 moles of PH3, so 3 moles produce 3 × 2 = 6 moles.
7. In the reaction P4 + 3NaOH + 3H2O → PH3 + 3NaH2PO2, how many moles of phosphine are formed from 1 mole of P4?
A.
1 mole
B.
2 moles
C.
3 moles
D.
4 moles
Correct Answer:
1 mole
Explanation:
The balanced equation contains a coefficient of 1 for both P4 and PH3, so 1 mole of P4 forms 1 mole of PH3.
8. According to the reaction P4 + 3NaOH + 3H2O → PH3 + 3NaH2PO2, how many moles of NaOH are required for 2 moles of P4?
A.
2 moles
B.
3 moles
C.
6 moles
D.
9 moles
Correct Answer:
6 moles
Explanation:
The equation requires 3 moles of NaOH for 1 mole of P4. Therefore, 2 moles of P4 require 2 × 3 = 6 moles of NaOH.
9. How many moles of sodium hypophosphite, NaH2PO2, are formed when 1 mole of P4 reacts completely with sodium hydroxide and water?
A.
1 mole
B.
2 moles
C.
3 moles
D.
4 moles
Correct Answer:
3 moles
Explanation:
The balanced equation shows that 1 mole of P4 forms 3 moles of NaH2PO2 along with 1 mole of PH3.
10. If 0.5 mole of Ca3P2 reacts completely with water, how many moles of PH3 are produced?
A.
0.25 mole
B.
0.5 mole
C.
1 mole
D.
2 moles
Correct Answer:
1 mole
Explanation:
One mole of Ca3P2 produces 2 moles of PH3. Therefore, 0.5 mole produces 0.5 × 2 = 1 mole of PH3.
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