For the reaction 2P + Q rArr R, 8 mol of p and 5 mol of Q will produce:

Options

A. 8 mol of R
B. 5 mol of R
C. 4 mol of R
D. 13 mol of R

Answer

To solve the problem of how many moles of R will be produced from the reaction \(2P + Q \rightarrow R\) given 8 moles of P and 5 moles of Q, we can follow these steps:

### Step 1: Write down the balanced chemical equation.
The balanced equation is:
\[ 2P + Q \rightarrow R \]

### Step 2: Determine the stoichiometric ratios.
From the balanced equation, we see that:
- 2 moles of P react with 1 mole of Q to produce 1 mole of R.

### Step 3: Calculate the amount of Q needed for the available P.
Since we have 8 moles of P, we can find out how many moles of Q are needed:
- For 2 moles of P, we need 1 mole of Q.
- Therefore, for 8 moles of P, we need:
\[ \text{Moles of Q needed} = \frac{8 \text{ moles of P}}{2} = 4 \text{ moles of Q} \]

### Step 4: Compare the available moles of Q with the required moles.
We have 5 moles of Q available, but we only need 4 moles of Q to react with 8 moles of P. This means that Q is in excess.

### Step 5: Identify the limiting reactant.
Since we need 4 moles of Q to react with 8 moles of P and we have more than enough Q (5 moles), P is the limiting reactant.

### Step 6: Calculate the amount of R produced.
According to the stoichiometry of the reaction:
- 2 moles of P produce 1 mole of R.
- Therefore, 8 moles of P will produce:
\[ \text{Moles of R produced} = \frac{8 \text{ moles of P}}{2} = 4 \text{ moles of R} \]

### Final Answer:
The reaction will produce **4 moles of R**.

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