A synthesis reaction takes place when carbon monoxide and hydrogen gas react to form methanol.

[tex] CO + 2H_2 \rightarrow CH_3OH [/tex]

How many grams of methanol are produced when 2.9 grams of carbon monoxide reacts with 0.50 grams of hydrogen?

A. 3.2 grams
B. 3.6 grams
C. 4.0 grams
D. 6.0 grams



Answer :

Let's go through the problem step by step to find out how many grams of methanol are produced when 2.9 grams of carbon monoxide reacts with 0.50 grams of hydrogen gas.

### Step 1: Calculate the moles of each reactant

First, we need the molar masses of the reactants and products:
- Molar mass of CO (Carbon Monoxide) = 28 g/mol
- Molar mass of H₂ (Hydrogen Gas) = 2 g/mol
- Molar mass of CH₃OH (Methanol) = 32 g/mol

#### Moles of CO:
[tex]\[ \text{Moles of CO} = \frac{\text{Mass of CO}}{\text{Molar Mass of CO}} = \frac{2.9 \, \text{g}}{28 \, \text{g/mol}} \approx 0.10357 \, \text{moles} \][/tex]

#### Moles of H₂:
[tex]\[ \text{Moles of H₂} = \frac{\text{Mass of H₂}}{\text{Molar Mass of H₂}} = \frac{0.50 \, \text{g}}{2 \, \text{g/mol}} = 0.25 \, \text{moles} \][/tex]

### Step 2: Determine the limiting reactant

The given reaction is:
[tex]\[ CO + 2 H_2 \rightarrow CH_3OH \][/tex]

This tells us that 1 mole of CO reacts with 2 moles of H₂ to produce 1 mole of CH₃OH.

From our calculations:
- Moles of CO = 0.10357
- Moles of H₂ = 0.25

Now we check if we have enough H₂ to react with all the CO:
[tex]\[ \frac{0.25 \, \text{moles of H₂}}{2} = 0.125 \, \text{moles CO needed} \][/tex]

Since 0.10357 moles of CO is less than 0.125 moles (the moles of CO needed), CO is the limiting reactant.

### Step 3: Calculate the moles of methanol produced

Given that CO is the limiting reactant and reacts in a 1:1 molar ratio with CH₃OH, the moles of CH₃OH produced will be equal to the moles of CO:
[tex]\[ \text{Moles of CH₃OH} = \text{Moles of CO} = 0.10357 \][/tex]

### Step 4: Calculate the grams of methanol produced

Finally, we convert moles of methanol to grams:
[tex]\[ \text{Mass of CH₃OH} = \text{Moles of CH₃OH} \times \text{Molar Mass of CH₃OH} = 0.10357 \, \text{moles} \times 32 \, \text{g/mol} \approx 3.3143 \, \text{grams} \][/tex]

Thus, the mass of methanol produced is approximately 3.31 grams. None of the given answer choices exactly match this value, but the closest option is 3.2 grams.