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What volume (in liters) of carbon monoxide gas, measured at a temperature of 212 K and a pressure of 676 mm Hg, is required to synthesize 19.3 g of methanol. How many liters of oxygen (at STP) are required to form 12.5 g of H2O ? Show your work

Respuesta :

Answer:

For 1: The volume of carbon monoxide required to produce given amount of methanol is 11.9 L.

For 2: The volume of oxygen required to form given amount of water is 7.77 L.

Explanation:

  • For 1:

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]     ......(1)

For methanol:

Given mass of methanol = 19.3 g

Molar mass of methanol = 32 g/mol

Putting values in above equation, we get:

[tex]\text{Moles of methanol}=\frac{19.3g}{32g/mol}=0.603mol[/tex]

The chemical reaction of formation of methanol from carbon monoxide follows:

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

By Stoichiometry of the reaction:

1 mole of methanol is produced from 1 mole of carbon monoxide.

so, 0.603 moles of methanol will be produced from = [tex]\frac{1}{1}\times 0.603=0.603mol[/tex] of carbon monoxide.

To calculate the volume of carbon monoxide, we use the equation given by ideal gas:

PV = nRT

where,

P = Pressure of carbon monoxide = 676 mmHg

V = Volume of carbon monoxide = ? L

n = Number of moles of carbon monoxide = 0.603 mol

R = Gas constant = [tex]62.3637\text{ L.mmHg }mol^{-1}K^{-1}[/tex]

T = Temperature of carbon monoxide = 212 K

Putting values in above equation, we get:

[tex]676mmHg\times V=\frac{19.3}{32g/mol}\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 212K\\\\V=11.79L[/tex]

Hence, the volume of carbon monoxide required to produce given amount of methanol is 11.9 L.

  • For 2:

Calculating the moles of water by using equation 1, we get:

Given mass of water = 12.5 g

Molar mass of water = 18 g/mol

Putting values in equation 1, we get:

[tex]\text{Moles of water}=\frac{12.5g}{18g/mol}=0.694mol[/tex]

The chemical reaction of formation of water from oxygen and hydrogen follows:

[tex]O_2+2H_2\rightarrow 2H_2O[/tex]

By Stoichiometry of the reaction:

2 moles of water is produced from 1 mole of oxygen gas.

so, 0.694 moles of water will be produced from = [tex]\frac{1}{2}\times 0.694=0.347mol[/tex] of oxygen gas.

At STP:

1 mole of a gas occupies 22.4 L of volume.

So, 0.347 moles of oxygen gas will occupy = [tex]\frac{22.4L}{1mol}\times 0.347mol=7.77L[/tex]

Hence, the volume of oxygen required to form given amount of water is 7.77 L.

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