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At 25.0°C the Henry's Law constant for dinitrogen monoxide (N2O) gas in water is 0.025 M/atm.

Calculate the mass in grams of N2O gas that can be dissolved in 325. mL of water at 25.0°C and a N2O partial pressure of 0.69 atm.
Be sure your answer has the correct number of significant digits.

1 Answer

10 votes

Answer:

The mass in grams of N₂O gas that can be dissolved is 0.18 g

Step-by-step explanation:

The solubility of a gas is proportional to the partial pressure of that gas, over a determined solvent. That's what Henry's law states. We see the formula:

S = K . Pp

Where S is solubility and K is Henry's constant. This specific for each gas and each temperature, while Pp means partial pressure.

We replace data:

S = 0.025 M/atm . 0.69atm

S = 0.01725 M

This is the solubility of the gas, so now, we need to know what mass of gas is solubilized. We convert the moles, with the volume of water.

0.01725 mol/L . 0.235 L = 4.05×10⁻³ moles

Now, we determine the mass in grams: 4.05×10⁻³ mol . 28 g / 1mol =

0.1782 g

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