Question

Dinitrogen difluoride gas is collected at in an evacuated flask with a measured volume of . When all the gas has been collected, the pressure in the flask is measured to be .

Answer 1

Here is the correct and the complete question

Dinitrogen difluoride gas is collected at 22.0°C in an evacuated flask with a measured volume of 25.0L. When all the gas has been collected, the pressure in the flask is measured to be 0.170atm. Calculate the mass and number of moles of dinitrogen difluoride gas that were collected. Be sure your answer has the correct number of significant digits.

Answer:

number of moles of dinitrogen difluoride gas = 0.1757 mol

mass = 12g

Explanation:

Given that;

Temperature (T) = 22.0°C ; to kelvin, we have:

                           = 22.0 + 273 k

                           = 295 k

Volume (V) = 25.0 L

Pressure (P) = 0.170 atm

Rate Constant (R) = 0.082 L mol/atm k

We are to find the number of moles and the mass of dinitrogen difluoride gas that were collected.

Using Ideal Gas Equation : PV= nRT   to find the numbers of moles of  dinitrogen difluoride gas that were collected.

n = $\frac{PV}{RT}$

n = $\frac{0.170*25.0}{0.082*295}$

n = $\frac{4.25}{24.19}$

n = 0.1757 mol

To find the mass of dinitrogen difluoride gas that were collected, we have;

no of moles= $\frac{mass}{molarmass}$

since no of moles of dinitrogen difluoride (N₂F₂) = 0.1757 mol

molar mass of dinitrogen difluoride (N₂F₂) = 66.01 $\frac{g}{mol}$

∴ mass = no of moles × molar mass

            = 0.1757 mol × 66.01 $\frac{g}{mol}$

            = 11.598 g

            ≅ 12g