Calculate the pressure in a 10 L vessel containing 51 g of ammonia and 7 g of nitrogen at 50 degrees Celsius.

Let’s use the Mendeleev-Clapeyron equation: p * V = n * R * T, p = n * R * T / V
It is known that gases occupy the entire volume provided to them, which means:
V = 10 l = 0.01 m3
The temperature in this equation should be in K, T = 273 + 50 = 323.
Let us find the amount of substances n = m / M, where m is the mass of the corresponding gas, M is the molar mass of the corresponding gas.
n (NH3) = 51/17 = 3 mol
n (N2) = 7/28 = 0.25 mol
R = 8.31 J / (mol * K)
p = (3 +0.25) * 8.31 * 323 / 0.01 = 872342.25 Pa = 0.87 MPa