Question

В цилиндре под поршнем находится кислород. Определите массу кислорода, если известно, что работа, совершаемая при нагревании газа от 273к до 473к, равна 16кДж. Трение не учитывать.Ребятушки, буду крайне благодарна)

Answer 1

$A=VR(T2-T1)= \frac{mR(T2-T1)}{M} ; m= \frac{AM}{R(T2-T1)}$
, где M - молярная масса кислорода, T2 - 473K, T1 - 273K, A - 16000 Дж, R - универсальная газовая постоянная

Answer 2

Calculation of the Mass of Oxygen in the Cylinder

To determine the mass of oxygen in the cylinder, we need to use the given information about the work done during the heating process. The work done is equal to the change in internal energy of the gas, which can be calculated using the equation:

W = ΔU = nCΔT

Where: - W is the work done (given as 16 kJ) - ΔU is the change in internal energy - n is the number of moles of gas - C is the molar heat capacity of the gas at constant volume - ΔT is the change in temperature

Since the gas in the cylinder is oxygen, we can use the molar heat capacity of oxygen at constant volume, which is approximately 20.8 J/(mol·K).

Now, let's solve for the number of moles of oxygen gas:

16 kJ = n * 20.8 J/(mol·K) * (473 K - 273 K)

Simplifying the equation:

16 kJ = n * 20.8 J/(mol·K) * 200 K

Converting kJ to J:

16,000 J = n * 20.8 J/(mol·K) * 200 K

Simplifying further:

16,000 J = n * 4,160 J/mol

Solving for n:

n = 16,000 J / 4,160 J/mol

Calculating n:

n ≈ 3.85 mol

Therefore, the number of moles of oxygen gas in the cylinder is approximately 3.85 mol.

To calculate the mass of oxygen, we need to use the molar mass of oxygen, which is approximately 32 g/mol. Multiplying the number of moles by the molar mass:

Mass of oxygen = 3.85 mol * 32 g/mol

Calculating the mass:

Mass of oxygen ≈ 123.2 g

Therefore, the mass of oxygen in the cylinder is approximately 123.2 grams.

Please note that this calculation assumes ideal gas behavior and neglects the effects of friction.