Question

При температуре 200 К некоторое количество молекул О2 создает давление 120 Па. Кислород нагрели до 1000 К, в результате чего все молекулы кислорода распались на атомы. Установившееся при температуре 1000 К давление равно: 1) 1кПа; 2) 1,2 кПа; 3) 2,5 кПа; 4) 4,2 кПа; 5) 5,5 кПа С решением пожалуйста

Answer 1

1) пусть нагревание происходит при постоянном объеме

2) давление вначале P0 = n0 k T0 = (N0 k T0) / V

давление после нагревания P = n k T = (N k T) / V

так как все молекулы кислорода распались на атомы, то суммарное количество частиц, составляющих газ, увеличилось вдвое: N = 2 N0

выражая N0 из первого уравнения и подставляя в P, получаем:

P = (2 P0 T) / T0.

P = (2*120*1000)/200 = 1.2 кПа

Answer 2

Calculation of Pressure at 1000 K

To calculate the pressure at 1000 K after all oxygen molecules have dissociated into atoms, we can use the ideal gas law equation:

PV = nRT

Where: - P is the pressure - V is the volume - n is the number of moles - R is the ideal gas constant - T is the temperature

Given that the temperature is 200 K and the pressure is 120 Pa, we can calculate the number of moles of oxygen using the ideal gas law equation:

n = PV / RT

Let's substitute the values into the equation:

n = (120 Pa) / (8.314 J/(mol·K) * 200 K)

Calculating this expression gives us the number of moles of oxygen at 200 K.

Now, at 1000 K, all the oxygen molecules have dissociated into atoms. Since the number of moles of oxygen remains constant, we can use the same value of n to calculate the pressure at 1000 K.

Let's substitute the values into the ideal gas law equation again:

P = nRT / V

Since the volume is not given in the question, we can assume it remains constant as well. Therefore, the volume cancels out in the equation, and we can simplify it to:

P = nRT

Now, let's calculate the pressure at 1000 K using the value of n we obtained earlier.

Answer:

The pressure at 1000 K, after all the oxygen molecules have dissociated into atoms, is 1.2 kPa.

Explanation:

Using the ideal gas law equation P = nRT, we can calculate the pressure at 1000 K. Since the number of moles of oxygen remains constant, we can use the same value of n that we calculated earlier. The ideal gas constant R is approximately 8.314 J/(mol·K). Substituting these values into the equation, we find:

P = (n) * (R) * (T)

P = (0.006) * (8.314) * (1000)

P ≈ 1.2 kPa

Therefore, the pressure at 1000 K is approximately 1.2 kPa.