Question

0.5 кг воды при 25 градусах смешали 0.2 кг бензола. Рассчитайте энтропию этой системы. Какой будет энтропия, если указанные вещества при 25 градусах смешать в газообразном состоянии

Answer 1

Пгнмтллбжжюббдрпва брешь лоб опешил да род

Answer 2

Calculating Entropy of the Water and Benzene Mixture

To calculate the entropy of the system, we can use the formula:

ΔS = ΣQrev / T

Where ΔS is the change in entropy, ΣQrev is the sum of the heat transferred reversibly, and T is the temperature.

Given: - Mass of water (m1) = 0.5 kg - Mass of benzene (m2) = 0.2 kg - Temperature (T) = 25°C

First, we need to calculate the entropy change for each substance and then sum them to find the total entropy change for the system.

Entropy of Water at 25°C

The entropy change for water can be calculated using the specific heat capacity of water and its temperature change.

Qrev,water = m1 * Cp,water * ΔT

Where: - Cp,water is the specific heat capacity of water - ΔT is the change in temperature

The specific heat capacity of water (Cp,water) is approximately 4.18 kJ/kg°C.

Qrev,water = 0.5 kg * 4.18 kJ/kg°C * (25°C - 0°C)

Qrev,water = 52.25 kJ

Entropy of Benzene at 25°C

Similarly, we can calculate the entropy change for benzene using its specific heat capacity and temperature change.

Qrev,benzene = m2 * Cp,benzene * ΔT

The specific heat capacity of benzene (Cp,benzene) is approximately 1.7 kJ/kg°C.

Qrev,benzene = 0.2 kg * 1.7 kJ/kg°C * (25°C - 0°C)

Qrev,benzene = 8.5 kJ

Total Entropy Change

Now, we can sum the entropy changes for water and benzene to find the total entropy change for the system.

ΔS = Qrev,water / T + Qrev,benzene / T

ΔS = (52.25 kJ + 8.5 kJ) / (25°C + 273.15)

ΔS ≈ 0.208 kJ/K

Entropy of Gaseous Water and Benzene at 25°C

When the substances are in the gaseous state, their entropy will change due to the change in state. The entropy of gaseous water and benzene can be calculated using their respective standard molar entropy values.

The standard molar entropy of water vapor (H2O(g)) is approximately 188.83 J/mol·K, and for benzene vapor (C6H6(g)) is approximately 269.9 J/mol·K.

The total entropy change for the gaseous state can be calculated by summing the entropy changes for water and benzene.

ΔS_gaseous = (m1/Molar mass of water) * S°_water + (m2/Molar mass of benzene) * S°_benzene

Where S°_water and S°_benzene are the standard molar entropy values.

After calculating the values, the total entropy change for the gaseous state can be determined.

This calculation will provide the entropy change for the system when the substances are in the gaseous state at 25°C.