Math Problem Statement

In an experiment to simulate conditions within an automobile engine, 0.165 mol of air at a temperature of 720 K and a pressure of 3.10×106 Pa is contained in a cylinder of volume 320 cm3 . Then 655 J of heat is transferred to the cylinder.the volume of the cylinder is allowed to increase while the pressure remains constant, find the final temperature of the air.

Solution

To solve this problem, we need to find the final temperature T2T_2 of the air after 655 J of heat is added to it under constant pressure. Let's break down the steps to get there.

Given Data

  1. Initial amount of air, n=0.165moln = 0.165 \, \text{mol}
  2. Initial temperature, T1=720KT_1 = 720 \, \text{K}
  3. Constant pressure, P=3.10×106PaP = 3.10 \times 10^6 \, \text{Pa}
  4. Initial volume, V1=320cm3=3.20×104m3V_1 = 320 \, \text{cm}^3 = 3.20 \times 10^{-4} \, \text{m}^3
  5. Heat added, Q=655JQ = 655 \, \text{J}

Step 1: Determine the final temperature using the ideal gas law and the heat capacity at constant pressure.

Since the process occurs at constant pressure, we can use the formula relating heat transfer at constant pressure to the change in temperature:

Q=nCp(T2T1)Q = n C_p (T_2 - T_1)

where CpC_p is the molar heat capacity at constant pressure for air. For diatomic gases like air, Cp29J/(mol\cdotpK)C_p \approx 29 \, \text{J/(mol·K)}.

Step 2: Substitute values and solve for T2T_2.

Rearrange the equation to solve for T2T_2:

T2=T1+QnCpT_2 = T_1 + \frac{Q}{n C_p}

Substitute the known values:

T2=720+6550.165×29T_2 = 720 + \frac{655}{0.165 \times 29}

Calculating the term inside the fraction:

T2=720+6554.785720+137T_2 = 720 + \frac{655}{4.785} \approx 720 + 137

T2857KT_2 \approx 857 \, \text{K}

Final Answer

The final temperature T2T_2 of the air is approximately 857 K.

Would you like more details or have any questions?


Here are 5 related questions to deepen understanding:

  1. What assumptions are made about the air to use the ideal gas law here?
  2. How would the final temperature change if the pressure were not constant?
  3. How would adding more moles of gas initially affect the outcome?
  4. What role does the molar heat capacity CpC_p play in such problems?
  5. Could this process be analyzed using the first law of thermodynamics?

Tip: When dealing with gas laws, remember to keep track of units—especially volume, temperature, and pressure.

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Math Problem Analysis

Mathematical Concepts

Thermodynamics
Ideal Gas Law
Heat Capacity

Formulas

Ideal Gas Law: PV = nRT
Heat transfer at constant pressure: Q = n C_p (T_2 - T_1)

Theorems

Ideal Gas Law
First Law of Thermodynamics

Suitable Grade Level

College Level Physics