To determine the temperature of the liquid using the information provided from the constant volume gas thermometer, we can apply the principles of gas laws, specifically the relationship between pressure and temperature. In this case, we will use the concept of absolute temperature, which is measured in Kelvin.
Understanding the Basics
In a constant volume gas thermometer, the pressure of the gas is directly proportional to its temperature when the volume is held constant. This relationship can be expressed mathematically as:
P1/T1 = P2/T2
Where:
- P1 = initial pressure of the gas
- T1 = initial temperature (in Kelvin)
- P2 = final pressure of the gas
- T2 = final temperature (in Kelvin)
Given Values
From the problem, we know:
- The pressure in melting ice (1 atm) corresponds to 80 cm Hg.
- The pressure in the liquid is 160 cm Hg.
Converting Pressures
First, we need to convert the pressures into a consistent unit. Since we are using cm Hg, we can keep them as is:
- P1 = 80 cm Hg
- P2 = 160 cm Hg
Finding the Initial Temperature
The temperature at which the pressure is 80 cm Hg (melting ice) is 0°C, which is equivalent to:
T1 = 0°C + 273.15 = 273.15 K
Setting Up the Equation
Now we can substitute the known values into the equation:
80 cm Hg / 273.15 K = 160 cm Hg / T2
Solving for T2
To find T2, we can rearrange the equation:
T2 = (160 cm Hg * 273.15 K) / 80 cm Hg
Calculating this gives:
T2 = (160 * 273.15) / 80
T2 = 43224 / 80
T2 = 540.3 K
Final Temperature Conversion
To convert this temperature back to Celsius, we subtract 273.15:
T2 (in °C) = 540.3 K - 273.15 = 267.15°C
Conclusion
The temperature of the liquid, when the pressure in the gas thermometer reaches 160 cm Hg, is approximately 267.15°C. This calculation illustrates how pressure changes in a gas can be used to determine temperature, showcasing the direct relationship between these two physical properties in a controlled environment.