Question #26795

2 Answers
Apr 16, 2017

T_2=2770"°C"

Explanation:

Gay-Lussac's Law states that for a constant volume and pressure of gas, P_1/T_1=P_2/T_2. Rearranged to solve for T_2, this is T_2=(T_1 times P_2)/P_1.

Keeping in mind that temperature has to be in Kelvin, T_1=31"°C"+273=304"K"

Plugging in the values from the problem,
T_2=(304"K" times 7450"Torr")/(745"Torr")=3040"K"

And to convert back to Celsius to answer the question,
T_2=3040"K"-273=2767"°C", and rounding to the appropriate number of significant figures gives 2770"°C".

Apr 16, 2017

The Celsius temperature required to reach "7450 torr" is "2770"^@"C".

Explanation:

This is an example of Gay-Lussac's law , which states that the pressure of a gas is directly proportional to its temperature in Kelvins , as long as the amount and volume is held constant. This means that as the pressure increases, the temperature increases, and vice-versa. The equation to use is:

P_1/T_1=P_2/T_2

Given:
P_="745 torr"
T_1="31"^@"C"+273.15="304 K"
P_2="7450 torr"

Unknown: T_2

Solution
Rearrange the equation to isolate T_2. Substitute the given values into the equation and solve.

T_2=(P_2T_1)/P_1

T_2=(7450color(red)cancel(color(black)("torr"))xx304"K")/(745color(red)cancel(color(black)("torr")))="3040 K" (rounded to three significant figures)

Convert Kelvin Temperature to Celsius Temperature

To convert the temperature in Kelvins to degrees Celsius, subtract 273.15 from the Kelvin temperature.

3040"K"-273.15=2770^@"C", rounded to three significant figures.