The volume of a mass of gas is 300 ml at 25°C and 685 torr. What will the gas occupy at STP?
Will the temperatures be the same when I do (P1V1/T1) = (P2V2/T2) ?
No. The T is 25C and STP is 0 C. Remember must be in kelvin.
So would 248 ml be correct
yes. See above.
No, the temperatures will not be the same when using the formula (P1V1/T1) = (P2V2/T2). In this equation, the temperatures are measured in Kelvin (K) rather than Celsius or Fahrenheit.
To convert the temperature given in degrees Celsius to Kelvin, you need to add 273.15 to the Celsius temperature. The temperature of 25°C in Kelvin would be 25 + 273.15 = 298.15 K.
On the other hand, STP (Standard Temperature and Pressure) refers to a temperature of 0°C or 273.15 K. Therefore, when solving for the gas volume at STP, you need to use this temperature value.
Let's proceed with the calculation:
Given:
Initial volume, V1 = 300 ml
Initial temperature, T1 = 25°C = 298.15 K
Initial pressure, P1 = 685 torr
We are trying to find the final volume at STP, V2.
STP temperature, T2 = 0°C = 273.15 K
STP pressure, P2 = 1 atm = 760 torr
Using the formula (P1V1/T1) = (P2V2/T2), we can rearrange it to solve for V2:
V2 = (P1 * V1 * T2) / (P2 * T1)
Plugging in the values:
V2 = (685 torr * 300 ml * 273.15 K) / (760 torr * 298.15 K)
Now, you can calculate the final volume by performing the multiplication and division:
V2 = 225.54 ml
Therefore, the gas will occupy a volume of 225.54 ml at STP.