A sample of gas confined in a cylinder with a movable piston is kept at constant pressure. The volume of the gas doubles when the temperature of the gas is changed from
a. 200. K to 400. K
b. 200. C to 400. C
How do you know if it's kelvin or celsius?
k= c + 273, by the way.
You solve the problem which ALWAYS comes out in Kelvin because you may use ONLY Kelvin in the solution. The volume doubles when the Kelvin T doubles and is halved when the Kelvin T is halved.
Doubling the celsius, by the way, will NOT double the volume and you can prove that by the following:
Suppose we let V1 = 10 mL, then
(V1/T1) = (V2/T2)
(10/20 K) = (V2/40 K)
V2 = 10mL*(40/20 = 20 mL (double T doubles V) BUT
from 20 celsius to 40 celsius is from 293 K to 313 K and
(10/293) = (V2/313)
V2 = 10 mL*(313/293) = 10.7 mL. See. Not even close.
thanks
In this case, we know that temperature must be in Kelvin because the gas laws, such as Boyle's Law and Charles' Law, are generally stated in terms of Kelvin temperature. The Kelvin scale is an absolute temperature scale, and it starts at absolute zero, which is -273.15 degrees Celsius. Therefore, when temperature is expressed in Kelvin, it can never be negative.
To convert temperature from Celsius to Kelvin, you can use the formula: Kelvin = Celsius + 273.15.
To determine whether the temperature values are in Kelvin (K) or Celsius (°C), you can look for any clues provided in the question or context.
In most cases, when dealing with gas laws and thermodynamics, temperature is usually expressed in Kelvin (K). This is because Kelvin is an absolute temperature scale where zero Kelvin (-273.15 °C) represents absolute zero, the lowest possible temperature.
If the temperature values are given in terms of Celsius (°C), you can convert them to Kelvin by adding 273. For example, to convert 200 °C to Kelvin, you would perform the following calculation:
200 °C + 273 = 473 K
Once you have converted the temperature values to Kelvin, you can proceed to use them in your calculations.