When you work with constants in science classes, you'll usually have a reference page that shows you lots of constant values to use to solve problems. Part of the problem for some students is knowing which constant to use. I want to ask you to look at the problem again and take a moment to answer the question below. calcute the volume occupied by0.845 moles of nitrogen gas at a pressure of 1.37 and 3.15 K Two common versions of r or the ideal gas constant are: R= o.o821 l-atm/mol-k or r=8.3145 j/mol k Part 1: Select one of the two gas constants seen in blue that you think you would use for 'R' in this math problem. (2 points) Part 2: Explain your choice of gas constants. Why do you think one is a better match for the math you would need to solve? (2 points) (4 points)

1 answer

To solve the problem of calculating the volume occupied by 0.845 moles of nitrogen gas at a pressure of 1.37 atm and a temperature of 3.15 K, we can use the Ideal Gas Law equation:

\[ PV = nRT \]

Where:

  • \( P \) is the pressure in atm,
  • \( V \) is the volume in liters,
  • \( n \) is the number of moles,
  • \( R \) is the ideal gas constant,
  • \( T \) is the temperature in Kelvin.

Part 1: Select one of the two gas constants for 'R':

In this case, I would use \( R = 0.0821 , \text{L·atm/(mol·K)} \).

Part 2: Explain your choice of gas constants:

I chose \( R = 0.0821 , \text{L·atm/(mol·K)} \) because the pressure is given in atmospheres (atm) and the volume we are trying to calculate is typically expressed in liters (L). This constant directly allows us to maintain the units in the Ideal Gas Law equation without needing to convert pressure or volume units.

On the other hand, \( R = 8.3145 , \text{J/(mol·K)} \) is more suitable when dealing with pressure in pascals (Pa) and volume in cubic meters (m³), which would complicate the calculations further if the values are not in the suitable units.

Thus, by using \( R = 0.0821 , \text{L·atm/(mol·K)} \), you streamline the calculations, ensuring consistent units throughout the equation, which is crucial for correctly applying the Ideal Gas Law.