A reaction requires 22.4 L of gas at STP. You have 35.0 L of gas at 100 kPa and 323 K.

Which statement is true?

The gas constant is 8.31 L-kPa/mol-K.

Responses

You do not have enough gas for the reaction to occur.

You do not have enough gas for the reaction to occur.

You will have an excess of gas and the reaction will occur.

You will have an excess of gas and the reaction will occur.

You cannot tell given this information.

You cannot tell given this information.

You will have too much gas for the reaction to occur.

1 answer

To determine whether you have enough gas for the reaction, we can use the ideal gas law:

\[ PV = nRT \]

where:

  • \( P \) is the pressure (in kPa)
  • \( V \) is the volume (in L)
  • \( n \) is the number of moles of gas
  • \( R \) is the gas constant (8.31 L-kPa/mol-K)
  • \( T \) is the temperature (in K)

First, let's find the number of moles (\( n \)) of the gas you have in the 35.0 L at 100 kPa and 323 K.

Given:

  • \( P = 100 , \text{kPa} \)
  • \( V = 35.0 , \text{L} \)
  • \( T = 323 , \text{K} \)
  • \( R = 8.31 , \text{L-kPa/mol-K} \)

Now, we can rearrange the ideal gas law to solve for \( n \):

\[ n = \frac{PV}{RT} \]

Substituting the values:

\[ n = \frac{100 , \text{kPa} \times 35.0 , \text{L}}{8.31 , \text{L-kPa/mol-K} \times 323 , \text{K}} \]

Calculating the denominator:

\[ n = \frac{3500 , \text{kPa·L}}{2677.93 , \text{L-kPa/mol}} \]

\[ n \approx 1.31 , \text{mol} \]

Next, we need to find out how many moles of gas are required to achieve 22.4 L at STP (Standard Temperature and Pressure, which is 0°C or 273 K and 1 atm or approximately 101.3 kPa).

1 mole of an ideal gas occupies 22.4 L at STP, meaning for 22.4 L:

\[ n_{required} = \frac{22.4 , \text{L}}{22.4 , \text{L/mol}} = 1 , \text{mol} \]

Now, comparing the moles you have and the moles required:

  • You have \( 1.31 , \text{mol} \)
  • You need \( 1 , \text{mol} \)

Since you have more moles than required, you will have an excess of gas, and the reaction will occur.

Therefore, the correct statement is: You will have an excess of gas and the reaction will occur.