Question

which of the following variables is not correctly matched with its value for this problem: what pressure is required to contain 0.023 moles of nitrogen gas in a 4.2 l container at a temperature of 20°c?
n = 0.023 mol
r = 0.0821 l·atm/mol·k
v = 4.2 l
p = 20°c

Explanation:

Step1: Recall ideal gas law variables

The ideal gas law is \(PV = nRT\), where \(P\) is pressure (in atm), \(V\) is volume (in L), \(n\) is moles, \(R\) is the gas constant (\(0.0821\ L\cdot atm/mol\cdot K\)), and \(T\) is temperature (in Kelvin).

Step2: Check temperature unit conversion

Temperature \(T\) in the ideal gas law must be in Kelvin. Given \(P = 20^{\circ}C\), this is incorrect as \(P\) should be pressure (e.g., in atm) and \(T\) (originally in \(^{\circ}C\)) needs to be converted to \(K\) (\(T = 20 + 273.15=293.15\ K\)).

Answer:

\(P = 20^{\circ}C\) is not correctly matched (it should be pressure in atm and temperature converted to Kelvin).