Question

calculate the density, in g/l, of cl₂(g) at stp.
0.316 g/l
3.16 g/l
46.9 g/l
2.13 g/l
1.58 g/l

Explanation:

Step1: Recall the molar volume at STP

At STP (Standard Temperature and Pressure: \(T = 273\space K\), \(P= 1\space atm\)), the molar volume of an ideal gas \(V_m=22.4\space L/mol\).

Step2: Find the molar mass of \(Cl_2\)

The molar mass of \(Cl\) is \(M_{Cl}=35.45\space g/mol\). For \(Cl_2\), \(M = 2\times35.45\space g/mol=70.9\space g/mol\).

Step3: Use the density formula \(

ho=\frac{m}{V}\)
Since \(n = \frac{m}{M}\) and \(V=nV_m\), then \(m = nM\) and \(V=nV_m\). Substituting into \(
ho=\frac{m}{V}\), we get \(
ho=\frac{M}{V_m}\).
Substitute \(M = 70.9\space g/mol\) and \(V_m = 22.4\space L/mol\) into \(
ho=\frac{M}{V_m}\), \(
ho=\frac{70.9\space g/mol}{22.4\space L/mol}\approx3.16\space g/L\).

Answer:

3.16 g/L