Question #8c9fd
1 Answer
It could be
Explanation:
We're asked to identify the gas based on some gas measurements and it's mass.
What we can do is find the molar mass
where
#d# is the density of the gas, in#"g/L"# . We're given that#4# #"g"# occupies#2.8# #"L"# , so the density is
#(4color(white)(l)"g")/(2.8color(white)(l)"L") = 1.43# #"g/L"#

#R# is the universal gas constant, equal to#0.082057("L"•"atm")/("mol"•"K")# 
#T# is the absolute temperature of the gas, in#"K"# . Standard temperature is defined as#273.15# #"K"# 
#P# is the pressure of the gas, in#"atm"# . Standard pressure is usually for these types of problems defined as#1# #"atm"#
Plugging in known values, we have
To me,