If samples of nitrogen gas and carbon monoxide gas have equa

If samples of nitrogen gas and carbon monoxide gas have equal volumes at the same temperature and pressure, which of the following will likewise be equal? (Please explain why)

1. Density

2. Mass

3. Number of molecules

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A) All of the above

B) 2 & 3 only

C) 1 & 2 only

D) 1 only

E) 2 only

Solution

Ideal gas law is:
P*V = n*R*T
Here: P, V and T is same for both
So, n will be same

since number of mol is same and molar mass is same for N2 and CO, there mass will be same

since number of mol is same, number of molecules will be same

since mass and volume is same, density will be same

Answer: A