Question

Calculate the number of molecules present in 350 cm^3 of NH3 gas st 273K and 2 atmospheric pressure

Answer 1

350cc =0.35L
T=273K
R=8.3244
use PV=nRT
Substituting the value and calculating for the value of n
we get n = 3.08 x 10-4.
I hope it helps u.

Answer 2

Answer: $0.18\times 10^{23}$ molecules of $NH_3$

Explanation:

Ideal gas law:

$PV=nRT$

where,

P = pressure of the gas  = 2 atm

V = volume of the gas  = $350cm^3$ = 0.35 L

T = temperature of the gas  = 273 K

n = number of moles of the gas  = ?

R = gas constant = 0.0821 Latm/moleK

$2\times 0.35=n\times 0.0821\times 273$

$n=0.03 moles$

Now 1 mole of $NH_3$ contains = $6.023\times 10^{23}$ molecules of $NH_3$

0.03 mole of $NH_3$ contains = $\frac{6.023\times 10^{23}}{1}\times 0.03=0.18\times 10^{23}$ molecules of $NH_3$