. A sample of NH₃ gas occupies 57.0 liters at STP. How many molecules of NH₃ is this?

15.30 ×10²³ molecules of ammonia

Explanation:

Given data:

Volume of ammonia = 57.0 L

Temperature = standard = 273 K

Pressure = standard = 1 atm

Number of molecules of ammonia = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

1 atm ×57.0 L = n ×0.0821 atm.L/ mol.K   × 273 K

57.0 L.atm =  n × 22.41 atm.L/ mol

n = 57.0 L.atm/22.41 atm.L/ mol

n = 2.54 mol

Number of molecules of ammonia:

1 mole of gas have 6.022 ×10²³ molecules of ammonia.

2.54 mol ×6.022 ×10²³ molecules / 1 mol

15.30 ×10²³ molecules

i belive it is water