In: Chemistry
A 10.5L bulb contains NH3 gas and HCl gas, which have equal partial pressures. The total gas pressure is 1.86atm and the temperature is 302K. These gases react completely:
NH3(g) + HCl(g) → NH4Cl(s)
Calculate the mass of NH4Cl formed.
*** Show your work
*** The answer is 21.1g but PLEASE show all of your work CLEARLY so I can understand! THANK YOU!!
In this problem we first find total number of moles of both gases. And we know that they both have same partial pressure so at same condition they must have same number of moles. Now we get moles of each gas by using total moles. As both are having same moles so we can use any of them to get moles of product. And by using molar mass and moles of product we can get the mass in g.
Solution:
As per the discussion we wet conversion factor.
1 mol NH3 : 1 mol NH4Cl ; (1 mol NH4Cl / 1 mol NH3 = 1 )
Calculation of total moles
We use ideal gas law.
n = pV/ RT
here n is number of moles , p pressure in atm, R is gas constant = 0.08206 L atm / (K mol)
T is in Kelvin
n = [ 1.86 x 10.5 / (0.08206 x 302 )] mol
= 0.788 mol
Moles of NH3 = 0.788 / 2 mol = 0.394 mol NH3
Moles of NH4Cl = moles of NH3 x 1 mol NH4Cl / 1 mol NH3
= 0.394 mol NH4Cl
Mass of NH4Cl = 0.394 mol NH4Cl x 53.491 g/mol
= 21.077 g
So the mass of NH4Cl is 21.077 g
OR ( in two sig fig.)
= 21.1 g