A4.80 mol sample of solid a was placed in a sealed 1.00 l container and allowed to decompose into gaseous b and c. the concentration of b steadily increased until it reaches 1.40 m, where it remained constant. a(s)↽−−⇀b(g)+c(g) then, the container volume was doubled and equilibrium was re‑established. how many moles of a remain

Answer : The number of moles of A remains are, 2.00 mole

Explanation :

As we are given that,

Number of moles of solid A = 4.80 mole

Volume of container = 1.00 L

Concentration of A =

Concentration of B = 1.40 M

The moles of B in 1 liter of solution =

When the volume is doubled then we are using volume 2 L instead of 1 L.

The moles of B in 2 liter of solution =

The balanced chemical reaction is,

initial conc.      4.80         0      0

At eqm.        (4.80-2.80)   2.80

The moles of A remains = 4.80 - 2.80 = 2.00 mole

Therefore, the number of moles of A remains are, 2.00 mole