Calcium carbide reacts with water to produce acetylene gas according to the following equation: CaC2(s) + 2H2O(l)C2H2(g) + Ca(OH)2(aq) The product gas, C2H2, is collected over water at a temperature of 25 °C and a pressure of 748 mm Hg. If the wet C2H2 gas formed occupies a volume of 5.50 L, the number of moles of CaC2 reacted was mol. The vapor pressure of water is 23.8 mm Hg at 25 °C.

Answer : The number of moles of reacted was, 0.214 moles.

Explanation :

First we have to calculate the mole of gas.

Using ideal gas equation:

where,

P = Pressure of gas = 748 mmHg - 23.8 mHg = 724.2 mmHg = 0.953 atm   (1 atm = 760 mmHg)

V = Volume of gas = 5.50 L

n = number of moles  = ?

R = Gas constant =

T = Temperature of gas =

Putting values in above equation, we get:

Now we have to calculate the moles of

The balanced chemical reaction is:

From the balanced chemical reaction we conclude that,

As, 1 mole of gas produced from 1 mole of

So, 0.214 mole of gas produced from 0.214 mole of

Therefore, the number of moles of reacted was, 0.214 moles.