A0.642g sample of an unknown gas was collected over water at 25.0°c and 1.04 atm. the collection cylinder contained 151.3 ml of gas after the sample was released. find the molar mass of the unknown gas.

Answer : The molar mass of unknown gas is 99.8 g/mole.

Explanation :

Using ideal gas equation:

where,

P = pressure of gas = 1.04 atm

V = volume of gas =

conversion used :

T = temperature of gas =

R = gas constant = 0.0821 L.atm/mole.K

w = mass of an unknown gas = 0.642 g

M = molar mass of an unknown gas = ?

Now put all the given values in the ideal gas equation, we get:

Therefore, the molar mass of unknown gas is 99.8 g/mole.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: