Question

A pure hydrocarbon is used in bottled gas for cooking and heating.

When 10cm³ of the hydrocarbon is burned in 70cm³ of oxygen (an excess), the final gaseous mixture contains 30cm³ of carbon dioxide and 20cm³ of unreacted oxygen. All volumes were measured under identical conditions.

What is the formula of the hydrocarbon?

A. C2H6
B. C3H6
C. C3H8
D. C4H10

I get this type of questions in my exam all the time, but I always wasn't sure how to approach this question can someone help??

Answer 1

Answer:

i need time to answer give it

Answer 2

Answer:

Let formula of hydrocarbon is C​​​​​​x​H​​​​​​y

C​​​​xHy ( g ) + ( x + y/ 4) O2( g ) →xCO2 ( g ) + y/2 H2O( l )

According to question volume of CO2 = x ( 10 )= 30 cc , x = 3

Volume of O2 reacted = 50 cc = ( x + y /4 )x 10

Solving this y = 8

So, the formula is C3H8

The correct answer is the C option.

C. C3H8

(i.e Propane

C3H8 is a three-carbon alkane with the chemical name Propane. Propane is also called n-Propane, or Dimethylmethane, or Propyl hydride.)