Question

Acetylene gas (c2h2) reacts with oxygen gas (o2) to produce carbon dioxide (co2) and water vapor (h2o). how many liters of c2h2 are required to produce 75.0 l of co2? l what volume of h2o is produced? l what volume of o2 is required? l when making the calculations, did you need to find the number of moles?

Answer 1

1. 37.5

2. 37.5

3. 93.8

4. no

Answer 2

According to the balanced equation of the reaction:

2C2H2 + 5O2 → 4CO2 + 2H2O

So we can mention all as liters,

A) as we see that 2 liters of C2H2 react with 5 liters of oxygen to produce 4 liters of CO4 and 2 liters of H2O 

So, when we have 75L of CO2

and when we have 2 L of C2H2 reacts and gives 4 L of CO2

 2C2H2 → 4CO2 

∴ The volume of C2H2 required is:

                    = 75L / 2

                    = 37.5 L

B) and, when we have 75 L of CO2


and 4CO2 → 2H2O 

∴ the volume of H2O required is: 
                               
                            = 75 L /2
                            = 37.5 L 


C) and from the balanced equation and by  the same way:

when 5 liters O2  reacts to give 4 liters of CO2

and we have 75 L of CO2:

5 O2 → 4 CO2 

   ??  ←  75 L

∴ the volume of O2 required is:

                              = 75 *(5/4)

                              = 93.75 L



D) about the using of the number of moles the answer is: 

no, there is no need to find the number of moles as we called everything in the balanced equation by liters and use it as a liter unit to get the volume, without the need to get the number of moles.