IIT JEE , AIEEE Forum - Chemistry , Physical Chemistry

m.viddya

Q.Assuming that petrol is Octane and has a density 0.8gm/ml ,1.425 lts of petrol on complete combustion will consume

1.50 moles of oxygen

2.100 moles of oxygen

3.125 moles of oxygen

4.200 moles of oxygen

sudakar

the ans is c .if correct please nudge me for the solution.

chetan_kp

ya the right option is (3)

m.viddya

can i have the solution plzzz

BALGANESH

the balanced chemical reaction is

2C8H18 +15 O2= 16CO2 +18H2 O

molecular weight of C8H18 = 114G AND molecular weight of O2 =32 g

therefore 228g of octane consume 480g of oxygen for complete combustion

therefore 1 g of octane will consume 480/228 g 0f oxygen

now the dendity of octane is 0.8 g/ ml

therefore 1 ml of octane wieghs 0.8g , so 1425ml (1.425 lts) will weigh =0.8 x 1425 g =1140

since 1g of octane will consume 480/228g

therefore 1140g of octane will consume = 1140x480/228 g of oxygen

=2400

sine one mole of oxygen = 32g

therefore 2400g = 75 moles of oxygen

this the no of moles consumed