$C_{3} H_{8} + 5 O_{2} ---\ \textgreater \ 3CO_{2} +4H_{2}O (-2012 \frac{kJ}{mol} )


3 mol 10 mol


C_{3}H_{8} is /excess /reactant

because 3 mol propane require 15 mol oxygen (by reaction)

5 mol oxygen ---1 mol propane, so

10 mol oxygen ---2 mol propane

Only 2 mole propane will be burned,

so 

2012 ( kJ/mol)*2 mol =4024 KJ heat will be given off

Correct answer is number 4.


$

5 0

3 years ago

2C2H2 + 5O2 → 4CO2 + 2 H2O How many grams of CO2 are required to react with exactly 3.00 mol of O2? 106 g 132 g 165 g 76.8 g

cricket20 [7]

Hey there!:

Given the reaction:

2 C2H2 + 5 O2 → 4 CO2 + 2 H2O

5 moles O2 ------------- 4 moles CO2

3.00 moles O2 ---------- ( moles of CO2 ?? )

moles of CO2 = 3.00 * 4 / 5

moles of CO2 = 12 / 5

moles of CO2 = 2.4 moles

So, molar mass CO2 = 44.01 g/mol

Therefore:

1 mole CO2 -------------- 44.01 g

2.4 moles CO2 ---------- ( mass of CO2 )

mass of CO2 = 2.4 * 44.01 / 1

mass of CO2 = 106 g

Answer A

Hope that helps!

8 0

3 years ago