How many moles of CO2 are produced when 10.0 moles of C3H8 are burned in
excess oxygen?
C3H8 + 5 O2 ---> 3 CO2 + 4H2O

30.0 mol CO₂

Explanation:

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

To answer this problem we need to convert moles of C₃H₈ into moles of CO₂: We'll do that by using the stoichiometric coefficients, using a conversion factor that has C₃H₈ moles in the denominator and CO₂ moles in the numerator:

10.0 mol C₃H₈ * = 30.0 mol CO₂

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2