I need help on my Stoichiometry homework!?

Question

OK this stuff is outrageously weird

and i have a some what clue to what to do, but my teacher wont help us =( or teach us
she is really horrible at this

well here are some the easy ones i figure it wouldnt hurt to get the easy ones done and do at least some of my homework

1. How many grams of carbon can be completely burned in 15 L of oxygen? How many liters of CO2 gas are produced in this reaction?

2. What volume of Cl gas is needed to completely replace 45 g of Br from Sodium Bromide? How many grams of NaCl are produced simultaneously?

and there are more but meehh

I know that you Start out with the given amount of the product in grams, convert to moles, and then multiply by your mole ratio, that is from the coefficients of the balanced chemical equation
I know that there is 22.4 L in 1 mol of gas
and that you do it twice to find your limiting reactant

but im confused on the volumes and what not




please help!

Answer 1

1. C + O2 ===> CO2

15LO2 x 1molO2/22.4LO2 x 1molC/1molO2 x 12gC/1molC = (15)(12)/(22.4) = 8 g C

15LO2 x 1molO2/22.4LO2 x 1molCO2/1molO2 x 22.4LCO2/1molCO2 = (15)(22.4)/(22.4) = 15L CO2

2. 2NaBr + Cl2 ===> 2NaCl + Br2
Atomic weights: Na=23 Cl=35.5 Br=80 NaCl=58.5

45gBr2 x 1molBr2/160gBr2 x 1molCl2/1molBr2 x 22.4LCl2/1molCl2 = (45)(22.4)/(160) = 6.3L Cl2

45gBr2 x 1molBr2/160gBr2 x 2molNaCl/1molBr2 x 58.5gNaCl/1molNaCl n= (45)(2)(58.5)/(160) = 33g NaCl