Stoichiometry hw help!!!!!!??? PLEASE!!?

Question

1. How many liters of oxygen are liberated when 399 grams of barium chlorate are heated to produce barium chloride and oxygen gas?

2. What volume of nitrogen gas is needed to react with 175 Liters of hydrogen gas in order to produce ammonia, NH3?

3. How many liters of oxygen are required to completely combust 1.27*10^24 molecules of pentane (C5H12) in a complete combustion reaction?

4. How many liters of chlorine gas are produced if 125 grams of sodium chloride are exposed to an electric current?

5. How many molecules of CO2 are produced when 75 grams of aluminum carbonate are heated?

6. How many grams of barium sulfate are produced if 86 grams of barium phosphate are reacted with excess sodium sulfate in a double replacement reaction?

Answer 1

I won't do your home work for you, but I'll (hopefully) help you understand HOW to do them yourself.

First, write a balanced equation for each of your problems. Without a balanced equation, you can't do anything else.

Once you have a balanced equation, look at your problem and determine what information you are given and what is being asked for. Once you have done that, you have to know that the balanced equation relates moles of one thing to moles of every other component of the reaction. So, the coefficients in the equation tell you how to convert a number of moles of one thing into a number of moles of any other reactant or product. Finally, you'll usually have to use molar masses of the compounds to convert masses given into the problem into moles.

So, the general scheme of conversions is:

Mass of A --> moles of A --> moles of B (using coefficients of the balanced equation) --> mass of B (or a volume using the ideal gas law...)

So, for your first question, the equation will be:

Ba(ClO3)2 --> BaCl2 + 3 O2

Starting with 399 grams of Ba(ClO3)2, use its molar mass to determine how many moles of that you are starting with. From the balanced equation, you will produce 3 moles of O2 for every mole of Ba(ClO3)2 you start with, so multiply the moles of Ba(ClO3)2 by 3 to convert that into moles of oxygen. Finally, you can assume STP conditions and the ideal gas law (or use the equivalence of 22.4 L/mol of a gas) to determine the volume of oxygen produced.

All of your problems are approached in the same way.

Answer 2

Answer: Read your text book your teacher is watching...