stoichiometric calculations?

Question

i have no idea how to do this my teacher does not know how to teach forreal....

How many moles of KCIO3 must decompose in order to produce 9 moles of oxygen gas?
2KCIO3(s)>2KCI(s)+3O2(g)




How many grams of KCIO3 are required to produce 7.50 moles of KCI?
2KCIO3(s)>2KCI(s)+3O2(g)


How many moles of water are produced from 58g of oxygen gas?
___H2+___02>___H2O



Iron reacts with chlorine gas to form iron (III) chloride. How many grams of iron (III) chloride are formed from 112g of iron? (first write the balanced equation)

Answer 1

for the first question:

set up a ratio for O2 and KCIO3 . it's a 3:2 ratio since theres 3 of the O2 and 2 of KCIO3. then write 9 moles for O2 and x for the KCIO3

O2 over KCIO3 = 2 / 3 = 9 mol / x
x = 6 moles of KCIO3

for the second question:

since you're already given 7.50 moles of KCl all you have to do is set up a ratio, just like the first one.

write the number of moles to its respecting element.

since theres 2 KCL and 2 KCIO3 so its a one to one ratio. So there's the same number moles of KCIO3 which is 7.50 moles.

to find the mass of KCIO3 finde the molar mass first of the KCIO3.

then set up a ratio comparing the molar mass of KCIO3 (g/mol) = 7. 5 mol / x. then cross multiply. your answer should be in grams not grams/mol.

for the third question:

find the molar mass of O2. it should be ..... some number g/mol = 58 g / x. x should be in moles since you can't compare mass only moles.

then set up a ratio. h20 / O2... then write the numbers that you have now to its respect element. final answer should be in moles.

Im sorry I don't have my Periodic Table with me so i cant help you with the numbers vert much. I hope this would help you a little though.

the last question i didn't do because i have to go. Im just killing some time here answering while waiting for my friend.

Answer 2

2KCIO3(s)>2KCI(s)+3O2(g)

this is a balanced equation that tells you that 2 moles of KClO3 will decompose to provice 3 moles of O2

if you want to make 9 moles of O2 you simply need to rewrite the equation like this:

2KCIO3(s)>2KCI(s)+3O2(g) original equation
6KCIO3(s)>6KCI(s)+9O2(g) new equation

notice all I did was change the number from 3 to 9 in front of the O2 and then rebalanced the equation

thus in the new equation you will see that 9 moles of O2 are generated from 6 moles of KClO3

How many grams of KCIO3 are required to produce 7.50 moles of KCI?
2KCIO3(s)>2KCI(s)+3O2(g)

similiar method to solve this problem
7.5KCIO3(s)>7.5KCI(s)+11.25O2(g)

so u need 7.5 moles of KClO3 to make 7.5 moles of KCl

so you need 7.5 moles so now u convert to grams by multiplying by the mole weight of KClO3

How many moles of water are produced from 58g of oxygen gas?
___H2+___02>___H2O

first balance the equation
2H2+ 02> 2H2O

now convert 58g of oxygen to moles
and rebalance the equation and you have the moles of water

Iron reacts with chlorine gas to form iron (III) chloride. How many grams of iron (III) chloride are formed from 112g of iron? (first write the balanced equation)

2Fe + 3Cl2 = 2FeCl3

that is the balance equation you should be able to take it from here let me know if u cant and i will help you out some more

good luck

Answer 3

From your reaction equation it is clear that 2 moles of chlorate will produce 3 moles of of O2, so 6 moles of KClO3 will produce 9 moles of O2.

One mole of KClO3 produces one mole of KCl; so 7.5 moles of chlorate are needed. The molecular mass of KClO3 is 122.55 g/mole, so 7.5 moles is 7.5*122.55 grams.

All the rest are done the same way--the reaction equation gives the number of moles reacting, while the molecular mass converts moles to grams and vice versa.

2H2 + O2 -> 2H2O

Chlorine gas is Cl2, so the reaction with Fe is

2Fe + 3Cl2 -> 2FeCl3

Answer 4

1.) moles of KClO3 = 9 moles of O2 x 2 moles of KClO3 / 3moles of O2. you can produce 3 moles of O2 when 2 moles of KClO3 is decomposed. therefore the answer is 6 moles.

2.) you need 2 moles of KClO3 to produce 2 moles of KCl so you need 7.50 moles of KClO3 to produce 7.50 Moles of KCl. And when you multiply it to its molecular mass found in your periodic table, you can get the no. of grams you need to produce 7.50 moles of KCl.
7.50 x (39 + 35 + 3x16) = 915 grams of KClO3.

3.) to balance the equation :
2H2 + O2 > 2H2O
you need 1 mole of oxygen to produce 2 moles of water. there are 32 grams in 1 mole of O2 ( you can find it at your periodic table) so there are 1.8125 moles in 58 grams of O2 and there are 3.625 moles of H2O.

4.)balanced equation is: 2Fe(s) + 3Cl2(g) > 2FeCl3
there are 56 grams in 1 mole of Fe(III) so there are 2 moles in 112 grams of Fe(III). And there are 2 moles of FeCl3 produced. Since there are 161 grams of FeCl3 in 1 mole therefore you can produce 322 grams of iron (III) chloride.

Hope you understand.

Answer 5

nicely first of all this equation is carefully incorrect! enable me provide you a various situation and you do despite your situation replaced into like this: ok, N2+3H2<->2NH3 The double arrow skill that this could be a helpful equilibrium reaction meaning it doesnt pass to ending touch yet 4 now in intro chem we could assume it does. how many mols of Ammonia are produced whilst a million mol of N2 reacts with water. Step a million: set up the proscribing reactant. ok so it is almost a recipe, u pick a million mol of N2 and 3 mols of H2 to furnish you 2 mols of ammonia. in this situation as wellas your guy or woman u assume that the reactant without quantity (in ur case water my case H2) is endless or in extra. Then u say, hmm I have been given a million mol of N2 in basic terms available, so tht is my proscribing reactant so with tht volume how many ammonia could be produced. the respond could be 2 mols.