i have a er gent Chemistry question?

Question

how much will 3.00 moles of o2 weigh in grams

32.0 grams
_________
1mole

and the harder one is how much volume in l will 56.0 grams of CO(g) have at stp? 1st i have to change gas into moles then i have to change moles into litres

Answer 1

For the first one, just multiply 3.00 by 32.00 and you will get your answer.

For the second one, change grams into moles by dividing 56.0g by 28.01(molar mass). Then remember, at stp, 1 mol=22.4 L. So then multiply by 22.4 and presto!

Answer 2

1 more corresponds to the Avogadro number, i.e. the number of molecules that'd weigh in grams what 1 atom would weigh. It is always 6.023X10^23. The atomic weight of oxygen is 16. There are two atoms...i.e. 32. So Avogadro number of molecules of O2 would weight 32 grams, i.e. 1 mol = 32g. So 3 moles will be? Calculate.

As for the second one...1 mol of any gas weighs around 22.4 L at STP...i.e. 1 atm P and 298 K (although recent IUPAC guidelines say that at STP, the temperature you do your experiement at is taken as 'Standard'). Now 1 mol of CO is 16+12 = 28g. No. of moles is always - Given Weight/Molecular Weight, following from previous paragraph. So you have 58. Divide 56 by 28 to get number of moles. Then ask...if I have 1 mol that weighs 22.4 L, how much will 2 moles weigh? Calculate and you'll have it.

Answer 3

ok, formulas for you to remember:

a) moles=grams/molar mass
b) volume of gas at STP (in L)= moles x 22.4 L/mol


problem 1:

using formula a, we see that two out of the three unknowns, moles and molar mass, can be determined (molar mass can be looked up on the periodic table)

O has a MM of 16 g/mol, so O2 must have a MM of 32 g/mol

next, we rewrite equation a to solve for grams:

moles=grams/MM
moles x MM= grams

now we substitute:

grams= 30g x 32 g/mol
= 960. grams




problem 2:

first we need to solve for the moles of CO, using formula a.

moles=grams/MM
=56/(12+16)g/mol
=56/28 g/mol
=2 mol

next, we use formula b to solve for the volume in L

Volume=22.4 L/mol x moles
=22.4L/mol x 2 mol
= 44.8 L

hope that helps


*this problem uses rounded molar masses, but the final answer follows AP significant figures rules*

Answer 4

How much will 3.00 moles of O2 weigh in grams?
Molar mass of O2 = 16*2 = 32
Mass of 3.00 moles of O2 = 32*3.00 = 96.0 grams

How much volume of gas is there in 56.0 grams of CO(g) have at stp?
Molar mass of CO = 12+16 = 28
No. of moles of CO = 56.0/28 = 2.00 moles
Volume of gas = 24dm3 * 2.00moles = 48dm3

48dm3 = 48*1000 = 48 000cm3 = 48 litres

Note: Avogadro's constant is 24dm3 per mole. All gases at stp will have this volume per mole.

Answer 5

1 mole of O2 has 32 grams. You can figure out 3 moles.

1 mole of CO2 will occupy 22.4 liters at stp. One mole of CO2 has 44 grams. You have 56 grams.

Figure out how many moles and multiply by 22.4

Answer 6

lol, well, the first one is easy.

like you said, 3 mol---32.0 grams/ 1 mol (3 * 32) 96 grams

The second one isn't that hard.

It's a Ideal Gas Problem. Change grams of CO to mol, and then insert into PV=nRT R=0.082058 L-atm/mol-K