Question

How many grams of Oxygen gas will occupy 1.12L space at STP?

Answer 1

@Somy

Answer 2

STP is standard temperature and pressure
temp = 273 K
perssure = 1 atm

Answer 3

PV= nRT
u know P , V and T
R is constant value, and u also know it

Answer 4

R = 0.0821

Answer 5

find n

Answer 6

How do you figure out R?

Answer 7

well its a constant value
http://www.csupomona.edu/~lllee/gasconstant.pdf

Answer 8

oh oh ideal gas, got it

Answer 9

because we are using P in atm, v in L and T in K
thats why K = 0.0821

Answer 10

i personally use SI system units
which is
P= pa
V= m3
T= K
thus
R = 8.31

Answer 11

but i don't want to confuse u so lets do it ur way

Answer 12

so I have (1atm)(1.12L)=n(0.08206L*atm/mol*K)(273K)

Answer 13

yup

Answer 14

I get 0.049995

Answer 15

yup

Answer 16

The answer is 1.6g

Answer 17

so now u have mole
use formula
mole= mass/Mr
Mr will be 16
mole u have
mass= X

and im getting 0.79992g

Answer 18

coz they are asking for Oxygen gas
they are not saying O2 gas, i've seen this happening a lot hhhh so i don't get if the question is asking for O2 or just O
usually when they don't specifically tell u O2, we take it as O

Answer 19

but what is the answer that u have?

Answer 20

i mean the right answer

Answer 21

The correct answer is 16g

Answer 22

alright then they mean O2
so yeah u got it

Answer 23

would this also work?

Answer 24

\[1.12LO * \frac{ 1mol O }{ 22.4L O } * \frac{ 16g O }{ 1mol O } = .8 g <-- *2 = 16g O\]

Answer 25

lol

Answer 26

no don't overdo it lol u'll kill the formula that exists

Answer 27

but but my formula worked lol

Answer 28

lol thats not your formula
there is another way of doing this lmao

Answer 29

I know is not mine, but still worked :o

Answer 30

volume= mole* 22.4 mole= volume/22.4
mole= mass/ Mr
mass= mole*Mr
mass= (volume/22,4) * Mr

Answer 31

this is what u did lol

Answer 32

so it work the way I did it :o

Answer 33

BUT it only works if pressure stays as 1 and temperature at 273K

Answer 34

yes

but u better play with formulas like i did just now
rather then 'as u think' making up a formula from nowhere

well if u did consider those formulas then u are on the right way

Answer 35

yes it only works as long as the condition is STP

Answer 36

do you think I will remember all if I fall sleep for 3 hours?

Answer 37

if its RTP its same but value 22.4 will change to 24

Answer 38

lol u will
if its test
before the test
DON'T LOOK THROUGH STUFF YOU DID
ur brain will be messed up

Answer 39

so look through everything u did before u sleep
that way it'll get fixed lol

Answer 40

I somehow remember every single digit from constants and stuff... even though im almost sleeping

Answer 41

lol well do ur best :)

Answer 42

I have another question. Which gases behave as a perfect ideal gas?

Answer 43

I just learned half a book of a material in 8 hours buh

Answer 44

hmm gas at high temp and low pressure behaves kinda ideally
noble gasses are one's that are closest to behaving ideally

Answer 45

so between Methane and Ammonia, which one behaves closer to an ideal gas? and I would like to know how you figure this out.

Answer 46

hmmm i'd say methane
coz i remember Ammonia not behaving ideally lol

Answer 47

let me check
just a sec

Answer 48

oh i think i understand
its not ammonia because of H bonding
intermolecular forces are just too strong so we cannot ignore it
in case of methane its just van der Waal's forces and are not much
thats why if we compare these 2
the one close to ideal gas behavior would be methane rather then ammonia

Answer 49

ok I understand it.

Answer 50

just read this through
http://www.s-cool.co.uk/a-level/chemistry/states-of-matter/revise-it/the-gaseous-state-and-the-gas-laws

Answer 51

:)

Answer 52

I have one last question before I die

Answer 53

What is the volume of 56 g of Nitrogen at STP? I did it but I forgot how I did it -.-?

Answer 54

lol use the awesome formula u made

Answer 55

I tried =.=

Answer 56

\[56g N*\frac{ 1mol N }{ 14g N }*\frac{ 22.4L N }{ 1mol N } = 89.6L \]

Answer 57

The answer is half of that. I am missing something..

Answer 58

\[mass = \frac{ volume }{22.4 }\times Mr\]
\[mass = \frac{ volume \times Mr }{22.4 } \]
\[mass \times 22.4 = volume \times Mr \]
so

Answer 59

\[volume = \frac{ mass \times 22.4 }{ M r }\]

Answer 60

You will get 89.6L too..

Answer 61

Nitrogen is N2 lol

Answer 62

so is divided by 28g

Answer 63

its not 14 xD its 28 the Mr

Answer 64

How am I suppose to know if there is just 1N or 2N? D;

Answer 65

N or N2*

Answer 66

idk im always confused in this
in previous question when they say Oxygen gas, they meant O2

Answer 67

so i thought here they mean N2
so i guess they will specify if its O or N
but when they don't specify then its O2 or N2

Answer 68

I suppose it is to be seen as Nitrogen Gas since it says Nitrogen at STP

Answer 69

I will do the work as if the professor is asking O2 or N2 or any other gas to subscript of 2

Answer 70

i guess thats how it is

Answer 71

I have to remember that now. I suppose this must be the reason why so many had low grade on this quiz of this chapter =.=

Answer 72

lol well good luck ))

Answer 73

since it is N2 it is still 1 mole of N right

Answer 74

1 mole of N2*

Answer 75

hmm yeah
tho it'll depend on the question

Answer 76

aaaaaaaaaaaaaa chem make it all so difficult lol

Answer 77

chem is interesting tho lol

Answer 78

take a look at this
http://openstudy.com/study#/updates/53a5b02ae4b0a819ab109a05

Answer 79

all to start over -.-. is same as calculus :D

Answer 80

I once took 3 times longer than that solving something with a friend

Answer 81

took us around 2-3 hours for one problem. is fun, I can imagine that being as fun as calculus lol

Answer 82

Instead of 8 hours I actually spent around 10 hours non stop learning half the book

Answer 83

lol that's cool
i mean doing this on ur own
must be tough

Answer 84

that's why I came here for any doubt I had =.=

Answer 85

lol that's good :) i can help out as long as its my level chem lol