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angelxtearz

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this is partly my fault for not entirely studying for the prelim but
for calculations of gas volumes isnt it just (conditions x no of moles)?

and i don't really understand the effect of pressure and all the other stimuli in correlation to the use or effectiveness of a catalyst.


thankyoz
 

mitsui

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i dont get the Q u r on about. ><''

but isnt effect of pressure meaning diff conditions?? so it is still (condition x no. moles)

...no idea for the catalyst
 

Dreamerish*~

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angelxtearz said:
this is partly my fault for not entirely studying for the prelim but
for calculations of gas volumes isnt it just (conditions x no of moles)?

and i don't really understand the effect of pressure and all the other stimuli in correlation to the use or effectiveness of a catalyst.


thankyoz
At 0°C and the pressure of 1 atmosphere, one mole of any gas will occupy a volume of 22.41 L.

At 25°C and the pressure of 1 atmosphere, one mole of any gas will occupy a volume of 24.79 L.


So yes. You just shove the number of moles into the formula. Moles x 22.41 or 24.79 = volume.

The second question depends on what equation you're talking about. For fermentation, for example, excess temperature will kill yeast - the catalyst. For the Haber process, presence of CO and sulfur will poison the catalyst.
 
P

pLuvia

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Yeh what are you trying to ask?

Here's an easy way to do the calculations
 

Dreamerish*~

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angelxtearz said:
those were 2 qz.

one on
-volume
-catalyst- how it is affected by different stimuli eg temp, pressure

ne1?
Dreamerish*~ said:
At 0°C and the pressure of 1 atmosphere, one mole of any gas will occupy a volume of 22.41 L.

At 25°C and the pressure of 1 atmosphere, one mole of any gas will occupy a volume of 24.79 L.


So yes. You just shove the number of moles into the formula. Moles x 22.41 or 24.79 = volume.

The second question depends on what equation you're talking about. For fermentation, for example, excess temperature will kill yeast - the catalyst. For the Haber process, presence of CO and sulfur will poison the catalyst.
Is this what you're talking about?
 

angelxtearz

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do i HAF ta put a title.....

with the moles, i was thinking that for a volume of a gas it wud b no of moles x conditions. (gay lussac principle) but the answers for da 2004 papr . q 9 disagreed
well this is wht i gut.
9.C
no. of moles for 03- <O:p
0.72g/48g= 0.02 mol<O:p</O:p
no. of moles for NO-<O:p</O:p
0.66g/30g=0.02<O:p</O:p
volume of NO2(g) produced = 0.02 x 22.71<O:p</O:p
=0.45 L
and...i wuz wrong...
 
Last edited:

Dreamerish*~

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angelxtearz said:
with the moles, i was thinking that for a volume of a gas it wud b no of moles x conditions. (gay lussac principle) but the answers for da 2004 papr . q 9 disagreed
well this is wht i gut.
9.Cffice:eek:ffice" /><o>:p></o>:p>
no. of moles for 03- <o>:p></o>:p>
0.72g/48g= 0.02 mol<o>:p></o>:p>
no. of moles for NO-<o>:p></o>:p>
0.66g/30g=0.02<o>:p></o>:p>
volume of NO2(g) produced = 0.02 x 22.71<o>:p></o>:p>
=0.45 L
and...i wuz wrong...
Wow...

Can you post up the question and the correct answer?
 

angelxtearz

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so weird

thts so weird, y r were there all these random emoticons, i swear i didnt do it, i copied it from mi word doc...............................ScArY!
 

angelxtearz

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questions

9​
Ozone reacts with nitric oxide according to the equation
NO(
g) + O3(g) NO2(g) + O2(g)
0.66 g NO(
g) was mixed with 0.72 g O3(g).
What is the maximum volume of NO
2(g) produced at 0°C and 100 kPa?
(A) 0.34 L
(B) 0.37 L
(C) 0.45 L
(D) 0.50 L

derz da qz

 

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angelxtearz said:
0.72g/48g= 0.02
0.66g/30g=0.02
DO NOT ROUND YOUR ANSWERS IN CHEMISTRY UNLESS ASKED TO DO SO IN THE QUESTION!!! :bomb:

By calculator, 0.72/48=0.015, which is 7.5% less than your rounded answer! This is most likely why you are ending up with the wrong answer.

Also 0.66/30=0.022, use this exact decimal in your calculation.

Try it again, you should get it right now. :)
 

Dreamerish*~

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angelxtearz said:
9​
Ozone reacts with nitric oxide according to the equation
NO(
g) + O3(g) NO2(g) + O2(g)
0.66 g NO(
g) was mixed with 0.72 g O3(g).
What is the maximum volume of NO
2(g) produced at 0°C and 100 kPa?
(A) 0.34 L
(B) 0.37 L
(C) 0.45 L
(D) 0.50 L

derz da qz

NO2(g) + O3(g) NO2(g) + O2(g)

0.66 g of NO is reacted with 0.72 g of O3.

n = m/M

The molar mass of NO is 14 + 16 = 30 g, therefore we have 0.66/30 = 0.022 moles. (Note that I didn't round off)

The molar mass of O3 is 16 x 3 = 48 g, therefore we have 0.72/48 = 0.015 moles. (Note that I didn't round off here, either)

The molar ratio of NO to O3 is 1:1. We have 0.022 moles of NO but only 0.015 moles of O3, therefore NO is in excess - only 0.015 moles of it reacts.

The molar ratio of NO to NO2 is 1:1. Therefore 0.015 moles of NO2 is produced.

At the temperature of 0
°C and 100 kPa, one mole of any gas occupies 22.41 L.

0.015 x 22.41 = 0.33615

Now, round off to two decimal places: 0.34.

. : The answer is (A).

 

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