Simple Chem Question =[ (1 Viewer)

[Finx]

Hi all,

I'm wondering HOW this answer is achieved.

What would ten molecules of N2O3 weigh?

I've been told that you get the answer by dividing the molar mass (76) by Avagadro's number, then multiply by ten.

If this is correct, can I assume that (Molar Mass / Av's # = weight of 1 molecule)?

 

[Continuum]

The molar mass (76) is how much N₂O₃ weighs when there is 6.022x10²³ (Avagadro's constant) molecules of them.

If you only want to find the mass of 10 molecules however, you need to divide 10 by Avagadro's constant and then multiply that by the molar mass.

 

[turmionkat]

yes you are correct molar mass/av would equal to the weight of 1 molecule.

(14x2)+(16x3)
6.0221415 × 1023

=8.84 e-17

times that by ten and you got the answer

 

[lolokay]

a mole is the mass of 6.02*10^23 atoms/molecules/formula units
so 1 molecule has a mass of 1 mol divided by 6.02*10^23

 

[bored of sc]

since it says weight, wouldn't that mean your answer is in newtons?

 

[kaz1]

since it says weight, wouldn't that mean your answer is in newtons?

I think he was meant to write mass. Anywayz you just convert the answer to kg and times it by 9.81 .

 

[Finx]

Thanks guys =]

 

[Continuum]

since it says weight, wouldn't that mean your answer is in newtons?

How come you don't do physics?

 

[Aerath]

since it says weight, wouldn't that mean your answer is in newtons?

Yeah, but in Chemistry - weight usually refers to grams and kilograms too.

 

[bored of sc]

How come you don't do physics?

It clashed with PDHPE - I am kinda regretting the choice (since PDHPE is not my cup of tea anymore). I would of loved the mathsy side to physics, but oh well, can't change now!

 

[bored of sc]

Yeah, but in Chemistry - weight usually refers to grams and kilograms too.

True... We use weight in PDHPE too, it just annoys me that in physics they teach you weight is a force that differs depending on the acceleration due to gravity, not how heavy something is.

 

[Devouree]

True... We use weight in PDHPE too, it just annoys me that in physics they teach you weight is a force that differs depending on the acceleration due to gravity, not how heavy something is.

wow, what kind of stuff do you study in PDHPE? The only stuff I remember was copying some kind of obsure notes off the board...

 

[Aerath]

wow, what kind of stuff do you study in PDHPE? The only stuff I remember was copying some kind of obsure notes off the board...

And if you had Farrington - not even that. He just walked out after marking the roll for 10 minutes.

 

[bored of sc]

what kind of stuff do you study in PDHPE?

um, we did a small topic on basic definitions
- then did Better Health for Individuals: looking at how exercise, nutrition, drugs etc affect health
- now we are doing the body in motion: biomechanics of human movement, components of fitness, muscular system, skeletal system, cardiorespiratory system etc

its okay I guess - but I would much rather have frees to finish the work from other subjects, thus giving me more free time - I'll have to wait till year 12..

oh yeh, just today we did the speed and acceleration of Carl Lewis over 100m when he set the world record of 9.92 seconds in the 80's olympics (very basic examples, just pluggling into formulas, not much thought required)

P.S PDHPE in year 11/12 is theory based