-
Finished your HSC? Check out our University Discussion, Non-School forums or help out next year's HSC students! -
YOU can help the next generation of students in the community! Share your trial papers and notes on our Notes & Resources page
Chemistry Concentration Moles question (1 Viewer)
- Thread starter enigma_1
- Start date
HeroicPandas
Heroic!
- Joined
- Mar 8, 2012
- Messages
- 1,547
- Gender
- Male
- HSC
- 2013
beaten by pappa
HeroicPandas
Heroic!
- Joined
- Mar 8, 2012
- Messages
- 1,547
- Gender
- Male
- HSC
- 2013
Avogadro's constant
Kurosaki
True Fail Kid
nah ideal gas law isn't in HSC syllabus, which is a shame
AB940
Member
- Joined
- Dec 23, 2012
- Messages
- 121
- Gender
- Female
- HSC
- 2012
- Uni Grad
- 2015
To solve this question as others have said you need to use the PV = nRT equation.
Re-arrange it so that it gives the number of moles:
n=PV/RT
R is a constant that links Pressure, volume and temperature mathematically. Boyles' and Charles' laws state that they are interrelated but to be able to use them in a formula, a constant must exist. R represents degrees (K) per litre per pressure unit, and it's important to remember that it is represented differently for different units of pressure. You've been given Kilopascals in this question and the R constant for kPa is ~8.31. For atm, it's 0.0821 if memory serves correctly.
Put the given values into the equation (remembering to convert degrees to kelvin) and that will give you the number of moles, then multiply that by avogadro's number and you have your answer.
Re-arrange it so that it gives the number of moles:
n=PV/RT
R is a constant that links Pressure, volume and temperature mathematically. Boyles' and Charles' laws state that they are interrelated but to be able to use them in a formula, a constant must exist. R represents degrees (K) per litre per pressure unit, and it's important to remember that it is represented differently for different units of pressure. You've been given Kilopascals in this question and the R constant for kPa is ~8.31. For atm, it's 0.0821 if memory serves correctly.
Put the given values into the equation (remembering to convert degrees to kelvin) and that will give you the number of moles, then multiply that by avogadro's number and you have your answer.