Calculation of reacting masses, gas volumes and mole concentrations Flashcards Preview

CHEM - 2.1.3 Amount of Substance > Calculation of reacting masses, gas volumes and mole concentrations > Flashcards

Flashcards in Calculation of reacting masses, gas volumes and mole concentrations Deck (9)
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1

Mass: n (mol) =

m (g) / Mr (gmol-1)

2

Gas volume: n (mol) =

volume (dm3) / 24 molar gas vol

3

Concentration: n (mol) =

conc. (moldm3) x vol (dm3)
* For mass concentration, multiply mol. concentration by Mr.

4

Standard solution

- A solution of known concentration.
- Prepared by dissolving an exact mass of the solute in a solvent and making up the solution to an exact volume.

5

Molar gas volume

- The volume per mole of gas molecules at a stated temperature and pressure.
- At RTP molar gas vol. is 24 dm3 mol-1

6

Ideal gas equation

pV = nRT
p is Pa
V is volume in M3
n is moles
R is the ideal gas constant 8.31
T is temperature in K so +273

7

Assumptions for the molecules making up an ideal gas

- Random motion
- Elastic collisions
- Negligible size
- No intermolecular forces

8

Conversions

- cm3 to m3 = x10^-6
- dm3 to m3 = x10^-3

9

Stoichiometry

- The ratio of the amount, in moles, of each substance, given by the balancing numbers in a balanced equation.