Amount Of Substance Flashcards
What unit can amount of substance be measured by
Mol
How many particles does one mole contain
6.02 x 10^23
What is the name given to this specific number of particles
Avogadros constant
Does the n.o of particles in one mole change dep on what the substance is
No it doesn’t change for atoms, molecules, electrons, ions etc
Fill in the gap
1 mole of any substance contains
6.02 x 10^23 atoms, ions, electrons, molecule
Eg one mol of sodium ions contains 6.02 x 10^23 ions
Eq for number of particles
N.o of particles (atoms, molecules, ions etc) = n.o of mol x avogadros constant
Finish the sentence
1 mol of any substance has a mass …
That’s the same as it’s relative molecular mass (Mr) in grams
Equation for n.o of moles
Mass
————
Mr
Eq and units for conc
Conc = mol / mass
———————
Vol
Conc = mol dm^-3
Vol = dm3
How many cm3 in 1dm3
1000cm3 = 1dm3
Ideal gas equation and units
Pv = nRT
P = pressure = pascals
V = volume = m3
R = gas constant = J mol ^-1 K-1
T = temperature = K/•c
Vol of one mol of any gas
One mol of any gas has a vol of 24dm3 at room temp and pressure
What is room temp and pressure
20 degrees Celsius
101,000 pa
Mol equation using vol
V
N = ——
24
How many dm3 in m3
1000dm3 = 1m3
Divide by 1000
How many cm3 in 1 m3
1,000,000 cm3 = 1m3
Divide by 1,000,000
What is ideal gas constant
8.314 J mol -1 K -1
How to convert from degrees Celsius to kelvin
Degrees celcius ——> kelvin
+ 273
From kelvin to degrees Celcius
K ——> celcius
-273
4 assumptions for ideal gas
1) gas molecules r tiny compared to spaces bet them
2) no forces acting bet gas mol
3) gas mol move randomly
4) collisions bet gas mol are elastic
What do ionic equations only show
Reacting particles
Steps of writing ionic equation
1) write full balanced equation
2) rewrite equation into its ions
3) cross out spectator ions on both sides of reaction
What cannot be broken down into ions
Gases and solids
Phenolphthalein colour changes
Pink in alkali
Colourless in acid
Methyl orange
Yellow in acid
Red in alkali
Equation for percentage yield
Percentage yield = actual yield
——————. X 100
Theorifcal yield
Atom economy
Mass if desired prod
—- —————————
Mass of total prod
Benefits of high atom economy
- less waste w high atom economy so helps environment
- raw materials used more efficiently so increased sustainability
- less by products and less time and money separating them from desired product
