amount of substance (foundations in chemistry) Flashcards
what is amount of a subtance
the number of particles in a substance . the unit = mol and one mol is the amount of a substance that contains 6.02 x 10 ^23 particles
what is the mass of one mol of magnesium
24.3g
what is the unit for molar mass
g mol -1
what is molecular formulae
the number and type of atoms of each element in a molecule eg cl2
what is emperical formulae
a formula that shows the simplest whole number ratio of the number of atoms of each element in a compound eg p4o10 = p2o5
what is relative formula mass
the weighted mean mass of the formula unit of a
compound compared with 1/12th the mass of an atom of carbon 12
flouride formula
F-
nitrate formula
NO3-
hydrogen carbonate
HCO3-
carbonate
CO3 2-
sulfide
S2-
sulfate(VI)
SO4 2 -
1 ton in grams
1,000,000
1 mg in grams
0.001g
What is molar mass
Molar mass of a substance is the mass of one mol of a substance and it has units g mol ^-1
1 cm^3 in ml
1 ml
1 Dm^3 in cm^3
1000cm^3
1 dm^3 in m^3
0.001 (/1000)
Equation linking moles , conc and vol with units
Moles (n) = concentration (mol dm ^-3) x volume (dm^3)
What is the concentration of a solution
The concentration of a solution is the amount of solute in moles dissolved in 1 dm^3 of solution
What is the assumption of volume of gases
All gases occupy the same volume of gas per mol at a fixed temp and pressure
What is the molar gas volume
24.0 dm^3 mol^-1 ( at 20c and 1 atm ) so at RTP 1 mol of gas molecules has a volume of 24dm^3
What is the ideal gas equation and units
P(pa)V(m3) = n(moles) R(8.314Jk-1 mol-1) T(K)
1 atm in pa
10^5 pa
25 c in K
298 K
0 c in K
273 K
How to convert kelvin (K) to degrees
-273 and vice versa
What is a neutralisation reaction
Acid + base - salt + water
How can you increase atom economy
Finding a use for all the products , creating no waste
Why would a reaction not have 100% yield
Reversible, so won’t go to completion , some may be lost when it is separated from the reaction mixture , some of the reactants may react in ways different to the expected reaction(side reactions)(impurities)
What is the equation for percentage yield
Actual yield / theoretical yield x 100
What is the equation for atom economy
Total Mr of desired product / sum of total mrs of all reactant x 100
Why is atom economy important
Profit , waste , sustainability
