foundation Flashcards
Relative isotopic mass
The mass of iostope relative to 1/12 of carbon-12 atom
Relative atomic mass
The weighted mean mass of an atom relative to 1/12 of a carbon-12 atom
Steps of mass spectroscopy
- sample is vapouried
- sample is ionised to 1+ charge
- ions are accelerated by a magnetic field
Aim of mass spectroscopy
To find the abundancy of each isotope
What does a mass spectrometry graph show?
Each peak represents the abundancy of a isotope.
Isotope
Same no. of proton but different no. of neturons
Charge of NO2 ion
1-
Charge of NO3 ion
1-
Charge of HCO3 ion
1-
Charge of MnO4 ion
1-
Charge of Ag ion
1+
Charge of SO3 ion
2-
charge of CrO7 ion
2-
Charge of Zn ion
2+
Charge of NH4 ion
1+
Charge of PO4 ion
3-
What does avogradro constant a value of?
The no. of atoms / molecules per moles
Equation of amount in gas (Room temp. and pressure)
volume (dm3) = moles * 24
Ideal gas equation
pv = nGT
Precentage yield eq.
actual/theoritical * 100 = %
Atom economy eq.
useful/total * 100 = %
Benefits of high atom economy
↓waste produced : ↑ product formed
Greater profit margin (as cost is reduced)
What may cause actual yield < theoritical yield?
- side reaction
- incompletion of reaction
- product loss during purification
dm3 –> cm3 conversion
x 1000
K to celcius
K = C + 273
Difference between strong and weak acids
Strong acid fully disociates
Weak acid partially disociates
[in solution]
Examples of strong acids
- HCl
- HNO3
- H2SO4
Examples of weak acids
Any carboxylic acids E.g. HCOOH, H3CCOOH
Products of acid and metal reaction
salt + H2
Products of acid and base
salt and H20
Example of base
Metal oxides, hydroxides, carbonate(have special reactions)
Products of Acid and carbonate
salt + H2O + CO2
Observation of strong acid reaction
- effervescence
- metal dissolves quicker
- ↑ exothermic
Volumetric analyisis
The use of volume of conc. of a standardised solution to determine the conc. of unknown solution.
Steps to making standardised solution
- weigh out precise amount of solid
- Dissolve solid to small volume of H2O
- Transfer it to a volumetric flask
- Add water until the bottom of meniscus is at the scratch mark
Use of burrette
To deliver precise volume of solution (WITH known conc.) until point of neutralisation
Steps of titration
- meausre out a known volume of the solution with unknown conc. and transfer to conical flask.
- Add indicator to the conical flask
- Add the known solution to burrette
- turn the burrette on and slow down as it approaches the end point.
- Take repeats until concordent
Define end point
The point where the indicator show the amount of solution required to react completely has been added.
Define concordant
when results are 0.1 cm3 apart
Resolution of result in titration
0.05 cm3
Ox. state of any element
0
Ox. state of Group 1 + 2
Group 1 = +1
Group 2 = +2