Key Skills And Core Knowledge Flashcards
(25 cards)
Standard lab conditions (SLC)
Temperature considered as normal room temperature 25 degrees or 298k
Pressure @SLC is 100kPa
To convert from mmHg -> kPa
(Pressure/750)x 100
To convert from kPa ->mmHg
(Pressure /100)x 750
To convert from atm ->kPa
(Pressure/0.987)x q00
To convert from kPa -> atm
(Pressure/100)x0.987)
Molar volume formula and it’s use
n=V/Vm at SLC
Universal gas equation
PV=nrt
R =universal gas constant of 8.31j/k/mol
P = kilopascal (kPa) V= litres temperature = kelvin (+273 to Celsius) quantity of gas = moles
Aim
Purpose /objective of an experiment
Independent variable
Variable that is deliberately manipulated or changed by the experimenter to find the effect on the dependent variable
Dependent variable
The variable that is measured by the experimenter
Controlled variable
Variable(s) held constant throughout the experiment
Hypothesis
Statement that predicts the outcome of the experiment/investigation
Qualitative analysis
Technique that determines the composition of the sample - what’s in it
Qualitative data
Non- numerical (descriptive) data collected based on observation taken during an experiment
Quantitative data
Data which provides a numerical value
Quantitative analysis
Technique that identifies the amount of substance present
Quantitative technique (Electrolytic cell):- purpose
To predict the amount of reactant used or mass of product formed
Example of quantitative data derived from electrolytic cells
The time , voltage and /or current at which electricity is passed through cell
Quantitative technique HPLC (high performance liquid chromatography);- purpose
To identify properties and the identity of the components in a sample
Example of quantitative data derived from HPLC
The retention time of different components in a sample
Quantitative technique (Volumetric analysis/titrations) ;- purpose
To determine the concentration /amount of an unknown compound
Example of quantitative data derived from Titration
The volume of the titrant used in the experiment
Quantitative technique (calorimetry) :- purpose
To determine the enthalpy (delta H) of a reaction
Example of quantitative data derived from calorimetry
The temperature change as a result of a reaction