14) LABORATORY Flashcards
Put in order from most accurate to least accurate
1) beaker
2) burette
3) measuring cylinder
4) pipette
Beaker
Measuring cylinder
Burette
Pipette
What is the most accurate equipment to measure a solution
Pipette
Why would a burette be used instead of a pipette
Pipettes only come in standard volumes like 25, 50, 10, 5 cm3.
Burette would be used to measure non standard volumes like 12, 45, 32 cm3
What is a standard solution
A solution of accurately know concentration
What is bromine used to test
Saturation
What would happen if you put bromine in an the following…
1) unsaturated
2) saturated
1) turn solution colourless
2) no colour change
Why would distilled water be used instead of water
There are impurities in water, which may affect experiment
What is a standard solution
A solution of accurately know concentration
Why would excess acid be used in a reaction
Supply H+ ions
Name the sources of error in an Enthalpy is solution reaction
State how an Enthalpy is solution reaction can be improved
Errors:
Heat loss to surrounding
Improved:
Use polystyrene cup as it a good insulator of heats
Use kid to keep in heat
Name the sources of error in an Enthalpy of combustion reaction
State how an Enthalpy of combustion reaction can be improved
Errors:
Heat loss to surrounding
Incomplete combustion because of draft
Improved:
Heat draft keep heat in
Metal beaker is a good conductor of heat
What would affect how far a substance travels during chromatography
Polarity
Particle size
How do you prepare a standard solution
1) fully dissolved __reactant___ in distilled water, in a beaker and transfer to a __vol__ standard flask
2) beaker rinsed and transferred to flask
3) flask filled to __vol__ with distilled water and use a stopper to ensure thorough mixing of solution
