5.3 Flashcards
what is a solute
a substance that is dissolved
what is a solvent
a substance that dissolves a solute
what is the equation for concentration
conc= m(g) / v(dm^3)
define a solution
solute dissolved in a solvent
how do you convert cm^3 into dm^3
divide by 1000
how do you calculate molar concentration (equation)
molar conc = moles / volume
what is a standard solution
a solution whose concentration is accurately known
what are primary standards
substances used to make a standard solution by weighing
what should the properties of primary standards be
-solid
-high molar mass
-high degree of purity
-chemically stable
-not absorb water from the atmosphere
-soluble in water
-react rapidly & completely
what is titration/volumetric analysis
a practical method with the aim of measuring the volumes of two solutions that react together
what is a base
alkali
what apparatus is needed for a titration
-conical flask
-burette
-clamp stand
-pipette + pipette filler
-deionized water
-small funnel
-white tile
why do you repeat titers to get concordant results
within 0.2cm^3 of each other
ensure accuracy
dismiss anomalies
state 2 indicators and their colour change
methyl orange
yellow/orange -> red
alkali -> acid
pink -> colourless
phenolphthalein
state a strong and a weak acid
strong: hydrochloric acid HCl
nitric acid HNO3
weak: ethanoic acid CH3COOH
state a strong and a weak base
strong: sodium hydroxide NaOH
potassium hydroxide KOH
weak: ammonia NH3
what is the equivalence point
the point at which there are exactly the right amounts of substances to complete the reaction
define meniscus
the curving of the upper surface of a liquid in a container
