Moles Flashcards
what is avogadro constant
number of particles in 1 mole. 6.02x10(23)
what is the formula to work out the mass
n x mr
Define empirical formula
simplest whole number ratio of atoms of each element present in a compound
Define molecular formula
the actual number and type of atoms of each element in a molecule
what is a hydrated salt
when water is part of its crystalline structure
name the steps for an experiment to make an anhydrous salt
- weigh an empty crucible
- use a pipe clay triangle to support crucible containing salt on a tripod. Gently heat for 1 minute and strongly for 3.
- Leave to cool then weigh anhydrous salt.
how can you ensure all water is gone from salt
the salts will be different colours. Repeatedly heat the compounds.
what is stoichiometry
relationship between the amounts of reactants and products in a chemical reaction
what is the gas volume equation
v=nx24
what is the concentration equation
n
- = c
v
what is the ideal gas equation
PV=nRT
how do you convert from degrees to K
+273
how do you convert kPa to Pa
x10(3)
what does R equal
8.314Jmo(-1)K(-1)
how can you convert cm(3) to m(3)
x10(-6)
what properties does the ideal gas have
random motion (HT), elastic collision, negligible size (LP) and no intermolecular forces (HT)
what is the atom economy formula
Mr of desired product
————————————– x100
sum total of all Mr products
what does a high atom economy lead to
less waste products and more sustainable
how can you increase atom economy
use a different reaction with a higher atom economy or find a use for the unwanted product
what is the % yield formula
amount of product you actually make
——————————————————- x100
amount you should theoretically make
what can you do to increase % yield
most efficient conditions and apparatus
outline a method to dilute a solution
- weigh out solid using mass balance on a weigh boat
- add water (less than volume needed)
- stir with a stirring rod until everything is dissolved (transparent)
- use a filter funnel to pour the solution into a volumetric flask
- rinse off stirring rod, weigh boat and beaker into volumetric flask
- add more distilled water until the bottom of the meniscus touches the line
- put the lid on and invert the solution to ensure solid is mixed throughout.
how can you calculate the concentration of a diluted solution
divide volume of stock solution used over final volume of diluted solution. Multiply this by the concentration of stock solution.
what is the solubility of carbonates and hydroxides
insoluble except for sodium potassium and ammonium
what is the solubility of nitrates
soluble
what is the solubility of chlorides
soluble except silver and lead chloride
what is the solubility of sulfates
soluble except lead, barium and calcium sulfate
what is the solubility of carbonates and hydroxides
insoluble except sodium, potassium and ammonium