Stoichiometric relations Flashcards
what is element ?
1) Single pure substance
2) made of only 1 type of atom.
Whats a compound ?
Chemical combination of different elements, containing fixed ratio of atoms.
Whats a mixture?
2 or more substances in which no chemical combination has occurred.
1) Elements/ compounds retain their characteristic properties.
2) Composition is not fixed
what are homogeneous mixtures?
1) Uniform composition and properties throughout.
what are heterogeneous mixtures?
1) Non uniform composition and properties
2) possible to see separate components
How can we separate the components of mixture ?
1) Solubility in water, filtration, sand and water
2) Boiling point, fractional distillation, hydrocarbons in crude oil.
3) Magnetism, Iron and sulfur
4) Diff amino acids, net charge at a fixed PH, gel electrolysis.
whats sublimation ?
Solid to gas
1) Iodine, CO2 and ammonium chloride goes through sublimation
Whats deposition
Gas to solid
1) Formation of snow, frost and hoar frost.
Sig Figs in Multiplication and Division
1) Answer should have same number of sig figs as the data value with least no of sig figs
Decimal places in Add and subtraction
1) Answer should have the same number of decimal places as the data value with least no of decimal places.
What is molar mass
Mass of 1 mole of a substance.
1) Expressed in grams
2) Units= gmol-1
3) Molar mass=M
Whats relative atomic mass ?
is the weighed average of 1 atom of an element relative to one twelfth of an tom of carbon 12
Empirical formula
Simplest whole no ratio of elements in a compound
Link between molar mass and empirical formula mass
X(mass of empirical formula)
What is limiting reactant
Reactant that determines the quantity of product.
What is theoretical yield ?
refers to the maximum amount of product obtainable assuming 100% of the limiting reactant is converted to product
Formula for % yield
percent yield=actual yield/theoretical yield×100
1) helps in determining the efficiency of a process.
How does Avogadro’s law relates to gas volumes
Avogardo’s Law
Equal volumes of all gases at same temperature and pressure contain an equal no of particles
V is directly proportional to n
What is STP
1) standard temperature and pressure
2) 273 K = 0 Celsius
3) Pressure : 100kPa
What is molar volume at STP
22.7 dm3mol-1
Formula for no of moles of a gas
Volume/ molar volume
Litre is equal to
dm3
milliliter is equal to
cm3
Kelvin to Celsius conversion
C+273.15
