Please enable JavaScript.
Coggle requires JavaScript to display documents.
1d) Relative Formula Masses and Molar Volumes of Gases and 1e) chemical…
1d) Relative Formula Masses and Molar Volumes of Gases and 1e) chemical formulae & chemical equations
-
-
Mole
the mass of one mole of substance calculated as follows
-for elements = Ar expressed in g
-for compounds = formula mass expressed in g
-
-
-
-
Empirical formula
-
-
e.g. find the emprical formula of the following substance using the data about composition by mass: C 13.6%; F 86.4%
working: 13.6g & 86.4g
mass (g) / molar mass moles / smallest no of whole numbers
Ca 13.6/12 1.1/1.1 = 1
F 86.4/19 4.5/1.1 = 4
SO
empirical formula = CF4
molecular formula
e.g. a compound of nitrogen and hydrogen has an empirical formula of NH2. The molar mass of the compound is 32g /mol. Calculate the molecular formula of the compound (relative atomic masses; N = 14, H=1)
working: NH2 = simplest ratio
actual mass is 32g (molar mass) molecular formula
14 + 2 x 1 = 16
NH2 = 16
how many NH2 =32
2NH2
i.e. N2H4 molecular formula
-
-
concentration
-
-
finding concentration of sulpuric acid experiment
-H2SO4 (aq) + 2NaOH (aq) →Na2SO4 (aq)+ 2H2O (l)
-titration
titrations
-
-
-
indicator:
-shows us when the acid has been neutralised by the alkali or visa versa because it will be one colour in acid and another in alkali
-when neutralisation happens it changes colour very sharply
-the colour of methyl orange is yellow in alkali, red in acid & orange (mid-point) in neutralisation
-
