Chemistry Flashcards
Relative Atomic Mass
The weighted mean mass of an atom of an element compared to 1/12th the mean mass of an atom of an element on carbon-12
Relative Isotopic Mass
The mean mass of an atom of an element relative to 1/12th the mean mass of an atom of carbon-12
Charge of NO3
-1
Charge of NO2
-2
Empirical Formula
Simplest whole number ratio
pV=nRT units
p=Pascals
V=M^3
n=Number of moles
T=Kelvin
Percentage yield formula
Experimental mass / theoretical mass times by 100
Strong Acid
An acid that fully dissociated in an aqueous solution
Standard Solution method
Weigh by weigh by difference
Dissolve the solid using less distilled water then needed and stir with a glass rod
Transfer to the volumetric flask and add washings
Make up to the 250cm^3 mark so that the bottom of the miniscus is on the line
Inverted multiple times so that the concentration is equal throughout.
Shells
A group of atomic orbitals that have the same principal quantum number
Atomic Orbitals
A region of an atom that can hold up to 2 electrons with opposite spins
Chlorine in cold alkali
Occurs at 15 degrees
Cl2 + 2NaOH gives you NaCl + NaClO + H(2)0
Chlorine with water (reactions that occur in the swimming pool)
Cl(2) + H(2)o gives HCl + HClO
What kills bacteria in the water
Chloric acid (HCLO) and (ClO-) - the product formed when chloric acid dissociates
Chlorine with sunlight
2Cl(2) + 2H(2)O gives 4HCl + O(2)
Acid
Proton Donor
Base
Proton Acceptor
Alkali
A soluble base that dissolves in an aqueous solution to release OH- ions
Colours of Chlorine, Bromine and Iodine in silver nitrate
Chlorine = White
Bromine = Cream
Iodine = Yellow
What happens to halides in dilute NH3
Chloride dissolves
What happens to halides in concentrated NH3
Bromine dissolves
Colours of Halogens in aqueous solution
Chlorine = Pale-green
Bromine = Orange
Iodine = Brown
What is the halogen that changes colour in cyclohexane
Iodine to violet
Test for carbonate ions
Add dilute acid, effervescence
Test for Sulfate ions
Barium nitrate, white precipitate forms
Solid Barium Nitride with water forming an alkaline solution
Ba3N2 + 3H(2)O gives 3Ba(OH)2 + 2NH3. Forms barium hydroxide
Explain the anomalous properties in water
Solid is less dense then the liquid state as in the solid lattice, hydrogen bonding hold molecules apart.
H(2)O have relative high boiling points compared to other simple covalent molecules due to the incredibly strong hydrogen bonding
H(2)O have a high surface tension
Dative Covalent Bond
A covalent bond where the bonding pair of electrons have been donated by 1 atom only
Covalent bond
Electrostatic attraction between the bonding pairs of electrons and the positive nucleus
Covalent structure of NO3-
Uses a triangle on the O- atom
Explain what is meant by an ionic lattice
Repeating pattern of oppositely charged ions
Down the group
Atomic radius increases
Shielding increases
These outweigh the increase in nuclear charge
Therefore the nuclear force of attraction on the highest energy electron increases
Across the period
Atomic radius decreases
Shielding stays the same
Nuclear charge increases
Force of attraction on the highest energy electron increases
Formula of Nitric Acid
HNO3
First ionisation energy ——— across a period and ——- down a group
Increases across a period and decreases down the group
Which type of ionisation energy graph looks weird
First ionisation energy
Explain the decrease in successive ionisation energy from group 2 to group 3
p-orbital has a higher energy than s-orbital. Therefore requires less additional energy to remove an electron
Explain the decrease of successive ionisation energy from group 5 to group 6
Group 6 causes a pair of electron to form which repels. Therefore less energy required to remove the highest energy electron
