Chem topic 1 + equilibrium Flashcards
What is the Lyman Series?
Electrons fall down to level 1 and emit ultraviolet waves
What is the Balmer Series?
Electrons fall down to level 2 emit waves in the visible spectrum
What happens in Alpha decay?
Helium nucleus released
Mass: -4
Atomic no: -2
What happens in Beta decay?
Electron (beta particle released)
Mass: same
Atomic no: +1
What happens in Gamma decay?
Gamma rays emitted
Often followed by beta or alpha decay
What are the 4 types of shells?
S P D F
How are shells 3 and 4 filled?
3s , 3p, 4s, 3d
What are the anomalies in shell filling?
Copper and Chromium
What are dative bonds?
A covalent bond where both electrons shared some from the same atom
What is electronegativity?
Strength/ pull of an atom on an electron
Name the shape and degree of an element with 2 regions of electron density. And an example.
Linear
180
Beryllium chloride BeCl2
Name the shape and degree of an element with 3 regions of electron density. And an example.
Planar triangular/ trigonal planar
120
Boron triflouride BF3
Name the shape and degree of an element with 4 regions of electron density. And an example.
Tetrahedral
109.5
Methane CH4
Name the shape and degree of an element with 5 regions of electron density. And an example.
Trigonal bipyramidal
90 120
Phosphorus (v) chloride PCl5
Name the shape and degree of an element with 6 regions of electron density. And an example.
Octahedral
90
Sulfur (VI) Fluoride SF6
Describe the water bond ( +angle)
Bent
2 lone pairs
104.5
Mass spectrometry describe
Sample ionised Accelerated Measures time how long it takes to travel Light ions faster Heavy ions slower
Detect isotopes and relative abundance
Spectroscopy
Describe emission and absorption spectra
Emission- coloured lines on black background
Absorption- black line on a coloured background
Related to specific energy gap between shells, move into an excited state, fall back down and release specific frequencies (wavelengths)
E=hf
Orbital shapes
S- spherical
P- dumbell
Le Chatelier’s Principle
Is a system is at equilibrium and a change is made in a by conditions the system will oppose the change
Equilibrium- if temp increases
Process will decrease temp, driving endothermic reaction
Equilibrium- pressure increases
Process will decrease, drive reaction with least moles as product
Equilibrium- concentration increases
Reactants increase, drive the reaction
Equilibrium constant Kc
Kc= C^c x D^d/ A^a x B^b
aA + bB —-> cC + dD
Lower case is n of moles
Kc = products/ reactants
What is a pi bond?
2 Found in double bonds
When p orbitals overlap
What is a sigma bond
Find in single bonds and double bond
When two orbitals overlap
