Chem topic 1 + equilibrium

Question 1

What is the Lyman Series?

Answer 1

Electrons fall down to level 1 and emit ultraviolet waves

Question 2

What is the Balmer Series?

Answer 2

Electrons fall down to level 2 emit waves in the visible spectrum

Question 3

What happens in Alpha decay?

Answer 3

Helium nucleus released
Mass: -4
Atomic no: -2

Question 4

What happens in Beta decay?

Answer 4

Electron (beta particle released)
Mass: same
Atomic no: +1

Question 5

What happens in Gamma decay?

Answer 5

Gamma rays emitted

Often followed by beta or alpha decay

Question 6

What are the 4 types of shells?

Answer 6

S P D F

Question 7

How are shells 3 and 4 filled?

Answer 7

3s , 3p, 4s, 3d

Question 8

What are the anomalies in shell filling?

Answer 8

Copper and Chromium

Question 9

What are dative bonds?

Answer 9

A covalent bond where both electrons shared some from the same atom

Question 10

What is electronegativity?

Answer 10

Strength/ pull of an atom on an electron

Question 11

Name the shape and degree of an element with 2 regions of electron density. And an example.

Answer 11

Linear
180
Beryllium chloride BeCl2

Question 12

Name the shape and degree of an element with 3 regions of electron density. And an example.

Answer 12

Planar triangular/ trigonal planar
120
Boron triflouride BF3

Question 13

Name the shape and degree of an element with 4 regions of electron density. And an example.

Answer 13

Tetrahedral
109.5
Methane CH4

Question 14

Name the shape and degree of an element with 5 regions of electron density. And an example.

Answer 14

Trigonal bipyramidal
90 120
Phosphorus (v) chloride PCl5

Question 15

Name the shape and degree of an element with 6 regions of electron density. And an example.

Answer 15

Octahedral
90
Sulfur (VI) Fluoride SF6

Question 16

Describe the water bond ( +angle)

Answer 16

Bent
2 lone pairs
104.5

Question 17

Mass spectrometry describe

Answer 17

Sample ionised
Accelerated
Measures time how long it takes to travel
Light ions faster
Heavy ions slower

Detect isotopes and relative abundance

Question 18

Spectroscopy

Describe emission and absorption spectra

Answer 18

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

Question 19

Orbital shapes

Answer 19

S- spherical

P- dumbell

Question 20

Le Chatelier’s Principle

Answer 20

Is a system is at equilibrium and a change is made in a by conditions the system will oppose the change

Question 21

Equilibrium- if temp increases

Answer 21

Process will decrease temp, driving endothermic reaction

Question 22

Equilibrium- pressure increases

Answer 22

Process will decrease, drive reaction with least moles as product

Question 23

Equilibrium- concentration increases

Answer 23

Reactants increase, drive the reaction

Question 24

Equilibrium constant Kc

Answer 24

Kc= C^c x D^d/ A^a x B^b
aA + bB —-> cC + dD

Lower case is n of moles

Kc = products/ reactants

Question 25

What is a pi bond?

Answer 25

2 Found in double bonds

When p orbitals overlap

Question 26

What is a sigma bond

Answer 26

Find in single bonds and double bond

When two orbitals overlap