Unit 1- Atomic Sructure, Amount Of Substances, Bonding, Energetics, Kinetics, Equiliburm And Redox

Question 1

1)Name the subatomic particles, their relative mass and relative charge?
2)Why do we use relative mass and not mass?

Answer 1

1)
Protons, 1, +1
Neutrons, 1, 0
electron, 1/2000, -1
2)
The mass of the subatomic particles are too small.

Question 2

1)What is the mass number (A) where is it located?
2)What is the atomic number (Z), where is it located?
3)How does the atomic number identify elements?

Answer 2

1)total number of protons and neutrons in the nucleus of an atom
2)number of protons in an atom
3)all atoms same element have the same number of protons

Question 3

1)What makes an atom a neutral atom?
2)How do you calculate the number of neutrons?
3)How do you find out the number of electrons?

Answer 3

1)overall they have no charge (number of electrons is the same as the number of protons)
2)mass number - atomic number = neutrons
3)same as the number of protons

Question 4

1)How do atoms form ions and what are their main characteristic?
2)Negative and postive ions electron and proton level?

Answer 4

1)gaining or losing electrons, they have different number of protons and electrons
2)
negative ions= more electrons than protons (gained electrons)
positive ions= less electrons than protons (lost electrons)

Question 5

1)what are isotopes?
2)Do isotopes have the same chemical properties of an element and why?
3)Do isotopes have the same physical properties and why?

Answer 5

1)atoms with the same number of protons but different number of neutrons. same atomic number and different mass number
e.g chlorine-35 and chlorine-27 (different mass numbers)
2)Yes, same number electrons same configuration of electrons= same chemical properties
3)No, different (densities and rates of diffusion). which varies with isotopes different numbers of neutrons, which affects the mass number. Mass number determines the physical properties such as boiling/melting/density

Question 6

1)explain John daltons model of the atom?
2)explain J.J. Thompsons model of the atom?

Answer 6

1)19th century, described atoms as solid spheres, different spheres made up different elements
2)an atom must contain even smaller negative charged particles- electrons surrounded by a positive charge (plum pudding model)

Question 7

1)Explain the experiment which lead the Rutherford model (nuclear model) and the date?
2)describe Ernest Rutherfords model?

Answer 7

1)1909 fired alpha particles (positive charge) at very thin sheet of gold
expected:
from the PP model most alpha particles to be deflected by the positive charge of model
truth:
most alpha particles passed through the gold atoms very few deflected by the nucleus

2)tiny positively charged nucleus at the centre
surrounded by a cloud of negative electrons. mostly empty space

Question 8

1)What was Bohrs models principles (3)?
2)what provided evidence for Bohrs models?
3)what mad the ‘cloud of electrons’ incorrect from Rutherfords model?

Answer 8

1)
1-electrons only exist in fixed orbits (shells)
2-each has a fixed energy so the radiation has fixed frequency
3-when an electron moves between shells electromagnetic radiation is emitted (down) or absorbed (up)
2) frequencies of radiation emitted and absorbed by atoms were already know form experiments.
3) spiral down into nucleus= atom collapse

Question 9

1)what was later changed about Bohrs model?
2)what is the most accurate model of the atom?

Answer 9

1)not all electrons in shell had the same energy, so changed to have sub-shells.
2)quantum model based on quantum mechanics

Question 10

1)what is relative mass?
2)Why use relative mass?

Answer 10

1)average mass of an atom of an element on a scale where carbon-12 is 12.
2)mass of atoms too small so, instead compare it to mass of one carbon atom
(not normally whole number)

Question 11

1)what is relative isotopic mass?

Answer 11

1)mass of atom of an isotope of an element on a scale where an atom of carbon-12 is 12.
(usually whole number)

Question 12

1)How to calculate the relative atomic mass of isotopes?

Answer 12

1)
1-find the percentage of the relative atomic mass of each isotope
2-add each isotope mass after step 1
3-divded by 100

Question 13

1)What is relative molecular mass?
2)how do you find relative molecular mass?

Answer 13

1)average mass of a molecule on scale where an atom of carbon-12 is 12.
2)add up relative atomic mass values of all atoms in the molecule.

Question 14

1)what is relative formula mass?
2)when is RFM used?
3)How do you find RFM?

Answer 14

1)average mass of a formula on scale where an atom of carbon-12 is 12.
2)compounds that are ionic, giant covalent
3)add up the RAM of all the ions in the formula unit. (same as RMM)

Question 15

What do the plus and minus mean on ions?

Answer 15

Minus= negative charge gained an electrons
Plus= positive charge lost electrons

Question 16

1)What do the atoms of the same element have?
2)How does the atomic and mass number change when atoms are isotopes?

Answer 16

1)same number of protons
2) same ATOMIC number but a different MASS number.

Question 17

1)why do isotopes have the same chemical properties?
2)why do isotopes have different physical properties?

Answer 17

1) similar chemical properties because isotopes of an element have the same number of electrons as an atom of that element. The electron arrangement is the same owing to same chemical properties.

2) different numbers of neutrons, which affects the mass number. Mass number determines the physical properties such as boiling/melting/density

Question 18

How to calculate isotope abundance?

Answer 18

Question 19

1)What are the charges of atoms?
2)Atoms of the same element have the same amount of?

Answer 19

1)no electric charge contain the same number of protons and electrons
2)protons

Question 20

1)what is a mass spec graph?
2)percentage mass spec graphs?

Answer 20

1)Mass spectrometry can be used to identify elements and relative molecular mass.
-giving accurate information about relative isotopic mass and also about the relative abundance of isotopes.

Question 21

1)relative abundance mass spec graph?

Answer 21

1)
-The average mass of the periodic table doesn’t exist.

Question 22

1)How can you find multiple isotopes of elements like chlorine?

Answer 22

1] -> use probability trees to find the ratio of a molecule to plot the graph

->isotopes of molecule come from a combined one, and two singles of the starting istopes

Question 23

1)How to calculate isotope abundance calculations?

Answer 23

1) (massxpercentage/abundance)(massxpercenatge/abundance)/ 100
2)missing values in the table equate out of 100

Question 24

1)what is a nitrade?
2)

Answer 24

1)nitrogen
2)

Question 25

1)

Answer 25

1)

Question 26

1)

Answer 26

1)

Question 27

1)

Answer 27

1)

Question 28

1)Are dashes used in units?
2)what is in the unit of moles?
3)how to show something has three significant figures?
4) 1g= ? mg
5) 1 tonne= ? grams
6)How to find mass?

Answer 28

1)no
2)gmol-1
3) 4.2x10^6, 4.20x10^6
4)1000mg
5) 1000000 grams
6) Mr x n

Question 29

1)Units for concentration of substance?
2)relative atomic mass?
3)relative molecular (ionic formulas)?
4)how to find the amount of atoms in a certain mass?
5)when given atoms find the amount mass?

Answer 29

1)mol dm-3
2) Relative atomic mass (Ar), RAM average mass of one atom of an element over one 1/12 mass of one atom carbon 12
3) Relative molecular (formula= ionic formulas) mass Mr or RMM average mass of one molecule over 1/12 mass of one atom of carbon 12
4)molesxAVO
5)atoms/AVO= mass

Question 30

1)writing formulas (Roman numerals)?

Answer 30

1)Roman numbers tell the charge on the first atom
E.g iron(III) oxide (Fe3+) Fe2O3
-> NEED to balance charges
->use brackets on complex ions only

Question 31

Ionic formulas:
1)nitrate?
2) carbonate?
3)ammonium?
4)hydroxide?
5)phosphate?
6)hydrogen carbonate?
7)sulphate?

Answer 31

Question 32

1)Can you use decimals in balancing equations?
2)what is a spectator ion in ionic equations?
3)How to find reacting mass and limiting reagent?
4)How to find how much the product is formed?

Answer 32

1)using decimals/fraction in combustion equations
2)doesn’t change state or bonding
3)
1-find the number of moles of the reactant and the mr
2-find the ratio of the reactants
3-multiply the moles the lowest ratio reactant with its moles to find how many moles of the other reactant is needed and compare to the moles first calculated for the limiting reactant (MUST SAY NEED E.G 0.270 MOLES OF HCL)

4)Finding how much of a product is formed:
4-limiting reactant determines how much product is formed
5-multiply moles of limiting reactant by the Mr of the product to get the overall weight in grams

Question 33

I
II
III
IV
V
VI
VII
VIII
IX
X
L
C
D
M

Answer 33

Question 34

1)What is the Avogardros constant and what can equation can you use it in?
2)How to find the mass from given atoms using Avogardos constant?

Answer 34

1)6.022x10^23 number of atoms in (1 mole) 12g of carbon 12
->atoms in a certain mass (molesxAVO)
2)given the atoms then do atoms/ AVO= mass

Question 35

1)Name the 3 tricks to mass spec graphs?

Answer 35

1)all peaks caused by positive ions
2)mass spec of compounds have M+ parent ion peak (big peak on RHS=mr the mass of the whole molecule)
3)M+1 peak caused by isotopes because carbon and hydrogen isotopes

Question 36

1)Empirical formula?
2)molecular formula?

Answer 36

1)Empirical formula is the simplest whole number ratio of atoms of each element in a compound.
2)Molecular formula is the actual number of atoms of each element in a compound

Question 37

1)What condition does time of flight need to be?
2)what is ionisation and what are the two types?

Answer 37

1)vacuum otherwise air particles would ionise and register on the detector
2) Electrons are lost or gained. Two of these: electron impact and electrospray ionisation

Question 38

1)what type of sample is used in electron impact and why?
2)Explain the process of electron impact and equation?

Answer 38

1)elements and substances with low formula mass. why: Electron impact can cause larger organic molecules to fragment

2)
1-Vaporised sample is injected at low pressure
2-An electron gun fires high energy electrons at the sample
3-This Knocks out an outer electron
4-Forming positive ions with different charges E.g. Ti->Ti+ + e–

Question 39

1)what type of sample is used in electro spray ionisation?
2)Explain the process of Electro spray ionisation and the formula?

Answer 39

1) larger organic molecules. The softer conditions of this technique mean fragmentation does not occur
2)
• The sample is dissolved in a volatile, polar solvent
• injected through a fine hypodermic needle giving a fine mist or aerosol
• the tip of needle has high voltage
• at the tip of the needle the sample molecule, M, gains a proton, H+, from the
solvent forming MH+
• M(g) + H+ -> MH+(g)
• The solvent evaporates away while the MH+ ions move towards a negative plate

Question 40

1)what is acceleration?
2)what particles travel fastest through the flight tube?

Answer 40

1)
->Positive ions are accelerated by an electric field
->To a constant kinetic energy
->causing acceleration due electric field so have same KE
2)
Given that all the particles have the same kinetic energy, the velocity of each particle depends on its mass. Lighter particles have a faster velocity, and heavier particles have a slower velocity.

Question 41

1)Explain the characteristics of a flight tube? (3)

Answer 41

1)•The positive ions with smaller m/ values will have the same kinetic energy as those with lighter m/ and will move faster.
•The heavier particles take longer to move through the drift area.
•The ions are distinguished by different flight times

Question 42

1)Describe how the detection work?
2)How does detection produce the current?
3)What are the two things mass spectrometers measure?

Answer 42

1)The ions reach the detector accept electrons from it and generate a small current, which is fed to a computer for analysis.
2)The current is produced by electrons transferring from the detector to the positive ions. The size of the current is proportional to the abundance of the species
3)For each isotope the mass spectrometer can measure a m/z (mass/charge ratio) and an abundance

Question 43

1)what are the two calculations involved in time of flight?
2)what are units of calculations?

Answer 43

1)distance = speed × time and KE = ½mv2.

2)t = time of flight (s)
d = length of flight tube (m)
v = velocity of the particle (m s-1)

KE = kinetic energy of particle (J)
m = mass of the particle (kg)
v = velocity of the particle (ms-‘)

Question 44

How to find the mass of Ions for time of flight?

Answer 44

->multiply by 1000 to go from grams to KG

Question 45

1) When you need to cancel out: time of flight?

Answer 45

1) given time of one isotope, need to work out time of the other isotope

Question 46

1)What does the size of the current suggest in time of flight?

Answer 46

1) size of the current gives a measure of the number of ions hitting the plate.

Question 47

1)what is the time of flight proportional to?
2)what is used to find the mass of each ion in a sample?
3)why are the ions attracted to in detection?

Answer 47

1) time of flight is proportional to the square root of the mass of the ions.
2) time taken to travel a fixed distance is then used to find the mass of each ion in the sample.
3)negatively charged metal plate as opposites attract and accepts electrons which generates a current

Question 48

1)what can mass spectrometry do? (2)
2)what do the small peaks in mass spec graphs represent?
3) what are the peaks in mass spec graphs lower m/z values due to?

Answer 48

1) time of flight
->find the abundance and mass of each isotope in an element allowing to determine its relative atomic mass
->find the relative molecular mass of substances made of molecules.

2) small peaks present around the molecular ion peak due to molecular ions that contain different isotopes
3) fragments caused by the break up of molecular ion.

Question 49

1)what is the empirical formula?
2)How to find the empirical formula?
3)What is the molecular formula?
4)How to find the molecular formula?

Answer 49

1) simplest whole number ratio of atoms in a compound
2)
1-find the moles of each element (mass/RFM)
2-Find the ratio of whole number (smallest)
Moles/smallest moles
3-Round up and present formula E.G: C2H4Br
3)actual number atoms present and type
4)
1-RFM of empirical formula
2-divide the Given RFM by the empirical RFM to get the multiplier E.g x2
C2H4Br -> C4H8Br2

Question 50

1) what do you need to confirm that molecular and empirical formula is the same?
2)How do you find a missing mole number E.g MgSo4 xH2O?

Answer 50

1)you need the RFM to confirm that molecular and empirical formula is the same
2)

Question 51

1)what is the equation of atom economy, what do you always include, and what does atom economy do?

Answer 51

1)

Question 52

1)How to find theoretical mass in percentage yields?
2)What is the equation of percentage yield/ theoretical mass and what is percentage yield a measure of?

Answer 52

1)
Maximum theoretical mass->
1-find moles limiting reactant
2-use ratio of desired product to limiting reactant to find moles of product
3-multiply moles by mr of products to find grams of theoretical mass
2)

Question 53

1) How: Amount of substance Practical- Determining empirical formula of magnesium oxide?
2)How is empirical formula worked out?
3)Equipment/method needed for Amount of substance Practical?

Answer 53

1)Work out the empirical formula of magnesium oxide by taking a known mass of magnesium and react it completely with oxygen into a known mass of magnesium oxide.
2)The empirical formula is the formula of a compound that has been worked out by practical experiments
E.G: combust a hydrocarbon and find that you get twice as much water vapour as carbon dioxide.
◦ empirical formula is CH4 (remember H2O contains two H atoms).

3)
1-Curl the magnesium
2-Measure crucible +lid and crucible + lid + magnesium
3-heat the magnesium
4-bright light produced and white powder
5-Measure mass of crucible + lid + magnesium oxide after heating

Question 54

1)What is relative atomic mass?
2)What is 1 amu defined as?
3)What is average mass?

Answer 54

1) Relative atomic mass (Ar) is the average mass of an element compared to one-twelfth the mass of a single carbon-12 atom.
2) 1amu is defined as one-twelfth of the mass of a single carbon-12 atom. Ar= is the average mass of an element in units of amu.
3) The average mass is the average of the masses of the elements, weighted according to their abundance.

Question 55

1)what is relative molecular mass and units?

Answer 55

1) average mass of a molecule compared to one-twelfth the mass of a single carbon-12 atom.
-> 1/12 moles of carbon-12 in 1g of carbon-12
->Mr is the average mass of a molecule in the units of amu.

Question 56

1)what does a mole contain?
2)number of particles?
3)How does one mole converts between amu and grams?
4)Density?

Answer 56

1) 6.02 ×1023 Avogadro’s constant
mole is set so that a mole of carbon-12 atoms weighs 12 grams (12 amu)
2)Number of particles = number of moles × Avogadro’s constant
3)mole converts between amu and grams: 1 g = 1 mol × 1 amu
4) Density= mass/volume

Question 57

1)Unit of litres?
2)How to find concentration?

Answer 57

1)Dm^3
2)moles ÷ (volume)dm3.= concentration (moldm-3.)

Question 58

1)Ideal gas equation?
2)what is the value of R in the Ideal gas equation?
3)The units of the Ideal gas equation?
4)How to find the volume?

Answer 58

1) Pressure × volume = number of moles × gas constant × temperature (pV = nRT)
2) R is a constant - its value is always 8.314.
3)
.Pressure must be in Pascals (Pa).
.Volume must be in cubic metres (m3).
.Temperature must be in Kelvin (K).
4) Volume= molesx 24

Question 59

1)What does ionic solids dissolve into?
2)what are ionic equation used to describe?
3)what should charge be in ionic equations?
4)What does Aq mean?
5)what is the density of water?

Answer 59

1) Ionic solids will dissolve in solution and will split into their constituent ions.
2) reactions in solution.
3) charge on either side of the ionic equation should be equal.
4)Aq= (substances dissolved in water)
5)The density of water is 1 gcm-3

Question 60

1)What is percentage yield less than?
2)6 reasons why the percentage yield would be low?

Answer 60

1)100%
2)

1-It might be difficult to fully separate the product from the reaction mixture.
2-Unexpected reactions (side reactions) can happen. meaning that the intended product is not created.
3-If a reaction is carried out in water, any extracted product may be ‘wet’, needs to be extracted.
4-incomplete reaction and reversible reaction some of the products have turned back into reactants.
5-The reaction is very slow and hasn’t been given enough time to happen.
6-chemicals will remain stuck to the glassware and will be wasted.

Question 61

1)How to collect gas to determine yields? (4)
2)Why would there be incorrect readings when collecting gas?

Answer 61

1)
1-Conduct the reaction in a conical flask.
2-Add a bung to the top of the flask after adding the reactants.
3-Connect the bung to a syringe so that the gas is collected in the syringe
4-The syringe will allow the volume of gas to be measured
2)
• Some hydrogen might have escaped if the bung was not fixed tightly.
• Some hydrogen may have escaped between starting the reaction and fixing the bung.
• Some hydrogen may have remained in the conical flask and not entered the syringe.
• Not all the HCI reacted meaning that not all the possible hydrogen was produced.

Question 62

1)Reaction pathways with high atom economies are good for what two reasons?

Answer 62

1)
->Using the smallest possible amount of reactants saves money.
->higher atom economy means that less waste is produced.

Question 63

1)what is crystallisation?
2)What is the 4 step process of crystallisation?

Answer 63

1) Crystallisation is a separation technique used to separate dissolved solids from a liquid.
.tripod, gauze, evaporating basin, bunsen burner.

2)
1) Filter the solution to remove any insoluble solids.
2) Heat the solution to boil off about half of the liquid.
3)Leave the remaining solution to cool and evaporate over time.
4)When the crystals have formed, pat them with tissue or paper towel to dry them.

Question 64

1)Why leave half the water during crystallisation?

Answer 64

1)
.Hydrated copper sulfate crystals. The crystals need some water in it.
.solution is boiled dry= anhydrous copper sulfate.
.white solid while hydrated copper sulfate is blue.

Question 65

1)what do you do on Electrospray ionisation mass spectrum?

Answer 65

1)-1 Relative molecular mass because a proton was added

Question 66

1)what do you do on Electrospray ionisation mass spectrum?

Answer 66

1)-1 Relative molecular mass because a proton was added

Question 67

1)what is ionisation energy?
2)How does a graph of IE work?
3)Why does IEs increase?
4)Why is there a big jump for 2nd/ other I.E?

Answer 67

1) 1st I.E-> energy required to remove 1 mole of e- from 1 mole of gaseous atoms

X(g)->x+(g)+e-

2nd I.E->
X(g)->x2+(g)+e-

2)

3) -> As taking electrons away from positive ions means more energy is required
4) ->new shell closer to nucleus so held more tightly more electrostatic attraction between electrons and nucleus
->LOOK for the big jump

Question 68

1)what is shielding?
2) why does I.E increases down the group (any group)?

Answer 68

1) ->shielding from shell reduce attraction not held very tightly to the nucleus so very reactive
2) ->easier to take E- as the outer E- is more shielded by other inner shells
->greater distance outer E- nucleus further away so is less attracted to the nucleus

Question 69

1)what is an example of I.E increasing down a group?

Answer 69

Question 70

1)How does IE work with different elements, how does the strength change?

Answer 70

Question 71

1)what is Avogadro law?
2)what is the molar volume?
3)what is the equation ideal gas equation?
4)what is a gas called that obeys the law?

Answer 71

1) Avogadro law-> equal volume different gases at the same pressure and temperature will contain equal number of particles
2) Standard temperature 273 k and pressure 100 kph at standard temperature and pressure 1 mole of any gas occupies volume of 22.7 dm^3. This is a molar volume.
3)PV=nRT
4)
P=pressure (PA)
R= gas constant (Jk-1 mol-1)
V=volume (m^3)
n= moles number
Temperature= K
5) A gas that obeys this law is called ideal gas.

Question 72

1)what is the gas constant?
2)Unit conversion: KPa->Pa, dm3->m3, cm3->m3, C->K?

Answer 72

1) Gas constant= 8.31
2) KPa -> Pa (x1000)
dm3 -> m3 (divide 10^3)
Cm3 -> m3 (divide 10^6)
C -> K (+ 273)

Question 73

1)Relative formula mass?
2)Molar mass?
3)In solutions what is units for concentration and volume?
4)Equation of moles in solution?
5)1000 cm3 to dm3?

Answer 73

1) is used if the species is ionic
2) mass of one particle x avogardos constant (mass of one mole substance)
3)concentration= mol dm-3
Volume= dm3
4) moles= concentration x volume
5) 1 dm3

Question 74

1)what is the law of conversation of mass?
2)what is percentage yield?
3)atom economy
4)Molar volume gas at rpt?
5)molar volume gas at stp?
6) 1 atmosphere in Pa?
7) 1 litre in dm3/ m3?
8)what happens when gases combine?

Answer 74

1) total mass of all atoms in the product is the same as that of all the atoms in the reactants
2)mass you get compared with the maximum you thought to get
3)measure how much of the products are useful
4)24 dm3 mol-1 or 0.024 m3 mol-1
5)22.4 dm3 mol-1 or 0.0224 m3 mol-1 (273k and 1.013 x 10^5 Pa)
6) 1.013x10^5 Pa
7)1 dm3 or 1x10^-3 m3
8) volumes that are in a simple ratio to each other and to that of any gas products
->all volumes must be measured at the same temperature and pressure

Question 75

1)methods to extract gas?
2)when does volume gas vary?
3)How do you convert a volume to that of which it will occupy at stp (or any other temperature or pressure)? (Boyles law and Charles law)
4)what are the units for this equation.

Answer 75

1) gas syringe, victor meyer, Dumas bulb
2)temperature and pressure
3)
4)

Question 76

1)How do you convert litre to dm^3?
2) How do you complete titration equations?

Answer 76

1) 1 litre to 1 dm^3

Question 77

1) Why is it difficult to do a titration with coloured solutions?
2)How do you convert moles to grams and grams to moles?

Answer 77

1) ->hard to see a colour change
2)

Question 78

Equation for moles in a solution and the units for the equation?

Answer 78

Question 79

1)What is the 12 equipment items you need to do titrations, and what do you use to measure acid and alkali?

Answer 79

• burette-> used for sodium hydroxide solution
• stand and clamp
• 25 cm3 pipette
• pipette filler-> used to measure acid
• two 250 cm3 conical flasks
• two 250 cm3 beakers
• funnel
• white tile
• wash bottle
• phenolphthalein indicator
• bottle of dilute hydrochloric acid
• bottle of sodium hydroxide solution

Question 80

1) Explain the method of completing titration?

Answer 80

1. Set up your burette.
2. Use a small volume of the dilute hydrochloric acid to rinse the burette before filling it with the dilute hydrochloric acid a couple of cm3 past 0. run a small amount of the dilute hydrochloric acid through the burette to get the level to exactly 0.00 cm3.
3. Rinse a conical flask with de-ionised water.
4. Rinse a 25 cm3 pipette with the sodium hydroxide solution from the labeled beaker and then, using a pipette filler, pipette exactly 25.0 cm3 of sodium hydroxide solution into a conical.
5. Add a few drops of phenolphthalein indicator to the sodium hydroxide solution in the conical flask and check the colour of the indicator.
6. Record the initial burette reading in the results table make sure that it is to 2 decimal places ending in either a 0 or a 5
7. Titrate the contents of the conical flask by adding dilute hydrochloric acid to it from the burette. Placing a white tile under the conical flask will help you see any colour change clearly.
   Add the dilute hydrochloric acid bit-by-bit quite fast at first swirling the conical flask the solution.
   As the colour change becomes more apparent start adding the dilute hydrochloric acid dropwise until the indicator undergoes a definite colour change.
   8.wash down the sides of your conical flask with de-ionised water from a wash bottle to ensure you return the hydrochloric acid stuck to the sides to the flask to ensure an accurate end point tire reading.
8. Record the final burette reading in your table of results and calculate the volume of dilute hydrochloric acid used.
9. Repeat the titration until you obtain two results, which are concordant. within 0.10 cm3 of each other.

Question 81

What was daltons theory?

Answer 81

Question 82

1)what was Rutherford model of atomic theory?

Answer 82

Question 83

1)what was Bhors model?

Answer 83

Question 84

1)what did Chadwick discover and when?
2)what is the timeline of the development of the atom?

Answer 84

1)
2)

Question 85

1)What are electron shells the same as?
2) What do shells have?
3) What is orbital space and what are the two types?
4) What is aufbau principle?
5) What is hunds rule?
6) How can use periodic table to find electron configuration?

Answer 85

1) Energy levels
2) Sub shells (sub levels)
3) Where electrons are likely to be found
S orbital
P orbital
4) electrons enter lowest energy shell
5) Every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied and all electrons in singly occupied orbitals have the same spin.
6)

Question 86

1) What does the big number and power number mean?
2) How do Electrons spin?

Answer 86

1) The power number is the number of electrons and the period is the big number
2) opposite directions in the same block but in separate blocks it can be any direction.

Question 87

How to find ions electron configuration?

Answer 87

Question 88

How do you find electron configuration using arrow method?

Answer 88

Question 89

How to find ions when the transition metals are included?

Answer 89