Midterm 1 (In Class Notes) Flashcards
Study for the first midterm
Provide an example of a pure substance
A pure substance (also known as a pure compound) would be sodium chloride (table salt) - NaCl
What is an example of not a pure compound?
If you were to add table salt into water H20 - you can then evaporate the water and the table sale will still be there.
How can you characterize ionic compounds?
You can use melting points to characterize ionic compounds. Example: Firemen can collect different products to characterize how a hot a fire was.
What is the IUPAC?
International Union of Applied and Pure Chemistry. They update the periodic table of elements.
Who created the periodic table of elements?
Dmitri Mandeleev in 1860’s?
Wha isa good property of metal?
Good conductors as electrons are very close to each other.
What is the volume in litres of a 3.9m3 container (hint 1L = 1000cm3)
3,900L
Rules of significant numbers?
- If a “0” is located between non-zero numbers then they are significant. example being 101 - has 3 significant numbers.
- If the “0” is at the beginning of a number with a decimal point, these are NOT significant –> 0.0015 - has only 2 significant numbers
- “0” at the end of a number with a decimal point is considered significant –> 25.20 - has 4 significant number.
- “0” at the end of a number not containing a decimal point –> 100 - has three significant numbers.
How do you write 100 with one, two, and three significant figures?
- 1 x 10(power of 2)
- 1.0 x 10(power of 2)
- 1.00 x 10 (power of 2)
How do you write 12,000 with 6 significant figures?
1.20000 x 10(power of 4) —–> 10,000 x 1.2 = 12,000
How do your write 0.000120 in scientific notation?
1.2 x 10(power of - 4) —>Using the number 1.20 and moving the decimal four places to the left.
List in chronological order the scientists who developed the idea of the atom?
- Democritus ~ 440B.C. (Greek) - Grains of sand
2.Pierre Gassendi (1600’s) - reopened the discussion of the atom to debate and did not contradict Christian beliefs.
- Antoine Lavoisier (1600) (French) - Conversion mass (mass off element will be the same regardless of state) and combustion
- Proust (1700’s): Created the law of definite proportions: Combinations of atoms create specific molecules with specific property.
- Dalton - created atomic theory and the law of multiple proportions. each molecule has its exact proption.
- Thompson = –> Negative charged electrons
- Rutherford = –> Positive charged electrons (1/1000 rays went through the foil but one bounced back)
- Chadwick -> Found the remainder of the neutron (neutrally changed)
What is the term for N20
Laughing gas (nitrous oxide)
What is the term for NO2
Nitrogen dioxide (what is burned in our engines)
What is Mario’s favourite periodic table?
Electron, Quark Up, Quark down, Neutrinos
What are the different types of carbon isotopes?
C12 (stable with 6 neutrons and 6 protons), C13 (stable 1 extra neutron), C14 (NOT stable - radioactive with 2 extra neutrons - Becomes N14
What is the Pauli exclusion principle?
No two electrons in an atom can have the same four quantum numbers. SO –> If one electron in an atom has quantum numbers n=1, l=0, m1 = 0, and Ms = +1/2 - no other electron can have these quantum numbers.
What is Hunds rule?
In 1927 Friedrich Hund stated that the lowest-energy arrangement of electrons in a subhsell is obtained by putting electrons into separate orbitals of the subshell with the same spin before pairing electrons.
What causes sub-shells to be at different level n’s?
Electron-Electron repulsion?
What are some elements that do not follow the rules of electron configuration?
Copper (Cu)
What is Aufbau’s Principle?
You need to build configurations from the ground up. (1s and then 1s + 2s and then 1s + 2s + 2p and then 1s +2s + 2p + 3s)– etc
What are degenerate orbitals?
Electron orbitals having the same energy levels
What is unique about Manganese in regards to its electron configuration?
It goes straight to “d’ which all have a single electron
What are the different periodic trends?
- Atomic radius: Bonding atomic radius increase as we go down the column, but decreases from left to right (same row)
- Cation X+ will be smaller as they have lost an electron
- Anions X- will be bigger as they have gained an electron
What is the isoelectric series of ions??
They all have the same number of electrons and the size goes down with increase in nuclear charge –> Example: O2- > F- > N > Na+
Give 2 principals of core electrons?
- They block energy from outer electrons
- Effective in screening outer electrons (but electrons in the same shell do not screen each other)
What type of energy is needed to remove electrons in the gas phase?
Oxidization
What is electron-affinity and energy change when adding on electrons?
Upon adding an electron forming anion X- will cause changes in electron. The electron-affinity is the need to add an electro because you have an affinity for them.
What occurs during a polar vortex?
No O3 is being made. When O3 is being made, heat is released from the making of strong bonds allowing for heat. This is absent because there is no atomic oxygen which is made when light “heats” up and breaks O2.
So air pressure (Pv) drops then so does pHT (Temperature)
Pressure (Pv) drops = hRT (temp) drops
In the spring, when there is more sun (energy) the ice melts and turns to liquid H20. It gives off heat and the vortex breaks.
What is electro-negativity?
The ability for an atom in a molecule to attract an electron to itself
Guelph Hard Water Example
Guelph had hard water which is made up of CaCO3. We buy water softener (NaCl+) which causes a cation exchange. The salt displaces the Ca2+ so it doesn’t reach the pipes using electrostatic forces.
How are pressure (Pv) and Temperature (hRT) related?
When the pressure goes up the temperature goes up and when pressure goes down, so does temperature.`
What is the Lewis Dot Structure Hydrofloric Acid (HF)?
What is the Lewis Dot Structure Water (H20)?
What is the Lewis Dot Structure for NH3 (Ammonium)?
What is the Lewis Dot Structure for CH4 (Methane)
Answer:
H
H - C - H
H
What is the Lewis Dot Structure for CO2 (Carbon dioxide)
What is the Lewis Dot Structure for CO2 (Carbon dioxide)
Is O3 a greenhouse gas and why?
Yes, technically O3 (ozone) is a green house gas. This is because it traps infared radiation coming from the earth in the atmosphere and heats it.
What is the Lewis Dot Structure for PCl3?
What is the Lewis Dot Structure for CH2Cl2
What is the Lewis Dot Structure for HCN?
What is the Lewis Dot Structure for CN-?
What is the Lewis Dot Structure for NO+
What. is the Lewis Dot Structure for BrO3-
What are resonance structures?
Resonance structures are a set of two or more Lewis Structures that collectively describe the electronic bonding of a single polyatomic species.
What are the different possible resonance structures for NCS-
What are the different resonance structure for NCO
What are the resonance structures for NO3
What are the resonance structures for SO3
What are the resonance structures for SO3(2-)
Which has the shorter sulfur-oxygen bonds? SO3 or SO3(-2)
SO3 has shorter sulfur-oxygen bonds compared to SO3-2; this is because SO3 has a higher bond order due to its neutral charge, resulting in stronger and shorter bonds with oxygen atoms compared to the negatively charged SO3-2 ion where the electrons are more distributed, leading to longer bonds.w
What are the resonance structures for HCO2 -
What are the resonance structure for CO3 (2-)
Define the electron configuration of ACTINIUM-225 (Ac^89) and LUTETIUM-177 (Lu71) from the d block ?
Actinium-225 (Ac *89) = [Rn] 6d1 7s2
Lutetium 117 (Lu71) = [Xe] 4f145d16s2.
HOW MANY ANTIPROTONS IN NUCLEUS OF ANTI-HELIUM-4?
2
What kind of bonds hold together the compounds (praseodymium orthoscandate)
Held together by ionic bonds.
Based on the graph in reading 3 what subshell the additional electron located in the Cl- (chlorine negative one) ion that is observed in Fig. 4.?
3p
Are electron geometry and molecular geomerty diferent?
Yes, they can be different as it depends on the lone pair of central atoms.
In regards to molecular geometry, what do regions mean?
Regions are the series of lone pair, single bonds, double bonds, or triple bonds that surround electrions
What are the typical geometry of the regions?
Two Regions: Linear or 180 degrees
Three Regions: Trigonal Planar or 120 degrees
Four Regions: Tetrahedral 109.5 degrees
What are the geometry of NH4+ and NO3-
NH4+ has four regions meaning it is tetrohedrayl
NO3- has 3 regions meaning it is trigonal
What is the electro geometry of nitrogen tri-iodide?
The electron geometry of NI3 is tetrahedral as we do not consider the lone pairs present in the molecule. The molecular geometry is trigonal pyramidal as one lone pair is on the nitrogen atom.
What is the shape of the SO2 molecule?
Bent - Trigonal Planar
Do noble gases make covalent bonds?
No there is 0 electronegativity so they make ionic compounds.
