Chemistry 32S Exam Flashcards
What does the mass number of an atom tell us?
The mass number of an atom tells us how many protons and neutrons there are.
Define the pressure inside a closed container in terms of the kinetic theory
A particle colliding with the interior walls of the container
What is the bond angle of linear or AB2?
180°
What volume of 0.196 M of LiOH is required to neutralize 27cm3 of 0.413M H2SO4? (Worth 3 marks)
1.) write the balanced chemical equation
(1/2) 2LiOH + H2SO4 —> LiSO4 + 2H2O
2.) n = CV
(1/2) n = 0.0113 mol (1/2)
(1/2) 2 to 1 ratio moles of LiOH = 0.02255mol (1/2)
(1/2) 115 ml of LiOH required
Describe how to prepare a 500.0 ml solution of 0.520 M of NaBr using 12.9g of NaBr. (4)
- ) Add 12.9g of NaBr to a 500ml volumetric flask
- ) Add distilled water and dissolve NaBr.
- ) Top up with distilled water until bottom of meniscus is at the etch mark
- ) Cap, invert several times to mix thoroughly
What does the atomic mass of an atom tell us?
The atomic mass of an atom tells us the average mass of the atom’s mass number
What is the bond angle of a linear or AB(E)small n?
N/A
The relative rates of diffusion of two gasses at constant temperature depend only on this factor:
Relative masses of molecules
State what happens according to kinetic theory to cause a drink to get squished when the juice inside is sucked out through the straw.(2)
Interior particles are removed, reducing interior pressure.
Atmospheric pressure is greater, crushing it.
What is the bond angle of trigonal planar or AB3?
120° —> 360/3
What is the melting point trend in halogens as you go down the periodic table?
The melting point trend in halogens as you go down the periodic table is that it increases
If 6 mol of H2 is reacted with 4 mol of O2 to form water, the limiting reactant is:
Hydrogen
As the temperature of the gas in a sealed glass container increases, what happens to the pressure?
The pressure of the gas will increase linearly
What is the bond angle of angular or AB2E?
120° > x > 109.5°
Define the temperature of a substance in terms of the kinetic theory
Average kinetic energy of the particles
Compare the boiling points of C2H6 and C3H8.
C2H6 and C3H8 are both polar. C2H6 has a lower boiling point because C3H8 is much heavier, it has more molar mass than C2H6. The higher the molar mass, the more energy you need to boil
The mass of 1.30*10 to the 23 molecules of water is:
44.8g
What is the bond angle of tetrahedral or AB4?
109.5°
What is the bond angle of pyramidal or AB3E?
109.5° > x > 90°
What condition must be fulfilled in order for boiling to occur?
Pressure of evaporated vapour must equal the atmospheric pressure
This is the number of molecules in 3.3*10 to the 14 mol of H2O
2.0*10 to the 32 molecules
What is the bond angle of angular or AB2E2?
109.5° > x > 90°
What is the name and reduced formula of this structural formula?
CH₃ — CH₂ — CH₃
C₃H₈ and propane
What is the name and reduced formula of this structural formula?
CH₃ — CH₂ — CH₂ — CH₂ — CH₂ — CH₂ — CH₂ — CH₃
C₈H₁₈ and octane
Define Amphoteric
A compound, especially a metal oxide or hydroxide able to react both as a BASE and as an ACID.
What does Accuracy mean? 3
It refers to how close the measurement is to the true value
Determined by the procedure used to obtain measurement
Improper method results in all values consistently too high or too low
=============================
For example: A dart board
Accuracy — I get most of my darts around the centre. Not necessarily close together
Precision — All my throws land in the exact same area (whether or not it is close to the center)
What is the name and reduced formula of this structural formula?
CH₃
CH₄ and methane
Define Structural Isomers.
They are compounds with the same formula but different arrangement of atoms
Give two examples on random error.
Uncertainty of measuring a liquid
Uncertainty of measuring mass
What is the name and reduced formula of this structural formula?
CH₃ — CH₂ — CH₂ — CH₃
C₄H₁₀ and butane
Define Anhydrous salt
When hydrates release water
How is a covalent bond formed? 2
A covalent bond is formed when two atoms share electrons. In a covalent bond, the stability of the bond comes from the shared electrostatic attraction between the two positively charged atomic nuclei and the shared, negatively charged electrons between them.
A covalent bond is formed when two atoms share electrons.
In a covalent bond, the stability of the bond comes from the shared electrostatic attraction between the two positively charged atomic nuclei and the shared, negatively charged electrons between them.
What is the name and reduced formula of this structural formula?
CH₂ — CH₂
C₂H₆ and ethane
What does STP mean? 3
It stands for Standard Temperature and Pressure
Standard Pressure is 100 kPa
Standard Temperature is 0°C
What is the name and reduced formula of this structural formula?
CH₃ — CH₂ — CH₂ — CH₂ — CH₃
C₅H₁₂ and pentane
What is Ammonium?
NH₄⁺
What is the name and reduced formula of this structural formula?
CH₃ — CH₂ — CH₂ — CH₂ — CH₂ — CH₂ — CH₃
C₇H₁₆ and heptane
What is Phosphate?
PO₄³⁻
What is the name and reduced formula of this structural formula?
CH₃ — CH₂ — CH₂ — CH₂ — CH₂ — CH₃
C₆H₁₄ and hexane
What is Nitrite?
NO₂⁻
What is Hydroxide?
OH⁻
What is Hydrogen carbonate?
HCO₃⁻
What is Sulfate?
SO₄²⁻
What is Nitrate?
NO₃⁻
What is Carbonate?
CO₃²⁻
State the three assumptions used for the kinetic theory of matter.
I.) All matter are made of small particles
II.) All matter is moving
III.) All particle collisions are elastic
A.) What is solute? 2
Smallest component in a solution
Particle separate from each other
In C = n/V, what do the letters represent?
(C) CONCENTRATION = MOLE/VOLUME
(n) MOLE = number of moles of solute (what you are dissolving into the solvent).
(V) VOLUME = total volume of the solvent.
State two unique ways in which, according to the kinetic theory, it is possible to cause water to boil.
I.) Increase temperature to increase average kinetic energy of particles
II.) Decrease pressure until it matches the vapour pressure of the liquid
What is unsaturated? 2
A qualitative measure
More solute may dissolve for given temperature
What is miscible? 2
Substance pair that can both completely dissolve in each other
Unlimited solubility
Example: alcohol and water
What is an ideal gas? Do they exist? Explain. 2
An Ideal Gas is a gas that exhibits no IMF (or does not condense into a liquid).
Most gases at LOW PRESSURE and/or HIGH TEMPERATURE act as ideal gas until IMF become significant
Using the kinetic theory of matter, explain why diffusion occurs when someone farts. 3
Flatulence contains gases (some are odourless, others not…) that have a velocity.
The particles will diffuse out of an area of higher concentration to an area or low concentration, away from the issuer.
They will be detected first by others near then those farther away until their concentration is below the threshold of most noses.
