Chemistry

Stochiometric relationships

1

If 25 mL of Potassium hydroxide is neutralized by 20 mL of 2.5 mol/L sulfuric acid, what is the concentration in mol/L of the alkali?

4.00 mol/L

2

Zinc react with hydrochloric acid to give zinc chloride and hydrogen gas. If 0.05 mol of zinc was added to 0.075 mol of HCl, identify the limiting reactant  

HCl is limiting reactant

3

What are 3 laws that combined into PV= nRT?

Boyle, Charles, Avogadro

4

Calcium oxide reacts with Hydrochloric acid according to the equation 

CaO(s)+2HCl(aq)→CaCl2(aq)+H2O(l) 

Calculate the number of moles of calcium oxide that reacts with 0.360 moles of hydrochloric acid? 

0.180 mol

5

What is it name? (Pic 1.1)

Mole

Atomic structure

1

Atomic Timeline; Who and how does the electron get discovered?

J.J Thomson, by conducting a “Cathode Ray Experiment”

2

Atomic sub Particles

Proton, Neutron, Electron

3

Use the Aufbau principle to obtain the full ground-state electronic configuration for Potassium (s,p,d,f)

1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

4

Electronic configuration ; Draw all of the “p orbital”

pic 2.1

5

Gallium has two naturally occurring isotopes: 69Ga with a relative isotopic mass of 68.93 and 71Ga with a relative isotopic mass of 70.92. Given that the relative atomic mass of gallium is 69.72, determine the percentage abundances of each isotope.

₆₉Ga = 60.3%

₇₁Ga = 39.7%

Chemical Bonding

1

What is an Intermolecular force?

Forces between molecules

2

Give 3 properties of ionic bonding

High melting and boiling point

soluble in polar solvents

insoluble in non-polar solvents

good conductor of electricity in molten or aqueous state

non-conductor in solid state 

hard, brittle

3

Give five examples of Electron domain geometry

Linear

Trigonal planer

Bent

Tetrahedral

Trigonal pyramidal

Octahedral

Trigonal bi-pyramidal

T-shape

Seesaw

4

Compare the Intermolecular force between H-bonding, dipole – dipole interactions, and London forces from strongest to lowest

H-bonding, dipole – dipole, London forces

5

Draw the Lewis diagram for Phosphorus pentachloride and state its chemical formula.

Pic 3.1

Kinetics

1

State main factors affecting Collision rate.

surface area, concentration, temperature, pressure, catalyst

2

State Collision theory

It is simply shown through the particles hit and then rebound.

3

According to collision theory, what must take place before chemical reaction can occur?

Particles must collide with sufficient energy / a collision must involve more than a certain minimum amount of energy(Ea). Particles must collide with correct orientation.

4

Explain how temperature affect rate of reaction?

As temperature increases, the molecules gain more energy, thus they move faster and result in more effective collision. Therefore, ROR increases.

5

How does catalyst work?

Catalyst lowers activation energy, so more reactants will possess this lowered Ea. Therefore, Rate of reaction increases.

Bonus

1

Draw the graph that show the relationship between PV and P

Pic 1.2

2

What is the constant number of R in the equation PV = nRT?

R = 8.31 JK^-1 mol^-1

3

Use the periodic table to find the condensed electron configuration of 41Nb

[Kr] 5s² 4d¹⁰

4

Draw a flowchart to summarize the major parts of a mass spectrometer.

Vaporization > Ionization > Acceleration> Deflection > Detection

5

Arrange atoms from lowest to highest electronegativity 

O Cl H  Br  Na 

Na H Br Cl O