gr 11 chem exam

Name of groups

1 Alkali Metals

2 Alkaline Earth Metals

3-12 Transition Metals

17 Halogens

18 Noble Gases

Atomic Notation

Mass number: #of protons + #of neutrons (goes on top)

Chemical Symbol

Atomic Number #of protons (goes on bottom)

Calculating Average Atomic Mass

You will be given masses and %abundance of multiple isotopes multiply the %’s by masses and then add them all up to get the average

aam=(mass 1) (%abundance 1) + (mass 2) (%abundance 2)...

To calculate abundance use the formula with abundance 1 as (x) and abundance 2 as (1-x) then use algebra to solve

Isotopes

Atoms with the same #of protons but different number of neutrons

Quantum numbers

n represents the number of final orbital (Ex. [Rn] 5f14 6d10 7s2 7p4 n=7)

l represents the orbital (s=0, p=1, d=2, f=3)

ml represents the number of electrons (for orbital s ml can only be one because each thing can fit 2 electrons but for orbital f it ranges from -3, -2, -1, 0, 1, 2, 3 twice)

ms represents the spin meaning if the thing is the first or second ml (can be either +1/2 or -1/2)

Orbitals in each sublevel

s-1

p-3

d-5

f-7

Full electron configuration vs Shorthand electron configuration

For full do every level up to the element

Ex. Livermorium 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 5d10 6p6

For shorthand do the Noble gas before in in square brackets and then the rest

Ex. Livermorium

[Rn] 5f14 6d10 7s2 7p4

Atomic Radius

The distance from the nucleus of the atom to the outermost (valence) electron energy level, measured in pm. Decreases across the period. Increases going down groups.

Ionic Radius

The distance from the nucleus of the ion to the outermost (valence) electron energy level, measured in pm. Decreases across the period. Increases going down groups.

Ionization Energy

The amount of energy required to remove the electron from the outermost (valence) energy level of an atom in the gaseous phase and form a positively charged ion (kJ/mol). Increases across the period. Decreases going down groups.

Electron Affinity

The amount of energy released when a neutral atom gains an electron to form a negative ion (kJ/mol). Increases across the period. Decreases going down groups.

Reactivity

Reactivity in metals: Decreases across the period. Increases going down groups.

Reactivity in non-metals: Increases across the period. Decreases going down groups.

Electronegativity

The ability of an atom to attract electrons when in a covalent bond. Increases going across the period. Decreases going down groups.

Cation vs Anion

Cation is a positively charged ion

Anion is a negatively charged ion

Ionic vs Covalent compounds

Ionic- metal and non metal, solid at room temperature, high melting and boiling point, most are soluble in water, can conduct electricity when dissolved in water or melted

Covalent- two or more non metals, can be any state in room temperature, low melting and boiling point, most are insoluble, poor conductor or not a conductor of electricity

How to predict whether compounds are ionic, covalent, or polar covalent

ionic-metal and non-metal

covalent- 2 non-metal with same electronegativity

polar covalent- 2 non-metal with different electronegativity

Endothermic vs Exothermic

Endothermic is when heat is absorbed

Exothermic is when heat is released

Chemical change vs Physical Change

Evidence of a chemical change is a change in colour or odour, energy is released or absorbed, gas is produced(bubbles), and a precipitate is formed.

Physical change is often reversible and involves a change in state

Decomposition (review says u dont need to know specific types)

compound → element + element

element chlorate → element-chloride + oxygen

element carbonate → element-oxide + carbon dioxide

metal hydroxide → metal oxide + water

acid → non-metal oxide + water

hydrated salt → anhydrous salt + water

Complete Combustion

anything + oxygen gas(excess) → carbon dioxide + water

Incomplete Combustion

anything + oxygen gas(lack of) → water (+ could be CO2(g), CO(g), and C(s)

Single Displacement Reactions

1. Metal Displacing Metal

Metal + Compound → Compound + Different Metal (only happens if first metal is higher in activity series than compound metal)

2. Metal Displacing Hydrogen from Acid

Metal + Acid → Compound + Hydrogen gas

3. Metal Displacing Hydrogen from Water

Metal + Water → Metal Hydroxide + Hydrogen gas

4. Halogen Displacing Halogen

Halogen + Halogen Compound → Halogen Compound + Halogen (only happens if halogen is higher on halogen activity series)

Double Displacement Reactions

All follow formula AB + CD → AD + CB

1. One Product is a Precipitate

follows formula just one product is aqueous and the other is solid

2. One Product is a Gas

Both products are aqueous one breaks down into gas and water

H2CO3 → CO2 + H2O

HSO3 → SO2 + H2O

NH4OH → NH3 + H2O

3. Acid-Base Neutralization

Acid + Base → Salt + Water

Ionic equations

Always balance first, only split up aq substances, ions are always aq, TIE equation is the equation with split up substances, NIE equation is without the duplicate substances, spectator ions are the ones which were cut out

Solute vs Solvent

Solute: Substance being dissolved and is usually present in a smaller quantity

Solvent: Substance in which other substances are dissolved in usually present in a higher quantity

Miscible vs Immiscible

Miscible is 2 liquids that dissolve in each other. Immiscible is 2 liquids that don't dissolve in each other.

Saturated solution vs Unsaturated solution

Saturated: Solution that contains the maximum amount of dissolved solute

Unsaturated: Contains less then the maximum amount of solute dissolved in a solvent

Heterogeneous vs Homogenous/solution

Heterogenous: Contains 2 or more visible components

Homogenous: A mixture of 2 or more pure substances with a single visible component

What happens to solubility when temperature increases

It decreases for gases

It increases for solids and liquids (in most cases)

How to read a solubility graph

Find the temp, mass, and compound on the chart. If its above the line its supersaturated, if its on the line its saturated, and if its below it's unsaturated

Sig digs when doing pH and pOH calcs

The number of sig digs in the molarity matches the number of sig digs after the decimal in the pH or pOH

How to get Molecular and Empirical formula given molar mass and percentages

1. Assume 100g (multiply each of the percents by 100g)

2. Convert the grams into moles to get empirical formula (if it doesn’t give a whole number multiply all amounts so they all have whole numbers)

3. Divide the given molar mass by the mass of the empirical formula to get a ratio for the molecular formula

4. Multiply the empirical formula by the molecular ratio

How to get Molecular formula given the mass of each atom in a substance

1. Turn all masses to mol

2. Divide each number of moles by the lowest mol to get the number of each element in the molecular formula (if there is an decimal number multiply all numbers by the same amount to get all whole numbers)

What to do in a titration question asking for molar concentration

1. Make a balanced chemical equation

2. Find the moles of one reactant using n=MV

3. Find the moles of the other reactant using molar ratio

4. Find molarity of the reactant using M=n/V

How to find the volume of a container at STP given grams of each substance in it

1. Turn all the grams into moles

2. Add all the moles up to get the total number of moles

3. Multiply the total number of moles by the volume/mol at STP (22.4L)

How to calculate amount excess reagent left over given 2 volumes when pressure and temp are constant

1. Make a balanced chemical equation

2. Use Volume ratios (Molar ratios with mL instead of mol) to find LR and ER

3. Compare the LR to the ER to see how much ER is used

4. Subtract the amount of ER used from the original to get how much is left over