MEMORIZE: chem exam 4

made: 11/13/26

What is released in combustion reactions?

heat

Hydrocarbon + O₂(g) →

CO₂(g) + H₂O(l)

Alkali metal + halogen →

salt

Metal + halogen →

salt

Halogen + Halogen →

interhalogen compound

Acid + base →

Salt + H₂O

Salt of weak acid + strong acid →

nitrate

When does a precipitation reaction NOT occur?

When BOTH reactants and products are soluble

(both can be insoluble tho)

In compounds, the less electronegative element has a ___ oxidation number and the more electronegative element has a ___ oxidation nunber

positive, negative

Oxidation numbers must add up to the ______

charge of the molecule

Which metals do NOT displace hydrogen from acids?

Cu, Ag, Au

T or F: nitrates are ALWAYS soluble

TRUE

Soluble or Insoluble?: Salts of alkali metals and ammonium cation

SOLUBLE

Moles of one compound ÷ stoichiometric ratio =

Moles of other compound ÷ stoichiometric ratio

Which metals displace hydrogen from aqueous solutions?

Metals to left of hydrogen in activity series

List electronegativity ranking:

F>O>N>Cl>Br>I>S

List strong acids and weak acids:

Strong: HCl, HBr, HI

Weak: HF

Hydrogen + halogen →

hydrogen compound

Alkali metal + water →

Metal ions

OH⁻

H₂

Element + O₂ →

element oxide

What changes in physical processes?

state of the substance

T or F: The composition of the substance changes in physical processes.

False

In chemical reactions, the ______ of the substance changes.

composition

What is the chemical formula for White Phosphorus?

P₄

What are metals state of matter in chemical equations?

solid (s)

chlorine formula in chemical equations:

Cl₂

List the diatomic elements (gas state) in chem eqs:

H₂, N₂, F₂, O₂, I₂, Cl₂, Br₂

Have No Fear Of Ice Cold Beer

When are ionic compounds are in solid state (s) in chem eqs?

when no water present

Metal Sulfide + O₂ →

Metal Oxide(s) + SO₂(g)

Metal Oxide + C →

Metal + CO₂(g)

Metal Oxide + CO →

Metal + CO₂(g)

Metal Oxide + H₂ →

Metal + H₂O(g)

What is transition metal oxidation state when dissolved in acid?

Lowest oxidation state

Metal(s) + Acid(aq) →

Metal Salt(aq) + H₂(g)

Do metals produce H₂ gas when reacting with concentrated acids?

NO

What state does a compound have in a diluted solution?

aqeous (aq)

Metal Oxide + Water →

Metal hydroxide

Non-Metal Oxide + Water →

Acid (Forms H⁺)

In precipitation reaction, the reactants _______ to form products

swap their cations/anions

How are insoluble compounds represented in ionic equations?

intact (s)

C, H, N Compound + O₂ →

CO₂ + H₂O + N₂

What oxidation state does a transition metal have when dissolved in non-oxidizing acid?

its lowest common oxidation state

What is the formula of sulfuric acid?

H₂SO₄

What is the formula of triiodine nitrate?

I₃NO₃

pentane formula=

C₅H₁₂

What is the formula of acetate?

C₂H₃O₂⁻

What is the formula of carbonate?

CO₃²⁻

What is the formula of hydrogen carbonate (or bicarbonate)?

HCO₃⁻

What is the formula of hydroxide?

OH⁻

What is the formula of nitrite?

NO₂⁻

What is the formula of nitrate?

NO₃⁻

What is the formula of chromate?

CrO₄²⁻

Dichromate formula=

Cr₂O₇²⁻

Phosphate

PO₄³⁻

Hydrogen phosphate=

HPO₄²⁻

Dihydrogen phosphate

H₂PO₄⁻

Ammonium

NH₄⁺

Hypochlorite

ClO⁻

Chlorite

ClO₂⁻

Chlorate

ClO₃⁻

Perchlorate

ClO₄⁻

Permanganate

MnO₄⁻

Sulfite

SO₃²⁻

Hydrogen sulfite (or bisulfite)=

HSO₃⁻

Sulfate

SO₄²⁻

Hydrogen sulfate (or bisulfate)

HSO₄⁻

Cyanide formula=

CN⁻

Peroxide formula=

O₂²⁻

What are the charges of Chromium (Cr)?

+2, +3

What are the charges of Iron (Fe)?

+2, +3

What are the charges of Cobalt (Co)?

+2, +3

What are the charges of Copper (Cu)?

+1, +2

What are the charges of Tin (Sn)?

+2, +4

What are the charges of Mercury (Hg)?

+1, +2

What are the charges of Lead (Pb)?

+2, +4

What is % yield?

(Actual Yield / Theoretical Yield) * 100%

Which reactant determines the theoretical yield?

limiting reactant

In problems, how do we determine which reactant is the limiting reactant?

Use the stoichiometric ratio (smaller mol is limiting)

Molarity formula=

moles of solute/ volume of solution

solute definition

smaller component of solution

solvent definition

larger component of solution

solution definition

homogenous mixture of 2 or more components

T or F: Ammonia is a weak base

True

T or F: Carbonic acid is a weak acid

True

List the weak acids and bases:

HF, HC₂H₃O₂(acetic acid)

NH₃(ammonia)

strong acids vs weak acids definitions=

strong acids= ionize completely, strong electrolytes

weak acids= dont ionize completely, weak electrolytes

When acids dissociate they lose their ___ in solutions.

protons H+

Hydrochloric acid =

HCl

Hydrobromic acid =

HBr

Hydroiodic acid =

HI

Nitric acid =

HNO₃

Sulfuric acid =

H₂SO₄

Perchloric acid =

HClO₄

Acetic acid =

HC₂H₃O₂

Hydrofluoric acid =

HF

Sodium hydroxide =

NaOH

Lithium hydroxide =

LiOH