CHS 2440

This set covers the topics within this course that I feel like I need to review. This includes primarily the common polyatomic ions, their chemical formula, and their charge.

Oxidation state of the four metals

Ag⁺ Zn²⁺ Cd²⁺ Al³⁺

Ammonium

NH₄⁺

Mercury(I)

Hg₂²⁺

Cyanide

CN^-

Hydroxide

OH^-

Peroxide

O₂^2-

Acetate

C₂H₃O₂^-

Oxalate

C₂O₄^2-

Nitrate

NO₃^-

Sulfate

SO₄^2-

Carbonate

CO₃^2-

Phosphate

PO₄^3-

Chlorate

ClO₃^-

Permanganate

MnO₄^-

Dichromate

Cr₂O₇^2-

How many moles are in 5.8E24 atoms of Aluminum

5.8E24 atoms * (1 mole)/(6.022E23 atoms) = 9.6 moles

What is the mass of 5.67E24 molecules of SO₂? (molar mass of SO₂ is 64.07 g/mol) (Chapter 2)

5.67E24 molecules (1 mole)/(6.022E23 atoms) (64.07g)/(1 mole) = 603g

-ite ending

One less O than -ate ending

Empirical Formula (Chapter 3)

Gives the ratio of the number of atoms of each element in a compound.

Hydrogen Peroxide Molecular formula: H₂O₂

Hydrogen Peroxide Empirical formula: HO

Percent Composition (Chapter 3)

mass of element / mass of compound * 100%

How do you find n (in context of molecular/empirical formulas) (Chapter 3)

n = molar mass of compound / empirical molar mass

Molarity, Molar Concentration (Chapter 3)

Molarity = moles of solute / volume of solution in Liters

Volume = Moles of solute / Molarity

Moles of solute = Molarity * Volume

What are the steps to determine Empirical Formula? (Chapter 3)

• assume 100 gram sample size

• find mass of element in 100g of compound (16% carbon > 16g carbon)

• convert mass of each element to moles using molar mass

• divide by smallest number of moles to get mole to mole ratio

What is the formula for dilution of chemicals? (Chapter 3)

M_iV_i = M_fV_f

i=initial and f=final

How do you determine what a spectator ion is? (Chapter 3)

Spectator ions are aqueous on both sides of the equation.

Fe(s) + Cu²⁺(aq) + 2NO₃^-(aq) > Fe²⁺(aq) + Cu(s) + 2NO₃^-(aq)

The NO₃ is aqueous on both sides and therefore is a spectator ion.

What is the formula for sulfuric acid?

H₂SO₄ (Hydrogen sulfate)