Chemical Formulas and Types of Compounds
What does a subscript (the little number after the element symbol) in a chemical formula represent?
The number of atoms of that element!
What prefix means “2”?
Di-
What is a positively charged ion called?
Cation
What ion do acids release in water?
H⁺ ions
How many particles are in 1 mole?
6.022 × 10²³ particles
How many Mg atoms are in Mg(ClO₃)₂?
1 Mg atom
Name CO₂.
Carbon dioxide
What is the formula for sodium bromide?
NaBr
Name HCl(aq).
Hydrochloric acid
What is the molar mass of CH₄ (approx.)?
16 g/mol
How many total oxygen atoms are in (NH₄)₂SO₃?
3 O atoms
Name N₂O₄.
Dinitrogen tetroxide
Write the formula for calcium nitrate.
Ca(NO₃)₂
Is H₂SO₄ monoprotic or polyprotic?
Polyprotic
Monoprotic - only one ionizable H atom
Polyprotic - more than one ionizable H atom
How many moles are in 32 g of O₂?
1 mole
What type of compound is CaCl₂?
Ionic
Write the formula for dinitrogen pentoxide.
N₂O₅
Determine the charge of iron in FeCl₃.
Fe³⁺
Name HNO₃.
Nitric acid
-ic = polyatomic ions ending with -ate
-ous = polyatomic ions ending with -ite
Define empirical formula.
The simplest whole-number ratio of atoms in a compound
Explain the difference between a molecular (covalent) compound and an ionic compound.
Molecular (covalent): NM with NM
Ionic: M with NM
Why is “mono-” usually omitted for the first element but used for the second?
Naming rules omit mono- for the first element to simplify names, but it is kept for the second to indicate the number of atoms clearly
Write the formula for chromium(III) carbonate. Show reasoning.
Cr³⁺ and CO₃²⁻ → least common multiple 6 → Cr₂(CO₃)₃
Explain how the name changes from chlorate (ClO₃⁻) to its acid form.
“-ate” becomes “-ic acid,” so chlorate becomes chloric acid (HClO₃)
How many grams are in 2.50 moles of CO₂? Show your setup.
Molar mass of CO₂ = 12.01 + 2(16.00) = 44.01 g/mol
2.50 mol × 44.01 g/mol = 110 g
Final answer: 110 g CO₂