CHM 1045 - Exam 1 (Chapters 1-3) Questions With 100% Correct Answers

Anions are - negative (ie, more electrons) Cations are - positive (ie, less electrions) Formula for density - d = m/v Formula Mass is measured by - adding up all the elements g/mol Formulas to conv. Celsius to Fahrenheit - 1. F = (C x 9/5) +32 2. C = (F +32) x 5/9 Formulas to conv. Kelvin to Celsius - C = K - 273.15 How do you find percent composition? - (# of element)(atomic mass of element) / (mass of entire compound) and then multiply by 100 How to find neutrons in an isotope? - number given - number of protons (equal to number on periodic table) How to name for molecular compounds - use prefixes How to name ionic compounds - use roman numerals for metals and add ide to non metals How to tell if ionic or molecular - It is ionic if it has a metal, and molecular if it is just non metals How to write formulas for ionic compounds - balance chargesLaws of Definite Proportions (who created it/what is it) - Proust. Elemental composition of a substance does not vary. name CrCl2 6H20 - Chromium (II) Chloride HexaHydrate Prefixes for naming covalent compounds - Mono, Di, tri, Tetra, Penta, Hexa, hepta, octa, nona, deca (also hemi = 1/2) What are oxyacids? - Oxygen + hydrogen + nonmetal What are possible charges of Al? - 3+ What are possible charges of Cr? - +2 and 3