Ch.11 - Liquids, Solids & Intermolecular ForcesWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: The karat scale used to describe gold alloys is based on mass percentages. If an alloy is formed that is 50 mol% copper and 50 mol% gold, what is the karat number of the alloy?

Problem

The karat scale used to describe gold alloys is based on mass percentages. If an alloy is formed that is 50 mol% copper and 50 mol% gold, what is the karat number of the alloy?

A diagram shows gold at the top vertex of a triangle and silver and copper at its left and right vertices, respectively. Along the left side of the triangle is mass percent silver, ranging from 0 to 100 percent, and along the right side is mass percent gold, ranging from 0 to 100 percent. Along the base of the triangle is mass percent copper, also ranging from 0 to 100 percent. The bottom left corner is white gold, and the bottom right corner is copper red gold. A tall vertical region around 60% copper is reddish, which includes 14-karat gold (58% gold and 45% Ag). The diagram shows that 18 karat gold is 75% gold by mass and has a yellow color, 14 karat gold is 58% gold by mass and has a reddish color, white gold is below 20% gold by mass and is white, and rose gold is below 20% gold by mass and red. The atomic radius of silver is 4.085 angstroms, the atomic radius of copper is 3.615 angstroms, and the atomic radius of gold 4.078 angstroms.