[CHEM 1101] - Final Exam Guide - Comprehensive Notes fot the exam (50 pages long!)

• School: Carleton University
• Department: Chemistry
• Course: CHEM 1101
• Professor: Pam Wolff

Document Summary

Significant figures give information about how precisely a measured value is known. Note that they don"t mention anything about accuracy (how closely a measured value is to the true value) Significant figures only give meaning to measured values. If a value is exact or counted, we treat the value as if it has infinite significant figures. There are exactly 34 students in that classroom, it has 100% precision. Unless otherwise stated, you must assume that the true value has an error of (+/- 2) of the last significant digit. The mass of a 747 aircraft is 58 986 kg . Since they are implying that they only know up to the nearest kilogram, the final value would be (58 986 +/- 2) kg. It follows the simple rules for rounding: If the first digit you reject is 0 - 4 inclusive, do not change. If the first digit you reject is 5 - 9 inclusive, round up.