Friday, September 6, 2013
What is the density of a mineral if 427 occupies 35.0 mL?
427g/35.0mL = 12.2 g/mL
The density of gold is 19.3 g/mL. What is the mass of 25.0mL of gold?
Find the mass
-sometimes called "heat capacity"
Specific heat of a material is the amount of heat energy in joules, calories, btn, etc. Required to raise 1
gram of the material by 1C
-Calculate the specific heat of a 125g solid if 1638J of heat raises the temp. of the solid from 25.0C to
*Law of Conservation of Mass
-Mass is neither created nor destroyed during a chemical reaction
MASS OF REACTANTS=MASS OF PRODUCTS
Na + Cl = NaCl
23.0g 35.4g 58.4g
*Law of Conservation of Composition
-Elements of a compound are present in a fixed and exact proportion by mass.
-Water is ALWAYS 11.2% H and 88.87% by mass
-Hydrogen Peroxide (H202) is ALWAYS 5.9% H and 94.17% by mass
-Analysis of 7.800g of a compound yields 3.202g of Carbon, 1.725g of Hydrogen, and 2.842g of Nitrogen.
Calculate the mass percentage of each element in the compound.
-3.202gCarbon/7.8gCompound = 0.4105 (turn in