Empirical Formula Due Today: Homework: 1. Empirical Formula Pre-Lab 2. Density Short Report Homework: 1. Empirical Formula Formal Lab Report Empirical Formula

Zinc and chloride reaction Objective Experimentally determine the empirical formula of: Zinc and chloride reaction Copper and sulfur reaction

Procedure Notes Part I: Zinc Chloride Procedure Change: Use 0.2-0.25g of zinc This MUST be done in the hood! DO NOT touch the evaporating dish with your fingers!

Procedure Notes HCl MUST be poured in the hood! DO NOT have the bunsen burner on! Heat water while you are waiting for the evaporating dish to cool and the reaction is proceeding

Procedure Notes When heating, AVOID spattering Make sure to get data from another lab group Return evaporating dish to the oven

Procedure Notes Part II: Copper Sulfide Compound DO NOT touch the crucible and lid with bare hands! When heating, a blue flame should be rising from inside the crucible

When the flame disappears, heat to red hot Procedure Notes When the flame disappears, heat to red hot Make sure to get data from another group Return crucible and lid to the oven

Waste Dispose of contents in an appropriate waste container

Risk assessment Hydrochloric Acid Danger Inhalation Hazard Corrosive

calculations To calculate moles: Mole Ratio:

calculations Mole ratio: Examples: 1:2 2:1 A ratio should never be reported as a single number