Synthesis of Potassium Dioxalatocuprate Dihydrate Lab 7

Outline Purpose Definitions Experiment Reaction Calculations Precautions Equipment Setup What to turn in today Spring Break and Next Lab Reminder

Purpose This lab will help you gain an understanding of stoichiometric relationships between reactants and products of chemical reactions. This includes an understanding of concepts such as limiting reagents, yields, and percent error.

Important Points Stoichiometry is the study of mass relationships in a chemical reaction. The law of definite proportions states that compounds or elements react chemically to form a new compound in definite proportions. Before any attempt at calculations are made, reactions have to be balanced first. Only then can we obey the law of definite proportions. The limiting reagent is the reagent that runs out first in a chemical reaction.

Reaction Add two water soluble compounds together to form an insoluble solid that precipitates out. Filter out all excess water soluble reagent. Isolate the precipitate on filter paper utilizing three rinses and vacuum filtration. Determine the percent yield recovered.

Reaction Reagents Products A B C 1CuSO45H2O(aq)+2K2C2O4H2O(aq) 1K2[Cu(C2O4)2]2H2O(s)+ D E 5H2O + 1K2SO4(aq) copper potassium oxalate potassium potassium sulfate monohydrate dioxalatocuprate sulfate pentahydrate dihydrate

Calculations Moles of A = Moles of B = Limiting Reagent (LR) Ratio = Moles of CLR = (moles of LR) x Theoretical Yield = (moles of C) x (fw of C) % Yield = x 100%

Precautions Filtrate should be disposed of in the wet copper waste container only. Dry product and waste copper sulfate should be disposed of in the dry copper waste container only. After all product is scraped off, filter paper should be placed on the paper towel next to the dry / wet waste containers. Cleaning and maintaining balances…

Equipment Hotplate function Ice bath preparation Filtration setup

Equipment Setup

Equipment Setup Filtering flask

Safety Concerns Reagents: Eye Contact: Skin Contact: Inhalation: Acetone Cupric Sulfate Denatured Alcohol Potassium Oxalate Eye Contact: Stinging, tearing, redness, pain, irritation, tissue burns, conjunctivitis, ulceration, clouding of cornea, and blurred vision Skin Contact: Defatting, dehydration, irritation, redness, pain, drying, flaking, cracking, itching, and severe burns Inhalation: Irritation, ulceration, and perforation of the respiratory tract, coughing, sore throat, shortness of breath, dizziness, dullness, drowsiness, loss of appetite, inability to concentrate, headache, nervousness, cramps, CNS depression, narcosis, and unconsciousness. Fumes from heating may cause symptoms similar to a cold. Ingestion: Abdominal pain, nausea, vomiting, headaches, gastritis, gastrointestitis, intoxication, blindness, and death. Aspiration into the lungs can cause severe lung damage.

Next Week: Spring Break No labs next week

In 2 Weeks: Lab 8 Reminder Read the required reading material from your textbook and lab manual. Complete your pre-lab questions. Study for the quiz. Submit your Lab 7 Report.