Chemistry

Title
Water and Aqueous Solutions
Introduction
In this experiment students are examine some of the properties of water, and test tap water and deionized water also known as distilled water, for the presence of some of the dissolved materials such as salt, gases, and ions. Water is polar molecule and following the general rule of like dissolving like, will dissolves only other polar materials. Non polar materials are dirt, oil, fats and air come in contact with the surface of water. Hard water contains calcium, magnesium, and iron ions. Another part of the experiment studying solution concentrations, students have to look at several properties solutions and some factors involved in solution process. There are two parts of solutions; the solute and the solvent.
Procedure
Same as the lab directions
Data
Present of the last few pages of lab report.

Post Lab Questions
Part I
1. Diagram the structure of the water molecule, showing its polar nature (you will need to draw the molecular geometry & use lone pairs)

2. What is the source of Cl- ions in Municiapal tap water?
Tap water may contain many minerals such as chloride, cooper, phosphate, and magnesium.
3. Under what conditions should patients avoid drinking softened water? Why?
Cardiovascular disease, low sodium diets, and high blood pressure are the three conditions.
4. Is rain water hard or soft? Explain your answer.
Rain water is soft because it doesn’t contain any minerals, but as it seeps through the ground it can pick up minerals, such as calcium and magnesium compounds from soil and rocks.

Part II
5. How many grams of sodium chloride do you need to prepare 250 mL of 5.00%(w/v) sodium chloride solution?

6. How many mL of the above 5.00% (w/v) solution are needed to make 100 mL of physiologic saline (0.90% (w/v) sodium chloride)?

7. How many grams of calcium nitrate, Ca(NO3)2 are needed to make 100 mL of a 0.5 M solution?