Making Ionic Compounds

Lab

1. As in any lab, clean all utensils carefully (utensils include: crucible, stirring rod, 100 mL beaker, plastic dropper, and micro spatula).

2. Arrange the ring on the ring stand so that it is about 7 cm above the Bunsen burner.  Place the clay triangle on the ring.

3. Measure the mass of the clean, dry crucible and record the mass in the data table.

4. Roll approximately 25 cm of magnesium ribbon into a loose ball and place it in the crucible.  Measure the mass of the ball and the crucible and record it. 

1. Place the crucible on the clay ring.  Heat with a hot flame making sure that the crucible is near the top of the flame.

Danger! Do not look at the bright light directly!  It will permanently damage your eyes!

2. Watch carefully!  When the metal ignites, move the Bunsen burner out from under the crucible and clay triangle, but do not turn off the flame. 

Caution!  Follow these directions carefully!  The crucible can shatter, sending hot pieces of material flying.

3. After everything has stopped reacting, wait a couple of minutes for the crucible to cool slightly.  Then take a plastic dropper and very carefully place one drop of water along the inside top edge of the crucible.  Allow the drop of water to roll down the inside of the crucible and come in contact with the magnesium products in the bottom.  Continue to add drops of water in this manner until the water no longer sizzles.

4. Reheat the crucible with the magnesium product and water until all the water has been boiled off.

5. Turn off the Bunsen burner and allow the crucible to cool.  After a few minutes measure and record the mass.

5. Use a micro spatula to scrape the solid magnesium product into a beaker for further testing.

6. Add 10 mL of distilled water to the beaker and stir.  Check with a conductivity tester and record your results.

6. Decant the water in your beaker into the sink with running water.  Wipe any solid products out of the beaker with a paper towel and dispose of it in the trashcan.  Wash out the crucible with water, wash out the beaker, wash off the micro spatula, and rinse all products down the drain.  Clean and return all lab equipment to its proper place. 

7. Complete all post-lab activities.

Post-lab

1. Calculate all masses and record them in the table.

2. In your lab notebook reflect on the following:

(Note: If you are asked to reflect on things in your lab notebook that should mean to you that you should write about them in your lab notebook.  Such reflections should NOT simply the answers to the questions, but should be in complete sentences so that someone reading it later would not have to read the question 1^st to understand what you have written.)

a)     Write the electron configuration for magnesium.   

·         Based on the configuration, will magnesium lose or gain electrons to become a magnesium ion?

·         Write the electron configuration of a magnesium ion.

·         What noble gas has the same configuration as magnesium ion?

b)     Repeat a) above for oxygen and nitrogen.

c)      What kind of energy was released during the reaction?  What can you conclude about the product of this reaction?

d)     How do you know that the magnesium reacts with certain components of air?

e)     Magnesium reacts with oxygen and nitrogen in the air at high temperatures.  Predict the binary formulas for the products. Write the names of these compounds.

f)        The product of the magnesium and oxygen is white and the product of magnesium and nitrogen is yellow.  Which one dominates your product?

g)     Did the product produce an electric current?  Does this indicate whether or not the compounds are ionic?

3. Write a lab report that includes the objectives and results.  Ask you teacher when this report will be due.

(Note: Remember that all lab reports must have a title page.  Go over the formal lab report guide, the grading sheet, and all notes on lab reports and make sure that you have done everything correctly before the due date.)

Note: The following MSDS was taken and adapted from www.espimetals.com.  This website has proven to be difficult for some web browsers to read.  I have adapted it here to make it easier for students to use it. It is used by permission of ESPI Metals.

MATERIAL SAFETY DATA SHEET  -  Magnesium Nitride

I. PRODUCT IDENTIFICATION

Trade Name: Magnesium Nitride

Chemical Family: Metal Nitride

Formula: Mg3N2

Molecular Weight: 100.93

CAS #: 12057-71-5

II. HAZARDOUS INGREDIENTS

Magnesium Fluoride ACGIH PEL/TLV: N/A

Other Limits: N/E

Sec.302 (EHS): No

Sec.304 RQ: No

Sec.313: No

Percent: 100

III. PHYSICAL DATA

Boiling Point: 700°C

Melting Point: 800°C

Specific Gravity: 2.712

Solubility in Water: Decomposes

Appearance and Odor: Green-yellow powder, no odor.

Physical States: Solid

IV. FIRE AND EXPLOSION HAZARDS DATA

Flash Point (Method used): N/A (non-flammable)

Autoignition Temperature: N/A

Flammable Limits: Non-flammable Upper: N/A

Lower: N/A

Extinguishing Media: N/A. Use extinguishing media for surrounding materials and type of fire.

Special Fire Fighting Procedures: Firefighters must wear full face, self-contained breathing apparatus with full protective clothing to prevent contact with skin and eyes. Fumes from fire are hazardous. Isolate runoff to prevent environmental pollution.

Unusual Fire & Explosion: When heated to decomposition, magnesium nitride may emit toxic fumes of magnesium oxide and ammonia. May be a moderate explosion hazard.

V HEALTH HAZARD INFORMATION

Routes of Entry: Inhalation, skin, eyes, and ingestion.

Health Hazards (acute and chronic):

To the best of our knowledge the chemical, physical and toxicological properties of magnesium nitride have not been thoroughly investigated and recorded.

Magnesium compounds have variable toxicity. There is no evidence that magnesium produces true systemic poisoning. Protection necessary for personal handling and processing magnesium is usually no different from that which is necessary for other metals (Sax, Dangerous Properties of Industrial Materials, 8^th ed.).

Nitrides: The details of the toxicity of nitrides as a group are unknown. However, many nitrides react with moisture to evolve ammonia. The gas is an irritant to the mucous membranes (Sax, Dangerous Properties of Industrial Materials, 8^th ed.).

Ammonia gas is a human poison by an unspecified route. Poison by inhalation, ingestion, and possibly other routes. An eye, mucous membrane, and systemic irritant by inhalation. Mutation data reported (Sax, Dangerous Properties of Industrial Materials, 8^th ed.). 

Ingestion: Acute: Ammonia gas may cause nausea, vomiting and burns.

Chronic: No chronic health effects recorded.

Skin: Acute: May cause irritation. Ammonia gas may cause severe irritation and possible chemical burns.

Chronic: Repeated or prolonged exposure to ammonia gas may cause tissue damage.

Eyes: Acute: May cause irritation. Ammonia gas may cause severe irritation and possible chemical burns.

Chronic: Repeated or prolonged exposure to ammonia gas may cause irreversible damage to the conjunctiva, cornea and lens.

Medical Conditions Generally Aggravated by Exposure: Pre-existing respiratory disorders.

Target Organs: May affect the respiratory system, skin and eyes.

Carcinogenicity: NTP? No

IARC? No

OSHA Regulated? No

LD/LC50: No toxicity data recorded.

Signs and Symptoms of Exposure:

Inhalation: May cause coughing, sneezing, difficulty breathing, swelling of the mouth and throat.

Ingestion: May cause tissue damage, chemical burns, nausea and vomiting.

Skin: May cause redness, burning, inflammation, itching, blistering and tissue damage.

Eye: May cause redness, itching, burning, inflammation, watering, lens opacities, ulceration of the conjunctiva and cornea.

EMERGENCY AND FIRST AID PROCEDURES:

INGESTION: Give 1-2 glasses of milk or water and induce vomiting, seek medical attention. Never induce vomiting or give anything by mouth to an unconscious person.

INHALATION: Remove victim to fresh air, keep warm and quiet, give oxygen if breathing is difficult and seek medical attention.

SKIN: Remove contaminated clothing, brush material off skin, wash affected area with mild soap and water, seek medical attention immediately.

EYES: Flush eyes with lukewarm water, lifting upper and lower eyelids for at least 15 minutes. Seek medical attention immediately.

VI. REACTIVITY DATA

Stability: Stable

Incompatibility (Material to Avoid): Water, moisture, strong acids and bases.

Hazardous Polymerization: Will not Occur

Hazardous Decomposition Products: Magnesium oxide and ammonia.

VII. SPILL OR LEAK PROCEDURES

Steps to Be Taken in Case Material Is Released or Spilled: Wear appropriate respiratory and protective equipment specified in Section VIII- Special Protection Information. Isolate spill area and provide ventilation. Vacuum up spill using a high efficiency particulate absolute (HEPA) air filter and place in a closed container for proper disposal. Take care not to raise dust.

Waste Disposal Method: Dispose of in accordance with Local, State and Federal regulations.

Hazard Label Information: Store in a cool, dry place. Store in a tightly sealed container. Wash thoroughly after handling.

Precautions to Be Taken in Handling and Storing/Other Precautions: Magnesium nitride evolves ammonia on contact with moisture and water. Handle and store in a controlled atmosphere and inert gas such as argon.

VIII. SPECIAL PROTECTION INFORMATION

Respiratory Protection (Specify Type): NIOSH/MSHA approved dust, mist, vapor cartridge respirator.

Ventilation: Local Exhaust: To maintain conc. at low exposure levels.

Mechanical (General): Not recommended

Special: Handle in a controlled atmosphere.

Other: Handle in an inert atmosphere such as argon.

Protective Gloves: Neoprene

Eye Protection: Safety glasses

Other Protective Clothing or Equipment: Protective gear not necessary for magnesium nitride.

Work/Hygienic/Maintenance Practices: Implement engineering and work practice controls to reduce and maintain concentration of exposure at low levels. Use good housekeeping and sanitation practices. Do not use tobacco or food in work area. Wash thoroughly before eating and smoking. Do not blow dust off clothing or skin with compressed air.

IX.  SPECIAL PRECAUTIONS

Some of the chemicals listed herein are research or experimental substances which may be toxic, as defined by various governmental regulations. In accordance with Environmental Protection Agency regulations and the Toxic Substance Control Act (TSCA), these materials should only be handled by, or under the direct supervision of a technically qualified individual, as defined in 40 CFR 710.2(aa).

The above information is accurate to the best of our knowledge. However, since, data, safety standards, and government regulations are subject to change, and the conditions of handling and use or misuse are beyond our control, ESPI makes no warranty, either expressed or implied, with respect to the completeness or continuing accuracy of the information contained herein, and dis-claims all liability for reliance thereon. Users should satisfy themselves that they have all current data relevant to their particular use.

Prepared by: S. Dierks

Dated: March 1994