Lab Report Experiment 1 31v2e

Experiment 1 “Determining the type of Bonding in unknown substances by conducting various experiments.” Name: Hussain Yawari Partner: Hose Kim AP Chemistry - F block Date: 26th of September 25, 2017 Teacher: Nada ElGhossein

ABSTRACT The objective of the experiment was to understand and be able to identify all the types of bonds by conducting different experiments. The experiments conducted to understand their bonds were – solubility, conductivity, melting point, pH level, polarity. The substances given were B, R, P, I. We heated the substances in an aluminum foil. Tried dissolving them in distilled water, hexane and ethanol. Checked for conductivity. The main results were: B – Iodine. Non-Polar, Low MP R – Sodium Bicarbonate. Polar, Conductive, High MP P – Iron. Metallic, High MP I - Wax. Buoyance, Low MP The real-world significance, Iodine is used to cure people exposed to radiation by reducing the harmful accumulation of radioactive substances in the thyroid. Iodine is also used for treatment of a number of different eye conditions. It also naturally protects against UVB radiation.

RESULTS Solubility: Use a spatula to take the unknown substance from the container and put into the well plate. Then add enough distilled water so that the substance can dissolve into it. Use a glass stirring rod to stir the solution. The substance is also tested the same way in ethanol and hexane. Then record the results.

Observations: Substance R is polar as it dissolves in water where as other substances such as B and I dissolved in Hexane, showing Non-polarity. Substance R is most likely metallic as it did not dissolve in any. Table 1: Solubility of unknown substances (BRPI) in Distilled water, Hexane and Ethanol. Unknown

Distilled Water

Hexane

Ethanol

Substance B

Not Dissolved

Dissolved into purple

Dissolved into

solution.

Reddish brown solution.

Substance R

Dissolved into murky white

Not Dissolved

Slightly Dissolved

solution. Substance P

Not Dissolved

Not Dissolved

Not Dissolved

Substance I

Buoyance

Dissolved

Dissolved slightly.

Conductivity: The substance that dissolved in water were then tested for conductivity. A conductivity probe connected to the TI-nspire was used to get values in (ms/cm). Then recorded the result. Table 2: Conductivity of substance R in Distilled water. Unknown

Conductivity (ms/cm)

Substance R

3577

pH Test1: The substances that dissolved in water were then tested for pH level. Use the litmus paper and put one end into the solution and check for color change.

Observations: As substance R changes the color to green, it shows us that it is an alkali. Table 3: pH test of the unknown substances B and R. Unknown

Change in Color of litmus paper

Substance B

Not measured since substance wasn’t dissolve in water.

Substance R

Green

Melting Point: Use the ring stand as a base on which a candle is placed. Use an aluminum foil to make a small cup shape container. Place substance into the cup by using a spatula. Then use a test tube holder to hold the cup over the flame. Table 4: Relative Melting point of substances. Unknown

Relative Melting Point

Time Taken (s)

Substance B

Low

12

Substance R

High

Undefined

Substance P

Very High

Undefined

Substance I

Low

14

Magnetism: Bring a magnet near the substance to check for magnetic properties. Observations: This test was conducted to make sure that substance P was a metal.

Table 5: Magnetism of Unknown Substances. Unknown

Magnetic properties.

P

Paramagnetic

I

No magnetic properties

B – Iodine R – Sodium Bicarbonate P – Iron I - Wax

DISCUSSION

Error Analysis In any experiment conducted, there is always human errors. In the experiment, we conducted there were a few errors that could not be solved completely. Example, while checking the conductivity of the solution, the result value kept fluctuating making it difficult to determine a constant value. To solve this, we should either take many values and find an average or get a third person to double check the value. Additionally, the melting point experiment had a few errors. If we had used a Bunsen burner instead of a candle, the heating process would have been more efficient and we could reach higher temperatures as compared to using a candle. In the same experiment, the time taken for the substance to melt was not accurate.

Expected Results Substance B: Iodine. The substance gave a purple flame when it was heated. It was a purple solid with metallic luster. Soluble in hexane and ethanol i.e. Non-Polar. Substance R: Sodium Bicarbonate. The substance turned the litmus paper green showing pH >8. Odorless. Soluble in water and slightly in ethanol. Ionic. Substance P: Iron. It is magnetic and has a very high MP and is dark black/grey color. Substance I: Wax. Low melting point and Buoyancy in water. Odorless. Non-Polar. Looking at the results we can say that the purpose of the experiment was accomplished. The experiments- solubility, polarity, melting point and conductivity determined the unknown substances. The result was compared and matched the actual values. Real World Significance: Iodine is used to cure people exposed to radiation by reducing the harmful accumulation of radioactive substances in the thyroid. Iodine is also used for treatment of a number of different eye conditions. It also naturally protects against UVB radiation. Post-Lab Questions 1. Melting point for Ionic compound are higher than polar covalent compound in insoluble substance, and still higher compared to non-polar covalent compound in soluble compounds. 2. Some of the solids when immersed into water were soluble while the others are insoluble. Example of soluble solids include J(sucrose) and N(ammonium chloride), while wax and iron were insoluble. Those which conduct electricity in water were the ones who were soluble in it, Sucrose and Ammonium Chloride.

3. I determined the bonding of the substances by determining if they were soluble or not, if they were soluble and had a high melting point than they would have been a metallic bond, If not they were non-polar covalent, On the other hand, if they were insoluble and had a high melting point then they were ionic bonds, if not they were polar covalent. 4. Not all ionic compounds will dissolve in water as they contain high polarizing ions, they will react with water rather than dissolving in it. 5. Distilled water, is a pure substance and has no concentration of any other element, which could damage the reliability of the experiments 6. Most metal oxides will form basic solutions with a Ph greater than 7. No, nonmetal oxides produces acids which have a pH smaller than 7 7. Wax is an organic compound that has no charge on the molecules, Sugar is organic as well but consist of as well some charged molecules and that’s why it doesn’t dissolve in water.

MLA Citation Dr. Edward Group DC, NP, DACBN, DCBCN, DABFM. “12 Uses For Iodine (And Other Useful Tips, Research & Resources).” Dr. Group's Healthy Living Articles, Global Healing Center, Inc, 21 Apr. 2016, www.globalhealingcenter.com/natural-health/uses-for-iodine/.