General Chemistry Laboratory Activity Name:Alzon Fine L. Pacada, Alyssa Kate J. Cabrillos, Maria Erica Mariano Date: March 4, 2023 Laboratory Report Worksheet Introduction: a. What was the purpose of this lab? What were you trying to find out? b. What is the definition of an Ionic Compound? A Covalent Compound? c. Why does ionic and covalent compounds have such different properties? Think about the bond strength and how these two bonds are formed? d. What was your hypothesis (prediction) for this experiment for each of the known compounds? WHY? Objective: At the end of the laboratory activity, the students will be able to: a. compare and contrast the properties of ionic and covalent compounds and identify key differences between them. b. distinguish between observations and inferences and understand the place each has in the data collection process. c. decide whether a compound is ionic or covalent by examining hypothetical data, and decide whether data presented is relevant and valuable. d. collaboratively with their group mates to test the properties of three unknown compounds that they have been assigned. e. work collaboratively with their group mates to test the properties of four known compounds: oil, wax, salt, and sand. f. analyze their results and those of their peers scientifically and respectfully, collaborating as scientists do in real laboratory situations. g. observe all required safety protocols for the duration of the experiment, including wearing goggles and closetoed shoes, and using great care around hot/heated objects. h. collect meaningful data on each of the known compounds that will be used to confirm the compound type in their written lab reports. Materials: 1 unit of Triple Beam Balance 1 test tube holder 1 alcohol lamp 50 g Wax 3 Unknow compounds Alcohol Procedure: 7 pcs of petri dish 1 100 ml graduated cylinder lighter/match 50 g sand 50 ml oil 7 pcs of spoons 6 pcs 200 ml beaker Conductivity tester 50 g salt gloves 7 pcs of test tubes 1 laboratory tripod 1stirring rod Distilled water safety googles 1. Obtain all necessary safety equipment and ensure it is fitted properly before beginning the experiment. This includes goggles, laboratory gown (if available), gloves, and close-toed shoes. 2. Gather the required materials (including the known compounds) listed above and return to your lab station to begin preparations. 3. Turn on the hot plate/alcohol lamp to give it time to warm up. 4. Place 50 g of each known compound into a beaker, keeping these samples separate. Label these compounds if not easily identifiable by physical features. General Chemistry Laboratory Activity 5. Place the beaker with the samples inside them onto the hot plate/ alcohol lamp carefully and observe them for five minutes. Record observations after five minutes have passed. Carefully remove the samples from the heat using tongs and allow to cool before disposing of these. Turn the hot plate/ alcohol lamp off to allow it to cool down. 6. Examine the physical appearance of the remaining sample of salt, noting color, obvious odor, texture, hardness, or any other distinguishing features. 7. Fill a beaker with 100 ml distilled water. Place 50 g of salt into the beaker and use a stirring rod to stir for one minute. Record observations on solubility. 8. Remove the cover of the conductivity meter. Touch the ends of the meter together briefly to ensure the meter is working properly. With the electrodes separated into their original position, submerge the metal electrodes into the sample cup containing the salt and distilled water from step six. Observe the meter to determine whether the solution is conductive. Record observations. Remove electrodes from the solution and touch them together briefly once more to ensure the meter is still working to prevent the likelihood of a false negative reading. 9. Rinse the electrodes of the conductivity meter with a small amount of distilled water and a rinse beaker to remove any contaminant that remains on the electrodes. 10. Repeat steps six through nine for the remaining compounds. 11. Repeat steps 1-10 for unknown compounds. e. What safety precautions did you take during this experiment? -Use tools, equipment and machinery properly and be aware of your surroundings to help avoid laboratory mishaps 2. Results: Please fill in the data tables below with the data collected in your experiment. Table One: Known Compound Observations Compound Appearance Does it Melt? Is it Soluble? Is it Conductive? Salt Clear, liquid solution Yes Yes Yes, It has 250 bolt Wax Red then the wax float to water No No No Sand Did not mix but the water turns brown No No Yes, it has 200 bolt Oil Did not mix and the oil floats in water No No No This data table shows the observations made and data collected for each of the known compounds as the experiment was carried out, including notes on physical appearance, relative melting point, solubility, and conductivity. General Chemistry Laboratory Activity Table Two: Unknown Compound Observations Compound Unknown Alcohol Appearance Does it Melt? Is it Soluble? Is it Conductive? Slowly No Yes, it has 200 bolt No No Yes, it has 200 Base our observation it the same to wax that float in water and its not mix. There's no happened between water and alcohol, they just mixed together. It mixed together and the water Yes Yes No becomes white. This data table shows the observations made and data collected for each of the unknown compounds as the experiment was carried out, including notes on physical appearance, relative melting point, solubility, and conductivity. Powder 3. Discussion: a. Please calculate the difference in electronegativity for each of your known compounds. THIS SHOULD BE IN YOUR NOTES. Electronegativity difference = Electronegativity of Element A – Electronegativity of Element B Electronegativity Difference of NaCl = 3.16 – 0.93 = Electronegativity Difference of C15H31 = 2.55 – 2.20 = Electronegativity Difference of SiO2 = 3.44 – 1.90 = Salt: 2.23 Wax: 0.35 Sand: 1.54 b. Did your experimental data agree with your calculated hypotheses? Why or why not? Yes, because in my calculated hypotheses the known compounds are composed of different elements that has number of electrons that we can calculated and it is the same to what we are expecting result. c. What were the possible sources of error in this experiment? The number of elements that we mix can be the source of the error. 4. Conclusion: a. Based on your data – was your hypothesis correct? How do you know this? Yes, because we calculate to the difference between element A and element B. b. Answer your Post-Lab Questions here: i. What type of compound did your experiment prove each unknown to be? How do you know this? - they are covalent compound because there chemical bonds are sharing of electrons to form electron pairs between atoms. Because Alcohol, unknown and powder compounds covalent bonds are attached to sharing atoms. General Chemistry Laboratory Activity ii. Do you have any guesses about the identity of your unknown compound? Why? - The identity of the unknown compound is a mixed of Jelly and Wax. Because of the texture, appearance and the result of the experiment in the unknown compound. iii. How would you improve this experiment if you were to do it again? - we would definitely imporove this experiment if we would given a chance by giving an extra effort and careful in doing the said experiment. iv. Improving measurement technique. - in improving the measurement technique we will carefully focused on the experiment that we were doing and it is important that we know the electronegativity of the elements that is present in the compounds. c. What could you do to research ionic and covalent compounds further? Did this experiment bring up any new questions for you? - Ionic and Covalent Compounds are important to known further and broad knowledge about this because they allow the synthesis of specific organic compounds and it can be formed a desired products just like in the experiments using different elements present already in the materials that we used. This experiment bring up a lot of questions for us because it made us to be curious in all the things that are present in our daily lives that most of them can be form and identified by knowing their compound name formed. References
