Description the mixture was (50% benzoic acid, 40% benzoin, 10% dibromobenzene) the report must include (introduction, observation, discussion, conclusion) the mixture i used = 0.503g methylene chloride = 4 ml sodium hydrous carbonate =4 ml then i removed the aqueous layer to another test tube 6M HCl was to the aqueous layer then saturated sodium chloride weight of the filter paper with benzoic acid (0.172 + 1.868) for the organic layer i added ethanol to recrystallize (benzoin, dibromobenzene) the filter paper for the organic component + crystal (0.180 + 0.23)
Description Unit 5 Lesson 2: Driving Force of Reactions Apply In this unit, you learned about calculating free energy change. Now, you will show your understanding of this concept by answering the following question. Make sure you are showing each step of your work. For the vaporization reaction Br2(l) ? Br2(g), ?H0 = 31.0 kJ/mol and ?S0 = 93.0 J/(mol • K). At what temperature will this process be spontaneous? "Make sure to show your work, and your answers should be provided with the correct amount of significant figures." YOU WILL RECEIVE A SCORE REDUCTION IF THE ABOVE REQUIREMENTS ARE NOT MET.
Description Explain why phosphate buffer needs both Na2HPO4 (sodium dibasic phosphate) and NaH2PO4 (sodium monobasic phosphate) in order to resist changes in pH?
Description A scientist who is trying to make an insecticide that is more toxic to mosquitoes than to humans would be involved in ________. Basic research Applied research Technology Serendipity How is chemistry defined? For each of the following activities, list the hazards involved and the ways in which exposure could occur. Then, decide if the benefit of the activity outweighs the risk. Propose ways in which the overall risk might be lessened. Installing a smoke detector that uses a radioactive capsule to detect particles in the air Eating food that has been treated with radiation to kill harmful bacteria Eating food derived from genetically modified organisms or plants Smoking cigarettes Identify the following as physical or chemical changes. Explain your choices. Formation of snowflakes Rusting of a piece of iron Ripening of fruit Fashioning a table leg from a piece of wood Fermenting grapes Boiling a potato An aspirin tablet usually contains 325 mg of aspirin. What is this in grams? What is the mass in grams for a 1000 mL volume (1 Liter) of iridium if it has a density of 22.42 g/mL? Write a chemical equation for the following descriptions: Two atoms of potassium metal react with two molecules of liquid water to produce two molecules of solid potassium hydroxide (KOH) and one molecule of hydrogen gas. One molecule of carbon dioxide gas reacts with one molecule of liquid water to produce one molecule of liquid carbonic acid (H2CO3). Classify each of the following as an element, a compound, or a mixture. Justify each answer. Mercury Milk Pure water A piece of lumber Ink Iced tea Pure ice Carbon Antimony Cytoxan, also known as cyclophosphamide, is widely used alone or in combination in the treatment of certain kinds of cancer. It interferes with protein synthesis and in the process kills rapidly replicating cells, particularly malignant ones. Cytoxan has the molecular formula C7H15O2N2PCl2. How many atoms are in one molecule of Cytoxan? What elements are present in Cytoxan? What is the ratio of hydrogen atoms to nitrogen atoms in Cytoxan? Would Cytoxan be classified as an organic compound? A cook wants to pour 1.5 Liters of batter into a 2-quart container. Will it fit?
Description Group Member Names: undefined undefined undefined Question #1. In your own words, describe the goal(s) of this experiment. undefined undefined undefined Calculation #1. Saturated solution sample temperature data undefined Enter the temperature data you recorded for your saturated Borax samples. undefined Calculate the mean temperature in units of C and K, and then calculate 1/T (1/K). undefined Report Table 1. Temperature data and calculation results. sample initial temperature (before sampling), oC temperature after sampling (oC) mean temp (oC) mean temp (K) 1/T (1/K) 45A 45.0 44.5 45B 44.5 43.9 35A 35.2 35.0 35B 35.0 34.5 25A 25.8 25.7 25B 25.7 25.7 15A 15.7 15.6 15B 15.6 13.2 5A 5.6 5.6 5B 5.6 5.3 undefined undefined undefined Question #2. (0.5 pt.) Record the concentration of the standard solution of HCl. undefined 0.1962 undefined undefined Calculation #2. undefined Enter the volume of HCl solution required to reach the endpoint in each of your titrations. Calculate the molar equilibrium concentration of B4O5(OH)42? in each borax sample solution your group titrated. (Refer to equation (7) in the lab for the molar ratio.) Calculate a value of Ksp and ln Ksp for each sample solution. (Refer to equation (6) in the lab). undefined Report Table 2 Equilibrium Concentrations of B4O5(OH)2? from Titrations of Saturated Solutions of Borax at Different Temperatures, and Ksp and ln Ksp values. sample volume of HCl required to reach endpoint (mL) equilibrium concentration of B4O5(OH)42? (M) Ksp ln Ksp 45A 21.9 45B 23.5 35A 46.6-21.9=24.7 35B 47.9-23.5=24.4 25A 15.2 25B 14.1 15A 27.6-15.2=22.4 15B 26.0-14.1=11.9 5A 33.2-27.6=5.6 5B 33.5-26.0=7.5 undefined undefined undefined undefined Calculation #3. Show an example calculation for the equilibrium molar concentration of B4O5(OH)42? using the titration data for sample 35A. undefined ?Include units and show all work, including the molar ratio of acid to base. undefined undefined undefined Calculation #4. Show an example calculation for the value of Ksp using the data for sample 35A. Refer to equation (6) in the lab. undefined ?Use appropriate significant figures and show all work. undefined undefined Question #3. Using Excel 365, construct a graph by plotting ln Ksp (y-axis) versus 1/T (x-axis) using data from the 10 samples of saturated borax solution. Make sure to use the mean temperature in units of K. Create a best-fit line (trendline) through the ten data points and determine slope and y-intercept of the line. Insert an image of your ln Ksp versus 1/T graph below. undefined ?Label the axes, provide a title, and display the best-fit line (trendline) and equation on the graph. undefined undefined Calculation #5. Calculate the values of ?Ho (in kJ/mol) and ?So (in J/molK) using your experimentally determined slope and y-intercept values from your graph of ln Ksp vs. 1/T. Refer to equations (10), (11), and (12) in the lab. undefined ?Include proper units (see above), use appropriate significant figures, and show all work. undefined undefined Calculation #6. Calculate the value of ?Go using equation (8) (?Go = ?RT ln Ksp) and the data for sample 35A. Enter your result in Report Table 3 below (Calculation #8). undefined ? Use appropriate significant figures and show all work. undefined undefined Calculation #7. Calculate the value of ?Go using equation (9) (?Go = ?Ho - T?So) and the data for sample 35A. Enter your result in Report Table 3 below (Calculation #8). undefined ?Use appropriate significant figures and show all work. undefined undefined undefined undefined undefined Calculation #8. Calculate the value of ?Go (in kJ/mol) by using equation (8) (?Go = ?RT ln Ksp) and by using equation (9) (?Go = ?Ho - T?So) for the nine remaining samples of saturated borax solution. undefined Report Table 3. Calculated Values of ?Go using Equation (8) and ?Go using Equation (9) sample ?Go (kJ/mol) using ?Go = ?RT ln Ksp ?Go (kJ/mol) using ?Go = ?Ho - T?So 45A 45B 35A 35B 25A 25B 15A 15B 5A 5B undefined Question #4. Does the value of the equilibrium constant change as the temperature changes? If so, explain why the value changes. undefined undefined Question #5. Compare your experimentally determined value for Ksp at 25oC (i.e. samples 25A and 25B) with the accepted value of 1.8 x 10?2. Are they the same? If they are not the same, explain how they differ. How might you modify the design of the experiment to improve the experimental results (i.e., to produce values that are in better agreement with the theoretical values)? undefined undefined Question #6. Consider your experimentally determined value of ?Ho for the dissolution of borax in water. Is this process exothermic or endothermic? Explain using your data and results. undefined undefined undefined Question #7. Based on your observations in this experiment, predict the sign of ?So for the dissolution of borax in water. What is the sign of your experimentally determined value for ?So? Are they consistent? Why or why not? undefined undefined Question #8. Based on your experimentally determined value for ?Go at 25oC, is the dissolution of borax in water a spontaneous process? If not, why does borax dissolve in water? Explain. (Hint: think about the difference between ?Go and ?G.) undefined
Description Acids and bases are types of solutions of particular importance to the nursing field. For proper function the body needs to maintain a pH value within a very narrow range. Nurses need to be aware of the basics of acid-base chemistry, which lay the foundation for understanding conditions which can influence bodily pH values and how to properly address these issues for optimal patient outcomes. The worksheet is attached
Description Hello Femma, Attached is my next lab assignment, The Chemistry of Metals: Exploring Reactivity. I have attached the link to the lab and the instructions. Please le me know if you have any problems with the link. Thank you for your help! http://chemcollective.org/vlab/106
