Description An instrument used to detect metals in drinking water can detect as little as 1 ug of mercury in 1 L of water. Mercury is a toxic metal; it accumulates in the body and is responsible for the deterioration of brain cells. Calculate the number of mercury atoms you would consume if you drank 1 L of water that contained only 1 ug of mercury. ( The mass od one mercury atom is 3.3 x 10^-22 g.)
Description Sulfur dioxide gas (SO2) is bubbled through a solution of acidified potassium permanganate (KMnO4). An oxidation-reduction reaction occurs. The unbalanced equation for this reaction is: MnO4– + SO2--> Mn2+ + SO42– A student wrote the two following half-equations: Equation One MnO4– + 8H+ + 5e– --> Mn2+ + 4H2O Equation Two SO2 + 4H+ + 2e– --> SO42– + 2H2O It is not possible to combine these two half-equations as the student had written Equation Two incorrectly. 1. Describe the mistake that was made in Equation Two. 2. Write Equation Two correctly. (Discuss, in terms of oxidation-reduction principles, electron transfer and charge, why Equation One and the original Equation Two cannot be combined into an overall balanced equation.) 3. Hydrogen peroxide is added to a solution of potassium bromide. You may use the resource tables given at the end of this assignment to help you answer the following questions. Identify which substance is being reduced. Use oxidation numbers and the transfer of electrons to justify your choice. 4.Describe what you would expect to observe for this reaction. Link all observations to the species concerned. (Tip: remember to describe both reactants and products.) 5.Write the balanced oxidation half reaction. 6. Write the balanced reduction half reaction 7. Write the full balanced equation.
Description Determine in which direction each of the following processes is spontaneous in the thermodynamic sense ("Forward" means the process as written). A piece of paper at room temperature reacts with oxygen to give carbon dioxide and water. Your food gets cold if you're late for supper. Water freezes at -10°C and 1 atm. Vodka at room temperature separates into two phases - water and alcohol.
Description Lab Instructions Time Requirements: approximately one hour Procedures: This lab is conducted in a virtual laboratory. Be sure to read through all of the instructions in both the virtual lab itself and look over the lab report form. Follow the lab instructions within the virtual lab to perform the laboratory investigations. Record your data (Pre-Lab Questions, Procedures, and Post Lab Questions) in your lab notebook. Before you turn in your lab, you will need to transfer all your documentation to your lab report form. Make sure to complete the purpose and hypothesis section before completing the lab. Click on the tabs below to begin your lab and to verify you have completed all parts of the lab. Completion Checklist: Read through the lab introduction. Read through the lab instructions within the virtual lab completely before setting up the materials for your experiment. Conduct the experiments–Experiment 1 and Experiment 2 and record your data. Complete the analysis, conclusions, and answer the Post-lab Questions. Purpose and Hypothesis Read through the lab instructions (in the virtual lab) and the lab report form. After reading through the lab instructions fill in the purpose and hypothesis section of the lab report form before proceeding with the lab. Chemistry Math In chemistry, we often have to perform calculations using formulas. In this lab, you will be using the formula for density.View the following presentation for information on solving formulas in chemistry and practice this essential skill.
Description QUESTION 1 Which is considered a fossil fuel? Coal Solar Wind Hydrothermal 2 points QUESTION 2 Which is considered a physical science? Physics Biology Zoology Botany 2 points QUESTION 3 Refrigeration has been used since the late 1800s and early refrigerants were Safe Flammable and toxic Inert Fluorine compounds, CFCs 2 points QUESTION 4 The smallest concentration listed below is Parts per million Parts per trillion Parts per billion Parts per thousand 2 points QUESTION 5 Which activity comes first in the scientific method? Conclusion Hypothesis Experimentation Observation 2 points QUESTION 6 A patient’s body weight is 158 pounds which is equivalent to 82.1 kg 34.8 kg 348 kg 71.7 kg 2 points QUESTION 7 The measurement 0.0000043 m, expressed correctly using scientific notation is 4.3 x 10-7 4.3 x 10-6 4.3 x 106 0.43 x 10-5
Description Journal: An Introduction to Chemistry Unit Throughout this unit, you have made four journal entries. It is now time to turn in your journal. Make sure you have made a journal entry for each of the following journal assignments: Funding Research, from the Science and Society section (20 points) How I Collect and Process Data, from the Scientific Measurements section (20 points) No Two Watches, from the Scientific Measurements section (20 points) Experience with Safety, from the Safety in the Chemistry Lab section (20 points) Please submit your journal entries to the Journal: An Introduction to Chemistry Unit assignment link for grading. For more information on how this assignment will be graded, please view the Journal Rubric.
Description Directions: Respond to the questions below. Alcohol in our digestive system reacts with oxygen gas to form carbon dioxide and water. How many grams of carbon dioxide are released if a 10.00 g alcohol sample reacts with 20.85 g of oxygen gas and produces 11.77 g of water? Using the periodic table, fill in the missing information in the following table: Protons Neutrons Electrons Isotope Symbol 5927CO 76 124 14C 21 24 21 Give the number of valence electrons for each of the following: Ba Al P Se Br K Give short definitions for the following terms: Atomic number Mass number Atomic weight Isotope Natural abundance Atomic mass unit Complete the following table: Isotope Atomic No. Mass No. No. of Protons No. of Neutrons No. of Electrons Bromine-81 81 Boron-11 5 Cl 17 52Cr 52 Ni-60 Sr-90 Lead-206 Explain how ozone is formed in the troposphere. Write the equation for the reaction that occurs when lightning causes nitrogen to react with oxygen. Describe two sources of carbon monoxide Write the formulas for the ionic compounds that will form between the following ions: Magnesium ion and chloride ion Lithium ion and fluoride ion Aluminum ion and oxide ion Zinc ion and iodide ion Which of the following compounds would you expect to exhibit hydrogen bonding? Explain your answer. CH3OH NH3 SO2 CO2 CH4 HF CH3OCH3
Description Need to find a carbon load in grams from 2000 cars with the given assumptions. 2000 cars in a parking lot, 15 gallons per tank in the average car, 1 liter of gasoline = 702.8grams gasoline is 100.0% octane C8H18
Description The atomic structure was a triumph to science in general. In the late 18th century and the beginning of the 19th century, the discovery of the subatomic particles, the electron and the proton and the neutron shed light on the particles that constitute the atoms. This task is related to the atomic structure studies. Task 1: 1) Discuss how are elements, compounds, neutrons, protons, atomic number ,mass number and isotopes are related under structure and bonding (15 marks) (Information should include the interrelationship between the structure and bonding in elements all in detail) 2) Consider the element selenium. Samples of natural selenium contain 6 stable isotopes. In terms of atomic structure; explain what theses isotopes have in common and how they differ from each other. (15 marks) (Information should include all the details about the 6 isotopes) 3) Hydrogen peroxide has both a higher viscosity and a higher boiling temperature than water. Discuss some factors about this behavior with the help of principles of atomic structure. (Report should contain at least 5 reasons) (10 marks) The ozone layer refers to a region of Earth's stratosphere that absorbs most of the Sun's UV radiation. It contains high concentrations of ozone (O3) relative to other parts of the atmosphere, although it is still very small relative to other gases in the stratosphere. The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometers above Earth. Task 2: 1) Some of the oxygen in the atmosphere is in the form of ozone (O3). Scientist believe that chlorine radicals are destroying ozone.Collect information about chlorine radicals and chlorine molecule. (15 marks) (Information should include details about chlorine radicals and chlorine molecule in detail. 2) Discuss the principal steps in stratospheric ozone depletion caused by human activities and collect information on how the emissions from human activities lead to ozone depletion? (Information should include at least 10 factors all in detail) (15 marks) The modern periodic table is arranged into blocks of elements based on their electronic configuration. There are different types of elements available in the periodic table. Task 3: 1) From the periodic table choose any element and describe the types of bonding orbitals and bonds that comprise C-C and C=C bonds. (15 marks) (Information should include details of both single and double bond) 2) Discuss the desirable material properties of that chosen element. (15 marks) (Report should contain at least 10 material properties) [Each task should contain minimum of 500 words and not exceed 1000 words. Report is evaluated on the basis of collection of literature, provision of Technical details, supported with appropriate photos and references in the prescribed format]
Description How many milliliters of 2 M NaCl solution are required to make 1 liter of 0.4 M NaCl solution? (a) 5,000 mL (b) 800 mL (c) 200 mL (d) 0.2 mL
