The boiling point of CH4 is −162 °C and the boiling point of CCl4 is 77 °C. Identify the principal intermolecular forces in each of these compounds and briefly explain the large difference in boiling points. Submit your response using the text editing tools in the box below.

The name of the SO42- ion is ________.

Complete the information in the chart below, filling in the empty boxes. Assume that all the atoms are uncharged; that is, they are not ions. For superscripted numbers in elemental symbols, enter them as regular numbers. For example, 131Xe would be written 131Xe.   Elemental Symbol 195Pt Number of Protons 92 Number of Neutrons Number of Electrons 50 Mass Number 238 118  

NH3 molecular shape: hybridization of the central atom write in normal characters sp, sp2, sp3 name: number of sigma bonds: number of pi bonds:

The sketch below shows the relative change in energy as two hydrogen (H) atoms are brought closer together. Copy the diagram, then label the point where the bond is most likely to form by inserting two dots to the hydrogens forming the bond, based on Coulomb’s theory. Show all work for this question for full credit. Write out your response on a separate sheet of paper, labeling the question number clearly and circling or highlighting all answers. You will upload a photo of your response at the end of the exam. See the description for details The image shows a graph depicting the relationship between energy (on the y-axis) and distance (on the x-axis). The curve starts from high energy, decreases to a minimum, and then increases again.

Some helium gas is stored in a tank at 5.0 °C and has a pressure of 5 atm. What is the pressure inside the gas tank if the temperature is raised to 40.0 °C?

The principal metals used for US coinage are elements 79, 47, 28, 29, and 30. Give the names, not the symbols, for these five elements and the name of the general group on the periodic table to which they all belong. Number Name 79 47 28 29 30 General Group:

Which element is designated by the electron configuration 1s2, 2s2, 2p5?

What type of light on the electromagnetic spectrum has the highest energy per photon? See the description for details The image shows a diagram of the electromagnetic spectrum, which represents the full range of electromagnetic radiation. It is divided into several regions based on wavelength and energy. On the left side, gamma rays have the highest energy and shortest wavelength, followed by X-rays and ultraviolet light. In the middle, the visible spectrum is shown, represented by a gradient of colors from violet to red, which corresponds to the light we can see. On the right side, waves like infrared, microwaves, and radio waves have progressively lower energy and longer wavelengths. Below the spectrum is a visual representation of a wave, illustrating the varying wavelengths of these different types of radiation.

Michelangelo’s David statue is 18½ feet tall, including the base. Based on the fact that the density of marble stone is 160 lbs/cubic foot, a person could estimate that the statue weighs about 5,300. lbs, or 2,325 kg (1 kg is 1,000 g). Marble has a chemical formula of CaCO3 (calcium carbonate). In the 1750s, Joseph Black found that if calcium carbonate is heated to a temperature of over 825°C, it decomposes and releases “fixed air,” which is CO2, and produces lime (not the citrus fruit but a solid, white chemical compound). The chemical formula of lime is CaO. Write out a balanced equation for the reaction that shows CaCO3 (calcium carbonate) reacting to produce CaO (lime) and CO2 (carbon dioxide).  BYU-Approved David Statue Note: Show all work for this question for full credit. Label the question number clearly and circle or highlight all answers. You will upload your work at the end of the exam.