A. For a chemistry lab final exam, a high school chemistry student was given a 1-mole sample of CaCl2 and a 1-mole sample of MgCl2 but was not told which sample was which. He was to identify the powders. He looked up the enthalpies of formation for both of the chemicals and calculated the ΔHreaction for dissolving each powder: CaCl2(s) Ca2+(aq) + 2Cl–(aq), and MgCl2(s) Mg2(aq) + 2Cl–(aq). He then put each powder in a coffee-cup calorimeter and added water.
When sample A dissolved, the temperature increased by 0.74°C. When sample B dissolved, the temperature increased by 0.39°C. Which chemical was A, and which was B? Use the table of enthalpies of formation to help you. Explain your reasoning.

How would you reduce the volume of gas

An atomic nucleus is composed ofa)protons.b)protons and neutrons.c)protons and electrons.d)protons, neutrons, and electrons.

For part 1, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least copper(ii) nitrate to the well with the most copper(ii) nitrate. which wells had the most distinct precipitate? for part 2, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least iron(ii) sulfate to the well with the most iron(ii) sulfate. which wells had the most distinct precipitate? for part 3, describe the changes in the colors of the well, if any, as you go from well 1 to well 9—that is, as you go from the well with the least iron(iii) nitrate to the well with the most iron(iii) nitrate. which wells had the most distinct precipitate?