CHEM 110 Answers to Tenth Take Home Quiz 1. Write a balanced equation for the reaction of sodium metal with water. 2Na + 2H2O <---> 2Na+ + H2(g) + 2OH- 2. Indicate the industrial uses of the following compounds. sodium chloride sodium carbonate production of Cl2 production of glass 3. What is the principal compound found in teeth and bones ? calcium phosphate 4. Which of the following pairs of elements are most similar in the chemical and physical properties ? C and Pb (Na and K) K and Ca Al and Cl 5. Write the formula for gypsum ? CaSO4ú2H2O 6. Write a balanced equation for the conversion of gypsum into Plaster of Paris ? CaSO4ú2H2O <---> CaSO4ú0.5H2O + 1.5H2O 7. Write the formula for calcium carbonate. CaCO3 8. Name some natural materials composed of calcium phosphate. teeth bones rock phosphate 9. Write the electronic configurations for a sodium atom, a magnesium atom, and an aluminum atom. Also write electronic configurations for a sodium ion, a magnesium ion, and an aluminum ion. Which electrons are lost when these atoms are converted into the corresponding ions ? Atom Ion Na 1s22s22p63s1 1s22s22p6 Mg 1s22s22p63s2 1s22s22p6 Al 1s22s22p63s23p1 1s22s22p6 Those in the outermost level . 10. What are the two most important allotropic forms of carbon ? diamond graphite Why are these allotropic forms so different ? 2 dimensional versus three dimensional bonds 11. Name some naturally occurring materials which contains silicon. quartz opal feldspar granite