- Several “characteristics of compounds that meet the criteria of being green” were
mentioned at the beginning of this chapter. Near the end of the chapter, acetic acid
was mentioned as a “green acid.” In what respects does it meet the criteria of green
compounds? - What is sodium stearate? Why is it regarded as being green?
- Which of the following is not usually regarded as a characteristic of green chemical
compounds? Why is it not so regarded?
A. Preparation from renewable resourcesB. Low tendency to undergo sudden, violent, unpredictable reactionsC. Readily biodegradableD. Extremely high stability- What are valence electrons? Why are they particularly important?
- What is the octet rule? Why is it particularly important in chemistry?
- What does the structure representing CH 4 below say about bonding and octets of
electrons around the central C atom? - Considering that the central nitrogen atom in ammonia, NH 3 , has an unshared pair
of valence electrons and 3 pairs shared between N and H, propose a structure for the
ammonia molecule based upon the structure of the methane molecule in the preceding
question. Use a pair of dots to represent the unshared pair of electrons. - What is an ionic bond? Why is it not regarded as being between one specific cation
and a specific anion in an ionic compound? - Do ionic compounds such as NaCl obey the octet rule? Explain.
- Why is NaCl referred to as a formula unit of the ionic compound rather than a
molecule of sodium chloride? - Energy is involved in several steps of the process by which an elemental metal and
an elemental nonmetal are converted to an ionic compound (salt). Of these, which
has the largest energy? - Place the following ions in decreasing order of size: Na+, Cl
-
, Al3+, K+- What is a major disadvantage of calcium chloride as a road de-icing agent? Why is
calcium acetate a good substitute? - List some important characteristics of a covalent bond.
Chap. 3, Compounds: Safer Materials for a Safer World 77