85) Additives can be used in soda-lime glass to alter its __________.
A) ability to withstand temperature change
B) color
C) hardness
D) melting point
E) any of the above
86) Silicones are
A) chains of alternating silicon and oxygen atoms with attached organic groups.
B) three-dimensional covalent networks of SiO4 tetrahedra.
C) three-dimensional covalent networks of silicon atoms.
D) flat sheets of silicon atoms.
E) flat sheets of silicon and hydrogen atoms.
87) Silicones can be oils or rubber-like materials depending on
A) the silicon-to-oxygen ratio.
B) the length of the chain and degree of cross-linking.
C) the percentage of carbon in the chain.
D) the percentage of sulfur in the chain.
E) the oxidation state of silicon in the chain.
88) Sodium borohydride, NaBH4, is a strong reducing agent because __________.
A) Na+ is easily reduced to Na (s).
B) boron easily changes its oxidation number from +3 to -3
C) boron is readily oxidized from -3 oxidation state to +3
D) hydrogen can be easily oxidized from -1 oxidation state to +1
E) hydrogen is easily reduced from +1 oxidation state to 0
89) The primary commercial use of nitric acid is __________.
A) in the manufacture of plastics
B) in the manufacture of explosives
C) in pool water maintenance
D) in the manufacture of fertilizers
E) in the manufacture of anti-depressant drugs