Chemistry – Chapter 9 Assessment Answers
9.1 Assessment
3. The positive charge of a group A metal is equal to its group number. The charge of a group A
nonmetal is the group number minus 8.
4. from the number of electrons lost
5. –ite or –ate
6. Group 1A metals, 1+; Group 3A (aluminum), 3+’ Group 5A nonmetals, 37. A monoatomic anion is a single atom with a negative charge; a polyatomic anion is two or more
bound atoms with a negative charge.
8. a.) K+, cation, potassium ion
b.) O2- anion, oxide ion
c.) Sn2+ cation, tin (II)
d.)Br- anion, bromide ion
e.) Be2+ cation beryllium ion
f.) Co3+ cation, cobalt(III) ion
9. a.) NH4+
b.) Sn2+
c.) CrO42d.) NO3
9.2 Assessment
14. Write the name of the cation followed by the name of the anion.
15. Write the symbol of the cation followed by the symbol of the anion, then use subscripts to balance
the charges.
16. Write the symbol for the metal ion followed by the formula of the polyatomic ion and balance the
charges. Name the cation first followed by the anion.
17. a.) BeCl2
b.) Cs2S
c.) Nal
d.) SrO
18. a.) Cr(NO2)3
b.) NaClO4
c.) Mg(HCO3)2
d.) Ca(C2H3O2)2
19. a.) incorrect; charges are not balanced MgSO4
b.)
c.) incorrect; charges are not balanced BeCl2
9.3 Assesment
20. Prefixes indicate the number of atoms of each element in a molecule of the compound.
Chemistry – Chapter 9 Assessment Answers
21. Write the symbols for each element with a subscript corresponding to the prefix before each
element in the name.
22. a.) nitrogen trichloride
b.) boron trichloride
c.) nitrogen triiodide
d.) sulfur trioxide
e.) dinitrogen tetrahydride
23. a.) carbon disulfide
b.) CBr4
c.) dichlorine heptoxide
d.) P2O3
24. a.) PCl5
b.) IF7
c.) CIF3
d.) IO2
25. No; the correct name is silicon tetrachloride.
9.4 Section Assessment
26. See the rules for naming on the SE facing page. (272)
27. The rules for writing the names of acids are used in reverse to write the formulas for acids.
28. The name of the cation is followed by the name of the anion.
29. a.) nitrous acid
b.) permanganic acid
c.) hydrocyanic acid
d.) hydrosulfuric acid
30. a.) lithium hydroxide
b.) lead(II)
c.) magnesium hydroxide
d.) aluminum hydroxide
31. a.) base
b.) acid
c.) base
d.) base
32. a.) H2CO3
b.)H2SO3
c.) Fe(OH)3
d.) Sr(OH)2
Chemistry – Chapter 9 Assessment Answers
33. Acid, hydrogen; base, hydroxide ion
9.5 Assessment
35. Law of definite proportions and law of multiple proportions
36. Follow the arrows and answer the questions on the flowchart.
37. See the four guidelines on the facing SE page (page 278)
38. No; 2:1
39. a. Calcium carbonate
b. lead (III) chromate
c. tin(II) dichromate
40. a. Sn(OH)2
b. BaF2
41. a. Incorrect; a Roman numeral is not used with a Group A metal, calcium oxide
b. correct
c. correct
d. Incorrect; ammonium ion, a polyatomic cation will not form a compound with a monatomic cation.