## Chemistry: Molecular Approach (4th Edition)

a. $Ca(OH)_2$ b. $CaCrO_4$ c. $Ca_3(PO_4)_2$ d. $Ca(CN)_2$
Use table 3.4 (Page 100) and figure 3.7 (Page 98) to see the charges and the formula of the ions. - Calcium has a charge of $2+$, and its symbol is $Ca$: $Ca^{2+}$ ------- a. Hydroxide ion is: $OH^-$ (See table 3.4). Calcium: $Ca^{2+}$ Put these two together, where the subscript number will be the charge of the other ion. Calcium will receive 1, and hydroxide will receive 2. $Ca_1(OH)_2$: $Ca(OH)_2$ b. Chromate ion is: $CrO_4^{2-}$ (See table 3.4). Calcium: $Ca^{2+}$ Put these two together, where the subscript number will be the charge of the other ion. Calcium will receive 2, and chromate will receive 2. $Ca_2(CrO_4)_2$: $CaCrO_4$ c. Phosphate ion is: $PO_4^{3-}$ (See table 3.4). Calcium: $Ca^{2+}$ Put these two together, where the subscript number will be the charge of the other ion. Calcium will receive 3, and phosphate will receive 2. $Ca_3(PO_4)_2$ c. Cyanide ion is: $CN^{-}$ (See table 3.4). Calcium: $Ca^{2+}$ Put these two together, where the subscript number will be the charge of the other ion. Calcium will receive 1, and cyanide will receive 2. $Ca_1(CN)_2$ : $Ca(CN)_2$