Problem 74 - Chemistry: The Central Science

Question

Assume that you encounter the following sentences in your reading. What is the chemical formula for each substance mentioned? (a) Sodium hydrogen carbonate is used as a deodorant. (b) Calcium hypochlorite is used in some bleaching solutions. (c) Hydrogen cyanide is a very poisonous gas. (d) Magnesium hydroxide is used as a cathartic. (e) Tin(II) fluoride has been used as a fluoride additive in toothpastes. (f) When cadmium sulfide is treated with sulfuric acid, fumes of hydrogen sulfide are given off.

Step-by-Step Solution

Answer

The chemical formulas for the given substances are: (a) NaHCO₃, (b) Ca(ClO)₂, (c) HCN, (d) Mg(OH)₂, (e) SnF₂, and (f) CdS.

Step 1: (a) Sodium hydrogen carbonate

To find the chemical formula for sodium hydrogen carbonate, first identify the symbols for each element mentioned: sodium (Na), hydrogen (H), and carbonate (CO₃). Then, identify the charges for each ion. Sodium has a charge of 1+, hydrogen 1+, and carbonate 2-. Combine the ions to create a neutral compound, resulting in the formula NaHCO₃.

Step 2: (b) Calcium hypochlorite

To find the chemical formula for calcium hypochlorite, first identify the symbols for each element mentioned: calcium (Ca) and hypochlorite (ClO). Calcium has a charge of 2+, and hypochlorite has a charge of 1-. Combine the ions to create a neutral compound, resulting in the formula Ca(ClO)₂.

Step 3: (c) Hydrogen cyanide

To find the chemical formula for hydrogen cyanide, first identify the symbols for each element mentioned: hydrogen (H) and cyanide (CN). Hydrogen has a charge of 1+, and cyanide has a charge of 1-. Combine the ions to create a neutral compound, resulting in the formula HCN.

Step 4: (d) Magnesium hydroxide

To find the chemical formula for magnesium hydroxide, first identify the symbols for each element mentioned: magnesium (Mg) and hydroxide (OH). Magnesium has a charge of 2+, and hydroxide has a charge of 1-. Combine the ions to create a neutral compound, resulting in the formula Mg(OH)₂.

Step 5: (e) Tin(II) fluoride

To find the chemical formula for tin(II) fluoride, first identify the symbols for each element mentioned: tin (Sn) and fluoride (F). The roman numeral II indicates that tin has a charge of 2+. Fluoride has a charge of 1-. Combine the ions to create a neutral compound, resulting in the formula SnF₂.

Step 6: (f) Cadmium sulfide

To find the chemical formula for cadmium sulfide, first identify the symbols for each element mentioned: cadmium (Cd) and sulfur (S). Cadmium has a charge of 2+, and sulfur has a charge of 2-. Combine the ions to create a neutral compound, resulting in the formula CdS.