Question

Write the formula for each of the following compounds: a. sulfur difluoride b. sulfur hexafluoride c. sodium dihydrogen phosphate d. lithium nitride e. chromium(III) carbonate f. tin(II) fluoride g. ammonium acetate h. ammonium hydrogen sulfate i. cobalt(III) nitrate j. mercury(I) chloride k. potassium chlorate l. sodium hydride

Short answer

The short answer to the list of chemical formulas is as follows: a. SF₂ b. SF₆ c. NaH₂PO₄ d. Li₃N e. Cr₂(CO₃)₃ f. SnF₂ g. NH₄C₂H₃O₂ h. (NH₄)HSO₄ i. Co(NO₃)₃ j. HgCl k. KClO₃ l. NaH

Step-by-step solution

a. sulfur difluoride

In this compound, we have sulfur and fluorine. Sulfur has a charge of +2 and fluorine has a charge of -1. To balance the charges, we need one sulfur atom and two fluorine atoms. The chemical formula is: SF₂.

b. sulfur hexafluoride

In this compound, we have sulfur and fluorine. Sulfur has a charge of +6 and fluorine has a charge of -1. To balance the charges, we need one sulfur atom and six fluorine atoms. The chemical formula is: SF₆.

c. sodium dihydrogen phosphate

This compound contains sodium (Na), hydrogen (H), and phosphate (PO₄). Sodium has a charge of +1, hydrogen has a charge of +1, and phosphate has a charge of -3. To balance the charges, we need one sodium atom, two hydrogen atoms, and one phosphate ion. The chemical formula is NaH₂PO₄.

d. lithium nitride

Lithium nitride contains lithium (Li) and nitrogen (N). Lithium has a charge of +1, and nitrogen has a charge of -3. To balance the charges, we need three lithium atoms and one nitrogen atom. The chemical formula is: Li₃N.

e. chromium(III) carbonate

This compound contains chromium (Cr) and carbonate (CO₃). Chromium has a charge of +3, and carbonate has a charge of -2. To balance the charges, we need two chromium ions and three carbonate ions. The chemical formula is: Cr₂(CO₃)₃.

f. tin(II) fluoride

Tin(II) fluoride contains tin (Sn) and fluorine (F). Tin has a charge of +2, and fluorine has a charge of -1. To balance the charges, we need one tin atom and two fluorine atoms. The chemical formula is: SnF₂.

g. ammonium acetate

This compound contains ammonium (NH₄) and acetate (C₂H₃O₂). Ammonium has a charge of +1, and acetate has a charge of -1. The charges are already balanced with one ammonium ion and one acetate ion. The chemical formula is: NH₄C₂H₃O₂.

h. ammonium hydrogen sulfate

This compound contains ammonium (NH₄), hydrogen (H), and sulfate (SO₄). Ammonium has a charge of +1, hydrogen has a charge of +1, and sulfate has a charge of -2. To balance the charges, we need one ammonium ion, one hydrogen ion, and one sulfate ion. The chemical formula is: (NH₄)HSO₄.

i. cobalt(III) nitrate

Cobalt(III) nitrate contains cobalt (Co) and nitrate (NO₃). Cobalt has a charge of +3, and nitrate has a charge of -1. To balance the charges, we need one cobalt ion and three nitrate ions. The chemical formula is: Co(NO₃)₃.

j. mercury(I) chloride

Mercury(I) chloride contains mercury (Hg) and chlorine (Cl). Mercury(I) has a charge of +1, and chlorine has a charge of -1. The charges are already balanced with one mercury ion and one chloride ion. The chemical formula is: HgCl.

k. potassium chlorate

This compound contains potassium (K) and chlorate (ClO₃). Potassium has a charge of +1, and chlorate has a charge of -1. The charges are already balanced with one potassium ion and one chlorate ion. The chemical formula is: KClO₃.

l. sodium hydride

Sodium hydride contains sodium (Na) and hydrogen (H). Sodium has a charge of +1, and hydrogen has a charge of -1. The charges are already balanced with one sodium ion and one hydrogen ion. The chemical formula is: NaH.

Key concepts

Ionic Compounds

Ionic compounds are formed when metals and non-metals exchange electrons to achieve full outer shells, resulting in oppositely charged ions. These ions are held together by the strong electrostatic forces of attraction known as ionic bonds. Understanding ionic compounds is essential in chemistry because many substances, including salts and minerals, are composed of such structures.
An ionic compound consists of a cation, which is the positively charged ion, and an anion, the negatively charged ion. For instance, in sodium chloride (NaCl), sodium (Na) acts as the cation, and chloride (Cl) as the anion.

• Metals tend to lose electrons, forming cations with positive charges.
• Non-metals tend to gain electrons, forming anions with negative charges.

Ionic compounds are usually solid at room temperature, with high melting and boiling points due to the strong forces holding the ions together. They also conduct electricity when dissolved in water or molten, allowing the ions to move freely.

Balancing Charges

Balancing charges is a critical step when learning to write chemical formulas for ionic compounds. It ensures that the total positive and negative charges in the compound cancel out, resulting in a neutral compound.
To balance charges, you need to:

• Determine the charge of each ion involved.
• Adjust the numbers of each ion so that the total charge is zero.

For example, in lithium nitride (Li₃N), lithium ions have a charge of +1, while the nitride ion has a charge of -3. To achieve a neutral compound, you need three lithium ions to balance the charge of one nitride ion. This yields a formula of Li₃N.
When writing formulas, always ensure the smallest whole number ratio of ions, as this simplifies the representation of the compound and reflects its true chemical structure.

Polyatomic Ions

Polyatomic ions are ions composed of two or more atoms bonded together, carrying a net charge. They behave as a single unit in a chemical reaction and help form complex ionic compounds. These ions are commonly found in many natural and synthetic substances.
Some well-known examples of polyatomic ions include:

• Ammonium (NH₄⁺)
• Carbonate (CO₃²⁻)
• Sulfate (SO₄²⁻)
• Nitrate (NO₃⁻)

When writing the chemical formula for a compound involving polyatomic ions, ensure the polyatomic ion is treated as a single entity. Use parentheses to denote multiple polyatomic ions in a formula, as in chromium(III) carbonate, Cr₂(CO₃)₃, where three carbonate ions are needed to balance two chromium(III) ions. Understanding polyatomic ions and their interactions within compounds is vital for writing accurate chemical formulas.