General Chemistry Midterm Study Guidance

Q1. From the list of binary compounds below, which compound is best described as predominantly ionic?

• N2

• SO2

• HF

• KBr

• PCl3

Background

Topic: Ionic vs. Covalent Bonding

This question tests your ability to distinguish between ionic and covalent compounds based on their constituent elements.

Key Terms:

• Ionic compound: Formed between metals and nonmetals, involves transfer of electrons.

• Covalent compound: Formed between nonmetals, involves sharing of electrons.

Step-by-Step Guidance

1. Identify which compounds are made from a metal and a nonmetal (ionic) versus two nonmetals (covalent).

2. Recall that ionic compounds typically have a large difference in electronegativity between the elements.

3. Look for a compound containing an alkali metal or alkaline earth metal paired with a halogen or other nonmetal.

Try solving on your own before revealing the answer!

Q2. Which bond would have the largest bond dipole moment?

• C–H

• O–C

• C–Cl

• Na–C

Background

Topic: Bond Polarity and Dipole Moments

This question tests your understanding of how differences in electronegativity between atoms affect the dipole moment of a bond.

Key Terms:

• Bond dipole moment: A measure of the separation of charge in a bond due to differences in electronegativity.

• Electronegativity: The tendency of an atom to attract electrons in a bond.

Step-by-Step Guidance

1. Recall that the dipole moment increases with greater difference in electronegativity between the two atoms.

2. Compare the electronegativities of the atoms in each bond.

3. Identify which bond has the largest difference in electronegativity.

Try solving on your own before revealing the answer!

Q3. Of the atoms listed below, which is the least electronegative?

• Mg

• Si

• Br

• P

• Al

Background

Topic: Electronegativity Trends

This question tests your knowledge of periodic trends, specifically electronegativity.

Key Terms:

• Electronegativity: The ability of an atom to attract electrons in a chemical bond.

• Periodic trend: Electronegativity increases across a period and decreases down a group.

Step-by-Step Guidance

1. Locate each element on the periodic table.

2. Recall the general trend: electronegativity increases from left to right and decreases from top to bottom.

3. Compare the positions of the elements to determine which is least electronegative.

Try solving on your own before revealing the answer!

Q4. Write the correct formula for each compound:

• Aluminium Sulfide

• Dinitrogen Tetroxide

Background

Topic: Chemical Nomenclature and Formula Writing

This question tests your ability to translate chemical names into their correct formulas.

Key Terms:

• Binary compound: A compound composed of two elements.

• Prefixes: Indicate the number of atoms (di-, tetra-, etc.).

Step-by-Step Guidance

1. Identify the elements in each compound.

2. Use the prefixes to determine the number of atoms for each element.

3. Write the formula using the correct subscripts.

Try solving on your own before revealing the answer!

Q5. Which is the correct name for Ca₃(PO₄)₂?

• A. Calcium phosphide

• B. Calcium phosphate

• C. Tricalcium diphosphate

• D. Calcium (II) phosphate

• E. Calcium phosphite

Background

Topic: Naming Ionic Compounds with Polyatomic Ions

This question tests your ability to correctly name compounds containing polyatomic ions.

Key Terms:

• Polyatomic ion: An ion composed of more than one atom (e.g., PO43−).

• Systematic naming: Use the correct name for the cation and anion.

Step-by-Step Guidance

1. Identify the cation (Ca2+) and the anion (PO43−).

2. Recall the name for PO43− is "phosphate."

3. Combine the names, ensuring correct stoichiometry is reflected in the name.

Try solving on your own before revealing the answer!

Final Answer Section

Here you would find the final answers and explanations for each question, once you have attempted them yourself.