Study Guidance for Chemistry 1305 Exam (Chapters 4–7)

Q1. What is the subatomic particle having a negligible mass and a negative charge?

Background

Topic: Atomic Structure

This question tests your understanding of the three main subatomic particles found in atoms: protons, neutrons, and electrons, including their charges and relative masses.

Key Terms:

• Subatomic particle: A particle smaller than an atom (proton, neutron, electron).

• Negligible mass: Mass so small it is often considered insignificant compared to protons and neutrons.

• Negative charge: Indicates the particle carries a charge of -1.

Step-by-Step Guidance

1. Recall the three main subatomic particles: protons (positive charge), neutrons (neutral), electrons (negative charge).

2. Compare their masses: Protons and neutrons have similar, significant masses; electrons have much less mass.

3. Identify which particle has a negative charge and negligible mass.

Try solving on your own before revealing the answer!

Final Answer: Electron

The electron is the subatomic particle with a negative charge and negligible mass compared to protons and neutrons.

Q2. What is the general term that refers to either visible or invisible radiant energy?

Background

Topic: Electromagnetic Radiation

This question is about the terminology used to describe energy that travels as waves, including both visible light and other forms of electromagnetic radiation.

Key Terms:

• Radiant energy: Energy transmitted in the form of electromagnetic waves.

• Visible spectrum: The portion of electromagnetic radiation visible to the human eye.

• Invisible spectrum: Includes ultraviolet, infrared, X-rays, etc.

Step-by-Step Guidance

1. Consider the types of energy that can be seen (visible light) and those that cannot (ultraviolet, infrared, etc.).

2. Think about the umbrella term that covers all these forms of energy.

3. Review the answer choices for the most general term.

Try solving on your own before revealing the answer!

Final Answer: Light

"Light" is the general term for radiant energy, including both visible and invisible forms.

Q3. How many neutrons are in the nucleus of an atom of $\text{Sn}_{118}^{50}$?

Background

Topic: Isotopes and Atomic Structure

This question tests your ability to determine the number of neutrons in an atom using its atomic number and mass number.

Key formula:

$\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}$

• Mass number (A): Total number of protons and neutrons.

• Atomic number (Z): Number of protons.

Step-by-Step Guidance

1. Identify the atomic number ($Z$) and mass number ($A$) for tin ($\text{Sn}$): $Z = 50$, $A = 118$.

2. Recall the formula: $\text{Number of neutrons} = A - Z$.

3. Set up the calculation using the values for tin.

Try solving on your own before revealing the answer!

Final Answer: 68 neutrons

$\text{Number of neutrons} = 118 - 50 = 68$

Subtracting the atomic number from the mass number gives the number of neutrons in the nucleus.

Q4. Given that the only naturally occurring isotope of sodium is $^{23}\text{Na}$, what is its isotopic mass?

Background

Topic: Isotopes and Atomic Mass

This question is about understanding isotopic mass and how it relates to the atomic mass of an element.

Key Terms:

• Isotope: Atoms of the same element with different numbers of neutrons.

• Isotopic mass: The mass of a specific isotope, usually in atomic mass units (amu).

Step-by-Step Guidance

1. Recall that the mass number of an isotope is the sum of protons and neutrons.

2. For sodium, the only naturally occurring isotope is $^{23}\text{Na}$.

3. Check the answer choices for the value closest to the mass number.

Try solving on your own before revealing the answer!

Final Answer: 22.99 amu

The isotopic mass of $^{23}\text{Na}$ is 22.99 amu, which matches the atomic mass listed on the periodic table.

Q5. What is the term for the minimum amount of energy to remove an electron from a neutral atom in the gaseous state?

Background

Topic: Atomic Properties

This question tests your knowledge of the energy required to remove an electron from an atom, a fundamental concept in chemistry.

Key Terms:

• Ionization energy: The energy needed to remove an electron from a neutral atom in the gaseous state.

Step-by-Step Guidance

1. Recall the definition of ionization energy.

2. Compare the answer choices to see which matches this definition.

Try solving on your own before revealing the answer!

Final Answer: Ionization energy

Ionization energy is the minimum energy required to remove an electron from a neutral atom in the gaseous state.

Q6. Which of the following is a representative element?

Background

Topic: Periodic Table Classification

This question is about identifying representative elements, which are found in Groups 1A–7A of the periodic table.

Key Terms:

• Representative elements: Elements in Groups 1A–7A (main group elements).

Step-by-Step Guidance

1. Review the periodic table to identify which elements are in Groups 1A–7A.

2. Check if the answer choices are all representative elements.

Try solving on your own before revealing the answer!

Final Answer: All of the above

B, Be, and Br are all representative elements (main group elements).

Q7. Which fourth period transition element has the highest atomic number?

Background

Topic: Periodic Table and Transition Elements

This question tests your ability to identify transition elements in the fourth period and compare their atomic numbers.

Key Terms:

• Transition elements: Elements in Groups 3–12.

• Fourth period: Row 4 of the periodic table.

• Atomic number: Number of protons in the nucleus.

Step-by-Step Guidance

1. Locate the fourth period on the periodic table.

2. Identify which elements in the answer choices are transition elements.

3. Compare their atomic numbers to find the highest.

Try solving on your own before revealing the answer!

Final Answer: Cd (Cadmium)

Cd is the fourth period transition element with the highest atomic number among the choices.

Q8. Which of the following elements are fourth period semimetals?

Background

Topic: Periodic Table and Element Classification

This question is about identifying semimetals (metalloids) in the fourth period of the periodic table.

Key Terms:

• Semimetals (metalloids): Elements with properties intermediate between metals and nonmetals.

• Fourth period: Row 4 of the periodic table.

Step-by-Step Guidance

1. Locate the fourth period on the periodic table.

2. Identify which elements in the answer choices are classified as semimetals.

3. Check which pairs are both in the fourth period and are semimetals.

Try solving on your own before revealing the answer!

Final Answer: Ge and As

Germanium (Ge) and Arsenic (As) are fourth period semimetals.

Q9. Which of the following is an alkali metal?

Background

Topic: Periodic Table Groups

This question tests your knowledge of alkali metals, which are found in Group 1A of the periodic table.

Key Terms:

• Alkali metals: Elements in Group 1A (Li, Na, K, Rb, Cs, Fr).

Step-by-Step Guidance

1. Review the answer choices and check which, if any, are in Group 1A.

2. Recall the properties and typical elements of alkali metals.

Try solving on your own before revealing the answer!

Final Answer: None of the above

None of the answer choices (Al, Fe, Ca) are alkali metals.

Q10. Predict the density for rhodium, Rh, given the density of cobalt, Co, (8.89 g/cm3) and iridium, Ir, (22.65 g/cm3).

Background

Topic: Periodic Trends and Properties

This question is about predicting the physical property (density) of an element based on the properties of related elements.

Key Terms:

• Density: Mass per unit volume, usually in g/cm3.

• Periodic trends: Patterns in properties across periods and groups.

Step-by-Step Guidance

1. Locate Rh, Co, and Ir on the periodic table to see their relative positions.

2. Consider the trend in density among these elements.

3. Estimate the density of Rh based on the values for Co and Ir.

Try solving on your own before revealing the answer!

Final Answer: 12.76 g/cm3

Rhodium's density is predicted to be between cobalt and iridium, closer to the average of their densities.

Q11. The compound Au2Se3 is classified as which of the following?

Background

Topic: Chemical Compounds Classification

This question tests your ability to classify compounds as binary ionic, ternary ionic, binary molecular, or binary acid.

Key Terms:

• Binary ionic: Compound made of two elements, one metal and one nonmetal.

• Ternary ionic: Compound made of three elements.

• Binary molecular: Compound made of two nonmetals.

• Binary acid: Acid with two elements.

Step-by-Step Guidance

1. Identify the elements in Au2Se3: gold (Au, metal) and selenium (Se, nonmetal).

2. Determine if the compound is binary (two elements) or ternary (three elements).

3. Classify the compound based on its composition.

Try solving on your own before revealing the answer!

Final Answer: Binary ionic

Au2Se3 is a binary ionic compound (metal + nonmetal).

Q12. What is the Stock system name for Cu+?

Background

Topic: Nomenclature of Ions

This question is about naming ions using the Stock system, which indicates the charge of the ion with Roman numerals.

Key Terms:

• Stock system: Naming convention for ions, using Roman numerals to indicate charge.

• Cu+: Copper ion with a +1 charge.

Step-by-Step Guidance

1. Recall the Stock system naming for transition metal ions.

2. Identify the charge of the copper ion (+1).

3. Choose the correct name with the appropriate Roman numeral.

Try solving on your own before revealing the answer!

Final Answer: Copper(I) ion

Cu+ is named "copper(I) ion" in the Stock system.

Q13. What is the systematic name for N3-?

Background

Topic: Nomenclature of Ions

This question tests your knowledge of naming anions, specifically the nitrogen anion.

Key Terms:

• Anion: Negatively charged ion.

• Systematic name: Standard naming convention for ions.

Step-by-Step Guidance

1. Recall the naming convention for anions: element root + "-ide".

2. Apply this to nitrogen with a 3- charge.

Try solving on your own before revealing the answer!

Final Answer: Nitride ion

N3- is called the nitride ion.

Q14. What is the chemical formula for the manganese(II) ion?

Background

Topic: Nomenclature and Chemical Formulas

This question is about writing the correct chemical formula for a transition metal ion with a specified charge.

Key Terms:

• Manganese(II) ion: Manganese with a +2 charge.

• Chemical formula: Symbol and charge notation for ions.

Step-by-Step Guidance

1. Recall the symbol for manganese: Mn.

2. Apply the charge (+2) to the symbol.

Try solving on your own before revealing the answer!

Final Answer: Mn2+

The chemical formula for the manganese(II) ion is Mn2+.

Q15. What is the predicted ionic charge of an element in Group IIA/2?

Background

Topic: Periodic Table and Ionic Charges

This question tests your knowledge of the typical ionic charges for elements in Group 2 (IIA) of the periodic table.

Key Terms:

• Group IIA/2: Alkaline earth metals (Be, Mg, Ca, Sr, Ba, Ra).

• Ionic charge: The charge an atom takes when it forms an ion.

Step-by-Step Guidance

1. Recall that Group 2 elements lose two electrons to achieve a stable configuration.

2. Determine the resulting charge after losing two electrons.

Try solving on your own before revealing the answer!

Final Answer: 2+

Group IIA/2 elements form ions with a 2+ charge.

Q16. What is the systematic name for CrO42-?

Background

Topic: Polyatomic Ions Nomenclature

This question is about naming polyatomic ions, specifically the chromate ion.

Key Terms:

• Polyatomic ion: An ion composed of more than one atom.

• Chromate ion: CrO42-.

Step-by-Step Guidance

1. Recall the names of common polyatomic ions.

2. Identify the correct name for CrO42-.

Try solving on your own before revealing the answer!

Final Answer: Chromate ion

CrO42- is called the chromate ion.

Q17. What is the name of a reaction in which two cations in different compounds exchange anions?

Background

Topic: Types of Chemical Reactions

This question tests your knowledge of reaction types, specifically double replacement reactions.

Key Terms:

• Double replacement reaction: Two compounds exchange ions to form new compounds.

Step-by-Step Guidance

1. Recall the definition of double replacement reactions.

2. Compare the answer choices to the definition.

Try solving on your own before revealing the answer!

Final Answer: Double replacement

This reaction is called a double replacement reaction.

Q18. Which of the following is evidence for a chemical reaction?

Background

Topic: Chemical Reactions and Observations

This question is about recognizing signs that a chemical reaction has occurred.

Key Terms:

• Evidence for chemical reaction: Gas formation, precipitate formation, color change, heat/light emission.

Step-by-Step Guidance

1. Recall the common signs of a chemical reaction.

2. Check which answer choices match these signs.

Try solving on your own before revealing the answer!

Final Answer: All of the above

Gas formation, precipitate formation, and flame observation are all evidence of a chemical reaction.

Q19. Which of the statements below best describes the following reaction?

Background

Topic: Chemical Equations and Reaction Types

This question tests your ability to interpret a chemical equation and describe the reaction.

Key Terms:

• Decomposition reaction: A compound breaks down into simpler substances.

• Reactants and products: Substances before and after the reaction.

Step-by-Step Guidance

1. Analyze the equation: Na2CO3(s) → Na2O(s) + CO2(g).

2. Identify the reactant and products.

3. Determine the type of reaction and describe it in words.

Try solving on your own before revealing the answer!

Final Answer: Solid sodium carbonate decomposes to give solid sodium oxide and carbon dioxide gas.

This is a decomposition reaction where sodium carbonate breaks down into sodium oxide and carbon dioxide.

Q20. What is the coefficient of oxygen gas after balancing the following equation?

Background

Topic: Balancing Chemical Equations

This question tests your ability to balance a chemical equation and identify the correct coefficient for oxygen gas.

Key Terms:

• Chemical equation: Representation of a chemical reaction.

• Coefficient: Number in front of a chemical formula indicating the number of units.

Step-by-Step Guidance

1. Write the unbalanced equation: P(s) + O2(g) → P2O3(s).

2. Balance phosphorus and oxygen atoms on both sides.

3. Determine the correct coefficient for O2(g).

Try solving on your own before revealing the answer!

Final Answer: 3

The balanced equation requires a coefficient of 3 for O2(g).

Q21. What is the predicted product from the following reaction? Balance this equation. What kind of reaction is it?

Background

Topic: Types of Chemical Reactions and Balancing Equations

This question tests your ability to predict products, balance equations, and classify reaction types.

Key Terms:

• Combination reaction: Two elements combine to form a compound.

• Balancing equations: Ensuring equal numbers of atoms on both sides.

Step-by-Step Guidance

1. Write the reactants: Ca(s) + O2(g).

2. Predict the product: Calcium reacts with oxygen to form calcium oxide.

3. Write the unbalanced equation: Ca(s) + O2(g) → CaO(s).

4. Balance the equation by adjusting coefficients.

Try solving on your own before revealing the answer!

Final Answer: CaO, Combination Reaction

The product is calcium oxide (CaO), and this is a combination reaction.

Q22. Which of the following metals does not react with aqueous Ni(NO3)2? Why?

Background

Topic: Activity Series and Reactivity

This question tests your understanding of the activity series and predicting metal reactivity.

Key Terms:

• Activity series: A list of metals ranked by their reactivity.

• Reactivity: Ability of a metal to displace another from solution.

Step-by-Step Guidance

1. Review the partial activity series: Mg > Al > Ni > (H) > Cu.

2. Determine which metals are more or less reactive than Ni.

3. Identify which metal cannot displace Ni from solution.

Try solving on your own before revealing the answer!

Final Answer: Cu, because it is not as active as Ni

Copper does not react with Ni(NO3)2 because it is less reactive than nickel.

Q23. What is the name of each compound?

Background

Topic: Nomenclature of Ionic Compounds

This question tests your ability to name common ionic compounds.

Key Terms:

• Ionic compound: Compound formed from a metal and a nonmetal.

• Naming convention: Metal name + nonmetal root + "-ide" or polyatomic ion name.

Step-by-Step Guidance

1. For each formula, identify the cation and anion.

2. Apply the naming rules for ionic compounds.

3. Write the systematic name for each compound.

Try solving on your own before revealing the answer!

Final Answer:

• a. Calcium Hydroxide

• b. Potassium Chloride

• c. Aluminum Bromide

• d. Sodium Fluoride

Q24. What are the chemical formulas for oxide ion and iodide ion?

Background

Topic: Chemical Formulas for Ions

This question tests your ability to write the correct formulas for common ions.

Key Terms:

• Oxide ion: Oxygen with a 2- charge.

• Iodide ion: Iodine with a 1- charge.

Step-by-Step Guidance

1. Recall the charge and symbol for each ion.

2. Write the chemical formula using the correct charge notation.

Try solving on your own before revealing the answer!

Final Answer:

• Oxide ion: O2-

• Iodide ion: I-

Q25. What is the core notation for the electron configuration of an aluminum atom?

Background

Topic: Electron Configuration

This question tests your ability to write the electron configuration using core notation.

Key Terms:

• Core notation: Uses noble gas abbreviation to represent inner electrons.

• Aluminum: Atomic number 13.

Step-by-Step Guidance

1. Identify the noble gas preceding aluminum (Neon).

2. Write the remaining electron configuration for aluminum.

Try solving on your own before revealing the answer!

Final Answer: [Ne] 3s2 3p1

Aluminum's core notation is [Ne] 3s2 3p1.

Bonus Question: What is the chemical formula of each of the following compounds?

Background

Topic: Chemical Formulas for Polyatomic and Ionic Compounds

This question tests your ability to write chemical formulas for common ions and compounds.

Key Terms:

• Sulfate ion: Polyatomic ion with formula SO42-.

• Barium chromate: Compound formed from Ba2+ and CrO42-.

• Aluminum chloride: Compound formed from Al3+ and Cl-.

• Magnesium oxide: Compound formed from Mg2+ and O2-.

Step-by-Step Guidance

1. Write the formula for each ion or compound based on their charges.

2. Balance the charges to write the correct formula for each compound.

Try solving on your own before revealing the answer!

Final Answer:

• a. Sulfate ion: SO42-

• b. Barium chromate: BaCrO4

• c. Aluminum chloride: AlCl3

• d. Magnesium oxide: MgO