Chem 1025 Homework 2 Name ✓ Solved

Chem 1025 Homework 2 Name

Complete the following table. (0.5 ea.) Symbol Protons Neutrons Electrons Charge 4 6 0 ð‘‡ð‘–+ ð‘†- ð‘ð‘Ž11 22 + 2. Determine whether the following elements are metals, nonmetals, or metalloids. Please circle the correct answer. (0.25 ea.) a. Pd Metal Nonmetal Metalloid b. Si Metal Nonmetal Metalloid c. Te Metal Nonmetal Metalloid d. Kr Metal Nonmetal Metalloid 3. (1pt) The horizontal rows of the periodic table are called _____________________. 4. An element has two naturally occurring isotopes.

One has an abundance of 37.40% and an isotopic mass of 184.953 amu, and the other has an abundance of 62.60% and a mass of 186.956 amu. What is the atomic weight of the element? (2 pts) 5. The element antimony has only two naturally-occurring isotopes. One isotope has an abundance of 57.30% and an isotopic mass of 120.904 amu. The other has an abundance of 42.70% and an isotopic mass of 122.853 amu.

Based on this data, what is the atomic weight of antimony? (2 pts) 6. Label which group on the periodic table the following elements belong. [Families: alkali metals, alkaline earth metals, transition metals, halogens, or noble gases]. (0.25 ea.) Family a. I _______________________ b. Li _______________________ c. Co _______________________ d. Rn _______________________ 7. Name the following ionic compounds that contain metals that can only form one charge: (1 pt ea) a. NaF __________________________________________ b. MgCl2 __________________________________________ c. Mg(OH)2 __________________________________________ d. Ag2O __________________________________________ 8. Write a formula for the ionic compound that forms between each pair of elements: (1 pt ea.) a. barium and oxygen _____________________________________ b. beryllium and chlorine _____________________________________ c. magnesium and sulfur _____________________________________ d. strontium and bromine _____________________________________ 9. Name each ionic compound: (1 pt ea.) a. NH4I _____________________________________ b. NaClO2 _____________________________________ c. Pb(C2H3O2)2 _____________________________________ d. KClO3 _____________________________________ 10. Write a formula for the compound that forms between barium and each polyatomic ion: (1 pt ea.) a. hydroxide b. chromate c. phosphate d. cyanide 11. Determine the name from the formula: (1 pt ea.) a. iridium(III) bromide b. potassium carbonate c. cobalt(II) phosphate d. copper(I) chloride 12. Name the following molecular compounds: (1 pt ea.) a. NF __________________________________________ b. N3Cl2 __________________________________________ c. XeO3 __________________________________________ d. CCl4 __________________________________________ 13. Write a formula for each molecular compound: (1 pt ea.) a. phosphorus trichloride __________________________________ b. chlorine monoxide __________________________________ c. disulfur tetrafluoride __________________________________ d. diphosphorus pentasulfide __________________________________ 14. Write the formula for each acid: (1 pt ea.) a. hydrofluoric acid __________________________________ b. carbonic acid __________________________________ c. sulfurous acid __________________________________ d. hydrocyanic acid __________________________________ 15. What is the formula mass for diboron tetrachloride? (2 pts) 16. What is the formula mass of copper (II) fluoride? (2 pts)

Sample Paper For Above instruction

Comprehensive Chemical Calculations and Concepts: Homework

This paper comprehensively addresses the key concepts, calculations, and nomenclature tasks outlined in the assignment, providing detailed explanations, step-by-step calculations, and critical analysis of periodic table elements, isotopic weights, ionic and molecular compounds, acids, and atomic/molecular masses. The goal is to demonstrate mastery of core chemical principles requisite at the collegiate level.

Periodic Table and Element Identification

The periodic table is organized into rows called periods and columns called groups or families. Each element’s position reflects its atomic number and chemical properties. For example, palladium (Pd), silicon (Si), tellurium (Te), and krypton (Kr) occupy specific groups which determine their classification as metals, nonmetals, or metalloids.

Palladium (Pd) is classified as a transition metal, characterized by its metallic properties, such as high conductivity and malleability. Silicon (Si) is a metalloid exhibiting properties of both metals and nonmetals. Tellurium (Te) is also a metalloid, often considered a semiconductor. Krypton (Kr) is a noble gas, a nonmetal inert element with full valence shells.

Periodic Table Rows and Atomic Weight Calculations

The horizontal rows are called periods, signifying the number of electron shells in an element. The vertical columns are groups, indicating elements with similar valence electron configurations.

To calculate the atomic weight of an element with known isotopic abundances, the weighted average formula is used:

Atomic weight = (abundance of isotope 1 × mass of isotope 1) + (abundance of isotope 2 × mass of isotope 2) + ...

Using the provided data for a hypothetical element with isotopic masses 184.953 amu and 186.956 amu, and abundances 37.40% (0.374) and 62.60% (0.626), respectively:

Atomic weight = (0.374 × 184.953) + (0.626 × 186.956) = 69.181 + 117.134 ≈ 186.315 amu

This corresponds closely to the atomic weight of the isotope-influenced element.

Isotopic Weight of Antimony

Applying the same method for antimony:

Atomic weight = (0.5730 × 120.904) + (0.4270 × 122.853) = 69.143 + 52.505 ≈ 121.648 amu

Hence, the atomic weight of antimony is approximately 121.65 amu.

Periodic Table Families and Element Groupings

Elements are classified into families based on similar valence electron configurations:

• Iodine (I): Halogen family
• Lithium (Li): Alkali metal family
• Cobalt (Co): Transition metal family
• Radon (Rn): Noble gas family

Nomenclature of Ionic Compounds with Fixed-Charge Metals

For metals with only one possible charge:

• Sodium fluoride: NaF
• Magnesium chloride: MgCl₂
• Magnesium hydroxide: Mg(OH)₂
• Silver oxide: Ag₂O

Formulas for Ionic Compounds

Formulating ionic compounds requires balancing the total positive and negative charges:

• Barium (Ba) and oxygen (O): BaO
• Beryllium (Be) and chlorine (Cl): BeCl₂
• Magnesium (Mg) and sulfur (S): MgS
• Strontium (Sr) and bromine (Br): SrBr₂

Naming Ionic Compounds

Names:

• NH₄I: Ammonium iodide
• NaClO₂: Sodium chlorite
• Pb(C₂H₃O₂)₂: Lead(II) acetate
• KClO₃: Potassium chlorate

Formulas with Polyatomic Ions

Formulas:

• Barium hydroxide: Ba(OH)₂
• Barium chromate: BaCrO₄
• Barium phosphate: Ba₃(PO₄)₂
• Barium cyanide: Ba(CN)₂

Named Compounds from Formulas

a. Iridium(III) bromide: IrBr₃

b. Potassium carbonate: K₂CO₃

c. Cobalt(II) phosphate: Co₃(PO₄)₂

d. Copper(I) chloride: CuCl

Molecular Compound Names

a. NF: Nitrogen monofluoride

b. N₃Cl₂: Trichloronitrogen

c. XeO₃: Xenon trioxide

d. CCl₄: Carbon tetrachloride

Molecular Formulas

a. Phosphorus trichloride: PCl₃

b. Chlorine monoxide: ClO

c. Disulfur tetrafluoride: S₂F₄

d. Diphosphorus pentasulfide: P₂S₅

Acid Formulas

a. Hydrofluoric acid: HF

b. Carbonic acid: H₂CO₃

c. Sulfurous acid: H₂SO₃

d. Hydrocyanic acid: HCN

Mass Calculations

Formula Mass of Diboron Tetrachloride (B₂Cl₄)

Atomic masses: B = 10.81 amu, Cl = 35.45 amu

Calculations: (2 × 10.81) + (4 × 35.45) = 21.62 + 141.8 = 163.42 amu

Formula Mass of Copper (II) Fluoride (CuF₂)

Atomic masses: Cu = 63.55 amu, F = 18.998 amu

Calculations: 63.55 + (2 × 18.998) = 63.55 + 37.996 = 101.546 amu

References

• Brown, T. L., LeMay, H. E., Bursten, B. E., Murphy, C., & Woodward, P. (2018). Chemistry: The Central Science (14th ed.). Pearson.
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• Zumdahl, S. S., & Zumdahl, S. A. (2014). Chemistry (9th ed.). Cengage Learning.
• Petrucci, R. H., Herring, F. G., Madura, J. D., & Bissonnette, C. (2017). General Chemistry Principles & Modern Applications (11th ed.). Pearson.
• Tro, N. J. (2019). Chemistry: A Molecular Approach (4th ed.). Pearson.
• IUPAC. (2014). Compendium of Chemical Terminology (the "Gold Book").
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