(c) Hydrogen peroxide is sold commercially as an aqueous solution in brown bottles to protect it from light. Calculate the longest wavelength of light that has sufficient energy to break the weakest bond in hydrogen peroxide.

The electron affinity of oxygen is -141 kJ/mol, corresponding to the reaction O(g) + e^- → O^-(g). The lattice energy of K₂O(s) is 2238 kJ/mol. Use these data along with data in Appendix C and Figure 7.10 to calculate the 'second electron affinity' of oxygen, corresponding to the reaction O^-(g) + e^- → O^2-(g)

One scale for electronegativity is based on the concept that the electronegativity of any atom is proportional to the ionization energy of the atom minus its electron affinity: electronegativity = k1I - EA2, where k is a proportionality constant. (b) Why are both ionization energy and electron affinity relevant to the notion of electronegativity?

One scale for electronegativity is based on the concept that the electronegativity of any atom is proportional to the ionization energy of the atom minus its electron affinity: electronegativity = k1I - EA2, where k is a proportionality constant. (c) By using data in Chapter 7, determine the value of k that would lead to an electronegativity of 4.0 for F under this definition.

One scale for electronegativity is based on the concept that the electronegativity of any atom is proportional to the ionization energy of the atom minus its electron affinity: electronegativity = k1I - EA2, where k is a proportionality constant. (d) Use your result from part (c) to determine the electronegativities of Cl and O using this scale. Use your result to determine the electronegativity of Cl using this scale.

Acetylene (C₂H₂) and nitrogen (N₂) both contain a triple bond, but they differ greatly in their chemical properties. (b) By referring to Appendix C, look up the enthalpies of formation of acetylene and nitrogen. Which compound is more stable?

Acetylene (C₂H₂) and nitrogen (N₂) both contain a triple bond, but they differ greatly in their chemical properties. (c) Write balanced chemical equations for the complete oxidation of N₂ to form N₂O₅(g) and of acetylene to form CO₂(g) and H₂O(g). Write a balanced chemical equation for the complete oxidation of acetylene to form CO₂(g) and H₂O(g).

Acetylene (C₂H₂) and nitrogen (N₂) both contain a triple bond, but they differ greatly in their chemical properties. (d) Calculate the enthalpy of oxidation per mole for N₂ and for C2H₂ (the enthalpy of formation of N₂O₅(g) is 11.30 kJ/mol).

Acetylene (C₂H₂) and nitrogen (N₂) both contain a triple bond, but they differ greatly in their chemical properties. (e) Both N₂ and C₂H₂ possess triple bonds with quite high bond enthalpies (Table 8.3). Calculate the enthalpy of hydrogenation per mole for both compounds: acetylene plus H₂ to make methane, CH₄; nitrogen plus H₂ to make ammonia, NH₃.

Under special conditions, sulfur reacts with anhydrous liquid ammonia to form a binary compound of sulfur and nitrogen. The compound is found to consist of 69.6% S and 30.4% N. Measurements of its molecular mass yield a value of 184.3 g/mol. The compound occasionally detonates on being struck or when heated rapidly. The sulfur and nitrogen atoms of the molecule are joined in a ring. All the bonds in the ring are of the same length. (a) Calculate the empirical and molecular formulas for the substance.

Under special conditions, sulfur reacts with anhydrous liquid ammonia to form a binary compound of sulfur and nitrogen. The compound is found to consist of 69.6% S and 30.4% N. Measurements of its molecular mass yield a value of 184.3 g/mol. The compound occasionally detonates on being struck or when heated rapidly. The sulfur and nitrogen atoms of the molecule are joined in a ring. All the bonds in the ring are of the same length. (b) Write Lewis structures for the molecule, based on the information you are given. (Hint: You should find a relatively small number of dominant Lewis structures.)

A common form of elemental phosphorus is the tetrahedral P₄ molecule, where all four phosphorus atoms are equivalent: 

(b) How many P-P bonds are there in the molecule?

A common form of elemental phosphorus is the tetrahedral P₄ molecule, where all four phosphorus atoms are equivalent: 

Draw a Lewis structure for a linear P₄ molecule that satisfies the octet rule. Does this molecule have resonance structures?

Trifluoroacetic acid has the chemical formula CF₃CO₂H. It is a colorless liquid that has a density of 1.489 g/mL (a) Trifluoroacetic acid contains one CF₃ unit and is connected to the other C atom which bonds with both O’s. Draw the Lewis structure for trifluoroacetic acid.

Trifluoroacetic acid has the chemical formula CF₃CO₂H. It is a colorless liquid that has a density of 1.489 g/mL. (b) Trifluoroacetic acid can react with NaOH in aqueous solution to produce the trifluoroacetate ion, CF₃COO₂. Write the balanced chemical equation for this reaction.

Trifluoroacetic acid has the chemical formula CF₃CO₂H. It is a colorless liquid that has a density of 1.489 g/mL. (d) How many milliliters of a 0.500 M solution of NaOH would it take to neutralize 10.5 mL of trifluoroacetic acid?

Ammonium chloride, NH4Cl, is a very soluble salt in water. (c) If you dissolve 14 g of ammonium chloride in 500.0 mL of water, what is the molar concentration of the solution?

Ammonium chloride, NH4Cl, is a very soluble salt in water. (d) How many grams of silver nitrate do you need to add to the solution in part (c) to precipitate all of the chloride as silver chloride?

(a) Compare the bond enthalpies (Table 8.3) of the carbon– carbon single, double, and triple bonds to deduce an average pi bond contribution to the enthalpy. What fraction of a single bond does this quantity represent?