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Ch.8 - Basic Concepts of Chemical Bonding
All textbooksBrown 14th EditionCh.8 - Basic Concepts of Chemical BondingProblem 104
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Chapter 8, Problem 104

Potassium peroxide is composed of 70.96% K and 29.04% O. Each peroxide ion has a net charge of 2-. (a) Given the molecular weight of the compound is 110.19, determine the chemical formula of potassium peroxide.

Verified step by step guidance
1
Step 1: Determine the molar mass of potassium (K) and oxygen (O) using the periodic table. Potassium has a molar mass of approximately 39.10 g/mol, and oxygen has a molar mass of approximately 16.00 g/mol.
Step 2: Assume you have 100 g of potassium peroxide. This means you have 70.96 g of K and 29.04 g of O. Convert these masses to moles by dividing by their respective molar masses: moles of K = 70.96 g / 39.10 g/mol and moles of O = 29.04 g / 16.00 g/mol.
Step 3: Calculate the mole ratio of K to O by dividing the moles of each element by the smallest number of moles calculated in Step 2. This will help determine the simplest whole number ratio of K to O in the compound.
Step 4: Use the information that each peroxide ion (O2^2-) has a net charge of 2- to deduce the number of oxygen atoms in the peroxide ion. This suggests that the peroxide ion consists of two oxygen atoms.
Step 5: Combine the information from the mole ratio and the charge of the peroxide ion to determine the empirical formula of potassium peroxide. Ensure the total molar mass of the empirical formula matches the given molecular weight of 110.19 g/mol.
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Textbook Question

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.

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Textbook Question

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.

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Open Question
The compound chloral hydrate, known in detective stories as knockout drops, is composed of 14.52% C, 1.83% H, 64.30% Cl, and 13.35% O by mass, and has a molar mass of 165.4 g/mol. (c) Draw the Lewis structure of the molecule, assuming that the Cl atoms bond to a single C atom and that there are a C–C bond and two C–O bonds in the compound.
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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.

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Textbook Question

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