Open Question
Niobium reacts with fluorine at room temperature to give a solid binary compound that is 49.44% Nb by mass. (a) What is the empirical formula of the compound? (b) Write a balanced equation for the reaction.
Ch.22 - The Main Group Elements
Chapter 22, Problem 5
Draw the electron-dot structure for BH3. What are the hybrid orbitals used by boron to form bonds with hydrogen, and will BH3 act as a Lewis acid or a Lewis base? (LO 22.9) (a) sp3; Lewis acid (b) sp3; Lewis base (c) sp2; Lewis acid (d) sp2; Lewis base
Verified step by step guidance1
Step 1: Determine the total number of valence electrons in BH3. Boron (B) has 3 valence electrons, and each hydrogen (H) has 1 valence electron. Therefore, the total number of valence electrons is 3 (from B) + 3*1 (from 3 H) = 6 valence electrons.
Step 2: Draw the electron-dot structure for BH3. Place boron in the center and arrange the three hydrogen atoms around it. Distribute the 6 valence electrons to form single bonds between boron and each hydrogen atom, resulting in a structure where boron is surrounded by three hydrogen atoms, each sharing a pair of electrons with boron.
Step 3: Determine the hybridization of boron in BH3. Boron forms three sigma bonds with hydrogen, and there are no lone pairs on boron. The steric number (number of sigma bonds + lone pairs) is 3, indicating sp2 hybridization.
Step 4: Analyze whether BH3 acts as a Lewis acid or a Lewis base. A Lewis acid is an electron pair acceptor, while a Lewis base is an electron pair donor. Since BH3 has an incomplete octet and can accept an electron pair, it acts as a Lewis acid.
Step 5: Based on the analysis, the correct answer is (c) sp2; Lewis acid.
Related Practice
Textbook Question
Which of the following elements is the best conductor of electricity? (LO 22.1)
(a) N (b) As
(c) P (d) Bi
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Textbook Question
Which element will react most vigorously with water, and what is the reaction that occurs?
(a) Lithium; 2 Li(s) + 2 H2O(l) → 2 Li+(aq) + 2 H–(aq) + H2O2(aq)
(b) Potassium; 2 K(s) + 2 H2O(l) → 2 K+(aq) + 2 OH–(aq) + H2(g)
(c) Magnesium; Mg(s) + 2 H2O(l) → Mg2+(aq) + 2 OH–(aq) + H2(g)
(d) Barium; Ba(s) + 2 H2O(l) → Ba2+(aq) + 2 H–(aq) + H2O2(aq)
Open Question
The silicate anion in the mineral kinoite is represented by the following structure. The mineral also contains Ca2+ ions, Cu2+ ions, and water molecules in a 1:1:1 ratio. What are the formula and charge of the silicate anion, and what is the complete formula for the mineral? (LO 22.11) (a) Si3O10^8-; Ca2Cu2Si3O10 · 2 H2O (b) Si3O8^10-; Ca3Cu2Si3O8 · 2 H2O (c) Si3O4^4-; CaCuSi3O8 · H2O (d) Si3O12^12-; Ca3Cu3Si3O12 · 3 H2O
Open Question
Write chemical equations for the reaction of potassium with the following substances, ensuring that the numbers and kinds of atoms are the same on both sides of the equations. If no reaction occurs, write N.R. (b) Br₂ (c) O₂
Open Question
Describe the shape of each of the following molecules or ions, and tell which hybrid orbitals are used by the central atom. (a) GeBr4 (b) CO2 (c) CO32- (d) SnCl3-