Question

what is the skeleton equation for the synthesis of aluminum oxide?
a. $\ce{al_{2} + o_{2} -> al_{2}o_{2}}$
b. $\ce{al_{2} + o_{3} -> al_{2}o_{3}}$
c. $\ce{al + o_{2} -> alo_{2}}$
d. $\ce{al + o_{2} -> al_{2}o_{3}}$
options: a, b, c, d
what products would you expect when beryllium hydroxide decomposes?
options: aqueous beryllium hydroxide, beryllium, hydrogen gas, and oxygen gas, beryllium oxide and water, beryllium hydride and oxygen gas

Explanation:

First Question (Skeleton Equation for Aluminum Oxide Synthesis)

Step 1: Recall Reactants/Products

Aluminum (Al) reacts with oxygen ($\ce{O_2}$) to form aluminum oxide ($\ce{Al_2O_3}$).

Step 2: Evaluate Options

• Option a: Product $\ce{Al_2O_2}$ is incorrect (aluminum oxide is $\ce{Al_2O_3}$).
• Option b: Reactant $\ce{O_3}$ (ozone) is not involved; oxygen is $\ce{O_2}$.
• Option c: Product $\ce{AlO_2}$ is incorrect (formula for aluminum oxide is $\ce{Al_2O_3}$).
• Option d: Correctly shows Al reacting with $\ce{O_2}$ to form $\ce{Al_2O_3}$ (skeleton equation, unbalanced).

Second Question (Decomposition of Beryllium Hydroxide)

Beryllium hydroxide ($\ce{Be(OH)_2}$) decomposes via a typical metal hydroxide decomposition: metal hydroxides break down into metal oxides and water. Thus, $\ce{Be(OH)_2 -> BeO + H_2O}$, so products are beryllium oxide ($\ce{BeO}$) and water ($\ce{H_2O}$). Other options are incorrect (e.g., decomposition does not produce elemental beryllium, hydrogen gas, or beryllium hydride).

Answer:

d. $\ce{Al + O_{2} -> Al_{2}O_{3}}$