Question

directions: solve each problem, showing all work including units1. dichloromethane (ch₂cl₂), used as a solvent in the decaffeination of coffee beans, is prepared by reaction of methane (ch₄) with chlorine.__ch₄(g) + cl₂(g) → ch₂cl₂(l) + __hcl(g)how many moles of chlorine (cl₂) are needed for a reaction with 414 l of ch₄?2. aspirin is prepared by reaction of salicylic acid (c₇h₆o₃) with acetic anhydride (c₄h₆o₃) according to the following balanced equation:1 c₇h₆o₃ + 1 c₄h₆o₃ → 1 c₉h₈o₄ + 1 ch₃coohsalicylic acid acetic anhydride aspirin acetic acidhow many grams of acetic anhydride are needed to react with 4.50 moles of salicylic acid?

Explanation:

Problem 1:

Step 1: Balance the chemical equation

First, we balance the reaction: $\ce{CH_{4}(g) + 2Cl_{2}(g) -> CH_{2}Cl_{2}(l) + 2HCl(g)}$. So the mole ratio of $\ce{CH_{4}}$ to $\ce{Cl_{2}}$ is $1:2$.

Step 2: Assume STP (Standard Temperature and Pressure)

At STP, 1 mole of any gas occupies 22.4 L. So moles of $\ce{CH_{4}}$ = $\frac{414\ L}{22.4\ L/mol}$ ≈ 18.48 mol.

Step 3: Use mole ratio to find moles of $\ce{Cl_{2}}$

From the balanced equation, moles of $\ce{Cl_{2}}$ = 2 × moles of $\ce{CH_{4}}$ = 2 × 18.48 mol ≈ 36.96 mol.

Step 1: Determine mole ratio

From the balanced equation, the mole ratio of salicylic acid ($\ce{C_{7}H_{6}O_{3}}$) to acetic anhydride ($\ce{C_{4}H_{6}O_{3}}$) is $1:1$. So moles of acetic anhydride = moles of salicylic acid = 4.50 mol.

Step 2: Calculate molar mass of acetic anhydride

Molar mass of $\ce{C_{4}H_{6}O_{3}}$: (4×12.01) + (6×1.008) + (3×16.00) = 48.04 + 6.048 + 48.00 = 102.088 g/mol.

Step 3: Calculate mass of acetic anhydride

Mass = moles × molar mass = 4.50 mol × 102.088 g/mol ≈ 459.4 g.

Answer:

Approximately 37.0 moles (or 36.96 moles) of $\ce{Cl_{2}}$ are needed.

Problem 2: