Question

What is the volume (in litre) of oxygen required at STP to completely convert \(1.5\) moles of sulphur to sulphur dioxide? (a) \(33.6\) (b) \(43.6\) (c) \(11.2\) (d) \(23.6\)

Short answer

The volume of oxygen required is 33.6 litres.

Step-by-step solution

Write the Balanced Chemical Equation

First, we need to understand the chemical reaction involved. Sulfur reacts with oxygen to form sulfur dioxide. The balanced chemical equation for this reaction is:\[ \text{S} + \text{O}_2 \rightarrow \text{SO}_2 \]}},{

Use Stoichiometry to Find Mole Ratio

According to the balanced equation, 1 mole of sulfur reacts with 1 mole of oxygen to form 1 mole of sulfur dioxide. Thus, the mole ratio for sulfur to oxygen is 1:1.

Calculate Moles of Oxygen Needed

Given 1.5 moles of sulphur, we need the same number of moles of oxygen because the mole ratio is 1:1. Therefore, moles of oxygen required are 1.5 moles.

Calculate Volume of Oxygen at STP

At Standard Temperature and Pressure (STP), 1 mole of a gas occupies 22.4 litres.So, the volume of 1.5 moles of oxygen is calculated as follows:\[ \text{Volume of O}_2 = 1.5 \times 22.4 = 33.6 \text{ litres} \]

Key concepts

Stoichiometry

Stoichiometry is a fundamental concept in chemistry focused on the quantitative relationships in chemical reactions. It allows chemists to predict the amounts of reactants needed and products formed. In our example, sulphur reacts with oxygen to form sulphur dioxide. To accurately calculate the volume of oxygen required, we must understand the stoichiometric relationship. This involves using the mole ratios derived from the balanced chemical equation. - The balanced equation tells us **1 mole of S** reacts with **1 mole of O extsubscript{2}**. - This information is crucial as it gives a **1:1 mole ratio**. By understanding these ratios, you can calculate how much of a substance is needed or produced in a chemical reaction.

Balanced Chemical Equation

A balanced chemical equation is essential for understanding and analyzing chemical reactions. It represents the reactants and products in a reaction and ensures that the number of atoms for each element is conserved. Balancing equations involves adjusting coefficients to match the number of atoms in both the reactants and products.For the reaction between sulphur and oxygen:- The equation is: \[ \text{S} + \text{O}_2 \rightarrow \text{SO}_2 \]- This equation shows one atom of sulphur combining with one molecule of oxygen to form one molecule of sulphur dioxide.Each side of the equation must have the same number of each type of atom to be considered balanced. This balance indicates that mass is conserved, and chemical laws are met.

Standard Temperature and Pressure (STP)

Standard Temperature and Pressure (STP) is a set of conditions used as a reference point for experiments involving gases. It defines the standard temperature as 0°C (273.15 K) and the standard pressure as 1 atmosphere (atm). Under these conditions, the volume of gases behaves predictably. - At STP, **1 mole of any gas occupies 22.4 litres**. - This property assists in simplifying calculations for reactions involving gases. In our problem, knowing that 1 mole of oxygen gas occupies 22.4 litres at STP allows us to directly calculate the volume based on the number of moles.

Mole Concept

The mole concept is a method in chemistry to measure the amount of substance. It defines the mole as a quantity of chemical entities, analogous to units like dozens or pairs, but on an atomic scale. - **1 mole** of any substance contains the same number of entities as there are atoms in 12 grams of carbon-12.- This number is Avogadro's number: **approximately 6.022 x 10\(^{23}\)**.Applying the mole concept, our exercise involves converting 1.5 moles of sulphur to calculate needed grams of oxygen. The calculations are grounded in breaking down the moles into tangible quantities likely useful in the lab. By relating the number of moles to volume through Avogadro's principles, computations become more accessible, and predictions about the reaction can be confidently made.