Skip to main content
Ch.3 - Chemical Reactions and Reaction Stoichiometry
Chapter 3, Problem 98a,b

An element X forms an iodide (XI3) and a chloride (XCl3). The iodide is quantitatively converted to the chloride when it is heated in a stream of chlorine: 2 XI3 + 3 Cl2 → 2 XCl3 + 3 I2 If 0.5000 g of XI3 is treated with chlorine, 0.2360 g of XCl3 is obtained. (a) Calculate the atomic weight of the element X. (b) Identify the element X.

Verified step by step guidance
1
Identify the chemical reaction: \(2 \text{XI}_3 + 3 \text{Cl}_2 \rightarrow 2 \text{XCl}_3 + 3 \text{I}_2\).
Determine the molar mass of \(\text{XI}_3\) and \(\text{XCl}_3\) using the given masses and the stoichiometry of the reaction.
Use the mass of \(\text{XI}_3\) (0.5000 g) and \(\text{XCl}_3\) (0.2360 g) to set up a ratio based on the stoichiometry of the reaction.
Calculate the molar mass of \(\text{XI}_3\) and \(\text{XCl}_3\) using the atomic masses of iodine and chlorine, and the unknown atomic mass of \(X\).
Solve the equations to find the atomic weight of element \(X\) by equating the molar masses derived from the given data.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
6m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Stoichiometry

Stoichiometry is the calculation of reactants and products in chemical reactions based on the conservation of mass. It involves using balanced chemical equations to determine the relationships between the amounts of substances consumed and produced. In this question, stoichiometry is essential for relating the masses of XI3 and XCl3 to find the atomic weight of element X.
Recommended video:
Guided course
01:16
Stoichiometry Concept

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic weights of all atoms in a molecule. To find the atomic weight of element X, one must first determine the molar masses of XI3 and XCl3, which will help in calculating the mass contribution of X in the reaction.
Recommended video:
Guided course
02:11
Molar Mass Concept

Conservation of Mass

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. This principle allows chemists to account for all reactants and products in a reaction. In this problem, the total mass of XI3 before the reaction must equal the total mass of XCl3 and I2 produced, which is crucial for calculating the atomic weight of X based on the given masses.
Recommended video:
Guided course
01:48
Law of Conservation of Mass
Related Practice
Textbook Question

Vanillin, the dominant flavoring in vanilla, contains C, H, and O. When 1.05 g of this substance is completely combusted, 2.43 g of CO2 and 0.50 g of H2O are produced. What is the empirical formula of vanillin?

1337
views
Textbook Question

An organic compound was found to contain only C, H, and Cl. When a 1.50-g sample of the compound was completely combusted in air, 3.52 g of CO2 was formed. In a separate experiment, the chlorine in a 1.00-g sample of the compound was converted to 1.27 g of AgCl. Determine the empirical formula of the compound.

2585
views
2
rank
Textbook Question
A compound, Na2Cr2Ox, where x is unknown, is analyzedand found to contain 39.70% Cr. What is the value of x?
393
views
Textbook Question

A method used by the U.S. Environmental Protection Agency (EPA) for determining the concentration of ozone in air is to pass the air sample through a 'bubbler' containing sodium iodide, which removes the ozone according to the following equation: O31g2 + 2 NaI1aq2 + H2O1l2¡ O21g2 + I21s2 + 2 NaOH1aq2 (a) How many moles of sodium iodide are needed to remove 5.95 * 10-6 mol of O3?

415
views
Textbook Question

A method used by the U.S. Environmental Protection Agency (EPA) for determining the concentration of ozone in air is to pass the air sample through a 'bubbler' containing sodium iodide, which removes the ozone according to the following equation: O31g2 + 2 NaI1aq2 + H2O1l2¡ O21g2 + I21s2 + 2 NaOH1aq2 (b) How many grams of sodium iodide are needed to remove 1.3 mg of O3?

537
views
Textbook Question

The fat stored in a camel's hump is a source of both energy and water. Calculate the mass of H2O produced by the metabolism of 1.0 kg of fat, assuming the fat consists entirely of tristearin 1C57H110O62, a typical animal fat, and assuming that during metabolism, tristearin reacts with O2 to form only CO2 and H2O.

1480
views