/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 152 Consider samples of phosphine \(... [FREE SOLUTION] | 91Ó°ÊÓ

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Consider samples of phosphine \(\left(\mathrm{PH}_{3}\right),\) water \(\left(\mathrm{H}_{2} \mathrm{O}\right),\) hydrogen sulfide \(\left(\mathrm{H}_{2} \mathrm{S}\right),\) and hydrogen fluoride (HF), each with a mass of \(119 \mathrm{g} .\) Rank the compounds from the least to the greatest number of hydrogen atoms contained in the samples.

Short Answer

Expert verified
The moles of each compound are as follows: \(1.18 \, \text{moles of PH}_3\), \(6.61 \, \text{moles of H}_2\text{O}\), \(2.96 \, \text{moles of H}_2\text{S}\), and \(13.23 \, \text{moles of HF}\). Multiplying the moles by the number of hydrogen atoms in each compound, we find that there are \(3.54 \times 10^{24}\) hydrogen atoms in PH3, \(7.95 \times 10^{24}\) in H2O, \(5.93 \times 10^{24}\) in H2S, and \(7.97 \times 10^{24}\) in HF. Thus, the ranking from least to greatest number of hydrogen atoms is: PH3, H2S, H2O, and HF.

Step by step solution

01

Compute the moles of each compound

For each compound, calculate the number of moles using the formula: moles = mass / molar mass For each compound: - compute the molar mass (mass of one mole). - calculate the number of moles.
02

Determine the number of hydrogen atoms in each compound

For each compound, determine the number of hydrogen atoms it contains based on its chemical formula.
03

Calculate the total number of hydrogen atoms in the samples of each compound

Multiply the number of moles of each compound by the number of hydrogen atoms it contains.
04

Rank the compounds based on the total number of hydrogen atoms

Now that we have the total number of hydrogen atoms in the samples of each compound, rank them from the least to the greatest number of hydrogen atoms.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Counting Hydrogen Atoms in Compounds
When trying to figure out how many hydrogen atoms are in a sample, we need to look closely at the chemical formula of each compound.
This formula tells us how many of each type of atom are present in a single molecule of the compound.
For example, let's take water \( \ ext{H}_2\text{O} \).
The subscript \( 2 \) next to hydrogen indicates that each water molecule contains two hydrogen atoms.
Hydrogen sulfide \( \ ext{H}_2\text{S} \) and phosphine \( \ ext{PH}_3 \) also have subscripts indicating the number of hydrogen atoms per molecule.
Meanwhile, hydrogen fluoride (HF) has no subscript for hydrogen, meaning there is only one hydrogen atom in each molecule.
By counting these hydrogen atoms, we can determine the starting point for our calculations.
However, to find out the total hydrogen atoms in a particular mass of a compound, we need to consider not only how many hydrogen atoms are in one molecule but also how many molecules are in the sample.
Understanding Chemical Formula Analysis
A chemical formula is like a simple map that shows which atoms are in a compound and how many of each kind there are.
This is crucial for understanding how to calculate various properties such as molar mass or the number of moles.
In the chemical formula \( \text{PH}_3 \), each molecule contains one phosphorus atom and three hydrogen atoms.
For water \( \text{H}_2\text{O} \), each molecule has two hydrogen atoms and one oxygen atom.
In hydrogen sulfide \( \text{H}_2\text{S} \), you have two hydrogen atoms and one sulfur atom per molecule.
Lastly, hydrogen fluoride (HF) has one hydrogen atom and one fluorine atom per molecule.
By breaking down these formulas, we can better understand the composition of each compound.
This allows us to accurately calculate the molar mass, which is the mass of one mole of a substance.
The Mole Concept in Chemistry
The mole is a basic unit in chemistry that tells us how many molecules or atoms are present in a sample.
It is a huge number, specifically Avogadro's number, which is about 6.022 \( \times 10^{23} \).
Using the mole concept, we can turn the mass of a sample into a count of molecules, giving us a better understanding of the scale we are dealing with.For any given compound, the number of moles is calculated as the mass of the sample divided by the molar mass.
The molar mass, in turn, is computed from the sum of the atomic masses of all the atoms in the compound's formula.
Once we know the number of moles, we use it to find the exact number of molecules and in this situation, the total number of hydrogen atoms.
This is done by multiplying the number of moles by Avogadro's number and then by the number of hydrogen atoms in one molecule of the compound.
By using the mole concept, we can tackle complex calculations with just simple multiplication and division.

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Most popular questions from this chapter

Ammonia reacts with \(\mathrm{O}_{2}\) to form either \(\mathrm{NO}(g)\) or \(\mathrm{NO}_{2}(g)\) according to these unbalanced equations: $$\begin{array}{l}\mathrm{NH}_{3}(g)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{NO}(g)+\mathrm{H}_{2} \mathrm{O}(g) \\\\\mathrm{NH}_{3}(g)+\mathrm{O}_{2}(g) \longrightarrow \mathrm{NO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)\end{array}$$ In a certain experiment 2.00 moles of \(\mathrm{NH}_{3}(g)\) and 10.00 moles of \(\mathbf{O}_{2}(g)\) are contained in a closed flask. After the reaction is complete, 6.75 moles of \(\mathbf{O}_{2}(g)\) remains. Calculate the number of moles of \(\mathrm{NO}(g)\) in the product mixture: (Hint: You cannot do this problem by adding the balanced equations because you cannot assume that the two reactions will occur with equal probability.)

With the advent of techniques such as scanning tunneling microscopy, it is now possible to "write" with individual atoms by manipulating and arranging atoms on an atomic surface. a. If an image is prepared by manipulating iron atoms and their total mass is \(1.05 \times 10^{-20} \mathrm{g},\) what number of iron atoms were used? b. If the image is prepared on a platinum surface that is exactly 20 platinum atoms high and 14 platinum atoms wide, what is the mass (grams) of the atomic surface? c. If the atomic surface were changed to ruthenium atoms and the same surface mass as determined in part b is used, what number of ruthenium atoms is needed to construct the surface?

The reusable booster rockets of the U.S. space shuttle employ a mixture of aluminum and ammonium perchlorate for fuel. A possible equation for this reaction is $$\begin{aligned}3 \mathrm{Al}(s)+3 \mathrm{NH}_{4} \mathrm{ClO}_{4}(s) & \longrightarrow \\ \mathrm{Al}_{2} \mathrm{O}_{3}(s)+& \mathrm{AlCl}_{3}(s)+3 \mathrm{NO}(g)+6 \mathrm{H}_{2} \mathrm{O}(g)\end{aligned}$$ What mass of \(\mathrm{NH}_{4} \mathrm{ClO}_{4}\) should be used in the fuel mixture for every kilogram of Al?

A gas contains a mixture of \(\mathrm{NH}_{3}(g)\) and \(\mathrm{N}_{2} \mathrm{H}_{4}(g),\) both of which react with \(\mathrm{O}_{2}(g)\) to form \(\mathrm{NO}_{2}(g)\) and \(\mathrm{H}_{2} \mathrm{O}(g) .\) The gaseous mixture (with an initial mass of \(61.00 \mathrm{g}\) ) is reacted with 10.00 moles \(\mathrm{O}_{2}\), and after the reaction is complete, 4.062 moles of \(\mathrm{O}_{2}\) remains. Calculate the mass percent of \(\mathrm{N}_{2} \mathrm{H}_{4}(g)\) in the original gaseous mixture.

Maleic acid is an organic compound composed of \(41.39 \%\) C, \(3.47 \%\) H, and the rest oxygen. If 0.129 mole of maleic acid has a mass of \(15.0 \mathrm{g},\) what are the empirical and molecular formulas of maleic acid?

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