Learning Goal: To understand what an empirical formula is and to learn the procedure for finding empirical formulas. An empirical formula expresses the simplest ratio of the elements volved. The compound P4010 has a P:O ratio of 4:10. However, this ratio can be simplified to 2:5. Therefore the empirical formula for P4O10 is P2O5. Another example is hydrogen peroxide, which has the formula H₂O2 and an empirical formula of HO. One way that chemists analyze new or unknown compounds is to determine the percentage composition of elements experimentally, which yields the empirical formula. A compound is 80.0% carbon and 20.0% hydrogen by mass. Assume you have a 100.-g sample of this compound. Part A How many grams of each element are in this sample? Enter the number of grams of carbon followed by the number of grams of hydrogen, separated by a comma (e.g., 30.0,70.0). mass of C, mass of H = VO ΑΣΦ C ? 6.0 g

Learning Goal: To understand what an empirical formula is and to learn the procedure for finding empirical formulas. An empirical formula expresses the simplest ratio of the elements volved. The compound P4010 has a P:O ratio of 4:10. However, this ratio can be simplified to 2:5. Therefore the empirical formula for P4O10 is P2O5. Another example is hydrogen peroxide, which has the formula H₂O2 and an empirical formula of HO. One way that chemists analyze new or unknown compounds is to determine the percentage composition of elements experimentally, which yields the empirical formula. A compound is 80.0% carbon and 20.0% hydrogen by mass. Assume you have a 100.-g sample of this compound. Part A How many grams of each element are in this sample? Enter the number of grams of carbon followed by the number of grams of hydrogen, separated by a comma (e.g., 30.0,70.0). mass of C, mass of H = VO ΑΣΦ C ? 6.0 g

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter2: Chemical Compounds

Section: Chapter Questions

Problem 92QRT

See similar textbooks

Similar questions

When analyzed, an unknown compound gave these experimental results: C, 54.0%; h, 6.00%; and O, 40.0%. Four different students used these values to calculate the empirical formulas shown here. Which answer is correct? Why did some students not get the correct answer? (a) C4H5O2 (b) C5H7O3 (c) C7H10O4 (d) C9H12O5
A binary compound of magnesium and nitrogen is analyzed, and 1.2791 g of the compound ¡s found to contain 0.9240 g of magnesium. When a second sample of this compound is treated with water and heated, the nitrogen is driven off as ammonia, leaving a compound that contains 60.31% magnesium and 39.69% oxygen by mass. Calculate the empirical formulas of the two magnesium compounds.
If 2.50 g of aluminum metal is heated in a stream of fluorine gas, it is found that 5.28 g of fluorine will combine with the aluminum. Determine the empirical formula of the compound that results.
Fulgurites are the products of the melting that occurs when lightning strikes the earth. Microscopic examination of a sand fulgurite shows that it is a globule with variable composition that contains some grains of the definite chemical composition Fe 46.01%, Si 53.99%. Determine the empirical formula of these grains.
Suppose Avogadro’s number was 1000 instead of 6.0221023 . How, if at all, would this affect the relative masses on the periodic table? How, if at all, would this affect the absolute masses of the elements?
By x-ray diffraction it is possible to determine the geometric pattern in which atoms are arranged in a crystal and the distances between atoms. In a crystal of silver, four atoms effectively occupy the volume of a cube 0.409 nm on an edge. Taking the density of silver to be 10.5 g/cm3, calculate the number of atoms in one mole of silver.
hat is the difference between the empirical and molecular for mulas of a compound? Can they ever be the same? Explain.
For each of the following samples of ionic substances, calculate the number of moles and mass of the positive ions present in each sample. l type="a"> 4.25 g of ammonium iodide, NH4I i>6.31 moles of ammonium sulfide, ( NH4)2S i>9.71 g of barium phosphide, Ba3P2 i>7.63 moles of calcium phosphate, Ca3( PO4)2
Which of the following compounds have the same empirical formulas? mg src=Images/HTML_99425-8-22ALQ_image001.jpg alt="" align="top"/>
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 1020 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?