PROBLEM-SOLVING EXAMPLE 3-6 Percent Compositionof Hydrated SaltEpsom salt is MgSO, 7 H,O. (a) What is the percent by mass of water in Epsom salt?(b) What are the percentages of each element in Epsom salt?Strategy and Explanationa. We first find the molar mass of Epsom salt, which is the sum of the molar masses ofthe atoms in the chemical formula:[1 mol Mg x (24.31 g Mg/mol Mg)] + [1 mol S x (32.07 g S/mol S)]+ [4 mol O x (15.9994 g O/mol O)] + [14 mol H x (1.0079 g H/mol H)]+ [7 mol O x (15.9994 g O/mol O)] = 246.49 g/mol Epsom saltBecause 1 mol Epsom salt contains 7 mol H,O, the mass of water in 1 mol Epsom salt is,7 mol H,O x (18.012 g H,O/mol H,O) = 126.08 g H,0126.08 g water per mol Epsom salt% H,O =x 100% = 51.15% H,O%3D246.49 g/mol Epsom saltb. We calculate the percentage of magnesium from the ratio of the mass of magnesiumin 1 mol Epsom salt to the mass of Epsom salt in 1 mol:mass of Mg in 1 mol Epsom salt% Mgmass of Epsom salt in 1 mol24.31g Mgx 100% = 9.862% Mg246.49 g/mol Epsom salt

Percent mass of element= mass of element×100÷mass of compound

Strategy and Explanation a. We first find the molar mass of Epsom salt, which is the sum of the molar masses of the atoms in the chemical formula: [1 mol Mg x (24.31 g Mg/mol Mg)] + [1 mol S x (32.07 g S/mol S)] + [4 mol O x (15.9994 g O/mol O)] + [14 mol H x (1.0079 g H/mol H)] + [7 mol O x (15.9994 g O/mol 0)] = 246.49 g/mol Epsom salt %3D Because 1 mol Epsom salt contains 7 mol H,O, the mass of water in 1 mol Epsom salt is, 7 mol H,O x (18.012 g H,O/mol H2O) = 126.08 g H,0 %3D 126.08 g water per mol Epsom salt 246.49 g/mol Epsom salt % H,O = x 100% = 51.15% H,O p. We calculate the percentage of magnesium from the ratio of the mass of magnesium in 1 mol Epsom salt to the mass of Epsom salt in 1 mol: mass of Mg in 1 mol Epsom salt % Mg %3D mass of Epsom salt in 1 mol 24.31 g Mg x 100% 9.862% Mg 246.49 g/mol Epsom salt

Strategy and Explanation a. We first find the molar mass of Epsom salt, which is the sum of the molar masses of the atoms in the chemical formula: [1 mol Mg x (24.31 g Mg/mol Mg)] + [1 mol S x (32.07 g S/mol S)] + [4 mol O x (15.9994 g O/mol O)] + [14 mol H x (1.0079 g H/mol H)] + [7 mol O x (15.9994 g O/mol 0)] = 246.49 g/mol Epsom salt %3D Because 1 mol Epsom salt contains 7 mol H,O, the mass of water in 1 mol Epsom salt is, 7 mol H,O x (18.012 g H,O/mol H2O) = 126.08 g H,0 %3D 126.08 g water per mol Epsom salt 246.49 g/mol Epsom salt % H,O = x 100% = 51.15% H,O p. We calculate the percentage of magnesium from the ratio of the mass of magnesium in 1 mol Epsom salt to the mass of Epsom salt in 1 mol: mass of Mg in 1 mol Epsom salt % Mg %3D mass of Epsom salt in 1 mol 24.31 g Mg x 100% 9.862% Mg 246.49 g/mol Epsom salt

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter1: Excel Basics

Section: Chapter Questions

Problem 8P

See similar textbooks

Similar questions

How are the molecular mass and the molar mass of a compound similar and how are they different?
Determine the molarity of each of the following solutions:(a) 1.457 mol KCl in 1.500 L of solution(b) 0.515 g of H2SO4 in 1.00 L of solution(c) 20.54 g of Al(NO3)3 in 1575 mL of solution(d) 2.76 kg of CuSO4∙5H2O in 1.45 L of solution(e) 0.005653 mol of Br2 in 10.00 mL of solution(f) 0.000889 g of glycine, C2H5NO2, in 1.05 mL of solution
A sample of sodium carbonate, Na2CO3. weighs 11.0 g. Calculate the following quantities. (a) moles of Na2CO3 (b) number of Na2CO3 formula units (c) number of Na+ ions (d) moles of CO32- (a) _?_ mol Na2CO3 (b) _?_ x 10 _?_ formula units Na2CO3 (c) _?_ x 10 _?_ Na+ ions (d) _?_ mol CO32-
Determine the percentage by mass of each element in the following compounds. (Round your answers to one decimal place.) (a) bleach, NaClO Na % Cl % O % (b) lye, NaOH Na % O % H %
Determine the molarity of each of the following solutions: (d) 2.76 kg of CuSO4·5H2O in 1.45 L of solution (e) 0.005653 mol of Br2 in 10.00 mL of solution (f) 0.000889 g of glycine, C2H5NO2, in 1.05 mL of solution
Determine the percentage by mass of each element in the following compounds. (Round your answers to one decimal place.) (a) ammonia, NH3 N % H % (b) washing soda, Na2CO3 Na % C % O % C) lye, NaOH Na % O % H % (D) milk of magnesia, Mg(OH)2 Mg % O % H %
(11) How many sodium sulfate formula units are in 0.333 mol?
What is the percent by mass of oxygen in water (the best estimate to 1 sig fig)?
How many total moles of ions are released when each of thefollowing samples dissolves completely in water?(a) 0.734 mol of NacHPO₄(b) 3.86 g of CuSO₄5H₂O(c) 8.66X10²⁰formula units of NiCl₂
help me with this assignment (2)
(c) How much volume of 1.3 M NaOH solution can be made by diluting 48 ml of 4 M NaOH. (d) Aspirin (C9H8O4) is a medication used to reduce pain, fever, or inflammation. Find out the mass of 2.5x1023 molecules of aspirin in gram. (d1) no of moles of Aspirin (d2) mass of aspirin
Determine the percentage by mass of each element in the following compounds. (Round your answers to one decimal place.) (a) milk of magnesia, Mg(OH)2 Mg % O % H % (b) lime, CaCO3 Ca % C % O %