Textbook Question
A 1.000 L sample of HCl gas at 25°C and 732.0 mm Hg was absorbed completely in an aqueous solution that contained 6.954 g of Na2CO3 and 250.0 g of water. (a) What is the pH of the solution?
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Ch.17 - Applications of Aqueous Equilibria
McMurry8th EditionChemistryISBN: 9781292336145
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Table of contents
- Ch.1 - Chemical Tools: Experimentation & Measurement143
- Ch.2 - Atoms, Molecules & Ions134
- Ch.3 - Mass Relationships in Chemical Reactions149
- Ch.4 - Reactions in Aqueous Solution157
- Ch.5 - Periodicity & Electronic Structure of Atoms92
- Ch.6 - Ionic Compounds: Periodic Trends and Bonding Theory73
- Ch.7 - Covalent Bonding and Electron-Dot Structures47
- Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure51
- Ch.9 - Thermochemistry: Chemical Energy104
- Ch.10 - Gases: Their Properties & Behavior138
- Ch.11 - Liquids & Phase Changes43
- Ch.12 - Solids and Solid-State Materials56
- Ch.13 - Solutions & Their Properties98
- Ch.14 - Chemical Kinetics79
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Aqueous Equilibria: Acids & Bases94
- Ch.17 - Applications of Aqueous Equilibria125
- Ch.18 - Thermodynamics: Entropy, Free Energy & Equilibrium66
- Ch.19 - Electrochemistry130
- Ch.20 - Nuclear Chemistry73
- Ch.21 - Transition Elements and Coordination Chemistry122
- Ch.22 - The Main Group Elements155
- Ch.23 - Organic and Biological Chemistry43
Chapter 17, Problem 148c
A 40.0 mL sample of a mixture of HCl and H3PO4 was titrated with 0.100 M NaOH. The first equivalence point was reached after 88.0 mL of base, and the second equivalence point was reached after 126.4 mL of base. (c) What percent of the HCl is neutralized at the first equivalence point?
Verified step by step guidance1
First, understand that the first equivalence point in a titration is when all of the acid in the solution has been neutralized by the base. In this case, the first equivalence point was reached after 88.0 mL of NaOH was added, meaning all of the HCl was neutralized.
Next, calculate the moles of NaOH used to reach the first equivalence point. This can be done using the formula: moles = Molarity * Volume. The molarity of NaOH is given as 0.100 M and the volume used to reach the first equivalence point is 88.0 mL (or 0.088 L).
Since HCl and NaOH react in a 1:1 ratio, the moles of NaOH used to reach the first equivalence point is equal to the moles of HCl in the original solution.
Then, calculate the molarity of HCl in the original solution using the formula: Molarity = moles / Volume. The volume of the original solution is given as 40.0 mL (or 0.040 L).
Finally, to find the percent of HCl neutralized at the first equivalence point, understand that 100% of the HCl is neutralized at this point. This is because the definition of the equivalence point is when all of the acid (in this case, HCl) has been neutralized by the base (NaOH).
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Titration and Equivalence Points
Titration is a quantitative analytical method used to determine the concentration of a solute in a solution. The equivalence point in a titration is reached when the amount of titrant added is stoichiometrically equivalent to the amount of substance in the sample. In this case, the first equivalence point indicates the complete neutralization of HCl, while the second equivalence point involves the neutralization of H3PO4.
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Guided course
03:06
Equivalence Point in Titration
Stoichiometry of Acid-Base Reactions
Stoichiometry involves the calculation of reactants and products in chemical reactions based on balanced equations. For the titration of HCl with NaOH, the reaction is a 1:1 ratio, meaning one mole of HCl reacts with one mole of NaOH. Understanding this ratio is crucial for determining how much HCl is neutralized at the first equivalence point.
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Guided course
01:09Acid-Base Reaction
Concentration and Volume Relationships
The relationship between concentration and volume is essential in titration calculations. The formula C1V1 = C2V2 relates the concentrations and volumes of the acid and base involved. By knowing the concentration of NaOH and the volume used to reach the first equivalence point, one can calculate the moles of HCl neutralized and subsequently determine the percentage of HCl in the original mixture.
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01:09Relationship of Volume and Moles Example
Related Practice
Textbook Question
Ethylenediamine (NH2CH2CH2NH2, abbreviated en) is an organic base that can accept two protons: (a) Consider the titration of 30.0 mL of 0.100 M ethylenediamine with 0.100 M HCl. Calculate the pH after the addition of the following volumes of acid, and construct a qualitative plot of pH versus milliliters of HCl added: (i) 0.0 mL (ii) 15.0 mL (iii) 30.0 mL (iv) 45.0 mL (v) 60.0 mL (vi) 75.0 mL
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Textbook Question
A 40.0 mL sample of a mixture of HCl and H3PO4 was titrated with 0.100 M NaOH. The first equivalence point was reached after 88.0 mL of base, and the second equivalence point was reached after 126.4 mL of base. (f) What indicators would you select to signal the equivalence points?
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Textbook Question
A 40.0 mL sample of a mixture of HCl and H3PO4 was titrated with 0.100 M NaOH. The first equivalence point was reached after 88.0 mL of base, and the second equivalence point was reached after 126.4 mL of base. (a) What is the concentration of H3O+ at the first equivalence point?
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Textbook Question
A saturated solution of an ionic salt MX exhibits an osmotic pressure of 74.4 mm Hg at 25 °C. Assuming that MX is completely dissociated in solution, what is the value of its Ksp?
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