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Ch.4 - Reactions in Aqueous Solution
McMurry - Chemistry 8th Edition
McMurry8th EditionChemistryISBN: 9781292336145당신이 사용하는 게 아니라요?교과서 변경
모든 교과서McMurry 8th EditionCh.4 - Reactions in Aqueous Solution문제 132
4장, 문제 132

Alcohol levels in blood can be determined by a redox reaction with potassium dichromate according to the balanced equation What is the blood alcohol level in mass percent if 8.76 mL of 0.049 88 M K2Cr2O7 is required for complete reaction with a 10.002 g sample of blood?

검증된 단계별 안내
1
Identify the balanced chemical equation for the reaction between ethanol (C2H5OH) and potassium dichromate (K2Cr2O7).
Calculate the moles of K2Cr2O7 used in the reaction using the formula: moles = concentration (M) \(\times\) volume (L).
Use the stoichiometry of the balanced equation to determine the moles of ethanol (C2H5OH) that reacted.
Convert the moles of ethanol to mass using the molar mass of ethanol.
Calculate the mass percent of ethanol in the blood sample using the formula: (mass of ethanol / mass of blood sample) \(\times\) 100%.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
9m

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Redox Reactions

Redox reactions involve the transfer of electrons between two species, resulting in oxidation and reduction processes. In this context, potassium dichromate (K2Cr2O7) acts as an oxidizing agent, facilitating the oxidation of alcohol in the blood. Understanding how to identify the oxidized and reduced species is crucial for analyzing the reaction and calculating the blood alcohol level.
추천 영상:
가이드 코스
03:12
Identifying Redox Reactions

Molarity and Stoichiometry

Molarity (M) is a measure of concentration defined as moles of solute per liter of solution. In this question, the molarity of K2Cr2O7 is essential for determining the number of moles reacting with the blood sample. Stoichiometry allows us to relate the moles of reactants to the moles of products, enabling the calculation of the blood alcohol level based on the balanced chemical equation.
추천 영상:
가이드 코스
03:10
Solution Stoichiometry

Mass Percent Concentration

Mass percent concentration is a way to express the concentration of a component in a mixture, calculated as the mass of the solute divided by the total mass of the solution, multiplied by 100. In this scenario, determining the blood alcohol level in mass percent requires converting the moles of alcohol oxidized into mass and then relating it to the mass of the blood sample to find the final concentration.
추천 영상:
가이드 코스
00:38
Mass Percent Calculation
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교과서 질문
Calcium levels in blood can be determined by adding oxa-late ion to precipitate calcium oxalate, CaC2O4, followed by dissolving the precipitate in aqueous acid and titrating the resulting oxalic acid (H2C2O4) with KMnO4: How many milligrams of Ca2+ are present in 10.0 mL of blood if 21.08 mL of 0.000 988 M KMnO4 solution is needed for the titration?
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교과서 질문
Standardized solutions of KBrO3 are frequently used in redox titrations. The necessary solution can be made by dissolving KBrO3 in water and then titrating it with an As(III) solution. What is the molar concentration of a KBrO3 solution if 28.55 mL of the solution is needed to titrate 1.550 g of As2O3? See Problem 4.128 for the balanced equation. (As2O3 dissolves in aqueous acid solution to yield H3AsO3: As2O3 + 3 H2OS 2 H3AsO3.)
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교과서 질문
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교과서 질문

A compound with the formula XOCl2 reacts with water, yielding HCl and another acid H2XO3, which has two acidic hydrogens that react with NaOH. When 0.350 g of XOCl2 was added to 50.0 mL of water and the resultant solution was titrated, 96.1 mL of 0.1225 M NaOH was required to react with all the acid. (a) Write a balanced equation for the reaction of XOCl2 with H2O.

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교과서 질문
Assume that you have 1.00 g of a mixture of benzoic acid (Mol. wt. = 122) and gallic acid (Mol. wt. = 170)), both of which contain one acidic hydrogen that reacts with NaOH. On titrating the mixture with 0.500 M NaOH, 14.7 mL of base is needed to completely react with both acids. What mass in grams of each acid is present in the original mixture?
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교과서 질문
The metal content of iron in ores can be determined by a redox procedure in which the sample is first oxidized with Br2 to convert all the iron to Fe3+ and then titrated with Sn2+ to reduce the Fe3+ to Fe2+. The balanced equation is: What is the mass percent Fe in a 0.1875 g sample of ore if 13.28 mL of a 0.1015 M Sn2+ solution is needed to titrate the Fe3+?
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