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Ch.3 - Mass Relationships in Chemical Reactions
McMurry - Chemistry 8th Edition
McMurry8th EditionChemistryISBN: 9781292336145당신이 사용하는 게 아니라요?교과서 변경
모든 교과서McMurry 8th EditionCh.3 - Mass Relationships in Chemical Reactions문제 86
3장, 문제 86

Urea, a substance commonly used as a fertilizer, has the for-mula CH4N2O. What is its percent composition by mass?

검증된 단계별 안내
1
Calculate the molar mass of each element in urea: C, H, N, and O.
Determine the total molar mass of urea by summing the molar masses of all atoms in the formula CH4N2O.
Calculate the mass percentage of carbon by dividing the total mass of carbon in one mole of urea by the molar mass of urea, then multiply by 100%.
Calculate the mass percentage of hydrogen by dividing the total mass of hydrogen in one mole of urea by the molar mass of urea, then multiply by 100%.
Repeat the process for nitrogen and oxygen to find their mass percentages in urea.

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
3m

주요 개념

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

Molar Mass Calculation

To determine the percent composition by mass of a compound, one must first calculate its molar mass. This involves summing the atomic masses of all the atoms in the molecular formula. For urea (CH4N2O), the molar mass is calculated by adding the masses of carbon, hydrogen, nitrogen, and oxygen based on their respective quantities in the formula.
추천 영상:
가이드 코스
03:12
Molar Mass Calculation Example

Percent Composition Formula

The percent composition by mass of an element in a compound is calculated using the formula: (mass of the element in 1 mole of the compound / molar mass of the compound) x 100%. This formula allows one to express the mass of each element as a percentage of the total mass of the compound, providing insight into its elemental makeup.
추천 영상:
가이드 코스
00:38
Mass Percent Calculation

Elemental Analysis

Elemental analysis involves identifying the types and amounts of elements present in a compound. In the case of urea, understanding the contributions of carbon, hydrogen, nitrogen, and oxygen to its overall mass is essential for calculating percent composition. This analysis is fundamental in chemistry for characterizing substances and understanding their properties.
추천 영상:
가이드 코스
06:11
Dimensional Analysis
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교과서 질문

The reaction of tungsten hexachloride (WCl6) with bismuth gives hexatungsten dodecachloride (W6Cl12).

WCl6 + Bi → W6Cl12 + BiCl3 Unbalanced

(c) When 228 g of WCl6 react with 175 g of Bi, how much W6Cl12 is formed based on the limiting reactant?

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교과서 질문

Calculate the mass percent composition of each of the following substances. (a) Malachite, a copper-containing mineral: Cu2(OH)2CO3

952
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교과서 질문

Calculate the mass percent composition of each of the following substances. (c) Prussian blue, an ink pigment: Fe4[Fe(CN)6]3

565
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교과서 질문

Sodium borohydride, NaBH4, a substance used in the synthesis of many pharmaceutical agents, can be prepared by reaction of NaH with B2H6 according to the equation 2 NaH + B2H6 → 2 NaBH4

(b) Which reactant is limiting, and how many grams of the excess reactant will be left over?

723
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교과서 질문

Calculate the mass percent composition of each of the following substances. (b) Acetaminophen, a headache remedy: C8H9NO2

889
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교과서 질문

Sodium borohydride, NaBH4, a substance used in the synthesis of many pharmaceutical agents, can be prepared by reaction of NaH with B2H6 according to the equation 2 NaH + B2H6 → 2 NaBH4

(a) How many grams of NaBH4 can be prepared by reaction between 8.55 g of NaH and 6.75 g of B2H6?

944
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