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

The ball-and-stick molecular model is a representation of caf-feine. Calculate the molecular weight of caffeine. (Gray = C, red = O, blue = N, ivory = H.) (LO 3.3)
Ball-and-stick model of caffeine showing atoms: gray for carbon, red for oxygen, blue for nitrogen, ivory for hydrogen.
(a) 194.2 (b) 182.2 (c) 192.2 (d) 180.2

검증된 단계별 안내
1
Count the number of each type of atom in the caffeine molecule. Identify the colors: Gray = Carbon (C), Red = Oxygen (O), Blue = Nitrogen (N), Ivory = Hydrogen (H).
Determine the atomic masses of each element: Carbon (C) = 12.01 g/mol, Oxygen (O) = 16.00 g/mol, Nitrogen (N) = 14.01 g/mol, Hydrogen (H) = 1.01 g/mol.
Multiply the number of each type of atom by its atomic mass to find the total mass contribution of each element.
Sum the total mass contributions of all elements to find the molecular weight of caffeine.
Compare the calculated molecular weight with the given options (a) 194.2, (b) 182.2, (c) 192.2, (d) 180.2 to determine the correct answer.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
2m

주요 개념

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

Molecular Weight

Molecular weight, or molar mass, is the sum of the atomic weights of all atoms in a molecule, expressed in grams per mole (g/mol). It is calculated by multiplying the number of each type of atom by its atomic weight and summing these values. For caffeine, which contains carbon, hydrogen, nitrogen, and oxygen, the molecular weight is essential for understanding its chemical properties and behavior.
추천 영상:
가이드 코스
03:45
Weight Conversion Example

Ball-and-Stick Model

The ball-and-stick model is a three-dimensional representation of molecular structures, where balls represent atoms and sticks represent the bonds between them. This model helps visualize the arrangement of atoms in a molecule, including bond angles and distances. In the case of caffeine, the model illustrates the connectivity and spatial orientation of carbon, hydrogen, nitrogen, and oxygen atoms.
추천 영상:
가이드 코스
02:43
Bohr Model of the Atom

Chemical Composition of Caffeine

Caffeine is an organic compound with the chemical formula C8H10N4O2, indicating it contains 8 carbon (C), 10 hydrogen (H), 4 nitrogen (N), and 2 oxygen (O) atoms. Understanding its chemical composition is crucial for calculating its molecular weight and for studying its biological effects and interactions. Each atom type contributes differently to the overall molecular weight, influencing its properties.
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가이드 코스
04:19
Matter Composition