Classify each of the following as a pure substance, a solution, or a heterogeneous mixture: (a) a leaf (b) a 999 gold bar
Ch.1 - Introduction: Matter, Energy, and Measurement
1장, 문제 63
Gold can be hammered into extremely thin sheets called gold leaf. An architect wants to cover a 30 m x 25 m ceiling with gold leaf that is twelve-millionths of a centimeter thick. The density of gold is 19.32 g/cm3, and gold costs \$1654 per troy ounce (1 troy ounce = 31.1034768 g). How much will it cost the architect to buy the necessary gold?
검증된 단계별 안내1
Calculate the volume of gold needed by multiplying the area of the ceiling by the thickness of the gold leaf. Use the formula: \( \text{Volume} = \text{Area} \times \text{Thickness} \).
Convert the volume from cubic centimeters to cubic meters, if necessary, to match the units of the area and thickness.
Use the density of gold to find the mass of gold required. Use the formula: \( \text{Mass} = \text{Density} \times \text{Volume} \).
Convert the mass of gold from grams to troy ounces using the conversion factor: 1 troy ounce = 31.1034768 g.
Calculate the cost by multiplying the number of troy ounces by the cost per troy ounce (\$1654).

비슷한 문제에 대한 검증된 영상 답변:
이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
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주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Volume and Thickness Calculation
To determine the amount of gold needed, one must calculate the volume of gold leaf required to cover the ceiling. This involves multiplying the area of the ceiling (30 m x 25 m) by the thickness of the gold leaf, converted into centimeters. Understanding how to manipulate units and perform volume calculations is essential for solving the problem.
추천 영상:
가이드 코스
Constant-Volume Calorimetry
Density and Mass Relationship
Density is defined as mass per unit volume, and it plays a crucial role in converting the calculated volume of gold leaf into mass. The density of gold (19.32 g/cm³) allows us to find the mass by multiplying the volume by the density. This relationship is fundamental in determining how much gold is needed in grams before converting it to troy ounces for cost calculation.
추천 영상:
가이드 코스
Density Concepts
Cost Calculation and Unit Conversion
Once the mass of gold is determined, the next step is to calculate the cost based on the price per troy ounce. This requires converting grams to troy ounces using the conversion factor (1 troy ounce = 31.1034768 g). Understanding how to perform these conversions and apply the cost per unit is essential for arriving at the final cost for the architect.
추천 영상:
가이드 코스
Conversion Factors Example
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