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Ch.1 - Introduction: Matter, Energy, and Measurement
Chapter 1, Problem 87

The mass of an empty oil drum is listed as 2.0×104 g. After a quantity of biodiesel fuel is added to the drum, the total mass is 7.05×105 g.
a. To how many significant figures should the mass of the biodiesel in the drum be reported?
b. The density of the biodiesel fuel is 0.875 g/cm3. What is the volume of biodiesel that has been added to the drum, in L?

Verified step by step guidance
1
Step 1: Calculate the mass of the biodiesel by subtracting the mass of the empty drum from the total mass. Use the formula: \( \text{Mass of biodiesel} = \text{Total mass} - \text{Mass of empty drum} \).
Step 2: Determine the number of significant figures for the mass of the biodiesel. The mass of the empty drum is given as 2.0×104 g (2 significant figures) and the total mass is 7.05×105 g (3 significant figures). The result should be reported with the least number of significant figures from the given values.
Step 3: Use the density formula to find the volume of the biodiesel. The formula is \( \text{Density} = \frac{\text{Mass}}{\text{Volume}} \). Rearrange it to solve for volume: \( \text{Volume} = \frac{\text{Mass}}{\text{Density}} \).
Step 4: Substitute the mass of the biodiesel and the density (0.875 g/cm3) into the volume formula to calculate the volume in cm3.
Step 5: Convert the volume from cm3 to liters. Remember that 1 L = 1000 cm3.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Significant Figures

Significant figures are the digits in a number that contribute to its precision. This includes all non-zero digits, any zeros between significant digits, and trailing zeros in the decimal portion. When performing calculations, the result should be reported with the same number of significant figures as the measurement with the least number of significant figures to ensure accuracy.
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Density

Density is defined as mass per unit volume and is typically expressed in units such as grams per cubic centimeter (g/cm³) or kilograms per liter (kg/L). It is a crucial property that helps in converting between mass and volume. In this context, knowing the density of biodiesel allows us to calculate the volume of the fuel added to the drum based on its mass.
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Volume Calculation

Volume can be calculated using the formula: Volume = Mass / Density. This relationship allows us to determine how much space a substance occupies based on its mass and density. In the case of the biodiesel, once the mass is determined, applying this formula will yield the volume in liters, which is essential for understanding how much fuel has been added to the drum.
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