A chemistry student needs 30.0 mL of tetrahydrofuran for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of tetrahydrofuran is [tex]$0.889 g cm ^{-3}$[/tex]. Calculate the mass of tetrahydrofuran the student should weigh out. Round your answer to 3 significant digits.
Answer (2)
Use the formula mass = density × volume.
Substitute the given values: mass = 0.889 c m 3 g × 30.0 c m 3 .
Calculate the mass: mass = 26.67 g.
Round the result to 3 significant digits: 26.7 g.
Explanation
Problem Analysis and Given Data We are given the volume and density of tetrahydrofuran and asked to calculate the mass. We know that:
Volume = 30.0 mL Density = 0.889 c m 3 g
We also know that 1 mL = 1 c m 3 . Therefore, we can use the formula:
Mass = Density × Volume
Applying the Formula Now, we can plug in the values into the formula:
Mass = 0.889 c m 3 g × 30.0 c m 3
Mass = 26.67 g
Rounding the Result We need to round the answer to 3 significant digits. The result of the calculation is 26.67 g. Rounding this to 3 significant digits gives us 26.7 g.
Final Answer Therefore, the mass of tetrahydrofuran the student should weigh out is 26.7 g.
Examples
Imagine you're baking a cake and the recipe calls for a specific volume of liquid ingredient, like milk. Knowing the density of milk allows you to accurately measure the mass needed using a kitchen scale, ensuring the cake turns out perfectly. This principle applies not only in cooking but also in various fields such as medicine, where precise dosages are crucial, and in engineering, where material quantities must be exact for structural integrity. By understanding the relationship between volume, density, and mass, you can accurately measure and control the amount of substances needed for any task.
To find the mass of tetrahydrofuran needed, we use the formula mass = density × volume. Substituting the given values, we calculate the mass to be 26.67 g and round it to 26.7 g. Thus, the student should weigh out 26.7 g of tetrahydrofuran.
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