Questions: A chemistry student needs 85.0 mL of pentane for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of pentane is 0.626 g/cm cm^-3. Calculate the mass of pentane the student should weigh out. Round your answer to 3 significant digits.

A chemistry student needs 85.0 mL of pentane for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of pentane is 0.626 g/cm cm^-3. Calculate the mass of pentane the student should weigh out.

Round your answer to 3 significant digits.

Transcript text: A chemistry student needs 85.0 mL of pentane for an experiment. By consulting the CRC Handbook of Chemistry and Physics, the student discovers that the density of pentane is $0.626 \mathrm{~g}_{\mathrm{cm}} \mathrm{cm}^{-3}$. Calculate the mass of pentane the student should weigh out. Round your answer to 3 significant digits.

Solution

Solution Steps

Step 1: Understand the Problem

The problem requires calculating the mass of pentane needed, given its volume and density. The relationship between mass, volume, and density is given by the formula: \[ \text{mass} = \text{density} \times \text{volume} \]

Step 2: Convert Units

The volume of pentane is given in milliliters (mL), and the density is given in grams per cubic centimeter (g/cm$^3$). Since 1 mL is equivalent to 1 cm$^3$, no unit conversion is necessary.

Step 3: Calculate the Mass

Using the formula from Step 1: \[ \text{mass} = 0.626 \, \text{g/cm}^3 \times 85.0 \, \text{cm}^3 \] \[ \text{mass} = 53.21 \, \text{g} \]

Step 4: Round the Answer

Round the calculated mass to 3 significant digits: \[ \text{mass} = 53.2 \, \text{g} \]