Question

How many molecules of butane are contained in 25.0 mL of butane? The density of butane is 0.6011 g/mL and the molar mass is 58.12 g/mol.

-7.14 × 10²⁵ molecules
-2.59 × 10²³ molecules
-1.56 × 10²³ molecules
-6.87 × 10²³ molecules
-1.46 × 10²⁷ molecules

Answer 1

To determine the number of molecules of butane in 25.0 mL of butane, you need to convert the volume to mass and then calculate the moles of butane using the molar mass. Finally, use Avogadro's number to determine the number of molecules.

Step-by-step explanation:

To determine the number of molecules of butane in 25.0 mL of butane, we need to convert the volume to mass.

Given: density of butane = 0.6011 g/mL

Volume in grams = volume in mL x density = 25.0 mL x 0.6011 g/mL = 15.0275 g

Next, we can convert the mass of butane to moles using the molar mass:

Molar mass of butane = 58.12 g/mol

Moles of butane = mass / molar mass = 15.0275 g / 58.12 g/mol = 0.259 moles

Finally, we can use Avogadro's number to calculate the number of molecules:

Number of molecules = moles x Avogadro's number = 0.259 moles x 6.02 x 10^23 molecules/mol = 1.56 x 10^23 molecules