What is the molar mass of pentane if 4.18 �~ 1016 molecules of pentane weigh 5.00 ƒÊg?
mols = 4.18E16/5.02E23 = ?
Then molar mass = g/mols = ?
That "funny" unit you posted must be microgram or 5E-6g.
To find the molar mass of pentane, we need to use the given information about the number of molecules and the weight.
First, we need to calculate the number of moles of pentane using the formula:
moles = number of molecules / Avogadro's number
Avogadro's number is approximately 6.022 x 10^23 molecules/mol.
So, moles = 4.18 x 10^16 molecules / 6.022 x 10^23 molecules/mol
Now, let's calculate the moles:
moles = 4.18 x 10^16 / 6.022 x 10^23
= 6.931 x 10^-8 mol
Next, we can use the definition of molar mass, which is the mass of one mole of a substance, to calculate the molar mass of pentane.
molar mass = mass / moles
Given that the mass is 5.00 μg (micrograms) and the moles is 6.931 x 10^-8 mol, we can plug in these values:
molar mass = 5.00 μg / 6.931 x 10^-8 mol
However, we need to convert micrograms to grams to ensure consistency. There are 1,000,000 micrograms in a gram.
molar mass = 5.00 x 10^-6 g / 6.931 x 10^-8 mol
Now, let's calculate the molar mass:
molar mass = 5.00 x 10^-6 / 6.931 x 10^-8
= 72.11 g/mol
Therefore, the molar mass of pentane is 72.11 g/mol.
To find the molar mass of pentane, we need to use the given information that 4.18 × 10^16 molecules of pentane weigh 5.00 μg.
First, we need to calculate the number of moles of pentane in 4.18 × 10^16 molecules using Avogadro's number, which is approximately 6.022 × 10^23 molecules per mole.
Number of moles = (Number of molecules)/(Avogadro's number)
Number of moles = 4.18 × 10^16/ 6.022 × 10^23
Number of moles ≈ 6.93 × 10^-8 moles
Next, we can use the formula for molar mass to calculate the molar mass of pentane. The molar mass is the mass of one mole of a substance.
Molar mass = (Mass of the substance)/(Number of moles)
Molar mass = 5.00 μg / 6.93 × 10^-8 moles
Molar mass ≈ 7.21 × 10^7 g/mol
Therefore, the molar mass of pentane is approximately 7.21 × 10^7 g/mol.