Question

Calculate the number of moles of nickel in a 2.4 kg sample of propanol if the concentration is 20 ppb?

a) 4.08 x 10^-5 moles
b) 1.2 x 10^-5 moles
c) 2.4 x 10^-5 moles
d) 3.6 x 10^-5 moles

Answer 1

To find the moles of nickel in a 2.4 kg propanol sample with 20 ppb concentration, convert the sample to grams, use the concentration to find the mass of nickel, and then convert that to moles using nickel's molar mass. The correct answer is not listed among the provided choices.

Step-by-step explanation:

To calculate the number of moles of nickel in a 2.4 kg sample of propanol with a concentration of 20 parts per billion (ppb), we need to first convert the mass of the sample to grams and the concentration to a unit that we can use for calculations. Here's the step-by-step process:

• Convert the sample mass from kilograms to grams: 2.4 kg × 1000 g/kg = 2400 g.
• Calculate the mass of nickel in the sample using the ppb concentration: (20 ppb) × (2400 g) / (1 × 10^9) = 4.8 × 10^-5 g of nickel.
• Finally, we convert the mass of nickel into moles by using the molar mass of nickel. The molar mass of nickel (Ni) is approximately 58.69 g/mol. So the number of moles is: (4.8 × 10^-5 g) / (58.69 g/mol) = 8.18 × 10^-7 mol.

None of the options provided (a to d) are correct based on the calculation, so there seems to be a discrepancy in the given choices.