Monel metal is a corrosion-resistant copper-nickel alloy used in the electronics industry. A particular alloy with a density of 8.80 g/cm3 and containing 0.073% Si by mass is used to make a rectangular plate that is 15.0 cm long, 12.5 cm wide, and 2.50mm thick and has a 2.50-cm-diameter hole drilled through its center such that the height of the hole is 2.50mm.

The silicon in the plate is a mixture of naturally occurring isotopes. One of the those isotopes is silicon-30, which has an atomic mass of 29.97376 amu and a percent natural abundance of 3.10%

How many silicon-30 atoms are found in this plate?

Express your answer numerically using two significant figures.

Question

Rapunzel

Chemistry

27 October, 08:47

Monel metal is a corrosion-resistant copper-nickel alloy used in the electronics industry. A particular alloy with a density of 8.80 g/cm3 and containing 0.073% Si by mass is used to make a rectangular plate that is 15.0 cm long, 12.5 cm wide, and 2.50mm thick and has a 2.50-cm-diameter hole drilled through its center such that the height of the hole is 2.50mm.

The silicon in the plate is a mixture of naturally occurring isotopes. One of the those isotopes is silicon-30, which has an atomic mass of 29.97376 amu and a percent natural abundance of 3.10%

How many silicon-30 atoms are found in this plate?

Express your answer numerically using two significant figures.

+2

Answers (1)

Know the Answer?

William Kaufman · Answer 1

For the answer to the question above, let us use this formula for finding density.

density = mass / volume

volume = (15.0 cm) * (12.5 cm) * (0.45 cm) = 84.375 cm^3

8.80 grams/cm^3 = mass / 84.375 cm^3

mass = 742.5 grams alloy

mass of Si in alloy = (742.5 grams alloy) * (0.00041) = 0.304 grams Si

mass of Si-30 = (0.304 grams Si in metal) * (0.0310) = 0.009424 grams Si-30

atoms Si-30 = (0.009424 grams Si-30) * (1 mol Si-30 / 29.97376 grams Si-30) * (6.02*10^23 atoms Si-30 / 1 mol Si-30) =

The answer is

1.893*10^20 atoms Si-30