Lead is a heavy metal that remains in the bloodstream, causing mental retardation in children. It is believed that 3 x 10(-7)g of Pb in 1.00mL of blood is a health hazard. For this amount of lead..
a) how many atoms of lead are there in 1mL of a childs blood
b) How many moles of lead are in 1L of blood
2006-09-22 02:08:36 · 7 answers · asked by 11 2 in Science & Mathematics ➔ Chemistry
Use Avogadro's number and create a ratio
207.2 g /6.022 x 10^23 = 3 x 10^-7 g / N atoms
cross multiply to solve for N = 9 x 10^14 atoms in 1 mL
For part b)
multiply the number of atoms in 1 mL x 1000 to get the number in one liter.
Now set up another ratio
6.022 x 10^23 atoms / mole = 9 x 10^14 atoms / x moles
cross multiply to find that x = 1.5 x 10^-9
Look back through this to get your significant figures correct.
Aloha
2006-09-22 02:21:54 · answer #1 · answered by Anonymous · 1⤊ 0⤋
I assume that the questions mean to ask how much lead is in the blood of a child suffering from hazardous levels of lead content.
Pb has an atomic mass of 207.2 g/mol. So 6.022 x 10^23 atoms of lead weigh 207.2 g. We only have 3 x 10^-7 g in part a, so divide (3 x 10^-7 g/mol) / (207.2 g) to get a number of moles. Multiply by Avogadro's number to get a number of atoms.
For part b, take the number of moles you already found to be in 1 mL of blood. We need to know how many are in 1 L of blood. Just take (1 L / 1 mL), which should be trivial for you to compute, and multiply it by that previous result.
2006-09-22 02:16:50 · answer #2 · answered by DavidK93 7 · 0⤊ 0⤋
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2016-05-16 05:07:26 · answer #3 · answered by Anonymous · 0⤊ 0⤋
you take advantage of Avogadro volume it truly is 6.022 x 10^23 atoms for each 1mole of an ingredient. solutions: (a million.00 x 10^25 atoms) / (6.022 x 10^23) = X moles Magnesium (3.01 x 10^23 atoms sodium) / (6.022 x 10^23) = X moles sodium. (then convert X moles sodium to grams)
2016-11-23 14:56:26 · answer #4 · answered by marinaccio 4 · 0⤊ 0⤋
3 x 10 7th grams divided by the molecular wieght of lead ( find it on a periodic table) will give you the number of moles per ml; multiply by 1000 to get the number in alitre.
2006-09-22 02:16:17 · answer #5 · answered by woofwoof 1 · 0⤊ 0⤋
lead has an atomic mass of 207.2 g/mol. so in 1ml of blood we have (3x 10^-7)/207.2 moles of lead
One mol contains 6.022 x 10^23 atoms, so in one ml of blood we have:
3/207.2 x 6.022 x 10^23 x10^-7 =
8.72 x 10^14 atoms.
1L = 1000ml, so 1L contains 1000 x (3x 10^-7)/207.2 moles of lead = 1.45x 10^-6 moles
2006-09-22 02:15:56 · answer #6 · answered by robcraine 4 · 0⤊ 0⤋
check it here.
http://en.wikipedia.org/wiki/lead...
2006-09-23 01:35:42 · answer #7 · answered by Anonymous · 0⤊ 0⤋