Tuesday, January 24, 2012

Which of the following have the same number of atoms?a. 2 grams of lead and 2 grams of carbon, b. 2 moles of lead and 2 moles of carbon, c. 2 moles...

Science is not my specialty, but I think I have an answer
for you.  Based on what I understand about chemistry, the correct answer to your problem
would be: B.


Let's look at
why.


A) This answer cannot be correct.  Though 2 grams of
lead and 2 grams of carbon would weigh the same, they would not contain the same number
of atoms because they have different atomic weights.  Only 2 grams of the same elements
would have the same number of atoms.


C) This answer is not
correct because of the definition of "mole."  A mole is a specific number of atoms,
roughly 600,000 billiion billions.  A gram is a measure of weight, not
atoms.


D)  Same type of wrongness.  Both are using carbon,
but one is double the weight.  It couldn't have the same number of atoms and still be
twice as may grams.


That leaves us with B.  Because a mole
is a measure of the number of atoms, it doesn't matter that one is carbon and the other
is lead.  If you have one of each, you have the same number of atoms because a mole
isn't a measurement of weight.  One mole of "this" is the same as one mole of
"that."


Hope this makes sense!

No comments:

Post a Comment

Calculate tan(x-y), if sin x=1/2 and sin y=1/3. 0

We'll write the formula of the tangent of difference of 2 angles. tan (x-y) = (tan x - tan y)/(1 + tan x*tan y) ...