Choose the false statement A 1 mole equals 6.02 x 1023 amu B 6.02 x 1023 atoms equals 1 mol of atoms C 6.02 x 1023 hydrogen atoms weigh 1.008 g D 1 mol of carbon atoms weighs 12.0 g E Fluorine is a di?

Answer 1

First off, you should try being a little more crafty when posting a question from a quiz/homework!

Second, (A) is definitely the false statement. One mole is equivalent to 6.02x1023 atoms or molecules. It's a measurement similar to "a dozen" because it only refers to the number of something, i.e. a dozen eggs and a dozen cows are two very different things except that there's 12 of them. So a mole of carbon is 6.02x1023 carbon atoms, and a mole of water is 6.02x1023 water molecules, even though a carbon atom and a water molecule weigh different amounts, are different in size, etc.

(A)"1 mole equals 6.02 x 1023 amu" - This would be like saying a dozen eggs equals twelve lbs. Like I said above, a mole is just a quantity of something, just a count, while an Atomic Mass unit (amu) is a measurment of mass (specifically the mass of one-twelve of a carbon atom, or more simply and less accurately the mass of a proton). This is the false statement.

(B) "6.02 x 1023 atoms equals 1 mol of atoms" - This is like saying "Twelve eggs is a dozen eggs". It's true.

(C) "6.02 x 1023 hydrogen atoms weigh 1.008 g" - Here's a cool thing about moles: One mole (specifically a "gram mole" if you're an engineer) of something has the mass of its elements in grams. Basically, one hydrogen atom weighs 1.008 amu, so if you use the same numner ("1.008") but instead of "amu" use "grams", that's the mass of a mole of hydrogen. It's a conversion you'll use non-stop in chemistry classes. So this statement is true.

(D) "1 mol of carbon atoms weighs 12.0 g" - Same as (c), one mole of something weights the atomic mass of that same something, but in grams.

(E) "Fluorine is a di" - I'm going to guess this was "Fluorine is a diatomic molecule" but was cut-off by the website. The answer to this is, yes, fluorine exists in its elemental form as a diatomic molecule (i.e. when you mention "fluorine" or "fluorine gas" it usually means F2). A good way to remember the diatomic molecules is: BrINClHOF (pronounced "brinkle-hoff"). Bromine (Br), Iodine (I), Nitrogen (N), Chlorine (Cl), Oxygen (O), and Fluorine (F) all exist as diatomic molecules "in the wild" so to speak.

Now get back to your quiz/homework!