Naturally occuring chlorine gas has 3 isotopes

35cl-35cl, 35cl-37cl , 37cl-37cl

a) mass of one molecule in terms of amu.
b) mass of one molecule in terms of grams.
c) mass of one mole in terms of grams.
d) Naturally occuring Cl has 75% 35cl and 25% 37cl, calculate the mass of one mole of cl(small 2) gas.

--I didn't really understood these as i am in prep chem and i guess my teacher is too stupid to understand that. He gave us this on first pop quiz when our first chapter was about conversions and basic stuff. Please help or get me started on this at least.

I'm sorry to hear that you're having trouble with this concept. I'll break it down step by step and explain each part for you.

a) To find the mass of one molecule of chlorine gas in atomic mass units (amu), we need to add up the masses of the individual isotopes. The atomic mass of an isotope is the sum of the number of protons and neutrons in its nucleus.

The mass of the two isotopes is given as follows:
- 35Cl-35Cl: 35 amu + 35 amu = 70 amu
- 35Cl-37Cl: 35 amu + 37 amu = 72 amu
- 37Cl-37Cl: 37 amu + 37 amu = 74 amu

b) To convert the mass of one molecule of chlorine gas from amu to grams, we need to use the molar mass constant (1 mole = 6.022 x 10^23 molecules) and Avogadro's number (6.022 x 10^23).

To find the molar mass of chlorine gas, we calculate the average mass based on the percent abundance of the isotopes. The given isotopic abundance is:
- 35Cl: 75%
- 37Cl: 25%

Now, we can calculate the average mass:
(0.75 * 35 amu) + (0.25 * 37 amu) = 35.5 amu

To convert from amu to grams, we use the conversion factor:
1 amu = 1.661 x 10^-24 grams

So, the mass of one molecule of chlorine gas in grams is:
35.5 amu * (1.661 x 10^-24 grams/1 amu) = 5.90 x 10^-23 grams

c) The mass of one mole of chlorine gas in grams is equal to the molar mass in grams. Therefore, the mass of one mole of chlorine gas is 35.5 grams.

d) To calculate the mass of one mole of chlorine gas, we multiply the molar mass by Avogadro's number (6.022 x 10^23 molecules/mol):
35.5 grams/mol * (6.022 x 10^23 molecules/mol) = 2.14 x 10^25 grams

I hope this explanation helps you understand the problem better. If you have any further questions, feel free to ask!