Chemistry 3a Test 2

fluorine is a diatomic molecule so multiply by 2. (2)(1.50 mol)(6.02x10^23 atoms/mol) = 1.81x10^24 atoms

5.80 mol He * 6.022*10^23 atoms He/ 1 mol He. This cancels out moles, leaving 3.49*10^24 atoms He.

true

false

When you are discussing oxygen as the free, uncombined element, then you are discussing oxygen gas, the formula of which is O2 and the molecular weight of which is 32. (which, as you well know, comes from 16 x 2).

44.01

342.2 g/mol

96.09 g/mol

9

false

true

2 moles of nitrogen

4moles hydrogen 2 moles of oxygen 2 moles of nitrogen

4 moles oxygen

3.5 1 mole of CaCO3 contains one mole of Calcium, one mole of Carbon, and 3 moles of Oxygen. the subscripts indicate the number of moles. so if you have 3.5 moles of CaCO3, then you also have 3.5 moles of C

Calcium Nitrate is Ca(NO3)2. = (1 x Ca40) + (2 x N14) + (6 x O16) = 164grams per mole (164g/mol).

5.87x10^(23) Molar mass SO3 = 32.066+(15.99*3) = 80.036g/mol 78.0/80.036*6.022*10^23 = 5.86*10^23 molecules.

XeF6 is Xenon hexafluoride.... 6 atoms F per 1 molecule XeF6.. right? 6 moles F per 1 mole XeF6 so that... 3.2 moles XeF6 x (6 mole F / 1 mole XeF6) = 19.2 moles F

False

False

False

False

1s2 2s2 2p6

Krypton