gen chem questios

[OU11BB]

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Im sure that these are easy problems but i missed them and not sure why?
1) The electronic configuration of a particular neutral atom is 1s2-2s2-2p6-3s2-3p2. What is the number of unpaired electrons in the atom?

Does neutral mean anything b/c i get Si which would have 2 unpaired electrons?

2) a 49 gram sample of sulfuric acid H2SO4 (98g mol^-1) contains
a 1 mol of s atom
b 16 grams of O
c 2 grams of H
d 2 moles of O atoms
e 1 mol of molecules

Im sure these are easy for all you out there busting 22+, but im stuck at a 15 and need to get easy stuff like this. any help is appreciated!

 

[tranv117]

Im sure that these are easy problems but i missed them and not sure why?
1) The electronic configuration of a particular neutral atom is 1s2-2s2-2p6-3s2-3p2. What is the number of unpaired electrons in the atom?

Does neutral mean anything b/c i get Si which would have 2 unpaired electrons?

2) a 49 gram sample of sulfuric acid H2SO4 (98g mol^-1) contains
a 1 mol of s atom
b 16 grams of O
c 2 grams of H
d 2 moles of O atoms
e 1 mol of molecules

Im sure these are easy for all you out there busting 22+, but im stuck at a 15 and need to get easy stuff like this. any help is appreciated!

1. should be 2 unpaired electrons. neutral just means an element at ground state.

2. D. 2 moles of oxygen. 49 gram sample of sulfuric acid is half a mole. since in 1 mole of sulfuric acid you have 4 mole oxygen, .5 of that is 2 mole oxygen.

 

[OU11BB]

For question 1 the answer key says 3 unpaired, so there must be an error. I thought it was 2 just wanted to double check. As far as the other one, well i feel like a real idiot. Thanks.

 

[ucla2134]

Im sure that these are easy problems but i missed them and not sure why?
1) The electronic configuration of a particular neutral atom is 1s2-2s2-2p6-3s2-3p2. What is the number of unpaired electrons in the atom?

Does neutral mean anything b/c i get Si which would have 2 unpaired electrons?

2) a 49 gram sample of sulfuric acid H2SO4 (98g mol^-1) contains
a 1 mol of s atom
b 16 grams of O
c 2 grams of H
d 2 moles of O atoms
e 1 mol of molecules

Im sure these are easy for all you out there busting 22+, but im stuck at a 15 and need to get easy stuff like this. any help is appreciated!

1/ is 2 unpair electrons. Neutral is Si atom,not ions.
2/ opps. it is d

 

[joonkimdds]

2) a 49 gram sample of sulfuric acid H2SO4 (98g mol^-1) contains
a 1 mol of s atom
b 16 grams of O
c 2 grams of H
d 2 moles of O atoms
e 1 mol of molecules

98g = 1 mol
thus 49g = 1/2 mol

1/2 mole of H2SO4 = 1/2 H2SO4 = 1H, 1/2S, 2O
a) 1 mol of S atom, no, we got half mol
b) 16 g of O, no we got 2 O thus 2 x 16 = 32g
c) 2 grams of H, no, we got 1 H so 1g
d) 2 moles of O atom, yes we got 2.
e) 1 mol of molecules, no we got 1/2 mole

am i right?

here is my question
how many mols are in O, 2O, 2O2 respectively?

 

[ucla2134]

98g = 1 mol
thus 49g = 1/2 mol

1/2 mole of H2SO4 = 1/2 H2SO4 = 1H, 1/2S, 2O
a) 1 mol of S atom, no, we got half mol
b) 16 g of O, no we got 2 O thus 2 x 16 = 32g
c) 2 grams of H, no, we got 1 H so 1g
d) 2 moles of O atom, yes we got 2.
e) 1 mol of molecules, no we got 1/2 mole

am i right?

here is my question
how many mols are in O, 2O, 2O2 respectively?

I think for O, it will be 1/2 mole. For 2O then will be 1 mole.
2O2, 4 mole. No??

 

[GCT]

Im sure that these are easy problems but i missed them and not sure why?
1) The electronic configuration of a particular neutral atom is 1s2-2s2-2p6-3s2-3p2. What is the number of unpaired electrons in the atom?

Does neutral mean anything b/c i get Si which would have 2 unpaired electrons?

2) a 49 gram sample of sulfuric acid H2SO4 (98g mol^-1) contains
a 1 mol of s atom
b 16 grams of O
c 2 grams of H
d 2 moles of O atoms
e 1 mol of molecules

Im sure these are easy for all you out there busting 22+, but im stuck at a 15 and need to get easy stuff like this. any help is appreciated!

For the first draw out the energy levels and fill them up according to the rules. For the second find the mole amount of sulfuric acid corresponding to the 49 gram value then use stoichiometry to figure the mole values for the constituent atoms.