Writing Formulas

  • Thread starter Quincy
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  • #1
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Homework Statement


Write the formula for Ammonium Sulfide


Homework Equations


NH4^+ = ammonium

S^2- = Sulfur

The Attempt at a Solution



NH4^+2S
 

Answers and Replies

  • #2
CompuChip
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How many of each do you need to get something neutral?
Does 1 NH4 and 2 S have total charge 0?
 
  • #3
Borek
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Quincy: final formula won't have charge inside. Could be you did OK, but ^+ are of no use here.

Try to format your formula properly using [ sub][ /sub] and [ sup][ /sup] tags (without spaces):

NH[ sub]4[ /sub][ sup]+[ /sup] = NH4+
 
  • #4
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Homework Statement


Calculate the percentage composition of Silver (I) Oxide

Silver's atomic mass: 107.87

Oxygen's atomic mass: 16

The Attempt at a Solution



Molecular mass: 123.87

(107.87/123.87) * 100 = 87.08% = Percent composition for Silver

(16/123.87) * 100 = 12.92% = Percent composition for Oxygen
 
  • #5
Borek
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You are half OK and half wrong. Approach is correct, but molar mass is wrong.

What is formula of the silver (I) oxide?
 
  • #6
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You are half OK and half wrong. Approach is correct, but molar mass is wrong.

What is formula of the silver (I) oxide?
Ag2O?
 
  • #7
Borek
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Yes, so what is the molar mass?
 
  • #8
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molar mass = 231.74?

percent comp of Silver = (215.74/231.74) * 100 = 93.10%?

percent comp of Oxygen = (16/231.74) * 100 = 6.90%?
 
  • #9
Borek
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3*ok
 
  • #10
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P4S10 -- Phosphorus Sulfide?
Hg2O2 -- Mercury Oxide? -- and shouldn't the formula be HgO?...
 
  • #11
Borek
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Check phosphorus sulfide article in wikipedia. Your answer is correct, but reality is much more complicated.

If Hg2O2 is HgO, same trick should be done to P4O10, converting it to P2O5. However, we know for sure that single molecule of these compounds is larger then its experimental formula shows.
 

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