This is a Hitskin.com skin preview
Install the skin • Return to the skin page
Someone Ask me AP Chem Questions
5 posters
Page 1 of 3
Page 1 of 3 • 1, 2, 3
Someone Ask me AP Chem Questions
Ehm...Lev
Also anyone can ask me Chem questions. Im a chemist after all
Also anyone can ask me Chem questions. Im a chemist after all
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
deduce the oxidation number of iodine in::
a) I2O7
b) IO3-
c) KIO4
d) Ba(IO2)2
a) I2O7
b) IO3-
c) KIO4
d) Ba(IO2)2
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
a)+7
b)+5
c)+7
d)+3
Harder please.
b)+5
c)+7
d)+3
Harder please.
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
eww i hate finding oxidation numbers
Fifi- NH Member
- Number of posts : 7932
Username Change Points : 13314
Reputation : 5
Registration date : 2009-11-11
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Methan can be trapped in water as solid methane hydrate, [CH4(H2O)6]. The reaction between methane gas and water to form methane hydrate is exothermic:
CH4(g) + 6H2O(l)<---> [CH4(H2O)6](s)
Huge quantities of methane hydrate are found at the bottom of the sea off the Canadian coast, where the pressure is very high.
a) Predict what would happen if the pressure on solid methane hydrate were predicted at 1 atm
b) Predict what would happen to methane hydrate if it were heated.
c) Predict what would happen if the methane hydrate crystals were brought to the surface of the sea, from the great depth of the Canadian coast.
======
<---> is my version of a reversible reaction by da way
CH4(g) + 6H2O(l)<---> [CH4(H2O)6](s)
Huge quantities of methane hydrate are found at the bottom of the sea off the Canadian coast, where the pressure is very high.
a) Predict what would happen if the pressure on solid methane hydrate were predicted at 1 atm
b) Predict what would happen to methane hydrate if it were heated.
c) Predict what would happen if the methane hydrate crystals were brought to the surface of the sea, from the great depth of the Canadian coast.
======
<---> is my version of a reversible reaction by da way
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
1-What do you mean by "...were predicted"?
2-It would become an anhydrate.
3-It would become gas
2-It would become an anhydrate.
3-It would become gas
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
soz "were reduced"
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Did I get 2 and 3 right?
1-It would become a gas
1-It would become a gas
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
ahmed, ur forgetting its a reversible reaction.. u gotta talk about equilibrium for a,b and c
have another shot at it..
have another shot at it..
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
I know it's at equib. That's why is aid it will become a gas (and water). If it wasn't at equib. it couldn't go back to being a gas.
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
kay..
a) There is 1 mol of gas on the left hand side of the equation and none on the right. By Le Chatelier's principal a decrease in pressure will cause the equilibrium to shift to the side with more gas molecules. This means that the methane hydrate will decompose and methane gas will be produced.
- so u get the mark for this Q... more detail would have been nice tho
b)The reaction written is exothermic. An increase in temperature will cause the equilibrium position to shift to the endothermic direction, therefore methane hydrate will be produced
- again u get the mark.. but u need detail in ur answer man
c)Raising the solid methane hydrate from the cold ocean floor means a decrease in pressure and an increase in temperature. This will result in methane hydrate decomposing into methane and water
- don't think u'll get marks for this one...
a) There is 1 mol of gas on the left hand side of the equation and none on the right. By Le Chatelier's principal a decrease in pressure will cause the equilibrium to shift to the side with more gas molecules. This means that the methane hydrate will decompose and methane gas will be produced.
- so u get the mark for this Q... more detail would have been nice tho
b)The reaction written is exothermic. An increase in temperature will cause the equilibrium position to shift to the endothermic direction, therefore methane hydrate will be produced
- again u get the mark.. but u need detail in ur answer man
c)Raising the solid methane hydrate from the cold ocean floor means a decrease in pressure and an increase in temperature. This will result in methane hydrate decomposing into methane and water
- don't think u'll get marks for this one...
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Yeah...I thought it wasn't neccessary to mention Le Charteir...it was implied.
Asfor C, I serislouy didn't get the Question then....
NEXT!
Asfor C, I serislouy didn't get the Question then....
NEXT!
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Explain why sulpher has a higher melting temperature than phosphorus, and why silicon has a much higher melting temperature than both sulpher and phosphorus
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Silicon has a higher MP than both becasue it is a metaloid.Whil the other two are nonmetals.
Phosphorous has a higher melting point because it has less nonmetalic character
Phosphorous has a higher melting point because it has less nonmetalic character
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
whats MP?
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Melting Point
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Both Sulpher and Phosphorus have simple molecular structures, with instantaneous induced dipole forces between the molecules.
Sulpher is S8 and so has more electrons in a molecule than does Phosphorus which is P4. This means that the dipole forces between the sulpher molecules are stronger than those between phosphorous molecules. Therefore mole energy is needed to separate them, this results to sulpher having a higher melting temperature than phosphorus.
Silicon has giant atomic structure with strong covalent bonds between the atoms. These have to be broken for silicon to melt and so a much higher temperature is required
Sulpher is S8 and so has more electrons in a molecule than does Phosphorus which is P4. This means that the dipole forces between the sulpher molecules are stronger than those between phosphorous molecules. Therefore mole energy is needed to separate them, this results to sulpher having a higher melting temperature than phosphorus.
Silicon has giant atomic structure with strong covalent bonds between the atoms. These have to be broken for silicon to melt and so a much higher temperature is required
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Covalent bonds are also between the P and S. You could have also explained that S is greater by london dispersion forces.
NEXT
NEXT
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
this ain't me answerin by the way.. its George Facer.. THE George Facer
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
I don't know that noob but Im also right
What happened to the next HARD Q...your Qs are waaaaay too easy Marwa
What happened to the next HARD Q...your Qs are waaaaay too easy Marwa
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
i'm going zzzz now... u can have another Q tomoz
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Aww, ok good night
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
A Thermometer is labelled as having an accuracy of "+ or -" 0.2 degrees Celsius.
In an energy of neutralisation reaction, the temperature before the reaction was 17.4 degrees Celsius and after the reaction was 24.5 degrees Celsius. The mass of the liquid was 100g. The specific heat capacity of the liquid is 4.18 /g C
Calculate the percentage error used by the thermometer and hence the error in the evaluation of the heat produced.
In an energy of neutralisation reaction, the temperature before the reaction was 17.4 degrees Celsius and after the reaction was 24.5 degrees Celsius. The mass of the liquid was 100g. The specific heat capacity of the liquid is 4.18 /g C
Calculate the percentage error used by the thermometer and hence the error in the evaluation of the heat produced.
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Re: Someone Ask me AP Chem Questions
Q=mCT
Q=(100g)(4.18/g C)(7.1 C)
Q=2967.8 kJ/mol
Q=(100g)(4.18 /g C)(7.3 C)
Q=3051.4 kJ/mol
Q=(100g)(4.18/g C)(6.9 C)
Q=2884.2 kJ/mol
(3051.4-2967.8 )/2967.8=2.82%
(2884.2-2967.8 )/2967.8=-2.82%
+/- 2.82%
Am I right?
NEXT QUESTION
Q=(100g)(4.18/g C)(7.1 C)
Q=2967.8 kJ/mol
Q=(100g)(4.18 /g C)(7.3 C)
Q=3051.4 kJ/mol
Q=(100g)(4.18/g C)(6.9 C)
Q=2884.2 kJ/mol
(3051.4-2967.8 )/2967.8=2.82%
(2884.2-2967.8 )/2967.8=-2.82%
+/- 2.82%
Am I right?
NEXT QUESTION
Ahmed- NH Admin
- Number of posts : 51452
Username Change Points : 61089
Reputation : 147
Registration date : 2007-10-14
Mood :
Country :
Re: Someone Ask me AP Chem Questions
have another stab at it...
The Banker- NH Member
- Number of posts : 15240
Username Change Points : 8501
Reputation : 24
Registration date : 2009-10-27
Mood :
Country :
Page 1 of 3 • 1, 2, 3
Similar topics
» Does anyone know where to get 2002 Ap chem questions?
» Chem Experiment-HELP PLEASE
» Chem Help!
» Chem help!!!!
» Chem help..... :O
» Chem Experiment-HELP PLEASE
» Chem Help!
» Chem help!!!!
» Chem help..... :O
Page 1 of 3
Permissions in this forum:
You cannot reply to topics in this forum
|
|