Edexcel CHEMISTRY DOUBTS!!!!

[Deadly_king]

Ya so it's because of the More shielding that's caused by the P-orbital ..Nice  

Thank u D

For Aluminium, it is the s-orbitals that shields the p-orbital since s-orbitals are smaller and closer to the nucleus.

Anytime  

[The Golden Girl =D]

Aha Okay

[The Golden Girl =D]

Suggest why copper compounds are hazardous     *Aslan they're hazardous :S *

[**RoRo**]

ok CH4 + 2O2----> CO2 + 2H2O
     10cm^3            10cm^3

C2H6 + 2.5 O2 -----> 2CO2 + 3H2O 
10cm^3                    20cm^3

in total 30 cm^3 CO2 was released which reacted with alkali         

Quote from: ashish on October 09, 2010, 01:39:58 PM
ok CH4 + 2O2----> CO2 + 2H2O
     10cm^3            10cm^3

C2H6 + 2.5 O2 -----> 2CO2 + 3H2O  
10cm^3                    20cm^3

in total 30 cm^3 CO2 was released which reacted with alkali          
Yeah......Ashish is right

From the 1st equation we note that :
1 mole of CH4 burns completely on oxygen to form 1 mole of CO2
I mole is equal to 24dm3 = 24000cm3
Therefore 24000cm3 of methane produces 24000cm3 CO2
Hence 10 cm3 of methane will produce 10cm3 of CO2

Same principle is applied for ethane  

Total volume absorbed : 30cm3

THANK YOU GUYS SO MUCH!!



Thank you so much & I apologize for the late reply!

[**RoRo**]

Hey guys, I got a couple of questions here, I grouped them all together to just post it all in one time! LOL

1. Explain why the melting temperature of sodium is much lower than that of magnesium [3 marks]

2. State the type of structure and the nature of the bonding in each of the following elements: [6 marks]
 i) aluminium
 ii) silicon
 iii) chlorine

3. a) Using sodium chloride, hydrogen chloride and copper, explain what is meant by covalent, ionic and metallic bonding. [9 marks]

   b) Compare and explain the conduction of electricity by sodium chloride and copper in terms of structure and bonding. [6 marks]

4. Give 5 advantages of alloys. [5 marks]

THANKS A LOT IN ADVANCE!

[Deadly_king]

Suggest why copper compounds are hazardous     *Aslan they're hazardous :S *

Hmm........i don't really know about it either

I don't think you need to know about this according to the syllabus.

Anyway to satisfy your curiosity try this :
http://www.scorecard.org/chemical-profiles/summary.tcl?edf_substance_id=CNK750

Hope it helps

[The Golden Girl =D]

Hmm........i don't really know about it either

I don't think you need to know about this according to the syllabus.

Anyway to satisfy your curiosity try this :
http://www.scorecard.org/chemical-profiles/summary.tcl?edf_substance_id=CNK750

Hope it helps

Yes i don't

satisfy my curiosity ? ..nah it came in the Quiz -__-

Anyways thx

[Deadly_king]

Hey guys, I got a couple of questions here, I grouped them all together to just post it all in one time! LOL

1. Explain why the melting temperature of sodium is much lower than that of magnesium [3 marks]

That has already been partially answered in this same thread. Take a look.  

Unfortunately.............I need to go for now. But i'll help once am back

Sorry for inconvenience.

[Deadly_king]

Yes i don't

satisfy my curiosity ? ..nah it came in the Quiz -__-

Anyways thx

Oops.......I did not mean to be mean

Sorry................i was not aware that it had something to do with your quiz

[The Golden Girl =D]

I can elp tho it'll take time :S

D --> I know u meant good ...I'm sorry i was being stupid there .

Talk to you later iA

[The Golden Girl =D]

Hey guys, I got a couple of questions here, I grouped them all together to just post it all in one time! LOL

1. Explain why the melting temperature of sodium is much lower than that of magnesium [3 marks]

Magnesium has got 2 PROTONS , hence more nuclear charge .and since thery are in the same period they have same shielding *numebr of shells * ...SO  electrons on the shells are ATTRACTED to the proton MORE than Sodium's electrons are *Na has less number of proton , remember *


2. State the type of structure and the nature of the bonding in each of the following elements: [6 marks]
 i) aluminium --> Bonding nature - METALLIC
 ii) silicon --> Boning nature - GIANT COVALENT BOND
 iii) chlorine --> bonding nature - SIMPLE MOLECULAR *of course covalent *

3. a) Using sodium chloride, hydrogen chloride and copper, explain what is meant by covalent, ionic and metallic bonding. [9 marks]

   b) Compare and explain the conduction of electricity by sodium chloride and copper in terms of structure and bonding. [6 marks]

4. Give 5 advantages of alloys. [5 marks]

THANKS A LOT IN ADVANCE!

That's what i got , my brain isn't working :S :S

[**RoRo**]

That has already been partially answered in this same thread. Take a look.  

Unfortunately.............I need to go for now. But i'll help once am back

Sorry for inconvenience.

Alright, I'll check that out!

& I'll be waiting for your replies!

No problem, its alright!

[**RoRo**]

Hey guys, I got a couple of questions here, I grouped them all together to just post it all in one time! LOL

1. Explain why the melting temperature of sodium is much lower than that of magnesium [3 marks]

Magnesium has got 2 PROTONS , hence more nuclear charge .and since thery are in the same period they have same shielding *numebr of shells * ...SO  electrons on the shells are ATTRACTED to the proton MORE than Sodium's electrons are *Na has less number of proton , remember  *

Magnesium has 24 PROTONS, but probably because when it's an ion it forms a +2 charge, it has a more positive charge compared to sodium which forms a +1 charge and hence, magnesium has a higher nuclear charge, so it'll attract more electrons, and hence more energy will be needed to break this force of attraction and hence, a higher melting temperature!

You just gave me an idea on how to write the answer!! Thank you!!

2. State the type of structure  and the nature of the bonding in each of the following elements: [6 marks]
 i) aluminium --> Bonding nature - METALLIC
 ii) silicon --> Boning nature - GIANT COVALENT BOND
 iii) chlorine --> bonding nature - SIMPLE MOLECULAR *of course covalent  *

I don't know what do they mean by "type of structure". It's a question from the textbook.

3. a) Using sodium chloride, hydrogen chloride and copper, explain what is meant by covalent, ionic and metallic bonding. [9 marks]

   b) Compare and explain the conduction of electricity by sodium chloride and copper in terms of structure and bonding. [6 marks]

4. Give 5 advantages of alloys. [5 marks]

THANKS A LOT IN ADVANCE!

Thank you for your help!!

[The Golden Girl =D]

np

[Deadly_king]

I can elp tho it'll take time :S

D --> I know u meant good ...I'm sorry i was being stupid there .

Talk to you later iA

No.......you were not being stupid. Actually I need to apologise since my words were quite offensive

Sorry again

Anyway seems you understood the trend of melting point across period 3 well
That was a 5 star explanation

No worries...............i'll take on the rest