MAJOR DOUBT IN CHEM

[The Ultimate]

1) Give two ways by which carbon dioxide is removed naturally fro the atmosphere.
Photosynthesis and..........?

2) This was in the syllabus but i didn't understand it. Could somebody explain?
"Describe the differences in volatility, solubility and electrical conductivity betweem ionic and covalent compounds." :?

3) What are some uses of electroplating?

:roll:

 

[XPFMember]

Assalamoalaikum wa rehmatullah!Let me see if I can help u!

1) Give two ways by which carbon dioxide is removed naturally fro the atmosphere.
Photosynthesis and..........?

dont know,as far as i know,its only photosynthesis which removes CO2

2) This was in the syllabus but i didn't understand it. Could somebody explain?
"Describe the differences in volatility, solubility and electrical conductivity betweem ionic and covalent compounds."

Volatility:
Ionic=>High melting and boiling points because ions are held together by strong forces.
Covalent=>Low melting and boiling points bcoz intermolecular forces r weak.
Solubility:
IOnic=>soluble in water but insoluble in organic solvents like ethanol.
Covalent=>mostly insoluble in water but soluble in organic solvents
Electrical conductivity:
Ionic=>conduct when molten or dissolved in water coz the ions r free to move.Do not conduct when solids coz ions cant move.
Covalent:do not cont conduct since they r molecules and have no ions.(some may conduct when aqueous since they form ions when react with water eg. hydrogen chloride.

3) What are some uses of electroplating?

I think u mean reasons!Electroplating is done to give an object a good appearance.Also it is done to prevent from corrosion!!

Hope this helps,if any doubt,let me know,I will help if I can!
JazakAllah Khair!

 

[niassu]

salam alaikom,
plz i would like to know if the topic of production of energy :
1-describe the production of heat energy by burning fuels
2-describe the use of hydrogen as a potential fuel reacting with oxygen to generate elect. in a fuel cell
what do they want us to know about those above?

 

[XPFMember]

waalaikumassalam

1-describe the production of heat energy by burning fuels

in my notes it says that "the most common way of producing heat energy is by burning fossil fuels like natural gas,coal nd petroleum products."

2-describe the use of hydrogen as a potential fuel reacting with oxygen to generate elect. in a fuel cell

I will tell u later InshAllah,cuz i didnt read about fuel cells cuz that was a new topic in the syllabus so we didnt take at school,so let me read abt. that and then i will tell u as soon as possible,InshAllah!!

 

[niassu]

yeah but the syllabus said no need for details ???!!!!
I just wanted to know what he wanted.?

 

[niassu]

can u see Q 2 IN paper3 nov 2005 aiii
Q62004 nov bi
2004may Q4 b(ii)(iii) hard question
2003may Q3 Dii

I am really very sorry for all my tough question but i know that Allah will give u goodnesses for this help
thnx alot Jazak ALLAH kairan

 

[XPFMember]

dont go anywhere ,i will just see them and help u as soon as possible!And Aameen for ur prayer ,may Allah bless u too,and may u acheive ur good goals in life!!

 

[XPFMember]

Q 2 IN paper3 nov 2005 aiii

You just have to extend the line cuz heating will cause an increase in the temp.!

Q62004 nov bi

___(__CO__C6H4___CO__O__CH2CH2___O___)n___

2004may Q4 b(ii)(iii)

b(ii) it will be above tat line and will require less NaOH until the height is same(horizontal line)since with iron(III) 1 mole of iron requires 3 OH but only 2 with iron(II) [just find the formula to understand!]so less vol. will be required!
b (iii) it will increase then decrease to zero.
reason-aluminium hyroxide is amphoteric so it will dissolve in the excess to form a soluble salt

2003may Q3 Dii

its impossible to draw the structure here but u try urself: C=C will change to __(__C__C__)n___
rest all will be as it is
hope this clears ur doubt!
JazakAllah Khair

 

[SuperXDE]

Wa Alikum Assalamu Wa Rahmatullahi Wa Barakatuh , May Peace , Mercy and Blessings of Allah ( refer to my signature if you don't know what Allah means ) be upon you

1) Give two ways by which carbon dioxide is removed naturally fro the atmosphere.
Photosynthesis and..........?

2) This was in the syllabus but i didn't understand it. Could somebody explain?
"Describe the differences in volatility, solubility and electrical conductivity betweem ionic and covalent compounds." :?

3) What are some uses of electroplating?

:roll:

Carbon Dioxide ( CO2 ) is removed by Photosynthesis , Vegetation and by dissolution in Oceans.

As for Question 2 , Math Angel has explained it all..

As for Question 3 , Electroplating is used in plating Tools ( Usually metals ) with other metals , Like Spoons plated with Silver , Plates , etc.... And if you want another use , there is Water Taps which are electroplated to avoid rust on the tap , and to give it a decorating look by plating it with chromium.

salam alaikom,
plz i would like to know if the topic of production of energy :
1-describe the production of heat energy by burning fuels
2-describe the use of hydrogen as a potential fuel reacting with oxygen to generate elect. in a fuel cell
what do they want us to know about those above?

As for 1. Make sure you know about the Heat of Reaction and its relation with Exothermic and Endothermic reactions , The more Exothermic the Fuel is the more heat energy produced.
2. That you know about the Hydrogen Fuel Cell , the 2 Electrodes , Platinum Catalysts , Electrolyte , H2 and O2 in , H2O and Energy are produced ..... or something like that , ¬¬"
and don't forget that something happens with hydrogen calls Fusion , which gives too much energy like at sun's core , remember that , the whole process is based on it.
And in the end ...Just skim read them in the book and make sure that you have an idea about the process , Enough to speak about it in a nice way it is a Theory paper after all.

May Allah bless us all , The Successful is the one who is supported by Allah , And our success is nothing without Allah's help , Jazaakom Allahu Khairan.



I am so sleepy -_-"

 

[XPFMember]

May Allah bless us all , The Successful is the one who is supported by Allah , And our success is nothing without Allah's help , Jazaakom Allahu Khairan.

Yes,absolutely right!! May Allah support us all in our good intentions,and may we follow the right path and fulfil the purpose of life in its correct meanings.Aameen!!

 

[niassu]

then plz what is the process of fusion that ????!!
and thnx alot but i need to know for the question about may 2004 Q4ii
why is the graph of ironii is above the other although it reacts with less volume of sodium hydroxide.

 

[SuperXDE]

then plz what is the process of fusion that ????!!
and thnx alot but i need to know for the question about may 2004 Q4ii
why is the graph of ironii is above the other although it reacts with less volume of sodium hydroxide.

The process of fusion is when Hydrogen atoms are fused together to produce helium , it produces to much energy ( the sun ) ... I believe it was in our Physics Syllabus

As for the Question mentioned , May 2004 Q4ii

I think the answer would be like this Pb(NO3)2 + 2 NaCl --> PbCl2 + 2NaNO3

As for the Graph question ... I don't know -_-" but it is related to the concentration thing , else it wouldn't have been mentioned in the question.

Hope I helped.