ICSE − Q & A

Which salt never react wid H2So4

Is gas laws in the syllabus

Highest electron affinity ??Chlorine or Flourine 
my ans is chlorine (i think this is an exception)

is metallurgy of iron [blast furnace] there in syllabus ?

Hello everyone!
I must say many people made my life hell here on respaper. 
What have you to do with my name? Are you me or am I you!?
Also, messages regarding nameand stuff?
Do you not know how to behave on Internet sites like respaper or is your mind devoid of all wit?
PLEASE stop troubling me and stop Trolling!
Concentrate on your result, future, ICSE !
LIVE AND LET LIVE!
THESE ANNOYING NOTIFICATIONS CONSTANTLY BADGER ME!
THIS IS  Q AND A page.
I.come here to answer questions and not to engage in wars with all of you.

At the same time do learn something from people like Tanisha, Heisenberg, Nishant,@booksboozer here !

Stop Troubling and irritating me and tunng my life hell.
I m trying my best to score a decent Percentage in ICSE boards, you should do the same!!!!!!

WHAT IS CHLORINE WATER + SULPHUR DIOXIDE

Can anyone pls gve me the ans of this MCQ- What happens when potassium iodide solution is added to lead nitrate solution?
 
1. 		Curdy white precipitate is formed.
2. 		Yellow precipitate is formed.
3. 		Gelatinous white precipitate, which dissolves in excess of potassium iodide is formed.
4. 		Black precipitate is formed.

How can we compare the stability of compunds of an element? (For example if Hydrogen and Na are present with oxygen. Will it combine with Na or H and why?)

in concise chemistry pg:98 electrolysis of nacl  at the cathode hydrogen is dischared  but there is high concentration of na+ than h+
please can anyone explain the reason

So many people are having doubts here!
I will frequently upload interesting questions and chapter wise analysis so you know what to learn.
I will start of with basic chemistry:
Equations.
1)
Do not mug them up. Just don't. You will mess up.
Understand equations. Understand their products. Learn balancing (use youtube for reference).
Suppose the reaction of HCl (conc) and K2Cr2O7 (acidified) is asked.
Understand what happens with reaction with conc HCl. Metallic chloride, chlorine gas and water is formed. Now K2Cr2O7 has two metals so 2 metallic chloride will be formed. KCl and CrCl3. Now as all water and oxygen will be used up to prepare water, number od HCl molecules = 2x the number of oxygen atoms.
Hence we have 14 HCl.
We have 2 K, so 2KCl will be formed.
We have 2 Cr, so 2CrCl3 will be formed.
This leaves 10Cl atoms = 5Cl2.
If you understand equations and know products, you can form any equation you want, even if you dont remember balancing or haven't learnt it.

2) Do not forget to write concentrated , dilute, acidified, alkaline or alcoholic. These carry 1/2 marks. the conditions I.e. temperate, pressure, catalyst, promoter. Remember if an equation is reversible or not. Remember if reaction is exothermic or endothermic. If it is the former, make a triangle ∆ with the products. If it is latter, make a triangle ∆ on the arrow.
That's all from this. Respond if you have a doubt regarding equations. I'll post chapter 1 and 2 analysis in the morning.