chem p1 doubts

[aliiiiiiiiii]

hi every 1 if u have any doubts post them here and ill help u

 

[Alool]

I don't know what to do now..i solved all the years from 2002 to 2011..but i still have a feeling that I'm not ready for the exam.. help?

 

[aliiiiiiiiii]

I don't know what to do now..i solved all the years from 2002 to 2011..but i still have a feeling that I'm not ready for the exam.. help?

well revise the tests and try to do 1999 to 2002 too because my experience with physics p1,many Q's came from 2000 to 2005 and if ur free revise the book like fast revision!!​

 

[ztabk95]

is the acid concentration affected by adding water ???

 

[sammm]

WHY pH doesnot change when NaCl is added to water???

 

[sammm]

in O/N ques.8 .How the ans. can be D??

 

[aliiiiiiiiii]

is the acid concentration affected by adding water ???

ya when u add more water the more its not concentrated it becomes dalute

 

[aliiiiiiiiii]

in O/N ques.8 .How the ans. can be D??

which year

 

[aliiiiiiiiii]

is the acid concentration affected by adding water ???

it doesnt because a salt made of stong acid and alkali like NaCl will form nutral solutions.

 

[Gunner7]

WHY pH doesnot change when NaCl is added to water???

NaCl is a salt which have a pH 7, all salts have pH 7 and so does water, so adding neutral substance to a neutral substance doesn't affect pH

 

[sammm]

o/n 10

which year

 

[sammm]

n in o/n 11 .How can we easil
y predict the ans of ques31 as B .plz tell me a method to do this.

 

[sammm]

in o/n 11 how the ans of ques4 isD??

 

[Alool]

n in o/n 11 .How can we easil
y predict the ans of ques31 as B .plz tell me a method to do this.

which variant?

 

[sammm]

1

 

[sammm]

r u sure that all salts have pH 7

 

[MTH]

r u sure that all salts have pH 7

Yes all salts have pH 7

 

[angel G]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdf
Please explain Q 4 and Q 23 !!

 

[MTH]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdf
Please explain Q 4 and Q 23 !!

If I'm not wrong, the answer is "A" right ?? (in Q 4)

For the explanation,
Student 1 : if you take the electron number of magnesium plus with 8 you will get calcium which is in the same group with Mg.
Student 2 : if you take the electron number of nickle plus with 8, you will get Krypton which is a noble gas. That means it's unreactive.


Question 23 : To get Copper chloride, you can use both Base ans carbonate to react with HCl but you can't use metal as copper is less reactive than hydrogen.

 

[angel G]

If I'm not wrong, the answer is "A" right ?? (in Q 4)

For the explanation,
Student 1 : if you take the electron number of magnesium plus with 8 you will get calcium which is in the same group with Mg.
Student 2 : if you take the electron number of nickle plus with 8, you will get Krypton which is a noble gas. That means it's unreactive.


Question 23 : To get Copper chloride, you can use both Base ans carbonate to react with HCl but you can't use metal as copper is less reactive than hydrogen.

Yes it is A !
Thank you !!