HALLO GYS HOW WAS THE CHEMISTRY PAPER? (5070)

[Sharukh khan]

HI GAYS HOW WAS THE CHEMISTRY THEORY PAPER TODAY( 5070)

 

[Sharukh khan]

DISCUSS ALL THE QUESTION HERE !

 

[thementor]

it was easy, well easy compared to june

 

[Sharukh khan]

it was easy, well easy compared to june

what was the answer of last question?

 

[thementor]

what was the answer of last question?

The last question had four or five parts, which part u talking about

 

[Sharukh khan]

The last question had four or five parts, which part u talking about

ETHENE REACTS WITH WATER TO FORM ETHANOL
C2H4 + H2O <==> C2H5OH ONLY 5% OF ETHENE COVERT TO FORM ETHANOL. 0.4 TONNES OF ETHENE REACT WITH WATER OR STEAM TO FORM ETHANOL WHAT IS THE MASS OF ETHANOL PRODUCE?
SOTHING LIKE THAT!

 

[thementor]

ETHENE REACTS WITH WATER TO FORM ETHANOL
C2H4 + H2O <==> C2H5OH ONLY 5% OF ETHENE COVERT TO FORM ETHANOL. 0.4 TONNES OF ETHENE REACT WITH WATER OR STEAM TO FORM ETHANOL WHAT IS THE MASS OF ETHANOL PRODUCE?
SOTHING LIKE THAT!

that was the second question of section B.
the one where we had to calculate the mass of ethanol produced right.
yeah that answer was : 0.02 tonnes of ethanol formed
since Mr = 28
1 mole of ethene = 28 g
but only 5% of ethene is converted to ethanol so 1.4g of ethanol produced
0.4 tonnes of ethene = 0.4*1000000 = 400,000g
so if 28g of ethene gives 1.4 g of ethanol
so 400,000g of ethene will give (400,000 * 1.4)/28 = 20,000g
which is 20,000/1000000 = 0.02 tonnes

 

[Sharukh khan]

GOOD

AND WHAT WAS THE ANSWSERS OF THESE QUESTION:
Q:WHY NITROGEN LOSS WHEN CALCIUM HYDROXIDE ADDED TO SOIL< SOMTHING LIKE THAT(SECTION B)
Q:ALMUNIUM IS HIGHER IN THE REACTIVITY SERIES THEN WHY IT DO NOT REACT WITH COPPER (II) SULFETE (SECTION B)

 

[Knightmare11]

GOOD

AND WHAT WAS THE ANSWSERS OF THESE QUESTION:
Q:WHY NITROGEN LOSS WHEN CALCIUM HYDROXIDE ADDED TO SOIL< SOMTHING LIKE THAT(SECTION B)
Q:ALMUNIUM IS HIGHER IN THE REACTIVITY SERIES THEN WHY IT DO NOT REACT WITH COPPER (II) SULFETE (SECTION B)

Hi!

Nitogen is lost as Ca(OH)2 is alkaline and (NH4)2SO4 is a salt.. As we know Alkali + Ammonium Salt --> Salt + Ammonia + Water, we see that gaseous ammonia is released. Ammonia is a nitrogen containing compound and escapes as a gas.

Alumium does not react due to an impervious layer of Aluminium Oxide. This prevents contact and hence, no reaction occurs.

 

[thementor]

GOOD

AND WHAT WAS THE ANSWSERS OF THESE QUESTION:
Q:WHY NITROGEN LOSS WHEN CALCIUM HYDROXIDE ADDED TO SOIL< SOMTHING LIKE THAT(SECTION B)
Q:ALMUNIUM IS HIGHER IN THE REACTIVITY SERIES THEN WHY IT DO NOT REACT WITH COPPER (II) SULFETE (SECTION B)

Calcium hydroxide is a base added to the soil to neutralise acidity. But when ammonium sulphate is also present, they will react to produce ammonia which will escape as a gas.
and for the second. Aluminium reacts with oxygen in air to form a thin tough coat of aluminum oxide which does not flake off and acts a barrier preventing any further reactions.

 

[Sharukh khan]

Hi!

Nitogen is lost as Ca(OH)2 is alkaline and (NH4)2SO4 is a salt.. As we know Alkali + Ammonium Salt --> Salt + Ammonia + Water, we see that gaseous ammonia is released. Ammonia is a nitrogen containing compound and escapes as a gas.

Alumium does not react due to an impervious layer of Aluminium Oxide. This prevents contact and hence, no reaction occurs.

 

[Sharukh khan]

Calcium hydroxide is a base added to the soil to neutralise acidity. But when ammonium sulphate is also present, they will react to produce ammonia which will escape as a gas.
and for the second. Aluminium reacts with oxygen in air to form a thin tough coat of aluminum oxide which does not flake off and acts a barrier preventing any further reactions.

BUT I DIDNT WRITTEN THE WHOLE STORY BCZ I THINK IT CONTAIN ONLY TWO MARKS IF IAM NOT WRONG I HAVE WRITTEN : CALCIUM HYDROXIDE IS AN ALIKALI IT REACTS WITH AMMONIUM SALT (AMMONIUM SULPHATE) THAT PRODUCES AMMONIA GAS DUE TO WHICH NITRIGEN IS LOSS ! IS IT OK OR NOT?

 

[Knightmare11]

Yep, it's okay The mark is "ammonia - nitrogen containing'


Btw, you should turn Caps off and edit the first post lol.

 

[Sharukh khan]

Yep, it's okay The mark is "ammonia - nitrogen containing'


Btw, you should turn Caps off and edit the first post lol.

 

[Sharukh khan]

PLZ TELL ME WILL YOU GIVE BIO PAPER AND TELL THE THE TIMING OF YOUR PAPER ITS ON MORNING OR AT AFTERNOON?

 

[thementor]

BUT I DIDNT WRITTEN THE WHOLE STORY BCZ I THINK IT CONTAIN ONLY TWO MARKS IF IAM NOT WRONG I HAVE WRITTEN : CALCIUM HYDROXIDE IS AN ALIKALI IT REACTS WITH AMMONIUM SALT (AMMONIUM SULPHATE) THAT PRODUCES AMMONIA GAS DUE TO WHICH NITRIGEN IS LOSS ! IS IT OK OR NOT?

The marking scheme only needs "produce ammonia", "after reaction with calcium hydroxide", "ammonia escapes (gas)"
Your answer would get full marks

 

[Knightmare11]

I don't do Biology

PLZ TELL ME WILL YOU GIVE BIO PAPER AND TELL THE THE TIMING OF YOUR PAPER ITS ON MORNING OR AT AFTERNOON?

 

[Knightmare11]

I don't do Biology

PLZ TELL ME WILL YOU GIVE BIO PAPER AND TELL THE THE TIMING OF YOUR PAPER ITS ON MORNING OR AT AFTERNOON?

 

[Yazka Shathir]

So good |:
What was the product of the reaction NH3 + H2SO4. ( NH4 )2SO4 only? Or water too?

 

[Knightmare11]

So good |:
What was the product of the reaction NH3 + H2SO4. ( NH4 )2SO4 only? Or water too?

Only this.. else you cannot balance

This is because on the left hand side there is 1 sulfur and 4 oxygen.. ON the right hand side, 1 Sulfur and 4 Oxygen. With the addition of Water (H2O), there are 1 Sulfur and % oxygen on the r.h.s

This implies 1s + 4o = 1s + 5o , you cannot balance