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Chemistry: Post your doubts here!

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Aoa, can someone help plz
 

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View attachment 54846
Why A?
CH4 has the maximum bond energy...

I think you have asked similar questions on this? This question is on intermolecular forces of attraction. HCl has the strongest intermolecular attraction (PD-PD) compared to the other options (VDW).


View attachment 54849
Why C? Why is it bad if ammonia is given off?

ammonium salt + base --> salt + water + ammonia

It is "bad" because, the nitrogen nutrient which is meant to be taken in by the plants is lost to the surroundings as ammonia gas.
 
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2qsm1dv.jpg

Why we dont count the two blue ones > they are tertiary?
 

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Given the following enthalpy changes,
I2(g) + 3Cl2(g) → 2ICl3(s) ∆Ho = –214kJ mol–1
I2(s) → I2(g) ∆Ho = +38 kJ mol–1
What is the standard enthalpy change of formation of iodine trichloride, ICl3(s)?

A +176kJ mol–1
B –88kJ mol–1
C –176kJ mol–1
D –214kJ mol–1

Correct answer is B.
 
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The Haber process for the manufacture of ammonia is represented by the following equation.
N2(g) + 3H2(g) 2NH3(g) ∆H = –92kJ mol–1
Which statement is correct about this reaction when the temperature is increased?

A Both forward and backward rates increase.
B The backward rate only increases.
C The forward rate only increases.
D There is no effect on the backward or forward rate.

Why is the correct answer A? The reaction in exothermic so by increasing the temperature, won't the backward reaction increase only?
 
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Use of the Data Booklet is relevant to this question.
2.920 g of a Group II metal, X, reacts with an excess of chlorine to form 5.287 g of a compound with formula XCl2.
What is metal X?
A barium
B calcium
C magnesium
D strontium

Correct answer is D.
 
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