VITEEE 2018 :: Chemistry :: General questions

• Chemistry - General questions

Which one of the following statements is correct?

Answer:

Explanation:

With the exception of glycine all the 19 other common amino acids have a uniquely different functional group on the central tetrahedral alpha carbon.

Given that the equilibrium constant for the reaction $2SO_{2}+ O_{2}\rightleftharpoons 2SO_{3}$ has a value of 278 at a particular temperature. What is the value of the equilibrium constant for the following reaction at the same temperature?

$SO_{3} \rightleftharpoons SO_{2} + 1/2O_{2}$

Answer:

Explanation:

$2SO_{2}+ O_{2}\rightleftharpoons 2SO_{3}$ K = 278 (given)

$SO_{3} \rightleftharpoons SO_{2} + 1/2O_{2}$ K' = $\left(\sqrt{\frac{1}{K}}\right)$

= $\left(\sqrt{\frac{1}{278}}\right)$ =$\sqrt{35.97\times10^{-4}}=6\times10^{-2}$

The following carbohydrate is

Answer:

Explanation:

It is a β-pyranose hence it is an aldohexose

The values of ΔH and ΔS for the reaction' C(graphite) + CO₂ (g) → 2CO(g) are 170 kJ and 170 JK^-1, respectively. This reaction will be spontaneous at

Answer:

Explanation:

ΔG = ΔH - TΔS

At equilibrium,ΔG = 0

→ 0 = (170 x 10³ J) - T (170 JK^-1)

→ T =1000 K

For spontaneity, ΔG is - ve, which is possible only if T > 1000 K.

The correct order of the thermal stability of hydrogen halides (H-X) is

Answer:

Explanation:

The H-X bond strength decreases from HF to HI. i.e. HF > HCl > HBr > HI. Thus HF is most stable while HI is least stable. The decreasing stability of the hydrogen halide is also reflected in the values of dissociation energy of the H-X bond

H-F                   H-Cl                  H-Br              H-I

135kcal mol^-1 103kcal mol^-1  87kcal mol^-1   71kcal mol^-1

• Chemistry - General questions