11.

In chromatography, which of the following statements is INCORRECT for R_f ?

• R_f value depends on the type of chromatography

• R_f value is dependent on the mobile phase.

• Higher R_f value means higher adsoption

• The value of R_f can not be more than more.

A hydrated solid X on heating initially gives a monohydrated compound X,Y upon heating above 373 K leads to an anhydrous white powder Z , X and Z respectively are :

• Baking soda and dead burnt plaster.

• Baking soda and soda ash

• Washing soda and dead burnt plaster

• Washing soda and soda ash

Number of stereo centers present in linear and cyclic structures of glucose are respectively

• 5 & 5

• 4 & 4

• 5 & 4

• 4 & 5

The increasing order of nucleophilicity of the following nucleophiles is :

(a) CH₃CO₂^Θ  (b) H₂O  (c) CH₃SO₃^Θ  (d) ^ΘOH

• b < c < a < d

• a < d < c < b

• d < a < c < b

• b < c < d < a

The major product ‘Y’ in the following reaction is :

The correct statements among (a) to (d) are:

a) Saline hydrides produce H₂ gas when reacted with H₂O

b) Reaction of LiAlH₄ with BF₃ leads to B₂H₆

c) PH₃ and CH₄ are electrons- rich and electron- precise hydrides, respectively.

d) HF and CH₄ are called as molecular hydrides.

• a, b, c and d

• a, b and c only

• a, c and d only

• c and d only

The correct option among the following is :

• Colloidal particles in lyophobic sols can be precipitated by electrophoresis.

• Brownian motion in colloidal solution is faster if the viscosity of the solutions is very high.

• Addition of alum water makes it unfit for drinking.

• Colloidal medicines are more Effective because they have small surface area

Which of the following graphs between molar conductivity ∧_m versus √C is correct?

The minimum amount of O₂(g) consumed per gram of reactant is for the reaction :
(Given atomic mass : Fe = 56, O=16, Mg=24, P= 31, C=12, H=1)

• 2Mg(s) + O₂(g) → 2MgO (s)

• 4Fe(s) + 3O₂(g) → 2Fe₂O₃(s)

• P₄(s) + 5O₂(g) → P₄O₁₀(s)

• C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O (l)

The INCORRECT statement is :

• The gemstoe, ruby has Cr³⁺ ions occupying the octahedral sites of beryl

• The spin – only magnetic moments of [Fe(H₂O)₆]²⁺ and [Cr(H₂O)₆]²⁺ are nearly similar.

• The color of [CoCl(NH₃)₅]²⁺ is violet as it absorbs the yellow light.

• The spin only – magnetic moment of [Ni(NH₃)₄(H₂O₂)]²⁺ is 2.83 BM.