Wolframite ore is separated from tinstone by the process of________.

(a)

Smelting

(b)

Calcination

(c)

Roasting

(d)

Electromagnetic separation

The basic structural unit of silicates is _______.

(a)

\(\left( SiO_{ 3 } \right) ^{ 2- }\)

(b)

\(\left( SiO_{ 4 } \right) ^{ 2- }\)

(c)

\(\left( Sio \right) ^{ - }\)

(d)

\(\left( SiO_{ 4 } \right) ^{ 4- }\)

The molarity of given orthophosphoric acid solution is 2M. Its normality is _______.

(a)

6N

(b)

4N

(c)

2N

(d)

none of these

The magnetic moment of Mn²⁺ ion is _______.

(a)

5.92BM

(b)

2.80BM

(c)

8.95BM

(d)

3.90BM

IUPAC name of the complex K₃[Al(C₂O₄)₃] is _______.

(a)

potassium trioxalatoaluminium (III)

(b)

possium trioxalatoaluminate (II)

(c)

potassium trisoxalatoaluminate (III)

(d)

potassium trioxalatoaluminate (III)

The number of unit cells in 8 gm of an element X (atomic mass 40) which crystallizes in bcc pattern is (N_A is the Avogadro number)________.

(a)

6.023 x 10²³

(b)

6.023 x 10²²

(c)

60.23 x 10²³

(d)

\(\left( \frac { 6.023\times { 10 }^{ 23 } }{ 8\times 40 } \right) \)

The decomposition of phosphine (PH₃) on tungsten at low pressure is a first order reaction. It is because the _____.

(a)

rate is proportional to the surface coverage

(b)

rate is inversely proportional to the surface coverage

(c)

rate is independent of the surface coverage

(d)

rate of decomposition is slow

Which will make basic buffer?

(a)

50 mL of 0.1M NaOH+25mL of 0.1M CH₃COOH

(b)

100 mL of 0.1M CH₃COOH+100 mL of 0.1M NH₄OH

(c)

100 mL of 0.1M HCl+200 mL of 0.1M NH₄OH

(d)

100 mL of 0.1M HCl+100 mL of 0.1M NaOH

Electrolyte	KCl	KNO3	HCl	NaOAC	NaCl
Λ- (Scm2 mol-1)	149.9	145.0	426.2	91.0	126.5

Calculate Λ^o_HoAC using appropriate molar conductances of the electrolytes listed above at infinite dilution in water at 25^oC_______.

(a)

517.2

(b)

552.7

(c)

390.7

(d)

217.5

Statement : To stop bleeding from an injury, ferric chloride can be applied. Which comment about the statement is justified?

(a)

It is not true, ferric chloride is a poison.

(b)

It is true, Fe³⁺ ions coagulate blood which is a negatively charged sol

(c)

It is not true; ferric chloride is ionic and gets into the blood stream.

(d)

It is true, coagulation takes place because of formation of negatively charged sol with Cl^-.