Uncertainty in the position of an electron (mass= 9.1 x 10^-31 kg) moving with a velocity 300 ms^-1 accurate upon 0.001 % will be (h = 6.63 x 10^-34 J-s)

• 19.2 x 10^-2 m

• 5.76 x 10^-2 m

• 1.92 x 10^-2 m

• 3.84 x 10^-2 m

An acid solution of pH = 6 is diluted 1000 times, the pH of the final solution becomes

• 6.01

• 9

• 3.5

• 6.99

When Zn is treated with excess of NaOH, the product obtained is

• Zn(OH)₂

• ZnOH

• Na₂ZnO₂

• None of the above

The common basic structural unit in silicates and silica is

• ${\mathrm{SiO}}_6^{4-}$

• ${\mathrm{SiO}}_3^{2-}$

• ${\mathrm{SiO}}_4^{4-}$

• ${\mathrm{Si}}_2{\mathrm{O}}_7^{6-}$

Which of the following species is an electrophile?

• H₂O

• NH₃

• C₂H₅OH

• SO₃

Which of the following compounds do not give different isomers on monochlorination?

• Neo-pentane

• n-butane

• Iso-butane

• Iso-pentane

34.2 g of cane sugar is dissolved in 180 g of water. The relative lowering of vapour pressure will be

• 0.0099

• 1.1597

• 0.840

• 0.9901

In a multistep reaction, the overall rate of reaction is equal to the

• rate of slowest step

• rate of fastest step

• average rate of various step

• the rate of last step

20.

According to Hess's law, the heat of reaction depends upon

• initial condition of reactants

• initial and final conditions of reactants

• intermediate path of the reaction

• end conditions of reactants