11.

Assume that you are travelling at a speed of 90 km/h in a small car with a mass of 1050 kg. If the uncertainty in the velocity of the car is 1% ($∆$ = 0.9 km/h), what is the uncertainty (in meters) in the position of the car ?

• $∆\mathrm{x} \ge 1\times {10}^{-35}\mathrm{m}$

• $∆\mathrm{x} \ge 2 \times {10}^{-37}\mathrm{m}$

• $∆\mathrm{x} \ge 2\times {10}^{-36} \mathrm{m}$

• $∆\mathrm{x} \ge 4 \times {10}^{-38}\mathrm{m}$

When 25 g of Na₂SO₄ is dissolved in 10 kg of solution, its concentration will be

• 2.5 ppm

• 25 ppm

• 250 ppm 

• 100 ppm

Stomach acid, a dilute solution of HCl in water,can be neutralized by reaction with sodium hydrogen carbonate,

${\mathrm{NaHCO}}_{3_{\left(\mathrm{aq}\right)}}+ {\mathrm{HCl}}_{\left(\mathrm{aq}\right)}\to {\mathrm{NaCl}}_{\left(\mathrm{aq}\right)} + {\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)} + {\mathrm{CO}}_{2\left(\mathrm{g}\right)}$

How many milliliters of 0.125 M NaHCO₂ solution are needed to neutralize 18.0 mL of 0. 100 M HCl?

• 14.4 ml

• 12.0 mL

• 14.0 mL

• 13.2 ml

Assertion : The equilibrium constant is fixed and a characteristic for any given chemical reaction at a specified temperature.

Reason: The composition ofthe final equilibrium mixture at a particular temperature depends upon the starting amount of reactants.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : PCl₅, is covalent in gaseous and  liquid states but ionic in solid state.

Reason : PCl, in solid state consists of tetrahedral PC${\mathrm{l}}_4^{+}$cation and octahedral PC${\mathrm{l}}_6^{-}$ anion.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : The position of an element in periodic table after emission of one $\mathrm{\alpha }-$ and two $\mathrm{\beta }$- particles remains unchanged.

Reason : Emission of one $\mathrm{\alpha }-$ and two $\mathrm{\beta }-$particles give isotope of the element which acquires same position in periodic table

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : S. l. unit of atomic mass and molecular mass is kilograms.

Reason : Atomic mass is equal to the mass of 6.023x 10²⁴atoms.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Bond energy and bond dissociation energy have identical value for diatomic molecules.

Reason : Greater the bond dissociation energy, less reactive is the bond.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : The molality of the solution does not change with change in tempe-rature.

Reason : The molality is expressed in units of moles per 1000 g of solvent.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

The strained tetracyclic alkane is isomerize thermally to the cyclic alkene. The reaction involves

• free radical

• carbocation

• carbanion

• carbene.