Some Basic Concepts of Chemistry

An element, X has the following isotopic composition;


²⁰⁰X: 90%

¹⁹⁹X : 8.0%

²⁰²X ; 2.0 %

The weighted average atomic mass of the naturally -occurring element X is closet to:

• 200 amu

• 201 amu

• 202 amu

• 202 amu

Work is being performed, when a weight lifter lifts a base ball off a weight rack. This is due to

• magnetic attraction

• gravity

• electrostatic repulsion

• mechanical force

11.2 L of gas at STP Weight 14g. The gas would be

• H₂

• CO

• B₂H₆

• All of these

For preparing 3.00 L of 1M NaOH by mixing portions of two stock solutions (A and B) of 2.50 M NaOH and 0.40 M NaOH respectively. Find out the amount of B stock solution (in L) added.

• 8.57 L

• 2.14 L

• 1.28 L

• 7.51 L

What would be the heat released when an aqueous solution containing 0.5 mole of HNO₃ is mixed with 0.3 mole of OH^-?  (enthalpy of neutralisation is- 57.1 kJ)

• 28.5 kJ

• 17.1 kJ

• 45.7 kJ

• 1.7 kJ

The number average molar mass and mass average molar mass of a polymer are respectively 30,000 and 40,000. The
polydispersity index (PDI) of the polymer is 

• -1

• 0

• > 1

• < 1

0.001 mole of [Co(NH₃)₅(NO₃) (SO₄)] was passed through a cation exchanger and the acid coming out of it required 20mL of 0.1 M NaOH for neutralisation. Thus, the complex is

• [Co(NH₃)₅(NO₃)] SO₄

• [Co(NH₃)₅(SO₄)]NO₃

• [Co(NH₃)₅] NO₃.SO₄

• None of the above

In order to prepare one litre 1N solution of KMnO₄, how many grams of KMnO₄ are required, if the solution to be used in acid medium for oxidation?

• 128g

• 41.75 g

• 31.60 g

• 62.34 g

The osmotic pressure of blood is 8.21 atm at 37$°$C. How much glucose would be used for an injection that is at the same osmotic pressure as blood?

• 22.17 gL^-1

• 58.14 gL^-1

• 61.26 gL^-1

• 75.43 gL^-1

A solution made by dissolving 40 g NaOH in 1000 g of H₂O is

• 1 molar

• 1 normal

• 1 molal

• None of these