Some Basic Concepts of Chemistry MCQ's

Some Basic Concepts of Chemistry

Multiple Choice Questions

  

 

1. Which of the following methods of expressing concentration are independent of temperature?
   1.   Molarity
   2.   Molality
   3.   Normality
   4.   None of the above
2. Which of the following term is unitless?
   1.   Molality
   2.   Molarity
   3.   Mole Fraction
   4.   Normality
3. The chemical formula which expresses the simplest ratio of the atoms of the various elements present in one molecule of a compound is …
   1.   Molecular formula
   2.   Empirical formula
   3.   Structural formula
   4.   None of the above
4. The concentration term which is defined as the number of moles of the solute present in 1 kg of solvent is
   1.   Molality
   2.   Molarity
   3.   Normality
   4.   Mole fraction
5. The concentration term which is defined as the number of moles of the solute present in 1 L of solution is
   1.   Molality
   2.   Molarity
   3.   Normality
   4.   Mole fraction
6. The concentration term which is defined as the number of gram equivalents of the solute present in 1 L of solution is
   1.   Molality
   2.   Molarity
   3.   Normality
   4.   Mole fraction
7. ------------ is equal to 1/12 th of the mass of an atom of carbon-12 isotope.
   1.   One mole
   2.   One amu
   3.   One gram equivalent
   4.   None of the above
8. -------- is defined as that amount of the gas which has a volume of 22.4 litres at STP.
   1.   One mole
   2.   One amu
   3.   One gram equivalent
   4.   None of the above
9. The number of water molecules is maximum in
   1.   18 gram of water
   2.   18 moles of water
   3.   18 molecules of water
   4.   1.8 gram of water
10. The relation between molecular mass and vapour density is
    1.   Molecular mass = Vapour density
    2.   Molecular mass = 2 x Vapour density
    3.   Molecular mass = 1 / Vapour density
    4.   2 x Molecular mass = Vapour density
11. Which one of the following will have largest number of atoms
    1.   One gram Au
    2.   One gram Na
    3.   One gram Li
    4.   One gram Cl₂
12. The limiting reagent is the reactant in the reaction which …..
    1.   consumes partially
    2.   left unreacted
    3.   consumes completely
    4.   None of the above
13. One mole of CO₂ contains
    1.   3 g atoms of CO₂
    2.   6.02 x 10²³ atoms of O
    3.   18.1 x 10²³ molecules of CO₂
    4.   6.02 x 10²³ atoms of C
14. The molecular mass of glucose (C₆H₁₂O₆) is :
    1.   175 u
    2.   180 u
    3.   175 u
    4.   176 u
15. If 1.5 moles of oxygen combines with Al to form Al₂O₃, the mass of Al in g (Atomic mass of Al = 27) used in the reaction is
    1.   2.7
    2.   54
    3.   40.5
    4.   81
16. The empirical formula of CH₃CH₂CH₂COOH is
    1.   C₄H₈O₂
    2.   C₂H₄O₂
    3.   C₂H₄O
    4.   CHO
17. The number of moles of NaCl in 3 litres of 3M solution is
    1.   1
    2.   3
    3.   9
    4.   27
18. The empirical formula and molecular mass of a compound are CH₂O and 180 g respectively. What will be the molecular formula of the compound?
    1.   C₉H₁₈O₉
    2.   C₂H₄O₂
    3.   CH₂O
    4.   C₆H₁₂O₆
19. If the concentration of glucose (C₆H₁₂O₆) in blood is 0.9 g/L, what will be the molarity of glucose in blood?
    1.   5 M
    2.   0.005 M
    3.   50 M
    4.   0.5 M
20. Which of the following compounds has/have percentage of carbon same as that in ethene (C₂H₄ ) ?
    1.   Propyne
    2.   Cyclohexane
    3.   Ethyne
    4.   Benzene
21. The number of atoms present in one mole of an element is equal to Avogadro’s number. Which of the following element contains the greatest number of atoms?
    1.   4 g He
    2.   46 g Na
    3.   0.40 g Ca
    4.   12 g He
22. For a reaction A + 2 B --> C, the amount of C formed by stating the reaction with 5 moles of A and 8 moles of B is
    1.   5 moles
    2.   8 moles
    3.   4 moles
    4.   1 mole
23. If 1 mL of water contains 20 drops, then number of molecules in a drop of water is (density of water = 1 g/mL)
    1.   1.673 x 10²¹
    2.   1.376 x 10²⁶
    3.   6.023 x 10²³
    4.   4.346 x 10²⁰
24. An element X has the following isotopic composition:
    X-200 = 90%, X-199 = 8.0%, X-202 = 2.0%
    The weighed average atomic mass of the naturally occurring element X is closest to:
    1.   199 amu
    2.   200 amu
    3.   201 amu
    4.   202 amu
25. What is the mass percent of carbon in carbon dioxide?
    1.   0.034%
    2.   28.7%
    3.   3.4%
    4.   27.27%

For Video Lectures Click Here