Some Basic Concepts of Chemistry Mock Test – Class 11 Chemistry

1. Among the following, the best everyday example of matter is:

2. A bottle label reads , while another record says . The two entries should not be treated as the same because:

3. Consider these statements about solution stoichiometry:
I. Molarity can convert solution volume into moles of solute.
II. A balanced equation converts moles of one reacting substance into moles of another.
III. Mass of product can be found from product moles using molar mass.

4. A table shows four gas samples measured at .

The row that needs correction is:

5. Mass percentage of a solute in a solution is best represented by:

6. Consider these statements about pure substances and mixtures:
I. A pure substance has fixed composition.
II. A mixture may have variable composition.
III. Every homogeneous sample must be a pure substance.

7. Scientific notation writes a number in the form . For standard scientific notation, the coefficient should satisfy:

8. A solution pathway is described below.

The most suitable calculation order is:

9. A student mixes of with excess solution. If , the amount of precipitated is:

10. In a precipitation reaction, of is mixed with excess . For , the mass of formed is closest to: .

11. A student observes three covered containers: one contains sand, one contains water, and one contains oxygen gas. On shaking each container gently, the contents show different behaviour. Which description is most suitable?

12. A student prepares of by diluting a stock solution. The volume of stock solution required is:

13. A chemistry record gives a liquid volume as , a sample mass as , and an amount as . The best interpretation is:

14. A solution is used to neutralise . The balanced equation is . The volume of this base needed to neutralise of is:

15. Use the information below to classify the samples.

The most suitable classification is:

16. A mass is reported as . The final zero is significant mainly because:

17. A colourless solution becomes blue when a few drops of another reagent are added, but no gas, precipitate, heat change, or new substance formation is confirmed. The most careful conclusion is:

18. A learner says, "If two samples have different total masses, they cannot be the same compound." The best reply is:

19. A compound contains of hydrogen for every of oxygen. If a pure sample of the same compound contains of oxygen, what mass of hydrogen should it contain?

20. The graph described below is drawn for an ideal gas at .

The slope of the graph represents:

21. A reaction is performed in four closed containers. The recorded masses are shown below.

The record that needs rechecking for a closed-system reaction is:

22. A sample of of carbon burns completely in oxygen according to . What volume of is produced at ? Use and gas at .

23. A formula gives concentration as . If amount is in and volume is in , the derived unit is:

24. A measurement written as only in a laboratory record is incomplete because:

25. A graph is described below.

The slope of the graph is:

26. At , the molar volume of an ideal gas is commonly taken as:

27. For , of and of are mixed. The limiting reagent is:

28. In the reaction , how many moles of are formed from of when hydrogen is in excess?

29. The statement " of " means:

30. A balance always shows even when nothing is placed on the pan. Masses measured without correcting this zero error are likely to have:

31. A claim says, "Liquids and gases are the same because both take the shape of their container." The best correction is:

32. A calculation gives , but the final result must be reported to significant figures. The correct report is:

33. Use the table below for complete dissociation in water.

The row that needs correction is:

34. A thermometer is used to measure a liquid whose true temperature is . The readings are , , and . The best description is:

35. A sample of contains of molecules. The amount of hydrogen atoms in the sample is:

36. Study the following limiting-reagent records for .

The case with the wrong conclusion is:

37. A solution contains of . It is diluted to . The final molarity is:

38. A naturally occurring sample of chlorine contains and . The average atomic mass is:

39. A binary mixture has mole fraction of solute . The mole fraction of solvent is:

40. A notebook lists unit-factor setups for converting into .

The row that uses the conversion factor in the wrong direction is:

41. A notebook gives four measured values and claimed significant figures.

The row that needs correction is:

42. A sample has of . The amount of oxygen atoms in the sample is:

43. A table gives possible interpretations of the equation .

The row that needs correction is:

44. Pure water samples obtained after purification from different sources always contains hydrogen and oxygen in the same mass ratio. This statement is an example of:

45. A particle diameter is recorded as . The same diameter in is:

46. A solution contains total chloride ions after complete dissociation of . The concentration of is:

47. A graph is described below.

If the total solution mass is fixed at , the slope of the graph is:

48. A formula contains parentheses: . The number of oxygen and hydrogen atoms in one formula unit is:

49. Burning a piece of paper is classified as a chemical change mainly because:

50. A concentration is written as . The same value in scientific notation with the same significant figures is: