Some Basic Concepts of Chemistry Mock Test – Class 11 Chemistry

1. A claim says, "If two solutions have the same molarity, equal volumes always contain the same mass of solute." The best correction is:

2. A student writes the unit of molar mass as . The best correction is:

3. A student treats as if it supplies only total ions. The best correction is:

4. A statement says, "The unit of mass is , because chemists commonly use grams." The best correction is:

5. A compound is written as . In Dalton-style particle language, this formula most directly means:

6. A property record for a substance says: "white solid, soluble in water, melts at a definite temperature, does not burn easily." The entries about colour, solubility, and melting mainly describe:

7. A claim says, "Relative molecular mass and molar mass are the same kind of unit." The best correction is:

8. A volume is reported as . Using , the same volume in is:

9. For the reaction where water is considered as vapour, the volume ratio of at the same and is:

10. A sample has mass and volume . Using , how should the density be reported?

11. A solution pathway is described below.

The most suitable calculation order is:

12. A table gives claimed mass percentages for , using and .

The row that uses the wrong denominator for is:

13. Density is obtained by dividing mass by volume. If mass is measured in and volume in , the unit of density becomes:

14. Molarity of a solution is defined as:

15. A measured value of a mass is , while the accepted value is . The percentage error is:

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

17. A sample of element X has isotope and isotope . What is the average atomic mass?

18. The prefix in a unit such as means:

19. A table shows four gas samples measured at .

The row that needs correction is:

20. A by mass solution of potassium nitrate contains:

21. In the mixture from the reaction, of is mixed with of . What amount of forms?

22. Carbon and oxygen form and . For the same mass of carbon, the masses of oxygen that combine are in the ratio:

23. A sample of is diluted to . After dilution, the concentration of ions is:

24. A pure copper wire is cut into smaller pieces again and again, but each piece is still identified as copper. This observation is best connected with the idea that copper is:

25. A compound contains carbon, hydrogen, and oxygen by mass. The empirical formula is:

26. A student records with a decimal point after the zeros. The decimal point indicates that:

27. A cube of ice melts to form liquid water and later the water is frozen again. This example shows that:

28. Study the table below for empirical formula work.

The step that needs correction is:

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

30. A lab assistant writes the following values for the same measured length: , , and . The main difference among them is:

31. A row in a notebook says, "A solution is always a mixture, but every mixture is not a solution." The best interpretation is:

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

33. Two samples are compared at : Sample P contains of , and Sample Q contains of . The best comparison is:

34. The formula mass of , using , , and , is:

35. A graph is described below.

The slope of the graph is:

36. 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.

37. The number is written in a lab record. How many significant figures does it have?

38. Consider the following statements about molarity and molality:
I. Molarity depends on volume of solution.
II. Molality depends on mass of solvent.
III. Both molarity and molality must always have the same numerical value.

39. Read the short record below.

The property that gives chemical information is:

40. A sample of is mixed with excess . For , what mass of forms? Use .

41. A gas-volume comparison is written below.

If of reacts completely, the volume of required is:

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

43. Match the chemistry focus in Column I with the most suitable description in Column II.

44. A mixture of sand and water is shaken and then allowed to stand. The sand gradually settles at the bottom. This observation supports the idea that the sample is:

45. of ethanol is mixed with water, and the final volume of the solution is made up to . What is the volume percent of ethanol?

46. A packet contains exactly test tubes, and each test tube is measured to have length . The number with unlimited significant figures in this context is:

47. Consider the statements below:
I. Coefficients in a balanced equation give mole ratios.
II. For gases at the same and , coefficients can also give reacting volume ratios.
III. Coefficients should be used as direct gram ratios without molar masses.

48. A compound has empirical formula and molecular mass . Its molecular formula is:

49. The number written in standard scientific notation is:

50. When of decomposes completely according to , what mass of is produced? Use and .