CHM191

1. Dissolution 0f sodium chloride in water results in __________ type of mixture

2. In this equation $$2NaHCO_{3} → Na_{2}CO_{3} + ? + CO_{3}$$, the compound represented by ? is __________

3. The technique employed for the separation of colours is called _________

4. Calculate the [OH^{-}] of an aqueous solution of Ph=11 ____________

5. The solution whose concentration is known is called ___________

6. A mixture in which the components are evenly distributed and the composition is uniform throughout the mixture is called _________ mixture.

7. The number of protons or electrons in the atom of an element is equal to the _________ of the element

8. 3.47g sodium carbonate was dissolved in a 250millilitre standard flask. What is the concentration of the resulting solution

9. A high percentage yield implies that ___________

10. The condensate collected during the vaporization of liquid is called _________

11. From the equation $$2HCl + Na_{2}CO_{3} → 2NaCl + CO_{2} + H_{2}O$$, given that 2 moles of HCl reacted with 1 mole of $$Na_{2}CO_{3}$$. What was the concentration of the acid?

12. An acid HA has a pka of 4.5, what is the Ka value? _________

13. A separation technique that is used to isolate a desired solid from a solid -liquid mixture or for freeing a desired liquid of solid impurities is called _________

14. The types of mixtures are _________, _________ mixture.

15. The number of gramequivalent weight of solute in one cubic decimeter of solution is ______

16. The molar mass of $$Na_{2}CO_{3}$$ ________

17. Convert 2 moles of NaOH to grams of NaOH. Answer is ________

18. $$The label on a stock bottle of an acid reads: 56% by mass and 1.25 specific gravity. If the molar mass of the acid is 56, find the volume of this acid that is required to prepare 250cm^{3} of 1.0 molar concentration of the acid$$.

19. The reagent that will not make any significant contribution to the theoretical yield is _________

20. The smallest unit of a compound that manifest all the chemical properties of the compound is called ________

21. The actual yield of product (in g or moles) expressed as a percentage of the theoretical yield (in g or moles ) is called ____________

22. The procedure by which a solution of known concentration is Added to another solution until the chemical reaction between the two ssolutes is complete is ______.

23. The process by which traces of water is removed by treating the liquid with suitable drying agents is called _________

24. If actual yield of an ester is 32.7g and theoretical yield is 35.1g .What is the percentage yield of the ester?

25. An acid HA has a pka of 4.5. What is the concentration of $$H_{3}^{+} $$ in 0.110M solution of the acid ? ________

26. In titration, the experimentally determined stoichiometric point of the titration is referred to as _______

27. There are _____ different techniques for  determination of an unknown sample in titrimetric analysis.

28. The concentration of the pure HCl used is 11.7 molar. If $$20.0cm^{3}$$ V1 of 1 1.7 molar of $$C_{1}$$ of HCl is diluted to 250cm^{3} of V_{2}, then the new concentration C_{2} will be ______

29. The base unit of a measured liquid called volume is __________

30. Convert 500g of $$ Na_{2}CO_{3}$$ to moles _______

31. When two or more elements combine chemically in fixed proportion by mass, _________ is formed

32. The technique of separation employed to purify an organic solid that may be contaminated by impurities is called __________

33. The base unit of a measured or weighed solid material in chemistry is ________

34. $$The label on a stock bottle of an acid reads: 56% by mass and 1.25 specific gravity. If the molar mass of the acid is 56, find the moles per dm^{3}$$

35. The residue of a chemical reaction is allowed to cool in a ________

A substance with a pH value of >7< 10 is a ______________

37. When two or more elements combine chemically in fixed proportion by mass, is formed _________

38. An apparatus that can be used to remove traces of water from a substance is ________

39. The reagent with a ________ stoichiometric amount (in moles) that limits the amount of desired product (in moles ) formed is called

40. In a standardization titration involving hydrochloric acid and sodium carbonate, a student recorded the following results for the volume of hydrochloric acid used against 10.00mL of the sodium carbonate solution : 15.60; 14.50; 14.70 aqnd 14.20. If the concentration of the $$Na_{2}CO_{3}$$ standard solution is 0.75moldm^-3, calculate the concentration of the HCl solution.

41. When a substance is not available in a pure form, its solution can be standardized by ___________

42. An undergraduate weighed out 20grams of sodium hydroxide pellets. If Na =23, O = 16 andH = 1, What is the mole of this sodium hydroxide. ___________

43. The separation technique employed to purify an organic liquid or to separate mixtures of liquids of different volatilities or boiling points is called __________

44. When propane reacts with oxygen, the products are ______  and ________

45. A compound in grams is converted to moles by diving by ________

46. A standard solution is a _________

47. The formular obtained by multiplying the number of each atom in the empirical formular by n is called ____________

48. The separation technique employed to separate mixtures of two or more liquids with slightly different boiling points is called __________

49. A standard solution of a substance can be prepared if the substance can be obtained in ______ state.

50. Calculate the $$[H^{+}] $$of an aqueous solution wity $$[OH^{-}] of 1× 10^{-10}M$$. What is the pH of the solution? Is the solution acidic or basic? ________