answer po plsss 19. How do you increase the concentration of a solution?
a. add more powder or solute
b.add more water
c.less powder or solute
d. less water or solvent
20. What will be the correct sequence if you will arrange the following solutions from most concentrated to least concentrated?
Solution A - of 61g/50mL
Solution B - 21g/50mL
Solution C - 41/50mL
a. A. B. C
b. C, B, A
c. A, C, B
d. C, A, B
21. What is the concentration of a 500 mL solution containing 0.3 mol of glucose?
a. 0.15 mol L-1
b.0.0006 mol L-1.
c. 1.67 mol L-1.
d. 0.6 mol L-1
22. . What mass of sucrose, C12H22O11 , is needed to make 500.0 mL of a 0.200M solution?
a. 34.2 g c. 17.1 g
b. 100 g d.68.4 g
23. . What mass of Na2SO4 is needed to make 2.5 L of 2.0M solution? (Na = 23 g; S = 32 g; O = 16 g)=
a. 178 g c. 356 g
b. 284 g d. 710 g
24. A concentrated orange juice sold in the grocery is labeled 95% orange juice. How many mL of water is present in a 100-mL bottle?
a. 5 mL b. 95mL c. 100mL d. 195mL
25. A mixture is yellow in color and cloudy in appearance. It made to stand undisturbed, solids deposit at the bottom for a time. What kind of mixture is described?
a. coarse mixture b. colloid c. solution d. suspension
26. . Carbon cannot be broken down into anything simpler by chemical means, so carbon must be _________
a. a heterogeneous mixture. b. a homogeneous mixture. c. an element. d. a compound
27. Jill has an unopened box of a 2-meter foil labeled 100% made of aluminum. Aluminum is a substance. Jill takes just a thumb-size piece of the aluminum foil. Which of the following statements is TRUE about the piece of aluminum foil that Jill took compared with the rest that was left in the box?
a. Its mass and melting behavior are different. b. Its mass and melting behavior are the same.
c. The mass is different but the melting behavior is the same. d. The mass is the same but the melting behavior is different
28 . . Which of the following is not a pure substance?
a. water b. salt c. soil d. iron
29. Which of the following statements is TRUE?
a. Ferrous sulfate cannot be broken down into simpler substances b. Compounds are made up of one kind of element.
c. Water is composed of more than two elements. d. Compounds are more complex than elements.
30. Calcium chloride is a compound of the two elements calcium and chlorine. Which of the following statements is TRUE?
a. Calcium chloride is listed in the periodic table. b. The symbol for calcium chloride includes Ca
and Cl
c. Chlorine may still be broken down into a simpler form. d. Calcium and chlorine belong to the same group in the periodic table
31. Sea water, smog and brass are all examples of ______________________
a. alloys b. ionic compounds c. mixtures d. covalent compounds
32. Each family, or group of elements in a vertical column of the periodic table has elements with chemical characteristics that are
a. exactly the same. b. similar. c. different. d. exactly opposite
33. About 99 percent of the earth's atmospheric air is made up of
a. silicon and oxygen. b. nitrogen and oxygen. c. hydrogen and oxygen. d. hydrogen, oxygen, and . carbon
34. . Which of the following belongs to the noble gas family of elements?
a. sodium b. calcium c. chlorine d. neon
35. Copper sulfate can be further subdivided into simpler substances by chemical means only. Therefore it is _____
a. compound b. mixture c. element d. metals
36. The following are characteristics of an element except_________
a. composed of a single kind of atom b. cannot be separated by chemical means
c. has its own properties d. can be separated into simpler substances
37. An element that is necessary in thyroid hormone synthesis
a. Chlorine b. Iodine c. Iron d. Calcium
38. Which of the following elements is most likely ductile at room temperature?
a. Sulfur b. Mercury c. Nitrogen d. Aluminum
39. Look at the illustration below. Which of the following represents an element?
a. A. A only b. A and C c. A, B, and D d. A, B, C, and D
40. Which of the following elements has a correct element symbol?
