Expression of Concentration

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By Eve Joyce E. Ablin

Multiple Choice

What is the molar mass of cyanide (CN-).

• 13 g/mol

• 24.02 g/mol

• 26.02 g/mol

• 42.02 g/mol

Multiple Choice

How many grams is 1.2 moles of Neon?

• 0.05 grams
• 16.6 grams
• 21.2 grams
• 24 grams

Multiple Choice

How many moles are in 564 grams of Copper?

• 0.11 mol Cu
• 25 mol  CU
• 87 mol Copper
• 8.87mol Cu

Multiple Choice

What is the molarity of 0.195 g of cholesterol (C27H46O) in 0.10 L of blood serum?

(Atomic weights: C = 12.01, H = 1.008, O = 16.00).

• 5.0

• 10^-3

• 5.0 x 10^-3

• None of them

Multiple Choice

The lowest limit of taste of MgSO4 in water is 0.040 g in 0.10 L. What is the molarity of MgSO4?

(Atomic weights: Mg = 24.30, S = 32.06, O = 16.00).

• 0.0033

• 0.033

• 0.33

• 33

Multiple Choice

Calculate the molarity of a solution of 0.0716 g of KMnO4 in 2.50 mL of solution.

(Atomic weights: K = 39.09, Mn = 54.94, O = 16.00).

• 0.181 M

• 181 M

• 1.81 M

• 18.1 M

Multiple Choice

What is the molality of a solution prepared by dissolving 5.00 g of chlorobenzene, C6H5Cl, in 115 g of benzene,

C6H6?

(Atomic weights: C = 12.01, H = 1.008, Cl = 35.45).

• 0.386 m

• 386 m

• 3.86 m

• 38.6 m

Multiple Choice

A 0.200 m solution of sucrose, C12H22O11, must be prepared. What mass (g) of sucrose must be dissolved in 250.0 g of water?

(Atomic weights: C = 12.01, H = 1.008, O = 16.00).

• 17.1 g

• 1.71 g

• 171 g

• 0.171 g

Multiple Choice

What is the mole fraction of Pb(NO3)2 in a solution prepared from 0.0543 moles of Pb(NO3)2 and 4.55 moles of water?

(Atomic weights: Pb = 207.2, N = 14.01, O = 16.00).

• 0.0118

• 118

• 0.000001180

• 0.000118

Multiple Choice

What is the mole fraction of C6H4Cl2 in a solution of 1.50 g C6H4Cl2 in 35.0 g of C6H6?

(Atomic weights: C = 12.01, H = 1.008, Cl = 35.45).

• 0.0223

• 0.223

• 223

• 2.23

Multiple Choice

A solution is prepared from 112 g of glucose, C6H12O6, and 100.0 mL of water (water density is 1 g/mL). What is the mole fraction of glucose?

(Atomic weights: C = 12.01, H = 1.008, O = 16.00).

• 0.100

• 100

• 0.000100

• 10

Multiple Choice

A solution is prepared by mixing 2.2 moles of CH2Cl2, 1.2 moles of CH2Br2 and 1.8 moles of CHCl3. What is the mole fraction of CH2Br2?

(Atomic weights: C = 12.01, H = 1.008, Cl = 35.45, Br = 79.9).

• 0.23

• 0.00023

• 2.3

• 230

Multiple Choice

What is the concentration, in ppm, of lead in a 6.0 kg solution that contains 12 mg of lead?

• 1.0 ppm

• 2.0 ppm

• 3.0 ppm

• 4.0 ppm

Multiple Choice

What is the concentration of a solution in parts per million if 0.02 grams of NaCl is dissolved in 1000 grams of water?

• 2 ppm

• 20 ppm

• 200 pm

• 0.2 ppm

Multiple Choice

What is the concentration of solution (in ppm) made up of 0.005 grams of solute in 350 grams of solution?

• 14.3 ppm

• 12.1 ppm

• 1.4 ppm

• 9.8 ppm