Day 1 - ARC Anachem and Phychem Flashcards
A solution with 8.5% acetone and 91.5% water by mass has a density of 0.9867 g/ml. What mass of acetone is present in 7.5L of the solution?
a. 0.424 kg
b. 0.629 kg
c. 1.041 kg
d. 0.085 kg
B
In normla blood, there are about 5.4x109 red blood cells per ml. The volume of a red blood cell is about 90x10-12 cm3, and its density is 1.096 g/ml. How many liters of whole bloodwould be needed to collect 0.5 kg of red blood cells?
a. 1.1 L
b. 0.9 L
c. 0.6 L
d. 2.1 L
B
An empty 3L bottle weighs 1.7kg. Filled with a certain wine, it weighs 4.72kg. The wine contains 11.5% ethyl alcohol by mass. How many grams of ethyl alcohol are there in 250 ml of this wine?
a. 28.9g
b. 38.2g
c. 11.5g
d. 18.7g
A
An aqueous solution that is 5.3% LiBr by mass has a density of 1.04 g/mL. What is the molarity of this solution?
a. 0.563 M
b. 0.634 M
c. 0.0633 M
d. 0.0563 M
B
A teardrop with a volume of 0.5ml contains 0.5mg salt. What is the molarity of the salt in the teardrop?
a. 0.04M
b. 0.03 M
c. 0.01 M
d. 0.02 M
D
A solution of calcium chloride is prepared with a 1L volumetric flask. A 60gsample of CaCl2 is added to a small amount of water in the flask, and then additional wateris added to bring the total volume of solution to 1L.What is the concentration of calcium chloride in units of molarity?
a. 0.29 M
b. 0.38 M
c. 0.54 M
d. 0.61 M
C
Organic carbon in seawater can be measured by oxidizing to CO2 with K2S2O8, followed by gravimetric determination of CO2 trappedby a column of Ascarite. Water weighing 6.234 g produced 2.378 mg of CO2 (44.01) . Find the ppm carbon in the seawater
a. 223.5
b. 104.01
c. 85.9
d. 456.6
B
A solution containing 1.263g of unknown potassium compound was dissolved in water and treated with excess sodium tetraphenylborate solution to precipitate 1.003g of insoluble K+ B(C6H5)4- (358.33). FInd the weight %K in the unknown.
a. 12.34
b. 57.62
c. 8.643
d. 32.05
C
A 0.2386g sample contained only NaCl and KBr. it was dissolved in water and required 48.4ml of 0.04837M AgNO3 for complete titration of both halides, giving AgCl and AgBr precipitates. Calculate the weight % of Br in the solid sample.
a. 11.45%
b. 85.23%
c. 56.35%
d. 43.16%
C
A 10.231g sample of window cleaner containing ammonia was diluted with 39.466g of water. Then, 4.37g of solution were titrated with 14.22 ml of 0.1063M HCl to reach a bromocresol green endpoint. Find the weight % of NH3 in the cleaner.
a. 10.2%
b. 14.5%
c. 5.76%
d. 2.85%
D
Find the concentration of H+ in a solution whose pH is 11.65
a. 2.24x10-12 M
b. 4.47x10-3 M
c. 4.23x10-7 M
d. 7.24x10-11 M
A
A 0.0722 M acid has a pH of 3.11. What is the Ka of the acid?
a. 4.2x10-6
b. 8.44x10-7
c. 8.44x10-6
d. 4.2x10-7
C
A 0.0222 M solution of HA is 0.15% dissociated. Calculate the pKa for this acid.
a. 4.7
b. 3.7
c. 7.3
d. 7.4
C
Assume that the density of compacted waste to be 490 kg/m3. What is the ratio of HPO4 2- / H2PO4 - in a phosphate buffer of pH 7.9? pKa = 7.21
a. 5:1
b. 2:1
c. 3:1
d. 4:1
A
Find the pH of a solution prepared from 2.53g of oxoacetic acid (74.04), 5.13g of potassium oxoacetate (112.13), and 103g of water, Ka= 3.5x10-4.
a. 5.23
b. 3.58
c. 4.35
d. 2.87
B
The phosphate in a 3000 mg sample of industrial detergent was precipitated by the addition of 1g of AgNO3. The solution was filtered and the filtrate required 18.23 ml of 0.1377M KSCN. Calculate the percentage of phosphate in detergent. AgNO3 = 169.87 g/mol, PO4 3- = 94.97 g/mol
a. 3.56%
b. 5.35%
c. 7.12%
d. 10.69%
A