1ST SEM SY 2012-2013
(GENERAL CHEMISTRY)
COCH11
Long Quiz 1
Always show complete solutions for every number. All inquiries must be referred to the instructor only. Answer the problems chronologically and systematically. Deductions will be given for those who do not know how to follow procedures.
Cheating is not tolerated and an automatic grade of 5.0 will be given to those who will be caught.
A. SIGNIFICANT FIGURES (10 pts.)
(Show the actual results first before rounding off the digits into their proper significant figures.)
A.1. Determine the number of significant figures in each numerical value below. (Assume all values are measurements.) 1. 357 ml 2. 1.0600 L 3. 0.000 501 g 4. 23, 000 tons 5. 1.8000 X 105 mi
A.2. Perform the following arithmetic operations and express the answer to the correct number of significant figures
1. 0.392 + 51.4 2. (5260 x 12.0) / 2.1 3. 273.15 – 28.3 4. 8.63 x 0.58 5. 6.02 / 3.0
B. SCIENTIFIC NOTATION (10 pts.)
B.1. Convert the following numbers from scientific notation to normal notation
1. 8.59 x 10 -3 2. 2.76 x 10 2 3. 2.76 x 10 -2 4. 7.2 x 109 5. 7.2 x 10-9
B.2. Convert the following numbers from normal notation to scientific notation
1. 0.000 000 000 8304 2. 9,500,000 3. 0.013 4. 58.3 5. 0.583
C. DENSITY and SPECIFIC GRAVITY (20 pts.)
(Observe proper Significant Figures in the answer)
1. Calculate the mass in grams of 15.0ml of a saline solution that has a density 1.05 g/ml 2. Copper has a density of 8.96 g/ml. Calculate the volume occupied by 125.0 g of copper. 3. A. If the density of a liquid is 0.80 g/ml, what is its specific gravity?
B. If the specific gravity of a substance is 2.3, what is its density?
D. TEMPERATURE (30 pts.)
(Observe proper Significant Figures in the answer)
Make the temperature conversions as indicated by the blanks in the following table