CHEM 103 Exam 1-6 Final - Complete Solutions, Graded
A
Exam 1-6
EXAM 1
Question 1
1. Convert 1005.3 to exponential form and explain your answer.
2. Convert 4.87 x 10-6 to ordinary form and explain your answer.
Answer:
1. Convert 1005.3 = larger than 1 = positive exponent, move decimal 3
places = 1.0053 x 103
2. Convert 4.87 x 10-6 =negative exponent =smaller than 1, move
decimal 6 places = 0.00000487
Question 2
Using the following information, do the conversions shown below, showing all
work:
1 ft = 12 inches 1 pound = 16 oz 1 gallon = 4 quarts
1 mile = 5280 feet 1 ton = 2000 pounds 1 quart = 2 pints
kilo (= 1000) milli (= 1/1000) centi (= 1/100)
1
,deci (= 1/10)
1. 2.73 liters = ? ml 2. 8.6 pts = ? qts
Answer:
1. 2.73 liters x 1000 ml / 1 liter = 2730 ml
2. 8.6 pts x 1 qt / 2 pts = 4.3 qts
Question 3
Do the conversions shown below, showing all work:
1. 248oC = ? oK
2. 25oF = ? oC
3. 175oK = ? oF
Answer:
1. 248oC + 273 = 521 oK oC → oK (make larger) +273
2
,2. 25oF - 32 ÷ 1.8 = -3.88 oC oF → oC (make smaller) -
32
÷1.8
3. 175oK - 273 = -98 oC x 1.8 + 32 = -144.4 oK → oC → oF
oF
Question 4
Be sure to show the correct number of significant figures in each calculation.
1. Show the calculation of the mass of a 17.9 ml sample of chloroform
with density of 1.49 g/ml
2. Show the calculation of the volume of 19.4 grams of cresol with
density of 1.02 g/ml
Answer:
1. M = D x V = 1.49 x 17.9 = 26.7 g
2. V = M / D = 19..02 = 19.0 ml
Question 5
1. 1.35601 contains ? significant figures.
2. 0.151 contains ? significant figures.
3. 1.35601 + 0.151 = ? (give answer to correct number of significant figures)
Answer:
3
, 1. 1.35601 contains 6 significant figures.
2. 0.151 contains 3 significant figures.
3. 1.35601 + 0.151 = 1.50701 = 1.507 (to the thousands place for 0.151)
Question 6
Classify each of the following as an element, compound, solution or
heterogeneous mixture and explain your answer.
1. Honey
2. Hydrogen iodide
3. Tea
Answer:
1. Honey - is not on periodic table (not element) - no element
names (not compound) appears to be one substance = Solution
2. Hydrogen iodide - is not on periodic table (not element) - has two element
names
= Compound
3. Tea - is not on periodic table (not element) - no element names (not
compound) appears to be one substance = Solution
4
A
Exam 1-6
EXAM 1
Question 1
1. Convert 1005.3 to exponential form and explain your answer.
2. Convert 4.87 x 10-6 to ordinary form and explain your answer.
Answer:
1. Convert 1005.3 = larger than 1 = positive exponent, move decimal 3
places = 1.0053 x 103
2. Convert 4.87 x 10-6 =negative exponent =smaller than 1, move
decimal 6 places = 0.00000487
Question 2
Using the following information, do the conversions shown below, showing all
work:
1 ft = 12 inches 1 pound = 16 oz 1 gallon = 4 quarts
1 mile = 5280 feet 1 ton = 2000 pounds 1 quart = 2 pints
kilo (= 1000) milli (= 1/1000) centi (= 1/100)
1
,deci (= 1/10)
1. 2.73 liters = ? ml 2. 8.6 pts = ? qts
Answer:
1. 2.73 liters x 1000 ml / 1 liter = 2730 ml
2. 8.6 pts x 1 qt / 2 pts = 4.3 qts
Question 3
Do the conversions shown below, showing all work:
1. 248oC = ? oK
2. 25oF = ? oC
3. 175oK = ? oF
Answer:
1. 248oC + 273 = 521 oK oC → oK (make larger) +273
2
,2. 25oF - 32 ÷ 1.8 = -3.88 oC oF → oC (make smaller) -
32
÷1.8
3. 175oK - 273 = -98 oC x 1.8 + 32 = -144.4 oK → oC → oF
oF
Question 4
Be sure to show the correct number of significant figures in each calculation.
1. Show the calculation of the mass of a 17.9 ml sample of chloroform
with density of 1.49 g/ml
2. Show the calculation of the volume of 19.4 grams of cresol with
density of 1.02 g/ml
Answer:
1. M = D x V = 1.49 x 17.9 = 26.7 g
2. V = M / D = 19..02 = 19.0 ml
Question 5
1. 1.35601 contains ? significant figures.
2. 0.151 contains ? significant figures.
3. 1.35601 + 0.151 = ? (give answer to correct number of significant figures)
Answer:
3
, 1. 1.35601 contains 6 significant figures.
2. 0.151 contains 3 significant figures.
3. 1.35601 + 0.151 = 1.50701 = 1.507 (to the thousands place for 0.151)
Question 6
Classify each of the following as an element, compound, solution or
heterogeneous mixture and explain your answer.
1. Honey
2. Hydrogen iodide
3. Tea
Answer:
1. Honey - is not on periodic table (not element) - no element
names (not compound) appears to be one substance = Solution
2. Hydrogen iodide - is not on periodic table (not element) - has two element
names
= Compound
3. Tea - is not on periodic table (not element) - no element names (not
compound) appears to be one substance = Solution
4
