Metric & Sig Figs
Lab Equipment & Scientific Method
Matter
Density & Percent Error
Temperature
100
Which quantity of heat does a kilocalorie represent? A. 100 calories B. 1000 calories C. 1 100 calories D. 1 1000 calories
B. 1000 Calories
100
What is the following lab equipment called?
Graduated Cylinder
100
Which pair are classified as chemical substances?
A. mixtures and solutions B. compounds and solutions C. elements and mixtures D. compounds and elements
D. compounds and elements
100
The solid block shown here has a mass of 146 grams. What is the block's density?
Hint: L= 6 cm W= 3cm H=3 cm
A. 0.37 g/cm3 B. 2.7 g/cm3 C. 8.1 g/cm3 D. 54 g/cm
L*W*H = 6*3*3= 54 cm3
Density = Mass/Volume
146g /54 cm3 =2.7 g/cm3
100
Energy is being added to a given sample. Compared to the Celsius temperature of the sample, the Kelvin temperature
A. will always be 273 degrees greater
B. will always be 273 degrees lower
C. will have the same reading at 0 degrees
D. will have the same reading at 273 degrees
A. K = C + 273 therefore Kelvin will always be 273 units higher
Therefore Celcius will always be 273 degrees lower
200
Which measurement contains a total of three significant figures?
A. 0.01 g B. 0.010 g C. 0.0100 g D. 0.01000 g
C. 0.0100 g Three significant figures
200
During a laboratory activity, a student combined two solutions. In the laboratory report, the student wrote "A yellow color appeared". The statement represents the student's recorded
A. conclusion B. observation C. hypothesis D. inference
b. Observation
200
Which process represents a chemical change?
A. Iodine sublimes. B. Water evaporates.
C. An ice cube melts. D. A candle burns in air.
D. A candle burns in air.
200
A student determined in the laboratory that one mole of KMnO4 had a mass of 171.54 grams. The mass of one mole of KMnO4 in an accepted chemistry reference is 158.04 grams. What is the percent error of the mass of one mole of KMnO4 as determined by the student? A. 0.787% B. 7.87% C. 8.54% D. 13.5%
[(measure-accepted)/accepted] *100%
[(171.54-158.04)/158.04]*100%
c. 8.54%
200
The temperature 30 K expressed in degrees Celsius is A. 243oC B. -243oC C. 303oC D. -303oC
B. -243oC
K= C +273
K - 273 = C
(30) - 273 = -243oC
300
Which quantity is equal to 50 kilojoules? A. 0.05 J B. 500 J C. 5 * 103 J D. 5 * 104 J
D. 5 * 104 J
300
What is this piece of equipment AND what is its function?
Erlenmeyer flask.
Used to measure and contain liquid, particularly useful to gently stir the content inside the liquid as it has a narrow neck and slanted sides.
300
Which terms are used to identify pure substances?
A. an element and a mixture B. an element and a compound
C. a solution and a mixture D. a solution and a compound
B. Element & Compound
300
Mass of graduated cylinder + distilled H2O sample is 163 g
Mass of empty graduated cylinder is 141 g
Mass of distilled H2O sample ____ g
Volume of distilled H2O sample is 25.3 mL
A student collected the data shown to determine experimentally the density of distilled water. Based on the experimental data collected, what is the density of the distilled water? A. 1.0 g/mL B. 0.253 g/mL C. 0.87 g/mL D. 1.15 g/mL
Density is Mass/Volume
Mass is 22 g, Volume is 25.3 mL --> (22g/25.3mL)
Therefore Density is 0.87 g/mL
C. 0.87 g/mL
300
Which temperature represents absolute zero?
A. 0oK B. 0oC C. 273oK D. 273oC
Daily Double: Convert to their corresponding temperatures
Absolute zero is the lowest temperature possible. At a temperature of absolute zero there is no motion and no heat. Absolute zero occurs at a temperature of 0 kelvin, or -273.15 degrees Celsius, or at -460 degrees Fahrenheit.
A. 0oK
400
Which milligram quantity contains a total of four significant figures? A. 0.3010 mg B. 3010 mg C. 3100 mg D. 30001 mg
A. 0.3010 4 significant figures
400
Which property could be used to identify a compound in the laboratory? A. mass B. melting point C. temperature D. volume
C. Temperature
400
Element A and element B chemically combine to form substance C. Substance C must be
A. a solution B. a compound
C. an element D. a mixture
B. a compound
400
In determining the volume of a mole of gas at STP in the laboratory, a student's experimental value was 3.36 liters greater than the accepted value (22.4 L). The percent error contained in the student's value is closest to A. 3.36 B. 15.0 C. 19.0 D. 25.8
[(measure-accepted)/accepted] *100%
(3.36/22.4) *100%=
B. 15%
400
The temperature of a substance changes from -173o C to 0o C. How many Kelvin degrees does the change represent?
A. 100 B. 173 C. 273 D. 446
B.
-173o C + 273 = 100o C
0o C + 273 = 273o C
therefore the difference in change is 173 degrees
500
How many calories are equivalent to 35 kilocalories? Hint: 1 Kilometer = 1000 = 103
A. 0.035 calorie B. 0.35 calorie C. 3,500 calories D. 35,000 calories
D. 35000 Calories
500
What is the difference between scientific law vs. theory?
A scientific law attempts to DESCRIBE a scientific phenomenon.
A theory attempts to EXPLAIN a scientific phenomenon.
500
Which species represents a chemical compound?
A. N2 B. NH4+ C. Na D. NaHCO3
D. NaHCO3
Sodium Bicarbonate
500
To determine the density of an irregularly shaped object, a student immersed the object in 21.2 milliliters of H2O in a graduated cylinder, causing the level of the H2O to rise to 27.8 milliliters. If the object had a mass of 22.4 grams, what was the density of the object?
A. 27.8 g/mL B. 6.6 g/mL C. 3.0 g/mL D. 3.4 g/mL
Given: Mass is 22.4 grams therefore
Volume = 27.8 mL - 21.2 mL = 6.6 mL
Equation: Density is mass/ volume
Unknown: Density
Plugin 22.4 grams/6.6mL
Answer: 3.4 g/mL
500
Some properties of the element sodium are listed below.
- is a soft, silver-colored metal
- melts at a temperature of 371 K
- oxidizes easily in the presence of air
Convert the melting point of sodium to degrees Celsius.
K = C + 273
Therefore C = K -273 --> (371) -273 = 98
98 oC