Chapter 2 chem quiz questions
what is the metric equivalent of 3.5in?
(3.5 in) (2.54/1 in) =8.9cm
Distinguish between density and specific gravity.
Density is the ratio of the mass of a substance to the volume occupied by that mass. Density has the units of mass over volume. Specific gravity is the ratio (no units) of the density of a substance to the density of a reference substance(usually water at a specific temperature for solids and liquids). Specific gravity has no units.
Compare the number of degrees between the freezing point of water and its boiling point on the Fahrenheit, Kelvin, and Celsius temperature scales.
Fahrenheit: 180 degrees Fahrenheit Celsius: 100 degrees Celsius Kelvin: 100 K
Determine whether the zeros in each number are significant.
a) 0.005: zeros are not significant b) 1500: zeros are not significant c) 250. : zeros are significant d) 10.000: zeros are significant e) 6.070 * 10^4: zeros are significant f) 0.2300: the first zero is not significant, the last zero is significant.
how many qt in a L
1L=.946
how many pounds are in a kg
1kg=2.205lbs
how many km=1mi
1mi=1.609km
how many cm=1inch
2.54cm=1in
Why does an astronaut weigh more on Earth than in space when his/her mass remains the same in both places?
weight is a measure of how much attraction the earth's gravity has for an object (or person). In this case, the farther the astronaut is from earth the less gravitational force is pulling on him or her. Less gravitational attraction means the astronaut will weigh less. The mass of the astronaut is the amount of matter that makes up him or her. This does not change as the astronaut moves away from the earth.
how many cm in a mm
10
how many centimeters are in a meter?
100
How many nanometers are in 1 cm?
100 cm= 1m 1,000,000nm= 1m (1cm) (1m/100cm) (1,000,000,000/m) = 10,000,000nm
how many g in a kg?
1000
how many mL in a L?
1000
how many meters are in a kilometer?
1000
how many mg are in a g?
1000
how many milliliters are in a meter
1000
how many microliters(uL) are in a liter?
1000000
How many milligrams are in 1kg?
1000mg= 1 g 1000g= 1kg (1kg) (1000g/kg) (1000mg/g)= 1,000,000 mg
how many angstroms are in a meter
10^-10
how many nanometers are in a meter?
10^-9
how many in=1m
39.37m=1in
how many qt in a gal
4
how many grams are in a pound?
453.6g=1lb
how many feet are in a mile?
5280 feet in a mile
If you collect a container of oxygen gas, should you store it with the mouth up or down?
If you collect a container of gas, you should store it with the mouth up. Oxygen gas is denser than air.
How can the number 642,000g be written to indicate that there are four significant figures?
It must be written in the scientific notation as 6.420*10^5 g.
Is it possible for the calculated answer from an multiplication or division problem to contain more significant figures than the measurements used in the calculation?
No, the number of significant digits in the calculated value may not be more than the number of significant figures in any of the measurements.
State the rules used in this text for rounding off numbers.
Rule 1: when the first digit after those you want to retain is 4 or less, that digit and all others to its right are dropped. The last digit retained is not changed. Rule 2: when the first digit after those you want to retain is 5 or greater, that digit and all others to the right of it are dropped and the last digit retained is increased by one.
Ice floats in water, yet is simply frozen water. If the density of water is 1.0g / mL, how is that possible?
The density of water is 1.0g/ mL at approximately 4 degrees Celsius. However, when water changes from a liquid to a solid at 0 degrees Celsius there is actually an increase in volume. The density of ice at 0 degrees Celsius is 0.917 g/mL. Therefore ice floats in water because solid water is less dense than liquid water.
when a very large number is written in scientific notation, should the exponent be a positive or a negative number?
The exponent will be positive for a large number and negative for a small number
Describe the order of the following substances(top to bottom) if these three substances were placed in a 100-mL graduated cylinder: 25mL glycerin, 25 mL mercury, and a cube of magnesium 2.0cm on an edge.
The three materials would sort out according to their densities with the most dense (mercury) at the bottom and the least dense (glycerin) at the top. In the cylinder, the solid magnesium would sink in the glycerin and float on the liquid mercury.
Is it possible for the calculated answer from an addition or subtraction problem to contain more significant figures than the measurements used in the calculation?
Yes, the number of significant digits depends on the precision of each of the individual measurements and the calculated value may have more or fewer sig figs than the original measurements as long as the precision is no greater than the measurement with the lowest precision.
How are significant zeros identified?
Zeros are significant when they are between non-zero digits or at the end of a number that includes a decimal point.
solve the following problems, stating answers to the proper number of sig figs a) 12.62 + 1.5 + 0.25= b) (2.25 * 10^3)(4.80*10^4) c) (452)(6.2)/ 14.3= d) (0.0394)(12.8)= e) 0.4278/59.6= f) 10.4 + 3.75(1.5 * 10^4)
a) 14.4 b) 1.08 * 10^8 c) 195.97= 2.0 * 10^2 d) .504 e) 7.18 * 10^-3 f) 5.6 * 10^4
How many sig figs are in each of the following numbers? a) 0.025 b) 22.4 c) 0.0404 d) 5.50 * 10^3
a) 2 b) 3 c) 3 d) 3
express each of the following numbers in exponential notation: a) 2,900,00 b) 0.587 c) 0.00840 d) 0.0000055
a) 2.9 * 10^6 b) 5.87 * 10^-1 c) 8.40 * 10^-3 d) 5.5 * 10^-6
Determine whether the zeros in each number are significant.
a) 2050: the first 0 is significant, the last 0 is not significant. b) 9.00 * 10^2: zeros are significant c) 0.0530: the first 2 zeros are not significant, the last zero is significant. d) 0.075: zeros are not significant e) 300: zeros are significant f) 285.00 zeros are significant
state the number of sig figs in each of the following: a) 40.0 b) 0.081 c) 129, 042 d) 4.090 * 10^-3
a) 3 b) 2 c) 6 d) 4
write each of the following numbers in exponential notation: a) 0.0456 b) 4082.2 c) 40.30 d) 12,000,000
a) 4.56 * 10^-2 b) 4.0822 * 10^3 c) 4.030 * 10^1 d) 1.2 * 10^7
round each of the following to 3 sig figs: a) 8.8726 b) 21.25 c) 129.509 d) 1.995 * 10^6
a) 8.87 b) 21.3 c) 130 d) 2.00 * 10^6
round each of the following to 3 sig figs: a) 93. 246 b) 0.02857 c) 4.644 d) 34.250
a) 93.2 b) .0286 c) 4.64 d) 34.3
what is the correct unit of measurement for each of the following? a. 1000m b. 0.1g c. 0.000001 L d. 0.01m e. 0.001 L
a. 1000 meters= 1 kilometer b. 0.1 gram= 1 decigram c. 0.000001 liter= 1 microliter d. 0.01 meter= 1 centimeter e. 0.001 liter= 1 milliliter
what is the relationship between millimeters and cubic centimeters?
they are equivalent units.
what is the numerical meaning of each of the following? a. kilogram b. centimeter c. microliter d. millimeter e. deciliter
a. kilogram= 1000 grams b. centimeter= 1/100 of a meter(0.01 m) c. microliter= 1/1,000,000 of a liter (0.000001 L) d. millimeter= 1/1000 of a meter (0.001 m) e. deciliter= 1/10 of a liter (0.1 L)
which substance has the greater volume; 25 g gold or 25 g silver?
density of gold=19.3 g/mL (25 g gold)(1mL/19.3g)= 1.3mL density of silver=10.5g/mL (25g silver)(1mL/10.5g)= 2.4mL 25g of silver has the greater volume
Arrange these materials in order of increasing density: salt, vegetable oil, lead, and ethyl alcohol.
ethyl alcohol, vegetable oil, salt, lead
state the abbreviation for each of the following units: gram microgram centimeter micrometer millimeter deciliter
gram=g microgram=ug centimeter=cm micrometer=um milliliter=mL deciliter=dL
Distinguish between heat and temperature
heat is a form of energy, while temperature is a measure of intensity of heat(how hot the system is)
state the abbreviation for each of the following units: milligram kilogram meter nanometer angstrom microliter
milligram=mg kilogram=kg meter=m nanometer=nm angstrom=A (with dot on top) microliter=uL
Ice floats in vegetable oil and sinks in ethyl alcohol. The density of the ice must lie between what numerical values?
the density of the ice must be less than 0.91 g/mL and greater than 0.789 g/mL
To write 6.35.2 * 10^-8 in the proper scientific notation form, should the exponent increase or decrease?
the exponent will decrease
Explain why the last digit in a measurement is uncertain
the last digit in a measurement is uncertain because if the quantity were to be measured multiple times, the last digit would vary.