Chemistry 111 ch 1
What would 0.038851 be rounded to if it needed to retain 3 significant figs
0.0389
What is the results of 1.0-0.093 including sig figs ?
0.9
Rules to determine which number is reported as significant or not
1) any nonzero digit is significant. 956 - all 3 are significant 2) any zeros between nonzero are significant. 9006 - all 4 are significant 3) zero at the end of a number without a decimal are not significant; they serve only to put the significant numbers in the correct position. 890000- first 2 digits are significant. However zeros at the end of any number with a decimal point are significant 890000. - now all 6 are significant 4) zeros at the beginning of a decimal are not significant 0.00000076 - last 2 are significant 0.0000007600 - now the last 4 are significant
Give the number of significant figures in each measurement. 1) 36.7 m 2) 0.006606 s 3) 2,002 kg 4) 306,490,000 people
1) rule 1 - 3 sig figs 2) rule 4 - last 4 are sig figs 3) rule 1 and 2 - all 4 sig figs 4) rule 1 and 5 and 3 - 5 sig figs
Process of Science
1) state a hypothesis 2) test the hypothesis 3)refine the hypothesis
What will be the results of the following series of operations: ( 14.93 + 4.777) \11.13 report your answer with correct number of sig figs
1.771
Deci (d)
10^-1
pico (p)
10^-12
centi (c)
10^-2
Fenton (f)
10^-3
milli (m)
10^-3
micro
10^-6
nano(n)
10^-9
Tera (T)
10^12
Kilo(k)
10^3
Mega (M)
10^6
Giga (G)
10^9
Give the result of the following expression with the correct number of sig figs : 84 m/s x 32.533s =
2700m
At what temperature does water boil in Kelvin and Fahrenheit?
373.15K and 212 F
How many compounds are known ?
50 million
Write the measurement 0.00860 in scientific notation using the correct amount of sig figs
8.60x10-3 power km
Which of the following is NOT a physical property ? A. Combustibility B. Conductivity C. Malleability D. Elasticity
A combustibility
Law
A pattern that has been established based on verified experimental data that describes an observation but doe not provide an explanation as to the reason why said observation occurs is a
intensive property
A property that doesn't depend on the amount of matter present
What is 101 Kelvins in Celsius? A) -172 C B) 374 C C) 38 C D) 101 C
A) -172 C
A temperature of a substance changes by 1 K. This is equal to a temperature change of ________? A) 1 C B) 1 F C) 273 C D) 273 F
A) 1 C
Which operation is preformed to convert a temperature given in Celsius to Kelvin? A) add 273.15 B) subtract 273.15 C) multiply by 273.15 D) divide by 273.15
A) add 273.15
When adding numbers, the sum with have: A) as many decimal places as the number with the fewer decimal places B) as many decimal places as the number with more decimal places C) as many significant figures as the number with the fewest sig figs D) as many sig figs as the number with more sig figs
A) as many decimal places as the number with the fewer decimal places
Which is a heterogeneous mixture? A) clam chowder B) water C) yea D) vinegar
A) clam chowder
You examine a substance and generate the following results. Which result describes a chemical property of that substance? A) the substance emits a gas when dropped in water B) the substance is dark green C) the substance is sour to the taste D) the substance has a pleasant odor
A) the substance emits a gas when dropped into water
Which of the following has 3 sig figs ? Select all that apply. A)123 B)12.3 C)123000. D) 1.23 x 10^4
A,B and C
A large change in temperature ( not resulting from external heating) with the appearance of gas bubbles is most likely a indication of: A. Chemical change B. Only physical changes occurring C. Molecules are undergoing physical change D. None of the above
A. Chemical change
Mixtures
Are physical combinations of more than one substance.
A yellow liquid is found to be corrosive. How are the properties of the liquid beat described? A) the corrosive nature of the liquid is a physical property B) the yellow color of the liquid is a physical property C) the corrosive nature of the liquid is a chemical property D) the density of the liquid is a chemical property
B and c
0.738x0.28 is 0.20664 but is rounded to 0.21. Which rule or rules apply to this calculation? A) round the result to the same number of decimal places as the value with the least number of decimal places B) round the result to the same number of significant figs as the value with the least number of significant figs C) round down if the digit to be dropped is less than 5 D) round up of the digit to be dropped is more then 5
B) and D)
What is the difference between atoms and molecules? A) molecules are made of 2 different atoms B) molecules are made up of 2 or more atoms C) molecules are smaller then atoms D) molecules are always larger then atoms
B) molecules are made up of 2 or more atoms
When reading a measurement from a analog instrument like a ruler or a mercury thermometer, how should you determine the number of sig figs to record? A) the least sig fig should be the place value of the smallest markings in the instrument B) the least sig fig should be estimated by reading between the smallest markings on the instrument C) the least sig fig should be one place-value greater than the smallest markings on the instrument D) use as many sig figs as the number of repeated measurements.
B) the least fish fig should be estimated by reading between the smallest markings on the instrument
Which of the following is a physical change? A) gasoline burns B) water freezes C) bread roasts D)metal rusts
B) water freezes
Explain when the trailing 0 should be considered significant A) when the number has no decimal B) when the number includes a decimal C) trailing 0 are always sig D) trailing 0 are never significant
B) when the number includes a decimal
If you travel to the moon, which statement would be correct. A) your mass is lower then your mass on earth, but your weight is greater B) your mass is the same as your mass on earth, but your weight is lower C) both your mass and weight are lower then on earth D) your mass is lower, but your weight is the same as your weight on earth
B) your mass is the same as your mass on earth, but your weight is lower
Choose the best explanation below for why dimensional analysis is also sometimes referred to as the factor lane approach A) it is sometimes called the factor label approach because it is only useful when multiplying quantities with units B) it is sometimes called the factor label approach because writing the units for all factors is an expression is the only way to give them unique labels C) it is sometimes called the factor label approach because units are treated as a factor ( along with numeric factor ) in a quantity like 25 g, allowing us to subject the unit to algebraic operations as if they were variables D) it is sometimes called the factor label approach because it is used exclusively to come up with conversion factors for unit conversion
C)
What is a unit conversion factor? A) an average of two numbers in different measurements B) 2 different numbers expressed in the same measurement unit C) a ratio of two equivalent quantities expressed in different measurement units D) a way to convert decimal numbers into factions
C)
Which of the following factors used in dimensional analysis calculation have a finite number of sig figs( in other words , they are not exact numbers ) that might limit the precision of the calculation value? A) a conversion factor for time of 60 min/ 1 hour) B) a conversation factor for distance of ( 1000m / 1 km) C) a measurement of speed equaling ( 27.7 km/hour) D) none of these
C) a measurement of speed equaling (27.7 km/hour)
The digits in a measurement including the uncertain last digit are know as: A) uncertainty digits B) precise measurement C) sig fig D) none of the above
C) sig fig
Which of the following is an element A) water B) ammonia C) sodium D) carbon dioxide
C) sodium
When computing using dimensional analysis: A) all unit conversion must be done separately B) all unit conversions must be done in a singular calculation C) unit conversion can be done either simultaneously or separately D) unit conversions are not a part of dimensional analysis
C) unit conversion can be done either simultaneously or separately
Which of the following temperatures are equivalent to absolute zero (0K)? Select all that apply A) 74.93 F B) -100 C C) -273.15 C D) -459.67 F
C)-273.15 C and D)-459.67 F
chemical properties
Characteristics of matter that describe how matter changes form in the presence of other matter Examples Burning is a chemical property
homogeneous
Composed of 2 or more substances, but when mixed, naked eye cannot see the two or more components Also called solutions
What is an intensive property? A) energy B) length C) mass D) melting point
D)
Which volume is equivalent to 0.01 L A) 10 dL B) 10 cL C) 10 kL D) 10 mL
D) 10 mL
Which of the following can be characterized as a physical change ? A. Copper pipe rust B. Milk going sour C. Firewood burns D. Sweat evaporating from your skin
D. Sweat evaporating from your skin
Who was the first to propose the idea of an atom?
Democritus
Quantitative
Description represents the specific amount of something. It means knowing how much of something is present
What are the two types of substances?
Elements and compounds
Properties of matter all into 2 categories which are:
Extensive properties, intensive properties
Which of the following fields would be considered science? 1) geology 2) ethics 3) political science 4) biology
Geology, biology
properties of solids
Have a defined shape and volume
properties of gases
Have no definite shape ( take shape of container ), do not have a specific volume ( they fill all of the available volume)
properties of liquids
Have no definite shape( takes shape of the container), do have a specific volume.
Accuracy
How close a measurement is to an accepted value
Precision
How close a set of measurements are to each other
Qualitative
Implies a description of the quality of an object For example: physical properties are generally qualitative descriptions: Sulfur is yellow, a math book is heavy, the statue is pretty
Compound
Is a combination of more than one element. Example: water , penicillin, and sodium chloride ( table salt)
Plasma
Is a gaseous state of matter that contains appreciable number of electrically charged particle
Theory
Is a general statement that explains a large number of observation
heterogeneous mixture
Is a mixture composed of 2 or more substances. The mixture is not uniform throughout, so it is easy to see the more then one substances.
Density
Is a physical property that is defined as a substances mass divided by its volume: d= m/V
substance
Is a sample of matter that has the same physical and chemical properties throughout
Law
Is a specific statement that is thought to be never violated by the entire natural universe.
Matter
Is a substance that has mass and takes up space
Hypothesis
Is an educated guess about how the natural universe works
scientific notation
Is an expression of a number using the power of 10
standard notation
Is straightforward expression of a number Example: 25, 106.3 , 18,000 , 0.000000359
Science
Is the process of knowing about the natural universe through observation and experiment.
Element
Is the simplest type of chemical substance; it cannot be broken down into simpler chemical substances by ordinary chemical means Examples: Iron, carbon and Gold
Atom
Is the smallest particle of an element that has properties of that element and can enter into a chemical combination
Temperature
Kelvin (K)
Mass
Kilogram (kg)
What are the fundamental SI units
Length = meter(m) Mass= kilogram (kg) Time = seconds (s)
What is the mass of 44.6 mL of mercury ?
M= 44.6 cm3 x 13.6 g/mL = 606.56g Mercury Limit to 3 sig figs = 607g Mercury
length
Meter (m)
Does physical change affect the chemical composition of matter?
No
physical change
Occurs when a sample of matter changes one or more of its physical properties Example: A solid melts, or alcohol in a thermometer may change volume as the temperature changes
time
Seconds (s)
What are physical characteristics of matter ?
Shape, color, size and temperature
What are the 3 fundamental phases of matter ?
Solid, liquid, and gas
Examples of mixtures
Syrup ( sucrose in water ),
significant figures
The concept of reporting the proper number of digits in a measurement or calculation.
extensive property
a property that depends on the amount of matter
electric current
ampere, A
luminous intensity
candela (cd)
Amount of substance
mole (mol)
Chemistry
the study of matter and energy
