Chem 111
Measurements
provide the information that is the basis of most of the hypotheses, theories, and laws in chemistry
compounds
pure substances that can be broken down into simpler substance by chemical changes. Consists os 2 or more types of elements chemically bonded. Properties of compounds are different from the uncombined elements making up the compound
Macroscopic domain
realm of everyday things that are large enough to be sensed directly by human sight and touch
Microscopic domain
realm of things that are much too small to be sensed directly. "Micro"=small
weight
refers to the force that gravity exerts on an object
solid
rigid and posses a definite shape
time
second (s)
atom
smelled particle of an element that has properties of that element that can enter a chemical combination.
unit
standard of comparison for measurements
Chemistry
study of composition, properties, and interactions of matter. Science based on observation and experimentation.
gas
takes both the shape and volume of its container
Scientific method
tentative explanation of observations that acts as a guide and checking info
law of conversation
these is no detectable change in the total quantity of matter present when matter converts from one type to another for both chemical and physical change
element
type of pure substance that can't be broken down into simpler substances by chemical changes. Examples gold (Au), Oxygen, 100 known elements
homogenous mixture
uniform composition and appears visually the same throughout aka solution.
Why is an object's mass, rather than its weight, used to indicate the amount of matter it contains?
weight changes with gravity, mass doesn't
Theory
well sustained, comprehensive, testable explanation of a particular aspect of nature
molecule
consist of 2 or more atoms connected by strong forces know as chemical bonds.
Symbolic domain
contains the specialized language used to represent components of the macroscopic and microscopic domains such as chemical symbols
deci
d 10^-1
Meter
defined as distance light travels in a vacuum in 1/299,792,458 of one second. meter is 3in longer than 1 yard
extensive property
depends on the amount of matter present
intensive property
does not depend on the amount of the matter present
femto
f 10^-15
liquid
flows and takes the shape of its container
kilo
k 10^3
mass
kilogram (kg)
mass
kilogram (kg) defined by certain cylinder of platinum iridium alloy. 1 kg is about 2.2 pounds
a) to three decimal places, what is the volume of a cube cm^3 with an edge length of 0.843cm? b) if the cube in part a is copper and has a mass of 5.34g, what is the density of copper to two decimal places? d=m/v
lxwxh = 0.843cx0.843x0.843=0.600cm^3 d=m/v= 5.34/0.600cm^3=8.91/cm^3
milli
m 10^-3
micro
m 10^-6
density
mass/volume
Mass
measure of amount of matter in an object
volume
measure of the amount of space occupied by an object
length
meter (m)
Amount of substance
mole (mol)
nano
n 10^-9
pico
p 10^-12
Yeast converts glucose to ethanol and carbon dioxide during anaerobic fermentation as depicted in the simple chemical equation here: glucose⟶ethanol+carbon dioxideglucose⟶ethanol+carbon dioxide (a) If 200.0 g of glucose is fully converted, what will be the total mass of ethanol and carbon dioxide produced? (b) If the fermentation is carried out in an open container, would you expect the mass of the container and contents after fermentation to be less than, greater than, or the same as the mass of the container and contents before fermentation? Explain. (c) If 97.7 g of carbon dioxide is produced, what mass of ethanol is produced?
(a) 200.0 g; (b) The mass of the container and contents would decrease as carbon dioxide is a gaseous product and would leave the container. (c) 102.3 g
When elemental iron corrodes it combines with oxygen in the air to ultimately form red brown iron(III) oxide called rust. (a) If a shiny iron nail with an initial mass of 23.2 g is weighed after being coated in a layer of rust, would you expect the mass to have increased, decreased, or remained the same? Explain. (b) If the mass of the iron nail increases to 24.1 g, what mass of oxygen combined with the iron?
(a) Increased as it would have combined with oxygen in the air thus increasing the amount of matter and therefore the mass. (b) 0.9 g
43. Visit this density simulation and click the "turn fluid into water" button to adjust the density of liquid in the beaker to 1.00 g/mL. Change the block material to foam, and then wait patiently until the foam block stops bobbing up and down in the water. (a) The foam block should be floating on the surface of the water (that is, only partially submerged). What is the volume of water displaced?(b) Use the water volume from part (a) and the density of water (1.00 g/mL) to calculate the mass of water displaced. (c) Remove and weigh the foam block. How does the block's mass compare to the mass of displaced water from part (b)?
(a) displaced water volume = 2.8 mL; (b) displaced water mass = 2.8 g; (c) The block mass is 2.76 g, essentially equal to the mass of displaced water (2.8 g) and consistent with Archimedes' principle of buoyancy.
Classify each of the following as an element, a compound, or a mixture: (a) iron (b) oxygen (c) mercury oxide (d) pancake syrup (e) carbon dioxide (f) a substance composed of molecules each of which contains one hydrogen atom and one chlorine atom (g) baking soda (h) baking powder
(a) element; (b) element; (c) compound; (d) mixture; (e) compound; (f) compound; (g) compound; (h) mixture
37. Indicate the SI base units or derived units that are appropriate for the following measurements: (a) the mass of the moon (b) the distance from Dallas to Oklahoma City (c) the speed of sound (d) the density of air (e) the temperature at which alcohol boils (f) the area of the state of Delaware (g) the volume of a flu shot or a measles vaccination
(a) kilograms; (b) meters; (c) meters/second; (d) kilograms/cubic meter; (e) kelvin; (f) square meters; (g) cubic meters
Identify each of the following statements as being most similar to a hypothesis, a law, or a theory. Explain your reasoning. (a) The pressure of a sample of gas is directly proportional to the temperature of the gas. (b) Matter consists of tiny particles that can combine in specific ratios to form substances with specific properties. (c) At a higher temperature, solids (such as salt or sugar) will dissolve better in water.
(a) law (states a consistently observed phenomenon, can be used for prediction); (b) theory (a widely accepted explanation of the behavior of matter); (c) hypothesis (a tentative explanation, can be investigated by experimentation)
Classify each of the following changes as physical or chemical: (a) condensation of steam (b) burning of gasoline (c) souring of milk (d) dissolving of sugar in water (e) melting of gold
(a) physical; (b) chemical; (c) chemical; (d) physical; (e) physical
Identify each of the underlined items as a part of either the macroscopic domain, the microscopic domain, or the symbolic domain of chemistry. For those in the symbolic domain, indicate whether they are symbols for a macroscopic or a microscopic feature. (a) A certain molecule contains one H atom and one Cl atom. (b) Copper wire has a density of about 8 g/cm3. (c) The bottle contains 15 grams of Ni powder. (d) A sulfur molecule is composed of eight sulfur atoms.
(a) symbolic, microscopic; (b) macroscopic; (c) symbolic, macroscopic; (d) microscopic
The volume of a sample of oxygen gas changed from 10 mL to 11 mL as the temperature changed. Is this a chemical or physical change?
physical
How does a homogeneous mixture differ from a pure substance? How are they similar?
The mixture can have a variety of compositions; a pure substance has a definite composition. Both have the same composition from point to point.
number
The size or magnitude of the measurement
39. Give the name of the prefix and the quantity indicated by the following symbols that are used with SI base units. (a) c (b) d (c) G (d) k (e) m (f) n (g) p (h) T
. (a) centi-, ×× 10−2; (b) deci-, ×× 10−1; (c) Giga-, ×× 109; (d) kilo-, ×× 103; (e) milli-, ×× 10−3; (f) nano-, ×× 10−9; (g) pico-, ×× 10−12; (h) tera-, ×× 1012
41. Visit this density simulation and click the "turn fluid into water" button to adjust the density of liquid in the beaker to 1.00 g/mL. (a) Use the water displacement approach to measure the mass and volume of the unknown material (select the green block with question marks). (b) Use the measured mass and volume data from step (a) to calculate the density of the unknown material. (c) Link out to the link provided. (d) Assuming this material is a copper-containing gemstone, identify its three most likely identities by comparing the measured density to the values tabulated at this gemstone density guide. (e) How are mass and density related for blocks of the same volume?
. (a) m = 18.58 g, V = 5.7 mL. (b) d = 3.3 g/mL (c) dioptase (copper cyclosilicate, d = 3.28—3.31 g/mL); malachite (basic copper carbonate, d = 3.25—4.10 g/mL); Paraiba tourmaline (sodium lithium boron silicate with copper, d = 2.82—3.32 g/mL)
What is the density of lead if a cube of lead has an edge length of 2.00cm and has a mass of 90.7g?
2.00x2.00x2.00= 8.00cm, 90.7/8.00cm^3= 11.3cm^3
Many of the items you purchase are mixtures of pure compounds. Select three of these commercial products and prepare a list of the ingredients that are pure compounds.
Answers will vary. Sample answer: Gatorade contains water, sugar, dextrose, citric acid, salt, sodium chloride, monopotassium phosphate, and sucrose acetate isobutyrate.
The density (d) of a substance is an intensive property that is defined as the ratio of its mass (m) to its volume (V). density=massvolumed=mVdensity=massvolumed=mV Considering that mass and volume are both extensive properties, explain why their ratio, density, is intensive.
Being extensive properties, both mass and volume are directly proportional to the amount of substance under study. Dividing one extensive property by another will in effect "cancel" this dependence on amount, yielding a ratio that is independent of amount (an intensive property).
Classify each of the following as an element, a compound, or a mixture: (a) copper (b) water (c) nitrogen (d) sulfur (e) air (f) sucrose (g) a substance composed of molecules each of which contains two iodine atoms (h) gasoline
Copper = element water = compound nitrogen = element sulfur = element air = mixture sucrose = compound g= element gasoline = mixture
. Explain the difference between extensive properties and intensive properties.
The value of an extensive property depends upon the amount of matter being considered, whereas the value of an intensive property is the same regardless of the amount of matter being considered.
Examples of Chemistry
Digesting food, clothing, cookware, credit cards, etc
giga
G 10^9
. Prepare a list of the principal chemicals consumed and produced during the operation of an automobile.
Gasoline (a mixture of compounds), oxygen, and to a lesser extent, nitrogen are consumed. Carbon dioxide and water are the principal products. Carbon monoxide and nitrogen oxides are produced in lesser amounts.
Matter is everywhere around us. Make a list by name of fifteen different kinds of matter that you encounter every day. Your list should include (and label at least one example of each) the following: a solid, a liquid, a gas, an element, a compound, a homogenous mixture, a heterogeneous mixture, and a pure substance.
Gatorade, soup, sweet tea, gas, water
How does a heterogeneous mixture differ from a homogeneous mixture? How are they similar?
Heterogenous=see differences, homogenous= constant. They both can be separated back into parts
How are the molecules in oxygen gas, the molecules in hydrogen gas, and water molecules similar? How do they differ?
In each case, a molecule consists of two or more combined atoms. They differ in that the types of atoms change from one substance to the next.
temperature
Kelvin (K)
temperature
Kelvin (K) Celsius degrees are same magnitude as those of kelvin. water freezes at 273.15k, boils at 373.15k
. What properties distinguish solids from liquids? Liquids from gases? Solids from gases?
Liquids can change their shape (flow); solids can't. Gases can undergo large volume changes as pressure changes; liquids do not. Gases flow and change volume; solids do not.
mega
M 10^6
The amount of heat required to melt 2 lbs of ice is twice the amount of heat required to melt 1 lb of ice. Is this observation a macroscopic or microscopic description of chemical behavior? Explain your answer.
Macroscopic. The heat required is determined from macroscopic properties.
How do molecules of elements and molecules of compounds differ? In what ways are they similar?
Molecules of elements contain only one type of atom; molecules of compounds contain two or more types of atoms. They are similar in that both are comprised of two or more atoms chemically bonded together.
Explain how you could experimentally determine whether the outside temperature is higher or lower than 0 °C (32 °F) without using a thermometer.
Place a glass of water outside. It will freeze if the temperature is below 0 °C.
tera
T 10^12
plasma
a gaseous state of matter that contains an appreciable amount of electrically charged particles. has unique properties distinct from ordinary gas. Can be found in certain high-temp environments. *Sun has a lot of this*
Identify each of the underlined items as a part of either the macroscopic domain, the microscopic domain, or the symbolic domain of chemistry. For any in the symbolic domain, indicate whether they are symbols for a macroscopic or a microscopic feature. (a) The mass of a lead pipe is 14 lb. (b) The mass of a certain chlorine atom is 35 amu. (c) A bottle with a label that reads Al contains aluminum metal. (d) Al is the symbol for an aluminum atom.
a) macroscopic domain b) microscopic domain c) symbolic domain-macroscopic d) symbolic- microscopic
35. Is a meter about an inch, a foot, a yard, or a mile?
about a yard
electric current
ampere, A
Matter
anything that takes up space and has mass.
centi
c 10^-2
luminous
candela cd
physical change
change in state or properties of matter without any accompanying change in its chemical composition.
chemical property
change of one type of matter into another
physical property
characteristic of matter that is not associated with a change in its chemical composition
mixture
composed of 2 or more types of matter that can be present in varying amounts and be separated by physical changes
heterogenous mixture
composition that varies from point to point
