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Chem Final
Final exam for CHEM 1024
Question | Answer |
---|---|
In a measured number, the ________ ________ are all the digits including the estimated digit. | significant figures |
To know how many significant figures are in an answer, convert it into scientific notation. All the numbers that make up the __________ are significant figures. | coefficient |
There is always some __________ in every measurement. When a measurement ends right on a marked line, a zero is written for the estimated digit. | uncertainty |
Counted numbers and numbers relative to definitions WITHIN one certain measurement system are called ________ _________. | exact numbers |
Metric system prefix that means "multiply base unit by 1,000" (10^3) | kilo |
Metric system prefix that means "divide base unit by 100" (10^-2) | centi |
Metric system prefix that means "divide base unit by 1,000" (10^-3) | milli |
In multiplication or division, the final answer is written with the same number of significant figures as the measurement with the ________ significant figures. | fewest |
In addition and subtraction, the final answer is written with the same number of _______ _______ as the measurement with the fewest significant figures. | decimal places |
_________ is relative to a comparison of the measured value of an individual measurement to that of the "true" value. (The true value os also clled the "literature value") | Accuracy |
A measure of how closely individual measurements agree with ONE ANOTHER when the same person repeats the same measurement using the same measuring devices under the same conditions: | Precision |
__________ is relative to each specific measuring device. It is the doubt range inherent to that measuring device. | Uncertainty |
________ ________ is the absolute difference of the literature value and the measured value divided by the literature value times 100. | Percent Error |
_______ _______ = (LV-MV/ LV) x 100 | Percent Error |
The absolute difference bewteen the actual value and the measured value: | Error |
Every valid equality has ____ possible conversion factors. | two |
Begin every Unit Factor Method problem with a(n) _______ ________. | incomplete equality |
Percentages can be turned into _________ _______with this formula: part/whole x 100. For example, if an alloy is 25% by mass silver, this could be written as 25 g silver/100 g alloy or 100 g alloy/25 g silver. | valid ratios |
The Universe consists of these two things: | Matter and Energy |
The ability to do work is defined as: | Energy |
The non-physical aspect of the universe that we measure in terms of change: | Energy |
The physical aspect of the Universe is matter. We can measure this in terms of _______ and ________. | mass and volume |
Measurement that describes a quantity of matter: | mass |
Measurement that describes space occupied by matter; | volume |
Anything that has mass and occupies space: | matter |
Matter that has a fixed or definite composition is called a _______ ________. | pure substance |
This is the simplest type of pure substance. It is composed of only one type of material: | Element |
This is a pure substance that consists of atoms of two or more elements, always chemically combined in the same ratio. | Compound |
In a ________, 2 or more substances are physically mixed, but NOT chemically combined. | mixture |
In any ________, the proportions of the components can vary. | mixture |
_______ ________ can be used to separate mixtures because there are no chemical interations between components. | Physical processes |
In _________ ________, also called solutions, the composition is UNIFORM throughout the sample. | homogenous mixtures |
In ________ _________, the components do NOT have a uniform composition throughout. | heterogenous mixture |
The energy of motion: | kinetic energy |
Stored energy (determined by the position of an object or by the chemical composition of a substance) | potential energy |
When matter undergoes a _________ _________, its state or appearance will change, but its composition remains the same. | physical change |
When matter undergoes a _________ _________, the original substance is converted into one or more new substances, which have different chemical and physical properties. | chemical change |
The type of energy associated with the motion of particles: | Heat (thermal energy) |
What are the 3 physical states of matter? | Solid, Liquid, Gas |
In a ________, the particles have enough energy to move freely in random diractions, but they are still close to each other and have enough attraction to maintain a definite volume. | liquid |
In a _______, the particles move at high speeds, which creates great distance between the molecules. | gas |
In a _______, very strong attractive forces hold particles close together. | solid |
Matter undergoes a _________ _____ _________ when it is converted from one state to another. This is a physical change. | change of state |
_______ _____ _______ is the energy associated with FREEZING and MELTING. | Heat of Fusion |
The ________ _____ ________for H20 is 80 cal/1 g ice. This means that 80 calories is needed to melt exactly 1 gram of ice. Conversely, 80 calories must be taken away from water at its freezing point for exactly 1 g of water to freeze. | Heat of Fusion |
True or False? The melting point of water and the freezing point of water is the same. | True. The MP and the FP of water is 0 degrees Celcius. |
During a change of state, the tempurature of the substance __________ __________. | remains constant! (equilibrium) |
________ _____ _________ is the energy associated with vaporization and condensation. | Heat of Vaporization |
The boiling point of water (which is also the point at which it condenses) is _______ degrees Celcius. | 100 |
The Heat of Vaporization for water is 540 cal/1 g water. This means when 540 cal is REMOVED from vapor at 100 deg Celcius, 1 gram of the water ________. Conversely, when 540 cal is ADDED to water at 100 deg Celcius, 1 gram of water will ________. | Condenses / Vaporizes |
_______ ________ is the heat energy required to raise one gram of water by one degree Celcius. | Specific Heat |
Heat energy released to the environment by a chemical reaction: | Exothermic Reaction |
Heat energy obtained from the surroundings by a chemical reactions: | Endothermic reaction |
The property of basic units of matter that determines the physical STATE of that matter is: | The amount of ATTRACTION the molecules have for one another. |
The atomic number of an element is its number of: | protons |
The subatomic particles contained in the nucleus of an atom: | protons and neutrons |
Subatomic particle that has mass but 0 charge: | neutron |
The Mass Number is the sum of the ________ and ________ of an atom. | neutrons and protons |
In Isotopic Notation, the _______ _______ is in at the top, left of the chemical symbol. | Mass Number |
In Isotopic Notation, the ________ ________ is at the bottom, left. | Atomic Number |
The number of electrons an atom has is equal to the number of its ________. | protons |
The weighted average number expressed in decimals below each element's chemical symbol onthe periodic table: | Atomic Mass |
The electrons of an atom are characterized by _________ _________. | relative energies |
Electrons that are of the highest main energy level are called ________ ________. | valence electrons |
_________ elements can form 2 or more ions. | Transition |
The volume of an atom can be described in terms of its _________ _________. | atomic radius |
In representative elements, Atom volume _________ going down a group. | increases |
In representative elements, Atom volume _________ from left to right across a period. | decreases |
In representative elements, Ionization energy _________ going down a group. | decreases |
In representative elements, Ionization energy ________ from left to right across a period. | increases |
___________is the most electronegative element. | Fluorine |
________ _________ is stored in chemical bonds. | Potential energy |
The basic unit for monoatomic elements (ex: O, Fe , Hg )is: | Atom |
The basic unit for polyatomic elements (ex: 02 , S8 ) and nonmetal compounds (covalent)(ex: C4H10) is: | Molecule |
The basic unit for ionic compounds (metal and nonmetal): | Ionic Formula Unit (IFU) |
A group of COVALENTLY bonded nonmetal atoms that has an overall electrical charge: | Polyatomic ion |
A chemical compound that contains exactly 2 different metal and nonmetal elements: | Binary Ionic Compound |
The electrostatic force of attraction between 2 nuclei, with shared pairs of valence electrons: | Covalent Bond |