Divers often inflate heavy duty balloons attached to salvage items on the sea floor. If a balloon is filled to a volume of 3.00L at a pressure of 2.50 atm, what is the volume of the balloon when it reaches the surface?
If the volume of a gas container at 32.0 C changes from 1.55L to 755mL, what will the final temperature be?
Which state of matter has a low density and is not easily compressed?
- both solids and liquids
- none of the above
none of the above
Increasing the intermolecular forces of a liquid will do which of the following?
- increase the surface tension
- decrease the vapor pressure
- decrease the evaporation rate
- increase the viscosity
- all of the above
all of the above
The rate of vaporization of a liquid can be increased by?
increasing the surface area and increasing the temperature
How many kilojoules of heat are needed to completely vaporize 42.8 grams of C4H10O at its boilng point?
Given: change in Hvap= 26.5 kJ/mol
If the solubility of sodium chloride is 36 grmns per 100 grams of water, which of the following solutions would be considered unsaturated?
5.8 moles of NaCl dissolved in 1 L of water
Which of the following compounds is a strong electrolyte?
- all of the above
all of the above
A solution contains 100.0 g water, 10.0 g NaCl, and 15.0 g methanol. What is the weight percent of methanol in the solution?
You need to prepare 2.00 L of 0.100 M Na2CO3 solution. The best procedure is weigh out :
21.2 g Na2CO3 and add water until the final solution has a volume of 2.00 L
WHich of the following is not an acid-base conjugate pair?
- H2CO3 and HCO3-
- NH4+ and NH3
- H2O and OH-
- H2S and OH-
H2S and OH-
A 25.0 mL sample of 0.105 M HCl was titrated with 31.5 mL of NaOH. What is the concentration of the NaOH?
Which of the following acids is a diprotic, weak acid?
- phosphoric acid
- carbonic acid
- sulfuric acid
- hydrobromic acid
Many metals react with halogens to give metal halides. For example
2AL (s) + 3Cl2 (g) yields 2AlCl3 (s)
If you begin with 13.5 g of aluminum, :
you will need 53.2 g Cl2 for complete reaction and will produce 66.7 g of AlCl3
COnsider the following generic chemical equation: 2A +5B yields C+3D
If you react 4 units of A with 10 units of B, which statement is true?
there are equivalent amounts of A and B
The theoretical yield of a reaction is 75.0 grams of product and the actual yield is 42.0 g. What is the percent yield?
How many grams of calcium phosphate are theoretically produced if we start with 3.40 moles of Ca(NO3)2 and 2.40 moles Li3PO4?
reaction: Ca(NO3)2 + 2Li3PO4 yields 6LiNO3 + Ca3(PO4)2?
A 24.0 g sample of nitrogen gas reacts with an excess of hydrogen gas to give an actual yield of 3.85 g NH3. What is the percent yield for this reaction?
Reaction: N2(g) + 3H2(g) yields 2NH3(g)
Which one of the following species has the electron configuration of 1s2 2s2 2p6?
all of them
Which of the following is considered a single electron group?
- single bond
- double bond
- triple bond
- all of the above
all of the above
Which of the following is NOT evidence that a chemical reaction has occurred?
- solid formation
- gas formation
- emission of light
- color change
- all are evidence of a chemical reaction
all are evidence of a chemical reaction
If you had an aqueous mixture that contained Ag+, K+, and Pb+ cations, how many different solids could precipitate if a chloride solution was added?
What is true of the scientific method?
The scientific method emphasizes observation and experimentation as the way to understand the world
What is an example of a scientific theory?
all matter is compose of small, indestructible particles called atoms
A sample of wood with a mass od 3.0 g was burned in an open dish. The ashes weighed 1.2 grams. What happened to the rest of the wood?
the remaining 1.8 grams was converted into gaseous compounds
Determine the answer to the following equations with correct number of significant figures:
(1.103 + 2.03) times 1.02521=?
A lead ball has a mass of 55.0 grams and a density of 11.4 g/cm3. What is the volume of the ball?
When 49.5 J of heat is transferred to 7.3 g iron at 22 C, the temperature of the iron increases to 37 C. What is the specific heat of iron in J/g C?
A fictional element has two isotopes, each making up 50% of the population. Isotope 1 has a mass of 80.0 amu, isotope 2 has a mass of 85.0 amu. Calculate the atomic mass of the fictional element.
_______is the science that seeks to understand what matter does by studying what atoms and molecules do.
__________ is a brief statement that synthesizes past observations and predicts future ones.
1. All nonzero digits are significant 1.05
2. Interior zeros are significant 4.0208
3. Trailing zeros are significant 3.00
4. Leading zeros are insignificant 0.00005
5. Zeros at the end of a number but before the decimal point are ambiguous
Rules of Significant Figures
___________ answer has the same number of significant figures as the factor with the lowest number of significant figures
Multiplying/Dividing Significant Figures
____________answer has the same number of decimal places as the factor with the lowest number of decimal places
Adding/Subtracting Significant Figures
________ atoms or molecules are arranged in geometric patterns with long-range; repeating order; salt, diamond
_________ atoms and molecules are close to each other, but move freely; have a fixed volume; assume shape of container
A _________ is composed of two or more different types of atoms and molecules combined in variable proportions
__________ is when matter changes its appearance but not its composition; ex: when ice melt
___________ is when matter changes its composition; ex: copper turns green upon continuous exposure to air
__________ is the process in which the mixture is heated to boil off the volatile (easily vaporizable) liquid
________ is the quantity of thermal energy (usually in J) required to change the temperature of a given amount of the substance by 1 C
___________ is when the elements are arranged in order of increasing relative mass, certain sets of properties recur periodically
_______ are atoms of the same element with the same number of protons but a different of neutrons
"All samples of a given compound have the same proportions of their constituent element." Describes which Law?
Law of constant composition
___________ do not normally exist I nature with single atoms as their basic units
____________ contains two atoms of that element bonded together as their basic units
When naming an ionic compound that is a _____________ metal forms only one type of ion
type I compound
When naming an ionic compound that is a__________ metal forms more than one type of ion
type II compound
__________ are ions that are themselves composed of a group of atoms with an overall charge
___________ are molecular compounds that form H+ ions when dissolved in water; composed of hydrogen; sour taste; ability to dissolve metals
Mass percent composition
mass percent of element X = mass of X in sample of compound / mass of sample of compound X 100 %
_________ gives the smallest whole-number ratio of each type of atom
Empirical formula- gives the smallest whole-number ratio of each type of atom