PHYS 1415 (Unit 3) Ch 14-17
Each circle represents an atom. Which of the following boxes contains an element? A compound? A mixture
#* ## *# #* #* #* ** ** ** ## *# *# #* #* #* ** ** ** Mixture Compound Element
Which box represents a compound?
#* #* #*#* #* #* #* #* #* #* #* #* C only
If a neutral atom loses one electron, what is the electrical charge of the atom?
+1
If the following generic atom were to undergo ionization, what would be the charge of the most likely product?. * X *
+2
If a neutral atom gains two electrons, what is the electrical charge of the atom?
-2
Which of the following is the correct electron dot structure for cholorine (atomic no. = 17)
. . : Cl . . .
Which of the following solution is the most concentrated?
0.5 liter of water with 50 grams of sugar
How many more electrons can fit within the valence shell of a hydrogen atom?
1
A sample of water that is 99.9999 % pure contains 0.0001% impurities. Consider that a glass of water contains on the order of a trillion trillion (1 x 10^24) molecules. If 0.0001% of these molecules were the molecules of some impurity, about how many impuritiy molecules would this be?
1,000,000,000,000,000,000 (one million trillion: 1 x 10^18)
How many electrons are used to draw the electron-dot structure for acetylene, a covalent compound with the formula, C2H2
10
If an element has a -1 charge and the following chemical symbol, how many electrons does it have? 19 F 9
10
What is the molarity of 0.5 liters of a solution with 5 miles of sucrose in it?
10 molar
How many chloride ions (Cl-1) are needed to balance the positive charge of a barium ion (Ba+2)
2
If the solubility of a compound is 30 grams per liter, how much solid is left undissolved if you mix 30 g of the compound in 0.33 L of solution?
20 g
A solid has a solubility at room temp of 78 grams per liter. If 1.0 L of a hot solution containing 100 g of solute is cooled to room temp, how much solid is formed?
22 g
How many different elements are in the compound C6H12O6?
3
How many valence electrons does gallium (GA, atomic no = 31) have?
3
If the concentration of gold in seawater is 2.0 milligram per ton of sea water and the mass of the ocean is 1.5 x 10^18 tons, how much gold is in the ocean?
3.0 x 10^12 kg
How many molecules of sucrose are in a 0.5 moles of sucrose?
3.01 x 10^23 molecules of sucrose
What is the molarity when water is added to 2 moles of sodium chloride to make 0.5 liter of solution?
4 M
How many atoms are in one molecule of Na2SO4?
7
How many valence electrons does bromine (Br, atomic no = 35) have?
7
Using the images illustrating identical volumes of different materials, which has the highest density? ............. . . . . . . . . . . . . ............. . . . . . . . . . ............. . . . . . . . . . . . A B C
A
From the diagram, at which point is water boiling
A (top right)
If you mix a typical aluminum ion (Al, atomic no = 13) with a typical oxygen ion (O, atomic no = 8), what compound is formed?
Al2O3
Barium ions carry a 2+ charge, and nitrogen ions carry a 3- charge. What would be the chemical formula for the ionic compound barium nitride?
Ba3 N2
The diagram on the left shows the interface of solid and liquid phases of a single substance. Which box best represents if heat were added? If heat were taken away? ...... . . . . . .......... . . . . . . . . ...... . . . . . .......... . . . . . . . . ...... . . . . . .......... . . . . . . . . A B C
C - heat added B - heat taken away
Which of the following bonds would be the least polar?
C-H
Which of the following would have the lowest melting point?
CF4
Which of the following might have the lowest solubility in water?
CH3 CH3
Which of the following molecules is most likely to show a hydrogen bonding interaction?
CH3 OH
Which of the following substances contains F- ions?
CaF2 (Ca=2+, F=-1)
Which of the following elements will most likely form an ion with a -1 charge
Cl
Which of the following has the greatest number of nonbonding pairs of electrons?
F
Which are closer together: the two nuclei within potassium fluoride, KF, or the two nuclei within molecular fluorine, F2?
F2
Which of the following molecules is polar?
H F C=C H F
Which of the following molecules contains a polar bond?
H-F
Which of the following is a covalent compound composed of nonpolar covalent bonds?
H2
Which of the following molecules contains an ionic bond?
MgCl2 (ionic bond characterized by a metal & non-metal polyatomic ion)
Which of the following elements will most likely form an ion with a +1 charge
Na
Which solute graphed above has a solubility in water that does not markedly increase with increasing temp?
Na Cl
Which of the following is a positive ion?
Na+
Take money away from your bank account and the bank will show a negative credit. Take an electron away from and atom, however, and the atom shows up positive. Explain
Neutral atoms contain identically charged but oppositely signed protons and electrons. Removing one of the negative electrons results in an excess of positively charged protons
Which bond is most polar?
O-H
Phosphine is a covalent compound of phosphorus, P, and hydrogen, H. What is its chemical formula?
PH3
Which of the following elements should exhibit some metallic and some non-metallic properties?
Si
Which of the following is the strongest form of interatomic attraction?
a chemical bond
The following image describes what type of change?
a chemical change (because the atoms are connected differently)
The following image represents which kind of matter? ** ## ## ** ## ## ** ## ** ## ** ## ** ## **
a mixture
What is a diatomic molecule?
a molecule that is composed of two atoms
If someone is able to explain an idea to you using small familiar words, what does this say about how well that person understands the idea?
a person who completely understands an idea is capable of explaining it using language that is familiar to both of you
The following image describes what type of change? .......... . . . . . . . . . . .......... . . . . . . . .......... . . . . . . . .
a physical change (because change only in position, not change in molecular structure)
How would you classify the following material - coffee (with milk)
a suspension
How would you classify the following material - milk
a suspension
What is the name for the following polyatomic ion - CH3CO2-1
acetate
Which of the following is a mixture?
air
Which of the following can be classified as matter?
all of the above (ice cream, water, sand, perfume)
Which of the following would be an ion with a double positive charge?
an Mg atom that loses two electrons
Which of the following describes the reason for the following application of metals: structural supports for buildings
are strong but can be bent
Of the trhree sciences, physics, chemistry, and biology, the most complex is
biology because it is based upon both the laws of chemistry and physics
The diagram on the far left shows the moving particles of a gaseous material within a rigid container. Which of the three boxes on the right best represents this material upon the addition of heat
box (b) because it shows the gas particles moving faster
If both are at the same temp, which box contains a higher boiling point liquid? == == ++ == == ++ == == += += == ++ == += += A B
box b - because form indicates liquid phase, plus it's a compound (different types of atoms)
Which of the following elements is diatomic in its natural state?
bromine
What is the name of the following compound - CaCl2
calcium chloride
What is the name of the following compound - CO2
carbon dioxide
Is the following transformation representative of a physical change or a chemical change? += ++ =+ ==
chemical change because the atoms are connected differently
Many dry cereals are fortified with iron, which is added to the cereal in the form of small iron particles. How might these particles be separated from the cereal?
collect the iron fillings with a magnet
Someone argues that he or she doesnt drink tap water because it contains thousands of molecules of some impurity in each glass. How would you respond in defense of the waters purity, if it indeed does contain 1000's of molecules of some impurity per glass?
compared to the billions and billions of water molecules, a thousand molecules of something else is practically nothing
Which of the following boxes represents a suspension?
definition of suspension = a homogenous mixture in which the various components are in different phases
Which of the following would be considered a physical property?
density
The separation of charges within a polar molecule is called a
dipole
What type of phase change does the following figure best describe? . . . . . . . . . . . . ........ . . . . . . ........ . . . . . .
evaporation
Which would have the most kinetic energy?
hot gas
Which of the following is the main form of intermolecular attraction in a water molecule?
hydrogen bonding
A sample of steel is composed of 5% carbon and 95% iron. Which is the solvent?
iron
What drives an atom to form a covalent bond: its nuclear charge or the need to have a filled outer shell
its nuclear charge
How would you describe the volume of the following object: the amount of water in a swimming pool
macroscopic
Chemistry is the study of
matter AND tranformations of matter
What type of phase change does the following figure best describe? ....... . . . . . . . ....... . . . . . . .
melting
What property of metal atoms account for many of the observed bulk phenomena seen in metal samples?
metal atoms easily lose one or more outer electrons
Which substance has a lower boiling point?
molecule A because it is the first to transform into a liquid
What is the main difference between an ionic and a covalent bond?
one is the sharing of a pair of electrons, the other is the transfer of at least one electron
Which of the following solutions is the most concentrated?
one liter of water with 10 grams of sugar
Which of the following would be considered a heterogeneous mixture?
salad dressing
From the diagram which is more dense: liquid xenon or solid xenon?
solid
What state of matter does this diagram of submicroscopic particles represent? . . . . . . . ........ ...... ....
solid-gas mixture
How are interatomic forces and solubility related?
solubility depends on the solvents ability to overcome the intermolecular forces in a solid
What is the name of the following compound - SF3
sulfur triflouride
What property of alloys make them ideal for developing new materials?
the characteristics of the material change depending on how much of each component is present
The same amount of red colored Kook-aid crystals are added to a still glass of thick sugar water and a still glass of distilled water. Both are the same temp. Neither is stirred. Which should become uniform in color first?
the glass of distilled water
What is a valence shell
the outermost shell of electrons in an atom
An example of basic research is
the study of the compostion of the atom
Which of the following would NOT be considered a chemical property?
the temperature at which liquid will boil
Why cant the elements of a compound be separated from one another by physical means?
their atoms are too tightly bound to one another
The neon atom tends NOT to gain any additional electrons because
there is no more room available in its outermost occupied shell
What is the role of unpaired valance electrons?
they take part in the formation of different types of bonds
What is the gas found within a bubble of boiling water?
water vapor
The boiling point of 1,4-butanediol is 230*C. Would you expect this compound to be soluble or insoluble in room temp water?
water would be attracted to both ends, and is infinitely soluble in water
How many covalent bonds would the following generic atom usually form? . . : X : . .
would not usually form any covalent bonds
If the following generic atom were to undergo ionization, what would the most likely product be? . . : X : . .
would probably not ionize (tend not to form ions because valence shell already filled to capacity)
