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Elements& Compounds

Properties of MatterChanges in MatterSolution

Chemistry


Based on their location on the periodic table, which of the following pairs of atoms would most likely share electrons when bonding?

A. Al and F B. Ca and I C. Na and Cl D. P and O


D. P and O


Elements in Group 16 of the periodic table usually —

F form large moleculesG gain electrons when bondingH act like metalsJ solidify at room temperature


G gain electrons when bonding


The chemical formula for calcium chloride is —

F Ca2Cl

G CaCl

H CaCl2

J Ca2Cl3


H CaCl2


An unidentified element has many of the samephysical and chemical properties as magnesium and strontium but has a lower atomic mass than either of these elements. What is the most likely identity of this element?

F SodiumG BerylliumH CalciumJ Rubidium


G Beryllium


Although it is located in Group 1A and can form ions, hydrogen most frequently shares electrons to become stable.

What type of bond is shown in the figure above and why?

A. ionic, because hydrogen loses the electron gained by chlorine B. polar covalent, because there is unequal sharing of electrons C. pure covalent, because any sharing of electrons is covalent D. pure covalent, because there is equal sharing of electrons


B. polar covalent, because there is unequal sharing of electrons


Compared to 250 g of gaseous nitrogen, 250 g of liquid nitrogen has greater —

A volumeB temperatureC massD density


D density


Swimmers find that they can float more easily in the ocean than in a freshwater pond. The most likely reason for this phenomenon is that the —

A viscosity of pond water is greater than that of ocean waterB density of ocean water is higher than that of pond waterC temperature of pond water is lower than that of ocean waterD mass of ocean water is greater than that of pond water


B density of ocean water is higher than that of pond water


This pipette is filled with a 20% NaOH solution. The solution is at 20°C and has a density of 1.23 g/mL. According to this information, what is the mass of this NaOH solution?

A 3.88 gB 15.7 gC 23.9 gD 24.6 g


C 23.9 g


Which of the following statements is true regarding the relationship between temperature and solubility in water?

A. All solids become more soluble as temperature increases. B. An increase in temperature of the water usually results in more solid solute dissolving. C. Gases become more soluble as temperature increases. D. The effect of temperature on the solubility of both gases and solids is the same.


B. An increase in temperature of the water usually results in more solid solute dissolving.


Suppose you need water that contains more oxygen than usual. You plan on bubbling air, which contains oxygen, into the water. What would you do to increase the amount of oxygen that will dissolve in the water?

A. Decrease the pressure on the system. B. Decrease the temperature of the water. C. Make water molecules more polar. D. Stir the water.


A. Decrease the temperature of the water.


Which of these changes in rocks is a physicalchange?

A Acid rain damaging marbleB Iron in rock combining with oxygen to form hematiteC Carbonic acid weathering limestoneD An ice wedge shattering a slab of shale


D An ice wedge shattering a slab of shale


When the above equation is balanced, thecoefficient for magnesium chloride is —

A 0B 1C 2D 4


B 1


If all the reactants in a chemical reaction arecompletely used, which of the following statements accurately describes the relationship between the reactants and the products?

F The products must have a different physical state than the reactants.G The total mass of the reactants must equal the total mass of the products.H The reactants must contain more complex molecules than the products do.J The density of the reactants must equal the density of the products.


G The total mass of the reactants must equal the total mass of the products.


What type of change is shown in the diagram above, which shows a distillation setup?

A. a physical change B. a chemical change C. both a chemical change and a physical change D. neither a chemical nor a physical change


A. a physical change


Which chemical equation supports the law of conservation of mass?

F 2H2O(l) → H2(g) O2(g)

G Zn(s) HCl(aq) → ZnCl2(aq) H2(g)

H Al2C3(s) H2O(l) → CH4(g) Al(OH)3(s)

J CH4(g) 2O2(g) → CO2(g) 2H2O(g)


J CH4(g) 2O2(g) → CO2(g) 2H2O(g)


Over time an open soft drink will lose carbonation (dissolved CO2). Which of these allows the CO2 to remain in solution the longest?

A Reduced air pressureB Exposure to direct sunlightC Increased air currentsD Cooler temperatures


D Cooler temperatures


In this apparatus, the seawater is an example of a —

F strong electrolyteG weak acidH nonelectrolyteJ strong base


F strong electrolyte


Which of the following statements is true regarding the effect of thermal pollution on the organisms living in a lake?

A. More dissolved oxygen will be present because an increase in temperature will increase the solubility of oxygen in the water.

B. The lake will be able to support more organisms because organisms grow better in warm water.

C. The water in the warmer lake will contain less dissolved oxygen, so fewer organisms that require oxygen will be able to live there.

D. Thermal pollution has no effect on the organisms

involved.


C. The water in the warmer lake will contain less dissolved oxygen, so fewer organisms that require oxygen will be able to live there.


Fish survive through severe winters because of the property of water that allows water to —

F form chemical bonds as it freezes, raising the water temperature below the iceG increase in density while it freezes, dissolving more oxygen from the airH expand when it freezes, creating a floating and insulating layer of iceJ precipitate vital nutrients when it freezes, increasing the food supply


H expand when it freezes, creating a floating and insulating layer of ice


Oil is nonpolar, water is polar, and the two do not dissolve in each other. The figure shows how soap cleans oily dirt. From the diagram, which of the following statements best summarizes how

soap enables water to remove oil?

A. Soaps contain alcohol, which dissolves oils. B. The charged part of soap makes oil polar, and it dissolves in

water. C. The nonpolar part of soap dissolves in oil, and its charged part is attracted to water. D. The nonpolar tail of a soap molecule knocks loose the oil particles.


C. The nonpolar part of soap dissolves in oil, and its charged part is attracted to water.

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Documents

g slide

pond water slide

o slide

room temperature slide

water molecules

slab of shale slide

viscosity of pond water

covalent d