As a scuba diver goes deeper underwater, thediver must be aware that the increasedpressure affects the human body by increasingthe —A body’s temperatureB amount of dissolved gases in the bodyC amount of suspended solids in the bodyD concentration of minerals in the body

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Going deeper under water, the gasses of the blood become more condensed and “dissolved”.Coming up too fast,

is like shaking a can of coke and then opening up.The body doesn’t like it. It’s called the ‘bends’.

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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 39

Carbon dioxide Gas

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Which bottle will lose it’s dissolved carbon dioxide to theatmosphere soonest?

The table shows temperature and pressure in four containers holding the same amount of water. According to the table, in which container can the most sodium chloride be dissolved in the water?

A QB RC SD T

Rule: With solubility of most salts, temperature is more important than pressure.

How does temperature affect solubility?

Usually, the warmer, the better.But gases dissolve better at

lower temperatures.

How does pressure affect solubility?The more pressure (lid on) the better the dissolving of a gas in a liquid.

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

F strong electrolyte

G weak acid

H nonelectrolyte

J strong base

The word “BRIGHT”Means the liquid isA strong electrolyte.

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Salt ions being separated by collisions of water molecules during “dissolving.”

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Bathwater normally has electrolytic behaviors even though distilled water does not. This is because bathwater —F contains isotopes of hydrogenG has been heatedH is separated into H+ and OH– ionsJ contains dissolved minerals

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Isotopes are elements with different number of neutrons although they have the same number of electrons and protons.

Heating water does NOT make the water an electricity carrier. Ions in the water, make water carry electricity.

Elements of water are covalently bonded meaning that they resist becoming ions. Some always do, but they do not conduct electricity because they are so attracted to the opposite ion.

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Sour Slippery

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pH indicatorspH paper tells pH numbersLitmus paper tells acid or base

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A certain commercial product used for cleaning ovens must be handled with rubber gloves. The product is slippery and turns litmus paper blue. It probably contains —F an acidG a baseH a saltJ an isotope

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Two clear solutions are placed in separate beakers. The first solution has a pH of 4, and the pH of the second solution is unknown. If the two solutions are mixed and the resulting pH is 5, the second solution must have —

A fewer suspended solidsB a lower temperatureC more dissolved salt (NaCl) particlesD a higher concentration of OH– ions

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Acid pH 4 Base with some –OH’s

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Acid + Base becomes Salt + Water

Many pitcher-plant species grow well in soil with a low pH. Soil pH could be decreased by adding a solution of —

A carbonic acidB potassium hydroxideC ammoniaD sodium chloride

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physical and

chemical change

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Which of the following processes is an

example of a physical change associated with

an oak tree?A Decomposition of bark

by bracket fungiB Starches and sugars

being broken down during energy production

C Water and carbon dioxide being converted to glucose

D Evaporation of water from the surfaces of leaves

Chemical change

Chemical change

Chemical change

Physical change

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Which of the following is an example of a chemical change?F Ice crackingG Sugar dissolvingH Milk souringJ Lead melting

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Physical changes:Getting smallerDissolvingChanging phases…solid,liquid,gas

Chemical changes:Bonding partners are changed. Milk sugar + proteins → carbon dioxide + water + other chemicals

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Which of these changes in rocks is a physical change?

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

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Which process in the rock cycle is most likely responsible for moon rocks being converted to lunar soil?A MetamorphismB WeatheringC SedimentationD Volcanism

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Weathering changes rock to soil on the earth, so it might apply to the moon as well.

Reheating of rocks.

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Which of these describes a pollution-producingprocess that involves only a physical change?

A Coal with a high sulfur content is burned,producing gases that cause acid rain.B Chlorofluorocarbons are released,changing ozone in the upper atmosphereinto oxygen.C Hot wastewater is discharged into a lake,lowering oxygen levels in the water.D Nitrogen oxide emissions combine withwater vapor, producing nitric acid.

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Coal + S + Oxygen → CO2 + SO3 + H2O → H2SO4

NO2 + H2O → HNO3

O3 → O2 + O1 with the

Hot water is added to a river or lake.

WarmedOxygen O2

bubbles toatmosphere.

Decrease in dissolved oxygencauses fish kill.

Thermal pollution causes a physical change.

Normal environment

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In the rock cycle, which of these is a chemical change involved with the formation of igneous rocks?F Compression of sedimentsG Heat loss from lavaH Subduction of platesJ Formation of minerals

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May cause a chemical change with pressure.

May result from chemical changes.

May cause a chemical change with heat/friction.Is the act of elements unbonding and rebonding.

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density

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A block of maple wood with a volume of 405 cubic centimeters and a density of 0.67 g/cm3 is sawed in half. The density of the two smaller blocks is now —

A one-fourth the original densityB one-half the original densityC two times the original densityD the same as the original density

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If all these blocks are maple, they all have the same density.

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A sample of an element has a volume of 78.0 mL and a density of 1.85 g/mL. What isthe mass in grams of the sample? Record and bubble in your answer to the nearest tenth on the answer document.

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Density = mass ÷ volume1.85 = ? ÷ 781.85 x 78 = ?

144.3 grams

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Which procedure is best to use when determining the density of a rock?F Place the rock in a water-filled beaker and find the height at which the rock floats above the water.G Use a ruler to measure the rock’s dimensions and then find its mass using an analytical balance.H Measure the mass of the rock on a balance and then find the volume of water itdisplaces in a graduated cylinder.J Place the rock in three liquids with different known densities and observe which liquid the rock floats in. 6

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161.02 – 22.35 = 139.67

Density = mass / volume

Density = 139.67g / 20.1 mL

60.4 – 40.3 = 20.1

Which of the following objects will float on water?

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Density greater than “1” sinks.Density less than “1” floats.

45/40 = greater than 1

50/45 = greater than 1

55/50 = greater than 1

60/65 = less than 1

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What is the mass of a 500.00 mL sample ofseawater with a density of 1.025 g/mL?F 487.8 gG 500.0 gH 512.5 gJ 625.0 g

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Density = mass ÷ volume1.025 = ? ÷ 500500 x 1.025 = ?

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

A volume

B temperature

C mass

D density

Gases have a greater volume than liquids.

Density is mass / volume

Gas N2 Liquid N2

250/big number

250/small number

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17 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 water

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

C temperature of pond water is lower than that of ocean water

D mass of ocean water is greater than that of pond water.

Density less than ‘1’ floats on water.Density more than ‘1’ sinks in water.

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From 1942 to 1945, U.S. nickels were made of an alloy that contained 35% silver, 9.0%manganese, and the rest copper, by mass. If one of these nickels has a mass of 5.0 grams, what is the mass of the copper?A 0.5 gB 1.8 gC 2.2 gD 2.8 g

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Silver + manganese + copper = 100% Copper = 100 - 35- 9 Copper = 56% or 56/100 or .56

÷ 56 / 100 x 5 grams = 2.8 grams

or .56 x 5 = 2.8

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What is the density at 20°C of 12.0 milliliters of a liquid that has a mass of 4.05 grams?A 0.338 g/mLB 2.96 g/mLC 16.1 g/mLD 48.6 g/mL

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Don’t need temp.

Density = mass ÷ volume ? = 4.05 g ÷ 12mL

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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 NaOHsolution?A 3.88 gB 15.7 gC 23.9 gD 24.6 g

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D = m ÷ VD x V = m1.23 x amount in graduated cylinder = mass

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