Objective 4…TAKS 10th and 11th grades

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Questions from TAKS: periodic chart placement

Questions from TAKS: water properties and solutions

Questions from TAKS: balancing equations

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Link to 10th grade study guide

Scroll to p.291 for objective 4Link to 11th grade study guide

Scroll to p.342 for objective 4

Interactive non-TAKS quizzes on the internet

Questions from TAKS: physical and chemical change

Questions from TAKS: density

Objective

428 questions about chemistry in general

Basics and periodic chart

An interactive periodic chart A complete tutorial of elements Grades 5 – 8 quizzes 440 questions...10 per quiz...5 grade levels 20 ques. quiz of basic chem 6 ques. matter 25 ques. chemistry of IPC 8 ques. elements, compounds, mixtures

Balance equations Balance equations with instant "right or wrong" Harder balancing equations with instant "right or wrong" 5 question quiz over balancing equations

Changes: physical or chemical

6 ques. physical/chemical change quiz Powerpoint tutorial physical/chemical changes 8 ques. quiz over physical/chemical changes 10 ques. properties of metals

Density, buoyancy, viscosity

Density Math --- Click on 'New Problem' ---Have a calculator handy! 10 questions about density reasoning Property of fluids, 8 ques. quiz

Water properties 20 difficult water questions. 5 questions Water properties Interactive water molecules/polarity illustrations

Solubility 6 ques. Solutions 25 ques. Solubility 12 ques. Solubility factors

Electricity and solvents

Difficult electronegativity animation Short electrolyte movie

pH 25 questions about pH 10 ques. pH and litmus 10 more ques. pH and litmus

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periodic chart placement

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The picture shows a model of the element —A fluorineB heliumC berylliumD oxygen

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If there are 4 electrons and 4 protons, the element’s atomic number is 4.

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The elements from which of the following

groups are most likely to react with

potassium (K)?

F Group 2

G Group 7

H Group 13

J Group 17

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Group 1 wants to give an electron to column (group) 17

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An unidentified element has many of the same physical 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 Sodium

G Beryllium

H Calcium

J Rubidium

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Mass increases with each lower row.

Elements in the same column share the same physical and chemical properties.

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The elements of which of these groups on the periodic table are most resistant

to forming compounds?

A Group 1

B Group 9

C Group 14

D Group 18

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

These are the noble gases and they don’t like to bond to anything.

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Elements in Group 16 of the periodic table usually —F form large moleculesG gain electrons when bondingH act like metalsJ solidify at room temperature

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These 3 columns gain electrons.They steal electrons.They need electrons.

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Which of the following groups contains members with similar chemical reactivity?A Li, Be, CB Be, Mg, SrC Sc, Y, ZrD C, N, O

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Elements in the same column have the same properties and reactivity.

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According to the periodic table, which element most readily accepts electrons?A FluorineB NitrogenC ArsenicD Aluminum

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Which of the following salts has the greatest solubility in water at 25°C?F CaCO3

G FeSH HgCl2J KClO4 50

Calcium carbonate - insoluble because of rule 3.

Iron sulfide - insoluble because of rule 3

Mercury chloride - insoluble because of rule 2.

Potassium perchlorate - soluble because of rule 1

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An unknown silvery powder has a constantmelting point and does not chemically orphysically separate into other substances. The unknown substance can be classified as —A an elementB a compoundC a mixtureD an alloy

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Mixtures and alloys can be physically separated.

Compounds can be chemically separated.

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Oxygen (O2) is an example of —

A an alloyB a moleculeC a saltD a mixture

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An alloy is a mixture or solution of two metals.

A salt is a an ionic bond between a metal and non-metal.

A mixture is two substances together but not bonding together.

A molecule is two or more atoms bonded covalently together.Usually included in the bonds are C, P and the diatomic elements bonded together.

A compound can be two or more elements bonded together, with ionic or metallic bonds.

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balancing equations

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Balance equations

Go to: CoefficientsGo to: Conservation of massGo to: Conservation of energy

Go to: Subscripts

According to this information, what is the chemical formula for aluminum sulfate?A AlSO4

B Al2(SO4)3

C Al3(SO4)2

D Al6SO4 23

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The chemical formula for calcium chloride is —F Ca2ClG CaClH CaCl2J Ca2Cl3

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HomeBalance equations

What are the coefficients that will balance this chemical equation?A 2, 1, 1B 3, 4, 2C 2, 2, 1D 4, 3, 2

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1 lead 1 lead2 oxygens ≠ 3 oxygens

Put a 2 here to make an even number of oxygens.

1 1 122 1

1 lead 2 lead2 oxygens ≠ 4 oxygens

2 lead 2 lead4 oxygens = 4 oxygens

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When the above equation is balanced, the

coefficient for magnesium chloride is —

A 0

B 1

C 2

D 4

2

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HomeBalance equations

What is the coefficient for H2O when the equation is balanced?A 1B 2C 3D 4 19

1 1 1 1 1

To make the hydrogens ‘even’, We put the coefficient 2 here.And have a sum of 4 hydrogens, 2 potassiums and 2 oxygens

2

Then we’ll need to putcoffecients on this side of the arrow to finish balancing it out.

2 2

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HomeBalance equations

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 Al4C3(s) + H2O(l) CH4(g) + Al(OH)3(s)J CH4(g) + 2O2(g) CO2(g) + 2H2O(g)

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4 hydrogens ≠ 2 hydrogens 2 oxygens 2 oxygens

1 zinc 1 zinc

1 hydrogens ≠ 2 hydrogens 1 chlorine 2 chlorines

4 aluminums 1 aluminum3 carbons 1 carbon

2 hydrogens ≠ 3 hydrogens 1 oxygen 3 oxygens

1 carbons 1 carbon

4 hydrogens = 4 hydrogens 4 oxygens 4 oxygens

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To produce 4 molecules of sugar, a plant needs —

F 6 molecules of hydrogenG 12 molecules of ATPH 18 molecules of waterJ 24 molecules of carbon dioxide

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Multiply the whole reaction by 4.

14( )4 x 6 carbon dioxide

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The chemical equation shows CaCO3 being heated. Which of these statements best describes the mass of the products if 100 g of CaCO3 is heated?A The difference in the products’ masses is equal to the mass of the CaCO3.B The sum of the products’ masses is less than the mass of the CaCO3.C The mass of each product is equal to the mass of the CaCO3.D The sum of the products’ masses equals the mass of the CaCO3.

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Reactants → Products

100 g HomeBalance equations

If all the reactants in a chemical reaction arecompletely used, which of the followingstatements accurately describes therelationship between the reactants and theproducts?

F The products must have a differentphysical state than the reactants.G The total mass of the reactants mustequal the total mass of the products.H The reactants must contain more complexmolecules than the products do.J The density of the reactants must equalthe density of the products.

Reactants become Products 2H2 + O2 2H2O20 grams + 10grams = 30 grams

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Balance equations

When 127 g of copper reacts with 32 g of oxygen gas to form copper (II) oxide, no copper or oxygen is left over. How much copper (II) oxide is produced?F 32 gG 95 gH 127 gJ 159 g

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127 + 32 = ?

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According to the law of conservation of mass, how much zinc was present in the zinc carbonate?A 40 gB 88 gC 104 gD 256 g

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64 + 192 = 152 + ? 64 + 192 – 152 = ?

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Balance equations

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Why is the sum of the products’ energy in this reaction less than the sum of the reactants’ energy?A Energy is given off as heat.B The products absorb available energy.C Energy is trapped in the reactants.D The reactants’ energy is less than the melting point of glucose. 37

+ = +≠Reactants = Products

The energy not stored in the bonds of the carbon dioxide and water must have left in the form of heat.

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The illustrations show a conservation-of-massexperiment. The solution in the beaker lost mass because —F materials have less mass at high temperaturesG the mass of the reactants and products was less than 100 gH sodium sulfate (Na2SO4) is lighter than airJ some of the water molecules turned into gas

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Before

Before(100 g)

After

After( less

than 100 g)

Some of the water evaporated because of the heat.

REACTANTS →Products The sum of the reactants = the sum of the products.

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An inventor claims to have created an internal combustion engine that converts 100 kJ of chemical energy from diesel fuel to 140 kJ of mechanical energy. This claim violates the law of conservation of —

F momentumG inertiaH energyJ mass 48

chemical energy = mechanical energy + heat

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Balance equations

water propertiesHome

Go to: Polarity

Go to: Solubility of liquids, solid

Go to: Solubility of gases in liquids

Go to: Electrolytic behaviors of solutions

Go to: pH

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What characteristic of water remains the same no matter what is dissolved in it?A The ratio of hydrogen to oxygenB The ability to refract lightC The hydroxide ion concentrationD The freezing temperature

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Water is defined as two hydrogens to one oxygen. If there were more or less of these elements, the compound would have a different name and not be water.

The bending of light depends on temperature and whether there is any solute in the water.

Usually, the amount of OH- and H+ ions are equal in pure water.

Water that is not pure, such as with solutes, does not always freeze at 0oC.

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Which factor makes water an effectivesolvent?F The presence of molecular oxygenG Its lack of covalent bondsH The polar nature of its moleculesJ Its abundance on Earth’s surface

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What is polarity?

polarity: a compound’s uneven distribution of electrons.

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Polarity acts like magnets.

polarity: a compound’s uneven distribution of electrons.

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The hydrogens are attracted to the oxygens of another molecule.

polarity: a compound’s uneven distribution of electrons.

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What does polarity do?Causes water to expand when it freezes.

ice

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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

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The air above the ice may be very, very cold… even - 60oF. But the water beneath the ice is no colder than 33oF.

The living things in the very cold water have adaptations for 33oF but may not be able to survive any colder water than that.

Freezing water becomes less dense.

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If the properties of water were to change so that the solid form was denser than the liquid form, organisms living in a cold pond environment would be less likely to survive because water would no longer —

F dissolve enough oxygen from the airG produce solutions containing vital nutrientsH remain neutral, instead becoming highly acidicJ produce a floating insulating layer of ice

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

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What are some solubility tricks?

• Grind large pieces of solute into small pieces, thereby increasing surface area for the water molecules to collide into.

• Raise the temperature to increase collisions of H2O’s into solute.

• Stir or shake which increases the collisions. surface area: smaller

particles have more surface area compared to one large particle.

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surface area: smaller particles have more surface area compared to one large particle.

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A 0.2 g crystal of gypsum dissolves very slowly in 100 mL of water while the water is stirred. Which of these would cause the gypsum to dissolve faster?

F Decreasing the water temperatureG Stopping the stirringH Lowering the air pressureJ Crushing the crystal 10

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All of these can affect the rate at which a solid dissolves in water except —A decreasing air pressureB stirring the waterC increasing the temperature of the waterD using larger crystals of the solid

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Air pressure only affects gas solubility.

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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

electrolyte.mov

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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