General Questions and Answers

Read the passage and answer the next 2 questions A teacher starts a new unit with a demonstration She fills two beakers with water She asks student A to add a measured amount of ammonium nitrate into beaker 1 and student B to add a measured amount of sodium hydroxide into beaker 2 Student A feels beaker 1 become cold while student B feels beaker 2 become hot 10 The model illustrates the energy change in a chemical reaction of ammonium nitrate and water Considering student A felt the flask become cold choose the answer that explains why the arrow goes up as the reaction progresses instead of down Energy K NH4NO3 solution NH4NO3 water Reaction progress A Energy was released from the surroundings to break bonds B Energy was absorbed from the surroundings to form bonds C Energy was released from the surroundings to form bonds D Energy was absorbed from the surroundings to break bonds

The structure of the coordination sphere of chloridobis ethylenediamine nitrito KN cobalt III bromide Co en NO CI Br is given Charges and ions are omitted for clarity Co en NO Cl Br CoN 0 N CI INI O Consider this structure of Co en NO Br Cl Co en NO Br Cl N Br O Consider this structure of Co en NO CIJBr Co en NO CI Br ON CI The structure of Co en NO CIJBr is optically active octahedral chiral tetrahedral Compared to the first structure of Co en NO Cl Br this structure of Co en NO Br Cl is Compared to the first structure of Co en NO Cl Br this structure of Co en NO Cl Br is

4 1p The accepted value for the density of certain metal is 7 87 g cm Calculate the percent error in a laboratory experiment that yields a value of 8 15 g cm rror experimental value true value x100 true value

1 point If H S reacted with O2 to produce SO2 and H 0 and the theoretical yield was to be 16 01 g of H 0 but the experiment yielded 12 45 g of H 0 what is the percent yield ROUND THE ANSWER TO A WHOLE NUMBER Type your answer

A metal object weighed 130 2 g When the object was submerged in water in a graduated cylinder the liquid level rose from 20 0 mL to 32 4 mL Using the table below which metal the object most likely to be Metal tin iron copper silver O Tin O Iron O Copper O Silver Density g cm 5 76 7 97 8 96 3 p 10 5

Now that we know the pH of the ocean we can determine how much of the DIC is CO3 using the graph Percent of CO 5 25 20 15 10 5 0 7 9 DIC H CO3 HCO3 CO3 pH vs CO g What percent of DIC is CO32 at pH of 7 95 10 8 0 25 8 1 pH h 8 2 8 3 Case Han Introduction Collect Data Data Analysis Data Interpreta pH CO Assess Analyze pH pH vs CO2 Findings Equilibrium C Hypothesis Experiment Review Results Conclusions

The figure shows a cylindrical waste container which was 25 full before and 60 full after the addition of 7 liters of solution What is the volume of the container in liters before O 12 0 14 O 20 43 25 T after 4 60 T

H S I2 N H O 7 Rank the compounds above from weakest to strongest in terms of intermolecular forces Justify your response

penny has a mass of 0 0027 kilograms and a volume of 0 48 milliliters et up the problem below and calculate the density of the penny in grams milliliter 0027 kg 0 48 mL X 1000 ml ased on your calculation will the penny float or sink in water rag and drop your selection from the following list to complete the answer 1000 kg g mL 1 mL 1000 g 1000 L

mplete the table below by writing the symbols for the cation and anion that make up each ionic compound The first row has been completed for you lonic compound Na Cl CrO MnSO4 Fe Br Cr PO4 cation Na anion CI X 3

Perform the following calculations and report your final answer with the correct number of significant figures and units 1 000 10 mL 1 L 261 25g 0 250 L X 2 054 g x X 1 mole C 12 01 g C 45 20 mL x 1 L 103 mL 1 045 g 1 mL X X 6 02 x 1023 atoms 1 mole C 0 110 mol HCl 1L 28g 2 054 x 12 01 C x 6 02 x 10 ade 45 20 ml X 10 ML X 0 110 mol HCL

Arrange these complexes in order of octahedral splitting energy A Largest A Smallest A

Read the passage and answer the following question Two students are conducting an experiment for a lesson on solubility and intermolecular forces They first weigh 50 g of table salt in a beaker Then they measure 250 mL of water in a graduated cylinder and add it to the beaker containing the 50 g of salt They notice that the salt dissolves in the water very easily Next they proceed to add another 50 g of salt After stirring for a while they notice not all the salt has dissolved 9 When NaCl is added to water the strength of intermolecular forces between water molecules and a substance s ions in solution affect the solubility in what way A The molecules dissociate into Na and Cl protons which are then surrounded by a shell of water molecules called a closed shell B The molecules dissociate into Na and Cl ions which are then surrounded by a shell of water molecules called a solvation shell C The molecules dissociate into Na and Cl photons which are then surrounded by a shell of water molecules called a valence shell D The molecules dissociate into Na and Cl neutrons which are then surrounded by a shell of water molecules called an electron shell

2 A gas collected when the pressure is 800 mm Hg has a volume of 380 mL What volume in milliliters will the gas occupy at standard pressure P P Gas Law Name V T V2 T1 na P V P V2 n T1 n2T2 mark out constants Show work

A 7 50 g sample of a hydrate is heated to drive off the water The resulting anhydrous salt is found to have a mass of 6 39 g Based on this information answer the following questions To get full credit you must show all your work and pay attention to significant figures and units A Determine the mass of water lost B Calculate the moles of water lost during heating

Bonus up to 1 pt Imagine two solutions with the same concentration and the same boiling point but one has ethanol as the solvent and the other has carbon tetrachloride as the solvent Determine that molal concentration m and boiling point T Solvent ethanol carbon tetrachloride Normal Boiling Pt 78 4 76 8 Kb C m 1 22 5 03

A small amount of acetonitrile CH CN is dissolved in a large amount of water Imagine separating this process into the four stages sketched below The sketches show only a portion of the substances so you can see the density and distribution of atoms and molecules in them CH CN H O Use these sketches to answer the questions in the table below The enthalpy of solution AH is negative when soln CH CN dissolves in water Use this information to list the stages in order of increasing enthalpy Would heat be absorbed or released if the system moved from Stage A to B What force would oppose or favor the system moving from Stage A to 8 Check all that apply D A B C O absorbed released O neither absorbed nor released none lonic bonding force covalent bonding force metal bonding force hydrogen bonding force dipole force Olon dipole force dispersion force 0 0 X solution

Of the two following reactions which will be the faster reaction Explain your reasoning 280 240 8200 160 120 80 40 Reaction Coordinate O Graph B O Graph A Question 2 OR PE kJ 250 200 150 100 50 Reaction pathway

mol 22 4 L 1 mol 6 02 x 1023 representative particles 1 mol g m 30 Know how to perform mole conversions using moles grams and representative particles What is a representative particle What is the name of the representative particle for the ionic compound The covalent compound An element a How many representative particles are in a 53 79 gram sample of SrCO b C How many moles of AlF3 are in a 10 0 gram sample of Alfs d How many grams of SO are in a 0 65 mole sample of SO e f How many moles of copper atoms in 75 g of Cu In a sample with 170 grams of water how many molecules of water are present

1 2 What is an indicator and how is it used

What type of reaction is shown in the LOL Diagram Energy 1 O Echemical Ethermal Endothermic O Exothemic O There is something wrong with this diagram Energy Echemical Ethermal

21 The molecular formula and boiling points of hydrocarbons are given in the table below Table 1 Hydrocarbon Bealing Feints Hydrocarbon Formula Butane Decane Ethane Heptane Hexane Methane Nonane Octane Pentane Propane C4H10 C10H22 C H6 C H16 CH14 CH4 C H 0 CgH 18 C5H12 C3H8 Boiling Point 0 5 174 0 88 6 98 4 68 7 161 7 150 8 125 7 36 1 42 1 Based on the information in the table what is the trend in the boiling point as the number of carbons

Read the following paragraph from the section Key Points An ionic bond essentially donates an electron to the other atom participating in the bond while electrons in a covalent bond are shared equally between the atoms Which idea is BEST supported by this paragraph A B C D The distinction between ionic and covalent bonds is determined by how equally the atoms in the bond share their electrons lonic bonds have atoms that donate one electron to another atom in the bond while atoms in covalent bonds have a tendency to donate all their electrons Electrons in a covalent bond always share their electrons equally between the atoms but electrons in ionic bonds only share equally occasionally Covalent bonds sometimes have bonds between identical atoms so they can share electrons equally while ionic bonds always

The rust that appears on steel surfaces is iron III oxide If the rust found spread over the surfaces of a steel boat hull contains a total of 1 324 x 1023 oxygen atoms how many grams of rust are present on the boat hull

Which of the following values represents the enthalpy change for the reaction CH4 g H O g CO g H g TABLE Single Bonds C H 55555 ISUOU T Si Average Bond Enthalpies kJ mol 413 348 293 358 185 328 276 259 323 226 368 461 Multiple Bonds IN 179 ZZZZZZ N H H NOFUE CI Br H H H F CI Br I P C 391 163 201 272 200 243 436 431 366 299 00000 HOFUL 140 4 S Br 463 146 190 203 234 339 327 253 218 266 F F CI F Cl Cl Br F Br CI Br Br Br 155 253 242 37 218 193 208 175 151

A 1 81 mol sample of Xe gas is confined in a 44 3 liter container at 25 0 C If the temperature of the gas sample is increased to 49 2 C holding the volume constant the pressure will increase because Choose all that apply With higher average speeds on average the molecules hit the walls of the container with more force With lower average speeds the molecules hit the walls of the container less often At higher temperatures molecules have higher average speeds As the average speed increases the number of molecule wall collisions decreases None of the Above

Which best describ the The individual particles are atoms of different types O There are too many particles in the diagram The diagram shows a balanced chemical equation O Mass is created in the diagram Mas is neither created nor destroyed in the diagram

Below is a particle diagram for a homogenenous mixture of two substances What do the hexagons 6 sided particles represent in the diagram O The solution The solute O The solvent

A scientist has a 100mL solution of HCI with an unknown concentration They titrate it with an LIOH solution and a pH indicator until it shows a neutral pH If the solution required 200mL of a 1M LIOH solution to be fully titrated what is the concentration of the HCI solution HCl aq LiOH aq H O aq LiCl aq O2M O 0 2M 0 4M O 3M 1M

A pencil is viewed through a concave lens Which of the following best describes the image Object OA Enlarged B Reduced O C Real OD Inverted Image F F

Dormant for so many centuries the gigantic beast Mount Etna awoke in 2001 causing panic Which of the following helped you infer that the reference above is about a volcano Antonyms General context Figurative language

DIRECTIONS Use the word bank to complete the table to describe the movement of carbon Each answer may be used once Photosynthesis Biosphere Fossilization of carbon Carbon flows from Atmosphere Geosphere 6 Geosphere Biosphere Word Bank Carbon flows to Biosphere 5 Atmosphere 7 Geosphere Atmosphere Hydrosphere Process 4 Volcanic eruption Cellular respiration Chemical weathering 8

Look at the equation below Ba2 aq 2 Cl aq 2 Na aq 5O2 aq BaSO43 2 Na ac 2 Crac Which ions would you expect to see in the net ionic equation

4 7 The chemical bonding in sodium phosphate Na3PO4 is classified as 3 both covalent and ionic 1 ionic only 2 metallic only 4 both covalent and metallic mtui cap auri

1 A water tank is composed of two hemispheres and a cylinder with the dimensions shown h 13 ft If the hemispheres have a radius of 3 feet how many cubic feet of water can the water tank hold A 153 cubic feet C99 cubic feet B 126 cubic feet D 817 cubic feet

8 hich type of 1 nonpolar covalent brod inslevou entis 2 polar covalent and brus abnod inolevas arrios P 3 metallic wol s a brus 4 ionic gnillom dyirl earl bra zbrod sinoi anisimos il

ulognovi to telo zbaod laabivibni ad A 14 Copper and Tin are melted down to make Bronze The mixture of metals is called an

12 What are the 5 properties of metals 13 Describe metallio handi sfog logrol tulognol urba

Consider the elementary reaction equation NO g CO g NO g CO g What is the order with respect to NO order What is the overall order of the reaction overall order Classify the reaction as unimolecular bimolecular or termolecular bimolecular unimolecular

The Carbon Cycle The carbon cycle on Earth can be described in terms of both fast and slow processes The fast carbon cycle moves millions of tons of carbon through life forms on Earth each year Plants and phytoplankton play a major role in the fast carbon cycle because they use carbon from the atmosphere to create food for themselves and other organisms on the planet Living organisms then release most of this carbon dioxide back into the atmosphere MEDIUM Carbon and the Ocean The slow carbon cycle may also involve living organisms or organisms that were once living but it generally Involves Earth s natural processes over a period of 100 200 million years For instance during certain time periods as carbon dioxide levels rise global temperatures rise as well leading to increased rainfall An increase in rainfall dissolves more rock and creates lons which deposit more carbon into the ocean floor when they are washed into Earth s oceans Without human interference the rate at which the oceans vent carbon dioxide into the atmosphere is balanced with the amount of carbon the ocean receives The image shows the movement of carbon in gigatons between the atmosphere hydrosphere geosphere and biosphere 120 3 Photosynthesis Solicarbon 2 300 Stored Carbon Plant Human respiration emissions Priant biomass 4550 Aticrobial respiration and decomposition Fossil carbon 10 000 Natural Rus 90 2 Phytoplankton photosynthesis Human Contributions Ocean sediments Air sea gas exchange 50 2 surface of th 69091 Respiration and decomposition Deep ocean 37 000 Reactive sediments 6 000 Multiple Choice DIRECTIONS Choose the best answer 1 Which TWO 2 ways does carbon directly enter the atmosphere Select TWO 2 of the following answer options a human emissions b creation of ocean sediments e chemical weathering of rock d photosynthesis from organism e respiration from organisms 2 How do plants most affect global temperature a Plants capture carbon dioxide and store carbon from the atmosphere keeping global temperatures stable b Plants release carbon dioxide into the atmosphere through respiration causing temperatures to decrease c Plants that are consumed remove carbon dioxide from the atmosphere keeping Global temperature stable d Plants decompose and release carbon dioxide into the atmosphere causing global temperatures to increase 3 Based on the information in the passage how are humans affecting carbon storage a They are moving carbon from the last cycle to the slow cycle leading to an increase in the storage of carbon in Earth s blosphere and geosphere b They are removing carbon from the slow cycle to the fast cycle leading to an increase in the storage of carbon in Earth s atmosphere and hydrosphere c They are moving carbon from the flow cycle to the cycle leading to an increase in the stores of carbon in Earth s biosphere and geosphere d They are moving carbon from the fast cycle to the slow cycle leading to an increase in the storage of carbon in Earth s atmosphere and hydrosphere

Is there force on a magnet from the coil How do you know Is there force on a coil from the magnet How do you know What can we do to switch the direction of the force between a magnet and a co Can the kinetic energy of a magnet or coil of wire change How do you know

5 The bonds between hydrogen and oxygen in a water molecule are classified as 3 ionic loquan polar covalent so ont 2 nonpolar covalent 4 metallic sluosiom 00

2 10 Based on intermolecular forces which of these substances would have the highest boiling point 1 He 20 3 CH4 4 NH3

ulate the theoretical yield of acetylsalicylic acid from 2 01 g of salicylic acid aming excess acetic anhydride This question is auto graded Round answers to the nearest hundredth For example rounding 0 843 to the nearest hundredth would give 0 84 Proctario provides a calculator for you to wy Hint MW of salicylic acid is 138 12 MW of acetylsalicylic acid is 180 15 MW of acetic anhydride is 102 09

Consider the mechanism Step 1 Step 2 E Overall A D B E Determine the rate law for the overall reaction where the overall rate constant is represented as k rate A B C C D equilibrium slow

Consider the mechanism Step 1 2A Step 2 B C Overall 2A C D Determine the rate law for the overall reaction where the overall rate constant is represented as k rate B D slow fast

4HF aq SiO s SiF4 g 2H O 1 With excess HF a chemist needs to know what mass in grams of silicon dioxide is needed in order to produce 18 0 mol of water Here is part of their work Solve this problem on your own first before completing this question g SiO Match each part with where it belongs in the stoichiometry set up One of them is not needed so match it with This is not needed for that part 18 0 mol H O 1 al 2 a2 a3 X This is not needed al a2 X a3 1 mol SiO Choose Choose 2 mol H2O 18 0 g H2O 1 mol SiO2 60 09 g SiO2 Choose

Volume L 100 80 60 40 20 100 200 300 400 500 600 700 800 900 Temperature K Created by E Lee for Virtual Virginia 2021 Based on this graph of gas temperature vs volume what exact volume should the gas have at a temperature of 727 K Answer L enter your answer to the tenths place

en 18 7 g of an organic compound known to be 38 70 C 9 7 H and 51 55 O by mass is dissolved in 970 7 g of lohexane the freezing point is 2 29 C The normal freezing point of cyclohexane is 6 59 C What is the molecular formula the organic compound Assume that the organic compound is a molecular solid and does not ionize in water Kf values for ious solvents are given in the colligative constants table lecular formula CHO

My Activities Tell me what you want to do Q Obesity experts called the Harvard findings important and praised the study for being prospective In other words the Harvard researchers spent 19 months following the children rather than capturing a snapshot of data from just one day It s considered statistically more valuable to conduct a study over a long period of time Researchers found that schoolchildren who drank soft drinks consumed almost 200 more calories per day than their counterparts who didn t down soft drinks That finding helps support the notion that we don t compensate well for calories in liquid form Which of Aristotle s three appeals does the excerpt above use in trying to convince readers that soda pop is harmful to children s health O Ethos O Pathos Ethos and logos Pathos and logos