General Questions and Answers

6 2 points The pages in an old book yellow over time Is this an endothermic or exothermic process Exothermic Endothermic

To provide improved service to its customers a phone company wants to install an additional cell tower in a region with many hills What is most likely to be the primary criterion that the telephone company should consider when selecting property on which to build the cell tower The proposed property is near a main highway for ease of access The proposed property is less expensive than other proposed properties The proposed property is far away from a scenic outlook along a local highway The proposed property is at an elevation where it can service the surrounding terrain

7 How many moles of oxygen gas occupy a 300 mL container at 2 0 atm and 125 degrees Celsius

CaCl2 Na2CO3 CaCO3 NaC

14 2 points What is the reducing agent in the following reaction Fe O3 2 Al 2 Fe Al O3 O Al Fe Fe3 02 A 3

The Nervous System The brain is a complex organ that controls motor skills emotion hunger and every process that The brain typically weighs about The other is water breathing memory The brain itself is not a It contains blood vessels and nerves including neurons and glial cells The 3 main components that makeup the brain are the forebrain the midbrain and the our body pounds and is about fat carbohydrates and

Determine the EA for the rate determining step step 1 for this reaction coordinate diagram in kJ PE kJ 100 87 kJ 78 kJ M 55 kJ 20 kJ 80 60 40 20 Reaction Progress 50 kJ Created by E

2A 3B 5C 4D 2 mol A produces 5 mol C 3 mol B produces 4 mol D 2 mol A reacts with 3 mol B 4 mol A produces 10 mol C 6 mol B produces 8 mol D 6 mol A reacts with 9 mol B 1 What do the coefficients of a balanced equation represent 2 If 6 mol A are reacted how many mol D are produced Explain as a group how you calculated this answer and show your work

Which of these compounds will form a precipitate when mixed with an aqueous solution of sodium sulfate Na2SO4 LINO3 KNO3 A B C Mg NO3 2 D Ba NO3 2 OD B OA

What is the weight percentage of hydrogen in C13H20N O2 8 5 11 9 66 1 54 1

1 How many formula units are in 1 mole of NH4 2SO4 2 How many moles are in 8 5 x 1026 molecules of CO 3 How many grams are in 6 51 moles of H SO4 atball SLIKAVA TUNTI 4 How many moles are in 2 56 x 104 grams of Fe O3

c CH3OH O2 CO2 H C

Complete the following table by determining the type of reaction and predicting the products that will be formed when the reaction occurs then balance the equations Reaction Type Reactants C5H12 0 AlBr3 Cl NH3 Ca OH 2 CaCl Sr s Ca ClO3 2 All 3 H SO4 AgNO3 Sn NO3 4 yield Products

A non spontaneous reaction is also considered an impossible reaction O True O False

7 beryllium nitride Be N2 molar mass of compound Be

5 Write the complete equation for the neutralization reaction of solid aluminum hydroxide with hydrochloric acid then answer the questions that follow a chemical equation b Calculate the mass of aluminum hydroxide that can be neutralized by 25 0 ml of a 0 750 M solution of hydrochloric acid c Calculate the theoretical yield in grams of aluminum chloride that can be produced by the reaction of 12 87 grams of hydrochloric acid with aluminum hydroxide d Calculate the percent yield for the reaction in part c given that 13 07 grams of aluminum

4 Calculate the total volume of gas that can be produced by the complete combustion of 16 94 grams of hexane under STP conditions 2 C6H 4 1 19 0 g 12 CO g 14 H O g A

Overall reaction 20 s 30 B 0 2 50 5 00 Initial Rate MX 1 67 10 3 34 10 Mechanism A O g O g O g O g O g 0 8 O g Mechanism B O g O g 0 g 0 g O g O g O g ch of the rate laws shown is the correct experimentally derived law rate k 0 1 rate k 0 1 Tate HOP slow fast slow fast

3 For each of following predict whether a precipitation reaction occurs If so write a balanced net ionic equation for the reaction If no reaction occurs write NR after the arrow Mix solution of a potassium sulfate and iron III bromide d sodium phosphate

The vapor pressure of liquid methanol CH3OH is 100 mm Hg at 294 K A sample of CH3OH is placed in a closed evacuated 509 mL container at a temperature of 294 K It is found that all of the CH3OH is in the vapor phase and that the pressure is 69 0 mm Hg If the volume of the container is reduced to 334 mL at constant temperature which of the following statements are correct Choose all that apply Liquid methanol will be present The pressure in the container will be 105 mm Hg Only methanol vapor will be present No condensation will occur Some of the vapor initially present will condense

References A balloon filled with 40 4 L of helium at 43 0 C and 0 98 atm pressure is submerged in liquid nitrogen at 196 C Calculate the final volume of the helium in the balloon L Volume

References If 53 3 g of NH3 occupies 35 1 L under a pressure of 92 6 in Hg what is the temperature of the gas in C Temperature

In order for a solution to be acidic OpH POH H3O OH H3O OH H3O OH

1 Solid aluminum metal reacts with liquid bromine giving solid aluminum bromide Write a balance equation for the reaction using complete formulas for the compounds with state of matter labels k Solid calcium phosphate and aqueous sulfuric acid solution react to give calcium sulfate precipitate The other product is phosphoric acid which remains in solution Write a balance equation for the reaction using complete formulas for the compounds with state of

2 points etermine the molecular mass of a gas where 2 32 g occupies 0 81 L at standard conditions of temperature and pressure to THE NEAREST WHOLE NUMBER Type your answer

Measurement 1 Measurement 2 Measurement 3 Measurement 4 Measurement 5 1 pts Question 1 Inspect the data and calculate the value of pi using two pairs of the data 0 5pts Value of pi using the first pair of the data 1 38 3 80 3 96 5 23 7 28 4 08 11 93 12 5 16 33 21 76

As a water treatment plant operator for the city of Arlington you need 55 0 Kg of chlorine dioxide to treat a week s worth of water for the city s residents Determine how many grams of potassium chlorate you will need to treat a week s worth of Arlington water Begin by balancing the equation SCIO Cin K n

Write a balanced overall reaction from these unbalanced half reactions In In Cd Cd balanced overall reaction

Select all that apply Select the major problems associated with the production of nuclear energ air pollution hazardous solid wastes depletion of natural resources potential reactor accidents harm to animal and plant life

KCIOA KCI 20 assign oxidation numbers to each element on each side of the equation K in KCIO4 Cl in KCIO4 O in KCIO Which element is oxidized CI O K in KCI Cl in KCI O in 0 Which element is reduced K CI

1 point Which of the following best describes the 1st Law of Thermodynamics Da Energy cannot be created or destroyed only altered in form When energy changes from one form to another in a closed system entropy increases Entropy reaches a constant value as temp reaches absolute zero Matter cannot be created or destroyed only converted from one form to another

Calculate the ratio of the number of molecules in the v 2 to the ground state at 25 C for HCl if the energy spacings are 2890 cm Select one O a 8 70x 10 10 b 7 57 x 7 Oc 8 76 10 d 7 64 10 13

23 2 points A balanced chemical equation is a OO quantitative qualitative Previous description of a chemical reaction

Written communication Knowledge and Thinking x 2 Claim 1 pt Evidence 1 pt Reasoning 3 pts 5 pts 5 points for working with someone else and providing feedback Framework 1 Combining Evidence What did you see Reasoning SCIENCE Precipitate Aqueous Spectator ion Net ionic equation and the lab that produced a precipitate and choose 1 reaction from the lab that was no reaction is a double replacement reaction

Question 5 of 11 In this equation CuCl NaOH Cu OH NaCl Which product is insoluble 4 points A sodium chloride B copper II hydroxide C copper II chloride OD sodium hydroxide

Consider the three ionic compounds named below Each compound dissociates when dissolved in water Identify the formula including the charge of the cation and the anion formed from the dissociation of each compound Tap on the table cells to toggle through answer options Cation Formula Tap Me Tap Me Compound Name Sodium sulfide Sodium sulfate IGHT Anion Formula Tap Me Tap Me

Mass of Solution Added mL 40 30 20 10 0 Mass of Solution Added mL 10 15 0 979 x 0 0193 R 1 20 25 30

Step 5 Show how the ring will close Step 6 Show structures of a and B variations of the D Sorbose Step 7 Explain how a and 6 variation J

Milk sours because of a chemical reaction that takes place between some of the chemicals that make up the milk Why does a carton of milk left out on a countertop sour sooner than a carton of milk left in the refrigerator

A radioactive sample contains 10 0 g of an isotope with a half life of 3 8 days The mass of the isotope that remains after 7 6 days is

Nishant II Circle the correct answer and place the letter on the line 1 An organism made up of more than one cell C Prokaryotic D Eukaryotic suoraslados nousame ork 2 An organism adapted to living in extreme conditions of high ter Unicellular B Multi cellular

Methane gas is compressed from 24 L to 2 5 L at a constant temperature The final pressure is 24 6 atm What was the original pressure Pressure Submit Answer atm Try Another Version 10 item attempts remaining

What is the molarity of a 1 5 L solution containing 3 2 moles of magnesium chloride Round your answer to the hundredths place

2 2 points In the reaction below what is the physical state of the product Ca Sg O solid liquid O O O aqueous gas

25 How does increasing temperature affect the collisions of reactant molecules in a chemical reaction A B C D O A OD O C The reactant molecules collide more frequently with greater energy per collision The reactant molecules collide more frequently with less energy per collision The reactant molecules collide less frequently with less energy per collision The reactant molecules collide less frequently with greater energy per collision

Table 3 Average Mass Change for Cell Model Versus Osmolarity of Intercellular Fluid Cellular Fluid Chemical Formula 10 0 mL N P04 Nach 03 Dextrose C6H120 0 Average Mass Change for Cell g Macl 6 H 0 0 757 0 905 0 831 UreeNH CON20747004 KI 2 0 173 0 186 011795 Z 101504 Ity number a particle 0324 0 684 2 Osmolarity of Intercellular Fluid Osmol show calculation 20 0515 0 5 2 1 Indukty 1 073 0 55 018115 Z 11034 01861 0 9475 U SX2 1 1 5 molanty 015 1 05 malority 0 5 x 3 1 5 molanty 0 5 1 0 5 molanty 0 5 1 0 5 molanty DISCUSSION On a separate piece of paper type the discussion of the results data you collected in this lab make sure to include all of the following points to receive full credit Use complete sentences to create each paragraph that contains cohesive content Use data examples reasons facts and explanations that are relevant appropriate and convincing in explaining if hypothesis was supported or not Specifically refer to values in all of the tables in the results section on trends in data and what is influencing those trends in mass change and osmolarity Explain how the solution you prepared compares to the other solution containing cells in mass change and osmolarity This ties into why the trends in data are occurring OSP O Discuss problems sources of error and or unexpected results thoroughly with scientifically valid reasoning CONCLUSION Continue typing one more paragraph after your discussion to address how you could refine your hypothesis to test for better accuracy or to answer a question that may have you where explaining your results Briefly describe how you would then go

4 A solution of a coordination complex absorbs light with a wavelength 670 nm a Use the color wheel on page 3 of the packet to determine the color of visible light absorbed by the complex b Recall that the observed color of the complex is the complement of the color of light absorbed Based on this predict the observed color of the complex

What is An for the gases in the following reaction C4H100 1 O2 g CO g H O l Tuno

1 2 Double replacement Synthesis 2 1 2 CaCl2 2 K CO3 3 2 2 Al 3 02 T 2KCL CaCO 3 2 ALO

7 Huge quantities of sulfur dioxide are produced from zinc sulfide when it reacts with oxygen The other product is zinc oxide If the typical yield is 86 78 what mass in grams of SO should be expected if 4897 g of ZnS is used ZnS 0 P SO ZnO SO ZnO