General Questions and Answers

At a certain temperature the equilibrium constant K for the following reaction is 2 18 x 10 H g Cl g 2 HCI g Use this information to complete the following table Suppose a 14 L reaction vessel is filled with 1 6 mol of HCI What can you say about the composition of the mixture in the vessel at equilibrium What is the equilibrium constant for the following reaction Be sure your answer has the correct number of significant digits 2 HCl 9 H 9 Cl 9 What is the equilibrium constant for the following reaction Be sure your answer has the correct number of significant digits 3 H 3Claral 6 HCla There will be very little H and Cl There will be very little HCI O Neither of the above is true x 0 x 0 0 5 X

The acceleration due to gravity is lower on the Moon than on Earth Which one of the following statements is true about the mass and weight of an astronaut on the Moon s surface compared to Earth On the Moon mass is less weight is the same Both mass and weight are the same On the Moon mass is the same weight is less On the Moon both mass and weight are less

Using the thermodynamic information in the ALEKS Data tab calculate the standard reaction free energy of the following chemical reaction CH g 20 g CO g 2H O g Round your answer to zero decimal places MAJ

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 223 kJ during a certain chemical reaction which is carried out at a constant pressure Furthermore by carefully monitoring the volume change it is determined that 51 kJ of work is done on the mixture during the reaction Calculate the change in energy of the gas mixture during the reaction Be sure your answer has the correct number of significant digits Is the reaction exothermic or endothermic kJ O exothermic O endothermic X

Write balanced half reactions for the following redox reaction 3 8 Fe aq AsH3 g 4H O 1 reduction oxidation 2 8 Fe aq H AsO4 aq 8H aq 0 0 e 00

Write a balanced half reaction for the reduction of dichromate ion symbols where appropriate 0 Cr 0 to to chromium ion Cr in acidic aqueous solution Be sure to add physical state 0 0

ammonium phosphate barium hydroxide

mistry graduate student is studying the rate of this reaction NH OH aq NH aq H O aq He fills a reaction vessel with NH OH and measures its concentration as the reaction proceeds time minutes 0 1 0 2 0 3 0 4 0 NH OH 0 500 M 0 241 M 0 159 M 0 118 M 0 0943 M Use this data to answer the following questions Write the rate law for this reaction Calculate the value of the rate constant k Round your answer to 2 significant digits Also be rate k k X 15 C

The acid dissociation constant K of hypobromous acid HBrO is 2 3 10 Calculate the pH of a 4 2 M solution of hypobromous acid Round your answer to 1 decimal place pH 0 X

reaction HCIO 4 aq H O 1 CIO4 aq H O aq CIO4 aq H O aq HCIO4 aq H O 1 CIO4 aq H O aq HCIO 4 aq H O 1 HCIO 4 aq H O 1 CIO4 aq H O aq t highlighted reactant Bronsted Lowry Bronsted Lowry neither acid base O O

A chemist dissolves 534 mg of pure nitric acid in enough water to make up 110 mL of solution Calculate the pH of the solution Be sure your answer has the correct number of significant digits 0 x10

What kind of intermolecular forces act between a neon atom and an oxygen 0 molecule Note If there is more than one type of intermolecular force that acts be sure to list them all with a comma between the name of each force m

acid H PO4 H PO4 H O conjugate base

ickel and carbon monoxide react to form nickel carbonyl like this Ni s 4 CO g Ni CO 4 g At a certain temperature a chemist finds that a 4 4 L reaction vessel containing a mixture of nickel carbon monoxide and nickel carbonyl at equilibrium has the following composition compound Ni amount 45 1 g K 0 CO Ni CO 4 Calculate the value of the equilibrium constant K for this reaction Round your answer to 2 significant digits 1 47 g 0 672 g 0

Consider this reaction 2H PO4 aq P O5 aq 3H O aq At a certain temperature it obeys this rate law rate 0 00353 s H PO4 Suppose a vessel contains H PO4 at a concentration of 1 12 M Calculate how long it takes for the concentration of H3PO4 to decrease to 0 246 M You r assume no other reaction is important Round your answer to 2 significant digits

5 As the atoms in Period 4 of the Periodic Table are considered from left to right the atoms generally show 1 an increase in radius and an increase in ionization energy 2 an increase in radius and a decrease in ionization energy 3 a decrease in radius and an increase in ionization energy 4 a decrease in radius and a decrease in ionization energy

An aqueous solution at 25 C has a OH concentration of 1 10 M Calculate the H O concentration Be sure your answer has the correct number of significant digits

Select the examples in which the names correctly match the formulas of the compounds indicated select all that apply wrong choices will be penalized que N O4 NH4 2SO4 CrCla 4H O Cl O S C110 Ca3 PO4 2 MnCl2 CoCl 6H O K SO3 HBr nitrogen oxide ammonium sulfate chromium III chloride tetrahydrate dichlorine oxygen disulfur decachloride calcium phosphate manganese chloride cobalt II chloride potassium I sulfite hydrogen bromide

points Which of the following statements are TRUE about COCI2 molecule select all that apply wrong choices will be penalized Hint Draw Lewis structure 0 The molecule is nonpolar The central atom is carbon C The central atom is oxygen O The central atom contains one lone pair The molecular geometry around the central atom is trigonal planer The molecule contains pi TT bond The molecular geometry around the central atom is trigonal pyramidal The electron pair geometry around the central atom is trigonal planer The hybridization of the central atom is sp There are 3 total electron domains around the central atom The angles between the bonding pairs are around 120 The molecule is polar The electron pair geometry around the central atom is tetrahedral

What word or two word phrase best describes the shape of the phosphorus trifluoride PF3 molecule

ead this paragraph 1 Zoos are needed to protect animals 2 The Wildlife Conservation Society has worked hard to create more than one hundred protected habitats around the world for the rerelease of different species 3 The National Zoo in Washington D C has bred Sumatran tigers boosting a population that was once only seven hundred in the world 4 An award winning education department can be found at the Bronx Zoo By educating children and adults zoos can inspire people to learn about ecological and conservation efforts 5 Zoos are crucial in saving endangered species where otherwise they may die from habitat loss or starvation 6 Many zoos have breeding programs that allow species to multiply and thrive 7 Seeing an animal in person can i foster compassion more than simply watching a documentary Which sentence is part of the analysis in this paragraph

Draw the Lewis structure for ethylamine C H N Ethylamine molecules have one amino group Be certain you include any lone pairs

What is the angle between the carbon oxygen bond and the carbon nitrogen bond in the cyanate OCN ion m

Select all the intermediates that would be isolated if the enzyme malate dehydrogenase was inhibited Isocitrate Succinate Malate a ketoglutarate Fumarate Citrate SuccinylCoA

Draw the Lewis structure for the triiodide 13 ion

Rank from largest to smallest S Sr C Mn Si

A 0 15 M aqueous solution of NaX the sodium salt of X has a pH of 10 70 What is the Ka for HX Select one O a 1 3x10 10 O b 1 7x10 6 O c 2 7x10 21 O d 6 0x10 9 O e 3 4x10 3

4 points The barometric pressure in a cavern was measured using a mercury barometer A value of 748 9 mm Hg was obtained What would the value be in atm Keep the answer with 3 decimal places Do not write unit in answer 3 73

Consider the following redox reaction Cu s 2NO3 aq 4H aq Which of the following statements are true select all that apply wrong choices will be penalized Oxidation number of N in NO2 is 4 NO3 is the oxidizing agent Cu oxidize to Cu H reduced to H O Oxidation number of Cu is 0 Oxidation number of Cu is 2 Cu2 aq 2NO g 2H O aq Oxidation number of N in NO3 is 1 Oxidation number of H is 4 Oxidation number of N in NO3 is 5 NO3 reduced to NO2 Cu is the reducing agent

4 points Express the answer to the following with the correct number of significant figures 327 207 x 1 153 x 2 50

A sealed glass container contains 1 31 moles of He gas and 2 60 moles of Ar gas If the total pressure inside the container is 0 803 atm wha the partial pressure of He in the glass container Keep the answer with 3 decimal places Do not write unit in answer 1 21

4 point Which units must be used in all gas law calculations O O no specific units as long as they cancel L for volume K for temperature atm for pressure

Express the answer to the following with the correct number of significant figures 327 207 x 1 153 x 2 50 27 183 456 OO 39 7561 39 756 39 7 39 8 39 76

would a unstable singular atom of sulfer be stable or

nk from largest to smallest S Sr C Mn Si

benzoic acid has ka value of 6 3x10 5 Calculate the pH range for which this acid would be effective

4 points A gas sample has a volume of 1 436 7 liters at STP How many moles of gas are there in the sample Keep the answer with 2 decimal places Do not write unit in answer

er to the acid base titration curve shown below Which point is best described as a solution containing only H A pH A Select one O a point A O b point B O c point C O d point D O e point E Of point F point G 20 B C D E F G Volume of Titrant Added mL H

would this configuration be more blue or red likely to release light M 15 25 2p 33 45

Ca 1s 2s 2p 3s 4s would this configuration be more likely to release blue or red light 2206281418

Fluering Write full lincas configuration the noble gas configuration and the dash configuration

To obtain pure lead lead II sulfide is burned in an atmosphere of pure oxygen The products of the reaction are lead and sulfur trioxide SO3 Write a balanced chemical equation for this process How many grams of lead will be produced if 2 54 grams of PbS is burned with 1 88 g of O Express your answer to the correct number of significant figures Be sure to show all steps completed to arrive at the answer Hint be sure to work the problem with both PbS and O www

The structure among the following that represents an amide protein bond is Oa 0 O b OC O d C NH N C N N N NH OH CNH 4

Calculate the pH of a 0 481 M solution of dimethylmalonic acid The K of dimethylmalonic acid 7 0 x 10 4 Write your answer to 2 decimal places

4 1 point Will a balloon filled with BCH5 sink or float in air float Osink Previous

The metabolic process that involves the synthesis of smaller molecules from larger ones is called O a glycolysis Ob catabolism O c anabolism O d gluconeogenesis

6 1 point n and P are doubled while V is held constant causing the temperature to remain unchanged decrease increase Previous

27 If 65 g of silver nitrate react with an excess of copper II chloride how many grams of copper II nitrate would be produced CuCl2 aq AgNO3 aq AgCl s Cu NO3 2 aq

1 point How many moles of hydrogen gas are required to produce 3 61 moles of H O Round answers to 2 decimals places NO units 2 H g O2 g 2 H O g Type your answer

1 point How many grams carbon dioxide are produced if 4 71 mol gaseous propane are combusted Round answers to 2 decimal places only numerals Type your answer