Practical Detection Questions and Answers

Given the formula M V M V2 where M stands for Molarity and V stands for Volume Calculate the molarity of acidic HNO3 if 25mL of it is neutralized by 32 1mL of a 0 15M KOH base 0 117 M 0 15 M 0 3 M 0 193 M

Write the equilibrium constant expression for the reaction A s 3B 1 2 C aq D aq in terms of A B C and D as needed Note that K which is sometimes symbolized as Keq denotes that the equilibrium constant is expressed using molar concentrations For this question Ke means the same thing as Keq

At a certain temperature 0 3211 mol of N and 1 601 mol of H are placed in a 3 50 L container N g 3 H g 2NH g At equilibrium 0 1801 mol of N is present Calculate the equilibrium constant Ke

Calculate the mass in grams of 6 95 mol of neon Ne mass of Ne Calculate the mass in grams of 0 867 mol of hydrogen peroxide H O mass of H O

PCI g PC13 g Cl g The concentrations of the products at equilibrium are PC13 0 220 M and Cl 0 280 M What is the concentration of the reactant PC15 at equilibrium PC s Ke 0 0420

t STP The volume of the gas was 6 79 L at 680 mm Hg and 62 C Answer L of gas 7 46 Question 2 What is the volume of 12 2 g of nitrogen gas at STP 19 5 0 1 pts

How many atoms are in 2 13 mol of pure aluminum

Which of the following is likely to react with Aluminum Al Chlorine CI O Magnesium Mg Calcium Ca Beryllium Be O Argon Ar

What is the analytical concentration of NH3 in 0 12 M NH3 solution L tfen birini se in a 0 12 M b 0 24 M c 0 06 M d 1 45 10 3 M O e 7 5 10 6 M

A solution is made by dissolving 5g of salt in 200g of water How would a person dilute the solution Take water out of it Add more solute to it Distill it Boil it O Measure its volume O Add more salt to it

A person mixes 4 80L of a 2M barium nitrate solution with a 3 25M sodium carbonate solution The reaction forms solid barium carbonate and aqueous sodium nitrate What volume in liters of the sodium carbonate solution would the person need to measure out to fully react the barium nitrate with no excess reactant left over round to two decimal places

Given the equation Q mcAT heat in Joules mass in grams e m C 4 18 AT www specific heat capacity change in temperature C How many Joules of heat energy are absorbed when 200 grams of water are heated from 20 C to

What is the molarity of a solution which contains 106 56g KCl potassium chloride and 179 96mL of solution Round to two decimal places 1000mL 1L

Question 6 Given the formula K C 273 What Kelvin temperature is equal to 73C

Fully balance the half reaction 2 1 Mn I MnO in base What is the sum of the coefficients 1 5 2 11 3 12 4 14 5 9

A scientist mixes 138mL of 1M copper II chloride with excess aluminum metal What mass in grams of aluminum chloride would form Round to 2 Decimal Places Reaction 3CuCl2 aq 2Al s 2AlCl3 aq 3Cu s

Question 7 Which phase change is endothermic gas to liquid liquid to solid gas to solid liquid to gas

PV Given the equation T P pressure mm Hg V volume mL T temperature K P2V T A gas has a volume of 1000 mL at a temperature of 20 K and a pressure of 760 mmHg What will be the volume in milliliters when the temperature is changed to 40 K and the pressure is changed to 380 mm

eview arted May 11 at 2 09pm Quiz Instructions his assignment has 22 multiple choice questions and will automatically submit at the end of Question 9 Which element has the greatest electronegativity ability to attract electrons O OLI

pply 7 Use Percentages Given that the molecular mass of magnesium hydroxide Mg OH is 58 32 amu and the atomic mass of an atom of oxygen is 15 999 amu what percentage of this compound is oxygen

1 Balance each of the following chemical equations by adding the correct coefficients in front of each substance a A b Na Al Cl c NaOH d f e F h AI CIO3 3 i CaCO3 4 H O Sb 05 Hf N Ca AIO 2 CH H SO4 1 AICI 1 CH4 0 NaOH H AICI3 0 CaO HCI Na SO4 SbF5 0 CO Hf3N4 AICI CaCl CO H O CO H O H O H O

Question 4 We can estimate column efficiency from information on a chromatogram What is the relation between the peak width and the column length Peak width is directly proportional to the column length w Peak width is inversely proportional to the column Mos CAS Peak width is inversely proportional to the square of the column length RAS Setel Peak width is inversely proportional to the square root of the column length 0 SOPAN length ugon sistentes Beauty There is no relation between peak width and the column length s PO C

Using average bond enthalpies linked above estimate the enthalpy change for the following reaction CH g 20 g CO g 2H O g kJ If neede

If 10 0 mL of 12 M NaOH is diluted to a final volume of 150 mL what is the concentration of the dilute NaOH solution

Which of the following are Michael donors Select all apply Points will be deducted for incorrect answers ss 0000 E 0 F NO B F H CN G NO CH3MgBr D CH3 2Culi H

A 1 25 dilution is done with a 10 0 ppb solution What is the concentration of the diluted solution A 0 400 ppb B 250 ppb

What will be the H3O if 0 001500 moles of HCI is added to 1 000 L of water The reaction gives the conversion factor HCI H O H30 CH equil 0 note this is related to the next problem A 0 000150 M B 0 00075 M start 0 00150 C 0 00150 M D 0 00300 M 0 0

Calculate the ppb when 0 1000 g of Mg3 PO4 2 are dissolved into a final volume of 500 0 L O A 0 0002000 ppb B 20 00 ppb C 50 00 ppb D 200 0 ppb E 50000 ppb

pH log H3O pOH log OH H3O 10 PH OH 10 POH H3O OH 10 14 pH pOH 14 What is the pH of a solution with OH 5 55 x 105 M A 2 2437 OB 4 2557 C 5 5000 OD 5 7443 E 9 7443

sample of carbon dioxide gas has a density of Submit Answer Try Another Version 1 item attempt remaining Use the References to access important values if needed for this question g L at a pressure of 0 830 atm and a temperature of 38 C Assume ideal behavior

How many mL of the 10 0 ppb solution in the previous problem are required to make 4 00 L of a 1 25 dilution A 160 mL B 1 00 x 105 mL

0 4 OSM wwwwww 0 3 OSM wwwwww True or false about the diagram where a cell is placed into the 0 4 osM solution the cell will shrink and appear crenated due to osmotic pressure True False

Use the References to access important values if needed fo A 1 01 mol sample of Kr gas is confined in a 24 4 liter container at 21 0 C If the temperature of the gas sample is raised to 41 7 C holding the volume constant the average molecular speed will O not enough information to answer the question remain the same increase decrease

A mixture of helium and argon gases in a 9 37 L flask at 65 C contains 1 06 grams of helium and 4 78 grams of argon The partial pressure of argon in the flask is atm Submit Answer Try Another Version Use the References to access important values if needed for this question 1 item attempt remaining atm and the total pressure in the flask is

Name Antigone Eurydice messenger ANTIGONE CLOZE PASSAGE SCENE 5 Directions Using the words in the text box fill in the blanks to complete the summary sons body final mistakes sword Haimon s Per Choragos flesh bride Tiresias corpse Haimon Date pride wife Creon happiness prophet wisdom The blind of Thebes enters the scene and tells Creon that the gods are angry and that all men make but good men own up to their mistakes and repair the damage According to Tiresias urges Creon to rethink his decision Creon says that he will not back down and he accuses Tiresias of selling his prophesies Creon s only crime is and Tiresias offers words to Creon Creon will pay corpse for of his own flesh for his actions The Choragos says that he cannot remember when Tiresias has ever spoken false words Creon agrees but says it worse to risk everything for pride The Choragos urges Creon to free Antigone and build a tomb for Polyneices Finally seeing his fault Creon agrees and leaves the scene A enters the scene and says Creon was once happy but now everything is gone The messenger tells the Choragos that they are all dead and that overhears this exchange The messenger tells her what he killed himself saw before Creon arrived at Antigone s vault arrived Haimon was there mourning his hung herself When and he accused Creon of taking her from him He then took his and lunged at Creon but drove it into his own side He died as he clung to Antigone Upon hearing this news Eurydice leaves the scene Creon enters carrying as he realizes he is at fault The messenger comes back with more bad new Eurydice is dead She killed herself Creon accepts that he is to blame for the deaths of his

Lewis Structures Lewis Structures are used to describe the covalent bonding in molecules and ions Draw a Lewis structure for NHF2 and answer the following questions based on your drawing 1 For the central nitrogen atom The number of lone pairs The number of single bonds The number of double bonds 2 The central nitrogen atom A Obeys the octet rule B Has an incomplete octet C Has an expanded octet

A What is the hybridization of the central atom in BeCl Hybridization What are the approximate bond angles in this substance Bond angles B What is the hybridization of the central atom in PO OH 3 Hybridization What are the approximate bond angles in this substance Bond anglos

1 Show the reaction of benzoic acid with potassium hydroxide 2 Show the dehydration reaction of phthalic acid 3 Show the reaction of benzene with bromine 4 Show the reaction of ethane with hydrobromic acid 5 Show the reaction of sulfuric acid with calcium hydroxide

Predict the major product of the following reaction CH8 x O A O B OC C C A Hg OAC MeOH NaBH NaOH Xa B OH you C D OH

The following reaction proceeds and the product has a specific rotation of 4 1 If the enantiomeric excess is 3 8 calculate the optical rotation of pure S 3 methylhexanol O 1 079 O 1 079 10 Br II H O

The freezing point of helium is approximately 270 C The freezing point of xenon is in the noble gas family Which of the following statements is supported by these data O Helium and xenon form highly polar molecules O As the molar mass of the noble gas increases the freezing point decreases O The London forces between the helium molecules are greater than the London forces between the xenon molecules O The London forces between the helium molecules are less than the London forces between the xenon molecules O none of these Question 7 The bonds between hydrogen and oxygen in a water molecule can be characterized as O hydrogen bonds O London forces O intermolecular forces 1 pts

3 Calculate the pH and pOH of 0 2M NaOH solution NAOH is a strong acid 4Pts a pH

O dilute O saturated O supersaturated O concentrated O unsaturated Question 40 You have 25 00 mL of a 0 1000 M sugar solution How much water must be added to make a solution O200 2 mL O 3 12 mL O 21 9 mL O 175 2 mL 0 01249 M 1 pts

A scientist reacts some aluminum metal with some iron III oxide If the scientist actually measures 7 45g of aluminum oxide in the lab and they expected to generate 11 82g of aluminum oxide based on their calculations what is their percent yield Reaction 2Al s Fe2O3 aq Al2O3 aq 2Fe s

Determine the pressure exerted by 2 94 mol of gas in a 2 92 L container at 32 C O2 64 atm O 73 6 atm 25 2 atm 7 72 atm

If 75 09grams 525 61grams of aluminum metal is reacted with of iron III oxide what mass of aluminum oxide is likely to form Reaction 2Al s Fe2O3 aq Al2O3 aq 2Fe s

8 The illustration on the left represents a mixture of H2 light blue molecules and 02 red molecules If these were to react to form H2O molecules what is the maximum number of H2O molecules that could Hint Atoms must be conserved in an ordinary chemical reaction H O molecules

According to the following reaction how many moles of barium sulfate will be formed upon the complete reaction of 0 655 moles barium hydroxide with sulfuric acid barium hydroxide aq sulfuric acid aq barium sulfate s water 1 moles barium sulfate

The inverse log or log as indicated by p can be reversed This converts pH back into H3O POH back into OH and pK back into Ka 1 Calculate the H3O when the pH 6 666 H30 1 10PH 10 6 666 2 Calculate the OH when the pOH 8 888 OH 10 POH 10 8 888 3 Calculate the Ka when the pka 7 777 Ka 10 pka 10 7 777 A 1 67 x 10 8 B 2 158 x 10 7 C 1 29 x 10 9

If 3 16 g of CuNO3 is dissolved in water to make a 0 330 M solution what is the volume of the solution in milliliters