General Questions and Answers
Physical Chemistry
GeneralA sample of gas with an initial volume of 29.3 L at a pressure of 735 mm Hg and a temperature of 309 K is compressed to a volume of 15.6 L and warmed to a temperature of 378 K.
What is the final pressure of the gas?
Pfinal=
Physical Chemistry
General14. What is the correct order of the given terms of size of solute particles from smallest particles to largest particles?
A. Colloid, solution, suspension
B. Solution, colloid, suspension
C. Suspension, colloid, solution
D. Solution, suspension, colloid
Physical Chemistry
GeneralCarbon occurs in two forms, graphite and diamond. The enthalpy of the combustion of graphite is -393.5 kJ/mol, and that of diamond is -395.4 kJ/mol:
C (graphite) + O₂(g) → CO₂ (g) ΔH=-393.5 kJ
C (diamond) + O₂(g) → CO₂ (g) ΔH=-395.4 kJ
Calculate ΔH for the conversion of graphite to diamond: C (graphite) → C (diamond) ΔH =?
Physical Chemistry
GeneralWhich statement concerning solution concentration is FALSE?
An unsaturated solution contains less than the maximum amount of solute that can be dissolved in the solvent.
The molarity of a solution is the number of moles of solute present in one liter of the solution.
A saturated solution contains more than 100 g of dissolved solute.
The concentration of a saturated solution is equal to the solubility of the solute.
A solution can be made less concentrated by adding additional solvent.
Physical Chemistry
GeneralA student is conducting a titration lab as part of their Grade 12 Chemistry course. The procedure asks them to titrate 35.00 mL of a 0.0.64 mol/L hydrobromous acid, HBrO(aq), a weak acid, with 0.150 mol/L of strong potassium hydroxide solution, KOH(aq). They observe the equivalence point is reached when 15.00 mL of the base has been added.
The student has already done some calculations and found that 0.00224 mol of acid and base were used to make 0.00224 mol of the basic salt. What should the student calculate as the pH at the equivalence point, given Kb = 3.6 x 10^-6?
Include any tables, formulas, and balanced reactions used. The acid-base equation has been provided. [HINT: Start by finding the concentration of salt!]
*SHOW YOUR WORK!
HBrO (aq) + KOH(aq) -> H₂O(l) + KBrO (aq)
Physical Chemistry
GeneralStudy this chemical reaction:
Ca+I₂ → Cal₂
Then, write balanced half-reactions describing the oxidation and reduction that happen in this reaction.
oxidation:
reduction:
Physical Chemistry
GeneralWild almonds taste bitter (and are dangerous to eat!) because they contain hydrocyanic
acid, HCN (aq). Answer the following about HCN:
a) Write the reaction of hydrocyanic acid and water. (2 marks)
b) Write the Ka expression. (1 mark)
Physical Chemistry
Generala. A block of sodium that has the measurements 3.00 cm × 5.00 cm x 5.00 cm has a mass of 75.5 g. Calculate the density of sodium.
b. Compare your calculated density with the value in the properties table for Group 1 elements. Calculate the percentage error for your density determination.
Physical Chemistry
GeneralIf 5.39 g of sodium carbonate is recovered from the decomposition of 1.55 g of sodium bicarbonate, what is the percent yield of the reaction? (Note: I messed up on this problem and the percent yield will be unrealistically large. You can still solve it but will get a number much larger than I intended.)
2 NaHCO3(s)→ Na2CO3(s) + CO2(g) + H₂O(l)
Physical Chemistry
GeneralRead this sentence and answer the question that follows.
The policemen arrived at the crime scene anticipating some trails to track the murderer.
What does anticipating mean in this context?
Expecting
Bitter
Surprised
Physical Chemistry
GeneralSilver sulfate is precipitated from solution according to the following reaction
2 AgNO3 (aq) + Na2SO4 (aq)-> Ag2SO4 (s) + 2 NaNO3(aq)
If 3.80 moles of AgNO3 and 3.05 moles of Na2SO4 are present initially, how many moles of excess reactant will remain after precipitation is complete? Write your answer to 2 decimal places.
Physical Chemistry
GeneralWhat is one reason to fill out the Free Application for Federal Student Aid (FAFSA), even if you do not expect aid?
A. You could be offered financial aid you didn't know was available.
B. You are required to fill out the FAFSA for admission to all schools.
C. You cannot graduate unless you fill out the FAFSA.
D. You can better qualify for merit-based financial aid.
Physical Chemistry
GeneralFind the meaning of the underlined word from the context of the sentence.
Christy has taken a perilous job. I'm not sure if it is worth risking her life.
Traveling
Creative
Dangerous
Physical Chemistry
GeneralVinegar is a solution of acetic acid in water. If a 325 mL bottle of distilled vinegar contains 24.1 mL of acetic acid, what is the volume percent (v/v) of the solution?
Express your answer to three significant figures.
Physical Chemistry
GeneralSnis a different compound than SnO₂. What is the difference regarding the cation?
The oxygen in Snhas a higher oxidation state than the oxgyen in SnO₂
The oxygen in Snhas a lower oxidation state than the oxygen in SnO₂
The tin in Snhas a higher oxidation state than the tin in SnO₂
The tin in Snhas a lower oxidation state than the tin in SnO₂
Physical Chemistry
GeneralWhat is the overall balanced equation for the precipitation reaction occurring between silver nitrate and calcium bromide?
2AgNO3(aq) + CaBr₂ (aq)→2AgBr(aq) + Ca(NO3)2 (aq)
AgNO3(aq) + CaBr₂ (aq) →AgBr(s) + Ca(NO3)2 (aq)
2AgNO3(aq) + CaBr2 (aq)→2AgBr(s) + Ca(NO3)2 (aq)
2AgNO3 + CaBr2-2AgBr + Ca(NO3)2
Physical Chemistry
GeneralWhich two sentences describe characteristics of a partnership?
The owners are free from personal liability.
The owners pool their resources to raise capital.
The owners in a partnership are called members.
The business benefits because owners can share responsibilities.
Physical Chemistry
GeneralPredict the products for the following precipitation reaction:
NiCl2 (aq) + (NH4)2S(aq) →
NiS (s) + 2NH₂Cl(aq)
NiS (s) + 2NH4Cl(s)
NiS (aq) + 2NH4Cl(aq)
NiS (s) + NH4Cl(aq)
Physical Chemistry
GeneralWhile I agreed with his view that some of the obsolete rules of our historic school did not apply to the students today, I thought he needed to be more cooperative.
What does obsolete mean in this context?
Significant
Outdated
Intricate
Physical Chemistry
General37.6 mL of aqueous 0.255 M Pb(NO3)2 is mixed with 34.2 mL of 0.415 M NaCl. The equation for the precipitate reaction is: Pb(NO3)2 (aq) + 2 NaCl (aq) -> PbCl2 (s) + 2 NaNO3 (aq)
How many moles of PbCl2 are formed?
Physical Chemistry
GeneralWhich answer correctly explains the idiom, "It is raining cats and dogs?"
It is raining very hard.
Cats and dogs are falling from the sky.
People are throwing stuffed animals at each other.
Physical Chemistry
GeneralA jet airplane reaches 643. km/h on a certain flight. What distance does it cover in 3.0 min? Set the math up. But don't do any of it. Just leave your answer as a math expression. Also, be sure your answer includes all the correct unit symbols.
Physical Chemistry
General9. If 45 grams of triamcinolone is added to 100 grams of Aquaphillic ointment, what is the percent
strength?
Physical Chemistry
GeneralAmmonia and gaseous hydrogen chloride combine to form ammonium chloride.
NH3(g) + HCl(g) → NH4Cl(s)
If 5.14 L of NH3(g) at 22.0 °C and 0.990 atm is combined with 4.08 L of HCl(g) at 37.0 °C and 2.69 atm, what mass of NH4Cl(s) will be produced?
Mass=
Which gas is the limiting reactant?
NH3
HCI
Physical Chemistry
GeneralThe solubility in acetone of organic compound O is measured and found to be 71.5
at 10. °C. Calculate the volume of a saturated solution of O in acetone that would contain 300. mg of O at this temperature. Be sure your answer has the correct unit symbol and 3 significant digits.
Physical Chemistry
GeneralFour liquids are described in the table below. Use the second column of the table to explain the order of their freezing points, and the third column to explain the order of their boiling points.
For example, select '1' in the second column next to the liquid with the lowest freezing point. Select '2' in the second column next to the liquid with the next
higher freezing point, and so on. In the third column, select '1' next to the liquid with the lowest boiling point, '2' next to the liquid with the next higher boiling point, and so on.
Note: the density of water is 1.00 g/mL.
8.7 g of sucrose (C12H22011) dissolved in 100. mL of water
8.7 g of propylene glycol (C3H8O₂) dissolved in 100. mL of water
8.7 g of potassium chloride (KCI) dissolved in 100. mL of water
100. mL of pure water
Physical Chemistry
GeneralWhat is true about the motions of electrons?
Select the correct answer below:
They display particle-like behavior.
They display wave-like behavior.
They display both particle-like and wave-like behavior.
They display neither particle-like nor wave-like behavior.
Physical Chemistry
GeneralWhich of the following properties describes colloids?
Colloids contain small solute particles, are homogenous mixtures, and can be filtered.
Colloids contain particles that are large molecules, are homogenous mixtures, and cannot be filtered.
Colloids contain particles that can be seen with the naked eye, are heterogeneous mixtures, and can be filtered.
Colloids contain small solute particles, are homogenous mixtures, and cannot be filtered.
Physical Chemistry
GeneralA certain substance X has a normal boiling point of 121.7 °C and a molal boiling point elevation constant K = 0.52 °C-kg-mol. A solution is prepared by dissolving some urea
((NH,),CO) in 200. g of X. This solution boils at 122.1 °C. Calculate the mass of urea that was dissolved.
Round your answer to 1 significant digit.
Physical Chemistry
GeneralHow does thermal energy move between objects?
It moves from objects of lower mass to objects with higher mass.
It moves from objects of higher mass to objects with lower mass.
It moves from objects of lower temperature to objects with higher temperature.
It moves from objects of higher temperature to objects
Physical Chemistry
GeneralWhat is the percent-by-mass, % (m/m), concentration of Na2SO4 in a solution made by dissolving 39.5 g of
Na2SO4 in enough water to give 96.0 g of total solution?
Type answer:
Physical Chemistry
GeneralFirst, launch the video below. You will be asked to use your knowledge of chemistry to predict the outcome of a demonstration. Then, close the video window and answer the questions at right. You can watch the video again at any point to review.
Water and toluene are not miscible. Which of the following is most likely the formula of toluene?
CH3COOH
C6H5 CH3
CH3OH
C6H12O6
Physical Chemistry
GeneralRegular treatment with low dose aspirin is used to help prevent cardiovascular disease. How many aspirin molecules are in 200. mg of aspirin? The molecular formula for aspirin is C9H8 O4.
Physical Chemistry
GeneralShirley knows the amount of a compound in grams.
Choose the values Shirley needs to use in her calculation to find the number of molecules in the given sample of her compound.
volume of the compound
Avogadro's number
density of the compound
molar mass of the compound
Physical Chemistry
GeneralIn order to dilute a solution, the volume which causes the concentration to
decreases; decrease
increases; decrease
increases; increase
decreases; increase
Physical Chemistry
GeneralIn which of the following options is the comma used correctly?
Elisa one of the partners in my company, decided to start her own business.
Elisa, one of the partners in my company decided to start her own business.
Elisa, one of the partners in my company, decided to start her own business.
Physical Chemistry
GeneralWhat is the molarity of the solution prepared by diluting 20.1 mL of 2.10 M AgNO3 to the final volume 98.5 mL?
Calculate your final answer to 2 decimal places.
Type answer:
Physical Chemistry
GeneralHow many grams of HNO3 are in 3.405 x 1022 molecules of HNO₂?
Show the conversions required to solve this problem and calculate the grams of HNO3.
3.405 x 1022 molecules HNO3 ×
Physical Chemistry
GeneralHow many milliliters of a 0.624 M KOH solution would be needed to provide 5.58 g of KOH to a chemical reaction?
Physical Chemistry
GeneralA 0.0965 g sample of aluminum metal reacts with sulfuric acid to give 129 mL of hydrogen gas at 26 °C and an atmospheric pressure of 766 mm Hg. The hydrogen gas is collected over water. a) Write a balanced chemical equation for the reaction between solid aluminum metal and aqueous hydrochloric acid.
Physical Chemistry
GeneralHow many grams of AIPO4 are in 1.606 x 10^22 molecules of AIPO?
Show the conversions required to solve this problem and calculate the grams of AIPO4.
Physical Chemistry
GeneralHow many grams of glucose (C6H₁206) are there in 911.47 mL of a 19.20 % (m/v) glucose-water solution?
Physical Chemistry
GeneralThe reaction
H3 AsO3 + 12 + H₂O →→→ H³AsO, +21¯+2H+
is one of a pair of reactions in an experiment
called the iodine clock reaction, an example
of chemical chaos. Which of the following
statements concerning this reaction is true?
1. As is being oxidized from +6 to +8.
2. As is being reduced from +8 to +6.
3. As is being oxidized from +3 to +5.
4. As is being reduced from +5 to +3.
Physical Chemistry
GeneralIn the redox conversion of SO3 to SO-, S is? and its oxidation number goes from ? to ? 1, oxidized; 2 to 6 oxidized; 3 to -3 3, reduced; 6 to 3 4, oxidized; 6 to 3 5, oxidized; 6 to 2 6, reduced: 6 to 1 7, oxidized; 6 to 1 8, reduced; 6 to 2 9, reduced; 2 to 6 10, reduced: 3 to 3
Physical Chemistry
GeneralWrite the net ionic equation for the precipitation reaction that occurs when aqueous solutions of barium sulfide and aluminum nitrate are combined. Be sure to specify states such as (aq) or (s). If a box is not needed leave it blank.
Physical Chemistry
GeneralHow many molecules of NaClO4 are in 3.061g NaClO4? Show the conversions required to solve this problem and calculate the molecules of NaCIO4.
Physical Chemistry
General(a) When aqueous solutions of AgNO3 and Znl₂ are mixed, does a precipitate form? (b) Write a balanced equation for the precipitation reaction that occurs when aqueous solutions of calcium iodide and potassium carbonate are combined. Be sure to include states such as (s) or (aq).
Physical Chemistry
GeneralHow many mL of isopropyl alcohol is present in a 48% solution of isopropyl alcohol by
volume if there are 170 mL of total solution? Show all work and remember units are part of
your answer.
Physical Chemistry
GeneralBalance the given chemical equations. Use the lowest whole-number coefficients.
equation 1: N₂ + O₂ → NO
equation 2: TiCl4 + H₂O → TiO₂ + HCl
equation 3: CH4+O2 → CO2 + H2O
equation 4: C2H6 +O2 → CO2 + H2O
Physical Chemistry
GeneralWhich of the options contains a sentence that uses the apostrophe correctly?
What did Megan mean by "Carls not going?"
What did Megan mean by, "Carl's not going"?
What did Megan mean by, "Carls not going"?