Questions and answers by

Hannah

Questions (2,007)

1) The standard molar entropy value of N2 (g) is 191.5 J/K-mol,of O2 (g) is 205.0 J/K-mol and of NO2 (g) is 240.0 J/K-mol. From
1. 1 answer
2. 2,198 views
1) For a reaction delta Go is more negative than delta Ho. What does this mean?a. delta So is zero. b. delta So is negative c.
1. 3 answers
2. 1,289 views
.50 - x / x = 3.20e-1I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not
1. 4 answers
2. 647 views
Which of the following four processes are accompanied by an increase in entropy?1. I2 (s) -> I2 (g) 2. 2 I (g) -> I2 (g) 3. 2
1. 3 answers
2. 2,102 views
Delta G^o for a reaction can be calculated from?1. delta G^o �f data 2. Delta H^o f and delta S data 3. equilibrium constants I
1. 2 answers
2. 553 views
1) Free energies of formation area. always positive b. always negative c. never zero d. measured at 298K e. more than one
1. 1 answer
2. 488 views
Which choice below has the highest standard molar entropy?SiCl4(s), CCl4(g), CCl4(l), Si(Cl4(l) I know that the gas state has
1. 4 answers
2. 1,260 views
An astronaut who is floating freely through space is seated upon a unicycle. He begins topedal the unicycle “forward.” As he
1. 1 answer
2. 480 views
Given the increase in government expenditures and the marginal propensity to consume, how would you find the change in
1. 0 answers
2. 870 views
.50 - x / x = 3.20e-1I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not
1. 0 answers
2. 542 views
Step 1:H2O2 + I^-^ = H2O + OI^-^step 2: H2O2 + OI^-^ = H2O + O2 + I^-^ What is the equation for the overall reaction? I am not
1. 0 answers
2. 524 views
.50 - x / x = 3.20e-1I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not
1. 1 answer
2. 621 views
A 21.2mL sample of 0.307M ammonia, NH3 is titrated with 0.259 M hydrobromic acid. What is the pH before the addition of any
1. 1 answer
2. 447 views
Calculate the pH of an aqueous solution of 0.15 M potassium carbonate.I know that pH = -log(H30+) but I am not sure how to start
1. 2 answers
2. 1,241 views
Step 1:H2O2 + I^-^ = H2O + OI^-^step 2: H2O2 + OI^-^ = H2O + O2 + I^-^ What is the equation for the overall reaction? I am not
1. 0 answers
2. 988 views
.50 - x / x = 3.20e-1I need to solve for x. I was going to do .50 X 3.20e-1 and then take the square root but this is not
1. 1 answer
2. 547 views
Step 1:H2O2 + I^-^ = H2O + OI^-^step 2: H2O2 + OI^-^ = H2O + O2 + I^-^ What is the equation for the overall reaction? I am not
1. 0 answers
2. 1,055 views
Calculate the pH of an aqueous solution of 0.15 M potassium carbonate.I know that pH = -log(H30+) but I am not sure how to start
1. 2 answers
2. 524 views
Calculate the concentration of HC6H6O6- in an aqueous solution of 0.0851 M ascorbic acid, H2C6H6O6 (aq).I do not know how to
1. 1 answer
2. 809 views
What is the percent by weight of a solution prepared by dissolving 25 g of NaCl in 150 g of water? What is the volume of water
1. 1 answer
2. 846 views
A buffer solution is prepared by adding 14.37g of NaC2H3O2 and 16.00g of acetic acid to enough water to make 500mL of solution.W
1. 1 answer
2. 1,314 views
Calculate the pH of an aqueous solution of 0.15 M potassium carbonate.I know that pH = -log(H30+) but I am not sure how to start
1. 2 answers
2. 622 views
How many 2 quart pitchers could you fill with 512 fluid ounces of juice?????
1. 1 answer
2. 468 views
If you add 0.35grams NaF to 150mL of a 0.30M HF, what is the pH of the resulting solution?To start off would I use the value of
1. 1 answer
2. 999 views
What is molar solubility of Al(OH)3 at 25 degrees C given the solubility product Ksp = 5.0e-33?I set this up as Al^3+ + 3OH^-
1. 3 answers
2. 1,428 views
You have 250mL of a 0.56M solution of sodium acetate. How many mL of 0.50M acetic acid should be added to make a buffer of pH
1. 1 answer
2. 1,468 views
If you add 0.35grams NaF to 150mL of a 0.30M HF, what is the pH of the resulting solution?To start off would I use the value of
1. 2 answers
2. 387 views
. Ksp for Fe(IO3)3 is 10-14. Two solutions, one being iron(III) nitrate and the other being sodium iodate, were mixed. At the
1. 1 answer
2. 3,240 views
For an experiment on the titration of a supernatant liquid I need to calculate the number of moles of S2O3^2-^ ion required
1. 1 answer
2. 576 views
A saturated solution of a certain metal(II) chloride has a chloride ion concentration of 0.032M. The Ksp for this compound can
1. 1 answer
2. 584 views
For an acetic acid-sodium acetate buffer to have a pH of 4.64, what molar ratioof CH3COOH to Na+ CH3COO– is needed? I know
1. 4 answers
2. 893 views
1)What is the pH of a saturated solution of lead(II) hydroxide? The Ksp= 4.0e-15Pb(OH)2 4.0e-15 = (x)(2x)^2 = 4x^3 I divided by
1. 1 answer
2. 960 views
. Ksp for Fe(IO3)3 is 10-14. Two solutions, one being iron(III) nitrate and the other being sodium iodate, were mixed. At the
1. 1 answer
2. 771 views
. The insoluble salts AV, B2W, C2X3, DY2, and EZ3, which were formed from the metal ions A+, B+, C3+, D2+, and E3+ and the
1. 1 answer
2. 590 views
Which of the following mixtures will be a buffer when dissolved in 1 liter of water?0.10 mol Ba(OH)2 and 0.20 mol HCl 0.30 mol
1. 1 answer
2. 1,215 views
The solubility product expression for mercury(I) iodide, Hg2I2 is Ksp = ?My answer is [Hg2^2+^][2I^-^]^2^ Would you agree?
1. 7 answers
2. 8,756 views
What is the pH of a 5.06E-2 M aqueous solution of sodium acetate?I know that I would set this up the same way I did for the
1. 1 answer
2. 653 views
The solubility product expression for mercury(I) iodide, Hg2I2 is Ksp = ?My answer is [Hg2^2+^][2I^-^]^2^ Would you agree?
1. 1 answer
2. 688 views
The Ksp values for three salts are given:AgCl = 1.0e-10 Ag2CO3 = 6.3e-10 Ag3PO4 = 2.0e-21 Determine the order of solubility for
1. 3 answers
2. 2,557 views
What is the pH of a 5.06E-2 M aqueous solution of sodium acetate?I know that I would set this up the same way I did for the
1. 6 answers
2. 471 views
What is the pH of 0.144M aqueous solution of ammonium nitrate?I am not sure what to do. Would I do 10^-0.144^ = 0.71?
1. 6 answers
2. 412 views
The ionization constant of HA is 4.0e-4. Using the ice table what is the equilibrium concentration of HA in terms of its initial
1. 2 answers
2. 464 views
Calculate the [H+] in a solution containing 1.00 M hydroflouris acid (Ka=7.2 x 10^-4) and .50 M sodium fluoride
1. 1 answer
2. 626 views
.050 mole of weak acid (HA) is dissolved in enough water to make 1.0 L of solution. The pH of this solution is 3.50. What is the
1. 1 answer
2. 599 views
Find the pH of 1.0M Na2SO3(aq) solution at 25 degrees Celsius.I am not sure how to start this problem. I started off by doing
1. 4 answers
2. 558 views
2.5E-5 = (x)^2/1.75So to solve for x i know I have to take the sqrt of both sides but first do I have to move the 1.75 to the
1. 3 answers
2. 346 views
Given the wage in dollar per day and the CPI for years 1 and 2 how do you calculate the nominal % increase in wage and the real
1. 0 answers
2. 435 views
1) The Ka for acetic acid is 1.8e-5. What is the pH of a 3.18M solution of this acid?I did 1.8e-5 = x^2/3.18 x=sqrt 1.8e-5 X
1. 1 answer
2. 915 views
What is the equilibrium constant for the reaction of ammonium ion with formate ion?I know that the ionization constant for
1. 0 answers
2. 481 views
A 0.0170 M solution of an acid has a pH of 2.5. What is the pKa?i did 10^-2.5=3.16e-3 Then 0.0170 - 3.16e-3=0.01384 ka=
1. 3 answers
2. 497 views
What is the ohms if voltage is 24 andI is 6?
1. 1 answer
2. 326 views
Which of the following equations correspond to the Ka2 for phosphoric acid?note: the double equal sign (==) means equilibrium.
1. 1 answer
2. 2,098 views
What is the equilibrium constant for the reaction of ammonium ion with formate ion?I know that the ionization constant for
1. 0 answers
2. 370 views
What is the equilibrium constant for the reaction of ammonium ion with formate ion?I know that the ionization constant for
1. 0 answers
2. 1,145 views
1) The Ka for acetic acid is 1.8e-5. What is the pH of a 3.18M solution of this acid?I did 1.8e-5 = x^2/3.18 x=sqrt 1.8e-5 X
1. 5 answers
2. 466 views
Which 0.10M solution has the lowest pH?NaCl, KCN, LiF, RbClO, all have the same pH. I think that the answer is that they all
1. 3 answers
2. 1,039 views
Given the wage in dollar per day and the CPI for years 1 and 2 how do you calculate the nominal % increase in wage and the real
1. 0 answers
2. 482 views
What is the [H3O+] for a neutral solution at 50 degrees celsius?I know that kw=[H3O+][OH-] but I am not sure what to do to get
1. 2 answers
2. 2,796 views
What is the [H3O+] for a neutral solution at 50 degrees celsius?I know that kw=[H3O+][OH-] but I am not sure what to do to get
1. 3 answers
2. 1,215 views
Given the wage in dollar per day and the CPI for years 1 and 2 how do you calculate the nominal % increase in wage and the real
1. 0 answers
2. 483 views
Given the wage in dollar per day and the CPI for years 1 and 2 how do you calculate the nominal % increase in wage and the real
1. 0 answers
2. 537 views
For an experiment on the effect of a buffer solution, I need to calculate the expected pH of the buffer.I know that I have to
1. 1 answer
2. 1,211 views
I'm looking for a site with all the pentene isomers, and all the pentyne isomers. Anyone got any suggestions?
1. 1 answer
2. 424 views
a) Write the chemical formula for the simplest pentyne isomer, b) give the name of the two isomers that have pentyne as the base
1. 0 answers
2. 502 views
4 a) Write the chemical formula for the simplest pentene isomer, b) give the name of the two isomers that have pentene as the
1. 1 answer
2. 541 views
Mark wanted to measure the height of a nearby building. He placed a mirror on the pavement at point P, 80 feet from the base of
1. 1 answer
2. 637 views
(4.44e-2 - x) (8.06e-2 - x) / (0.331 + 2x)^2 = 1.80e-2I need to rearrange this equation so that I can get a,b, and c, for the
1. 3 answers
2. 655 views
(4.44e-2 - x) (8.06e-2 - x) / (0.331 + 2x)^2 = 1.80e-2I need to rearrange this equation so that I can get a,b, and c, for the
1. 2 answers
2. 437 views
Determine the concentration in parts per million if 0.500 moles of NaCl are found in 35000g of a salt water solution.Okay, so
1. 1 answer
2. 393 views
1) Which statement below is correct (true)?a) Since HNO2 is a stronger acid than HF it must have a greater pKa. b) Since HOCℓ
1. 5 answers
2. 1,098 views
1) Which of the following is not amphiprotic?H20, NH4^+^, HSO4^-^, H2PO4^-^, all choices are amphiprotic. I think that all of
1. 1 answer
2. 4,713 views
1) The approximate pH of a 3.0 X 10^-3 M solution of the strong acid H2SO4 is?I did pH= -log(3.0 X 10^-3) = 2.5 2)If HCLO2 is a
1. 2 answers
2. 615 views
Write the chemical formula for the simplest heptane isomer and give its name, b) give the names of two heptane isomers with
1. 1 answer
2. 641 views
What is the mass in kg of 20.0 L of diesel fuel? Assume the fuel has a density of 0.85 g/mL.
1. 1 answer
2. 1,042 views
Consider the reaction: PCl3(g) + Cl2(g) PCl5(g). If [PCl3] = 0.78 M, [Cl2] = 0.44 M, and [PCl5] = 0.88 at equilibrium, what is
1. 2 answers
2. 3,346 views
For an experiment we had to test the equilibrium of BiCl3 - BiOClFirst I had to mix a small amount of BiCl3 with 2mL of water.
1. 1 answer
2. 617 views
The average score on a science test was 72 with a standard deviation of 6. The average score on a history test was 89 with a
1. 1 answer
2. 503 views
For an experiment I had to add 1 drop of 1.0M HCl into a test tube that had 2.5mL of 0.10M Na2CrO4 and record the color.The
1. 7 answers
2. 921 views
Factor12^2-3
1. 2 answers
2. 383 views
In the 1970s, when lead was widely used in "ethyl" gasoline, the blood level of the average American contained 0.25 ppm lead.
1. 3 answers
2. 2,990 views
2.5 X 10^(-3) = (.28)(.38) / x^2Solve for x. 2.5 X 10^(-3) = 0.1064 / x^2 2.5 X 10^(-3) X 0.1064 = 266 sqrt 266 = 16.3 Did I do
1. 3 answers
2. 542 views
The original equation was1.7e-3 = (0.0015 -x)^2 / (0.025 +1/2x)(0.025 + 1/2x) Square root of both sides is 0.0412 = (0.0015-x) /
1. 4 answers
2. 606 views
The original equation was1.7e-3 = (0.0015 -x)^2 / (0.025 +1/2x)(0.025 + 1/2x) Square root of both sides is 0.0412 = (0.0015-x) /
1. 7 answers
2. 625 views
The table below shows the market basket quantities and prices for the base year (year 1)Base year 1 Price in price Quantity base
1. 0 answers
2. 871 views
The table below shows the market basket quantities and prices for the base year (year 1)Base year 1 Price in price Quantity base
1. 0 answers
2. 1,240 views
Pure water boils at 100ºC (212ºF). When a substance is added to the water the boiling point increases due to what is referred
1. 1 answer
2. 916 views
0.0412 = 0.0015 - x / 0.025 + 1/2xSolve for x. 0.0412 = 0.015-x / 0.525x I am not sure where to go from here since there are two
1. 15 answers
2. 840 views
Using this data,2 NO(g) + Cl2(g) == 2 NOCl(g) Kc = 3.20 X 10-3 NO2(g) == NO(g) + ½ O2(g) Kc = 3.93 calculate a value for Kc for
1. 0 answers
2. 809 views
A study of the system, H2(g) + I2(g) == 2 HI(g), was carriedout. Kc = 54.9 at 699.0 K (Kelvin) for this reaction. A system was
1. 0 answers
2. 608 views
For the system CaO(s) + CO2(g) = CaCO3(s), I added 1.00 mol of CaO(s) to 1.00L of 0.500M CO2(g) at 200 oC. At equilibrium the
1. 5 answers
2. 795 views
Determine the mass of zinc sulphide, ZnS, produced when 6.2g of zinc and 4.5g of sulphur are reacted.Equation given: Zn + S8 >>
1. 5 answers
2. 3,105 views
I did an experiment to study the effects of changes in conditions on an equilibrium system. The first system was the
1. 2 answers
2. 1,434 views
For the reaction, 2 SO2(g) + O2(g) == 2 SO3(g), at 450.0 K (Kelvin) the equilibrium constant, Kc, has a value of 4.62. A system
1. 1 answer
2. 749 views
For the system CaO(s) + CO2(g) = CaCO3(s), I added 1.00 mol of CaO(s) to 1.00L of 0.500M CO2(g) at 200 oC. At equilibrium the
1. 3 answers
2. 903 views
A study of the system, H2(g) + I2(g) == 2 HI(g), was carriedout. Kc = 54.9 at 699.0 K (Kelvin) for this reaction. A system was
1. 2 answers
2. 612 views
Using this data,2 NO(g) + Cl2(g) == 2 NOCl(g) Kc = 3.20 X 10-3 NO2(g) == NO(g) + ½ O2(g) Kc = 3.93 calculate a value for Kc for
1. 3 answers
2. 783 views
The equilibrium constant for the reaction,H2(g) + I2(g) == 2 HI(g) is 54.9 at 699.0 K (Kelvin). What is the equilibrium constant
1. 3 answers
2. 1,460 views
1) For the reaction system, 2 SO2(g) + O2(g) = 2 SO3(g), Kc hasa value of 4.62 at 450.0 K (Kelvin). A system, at equilibrium has
1. 3 answers
2. 1,459 views
what are the largest stars in the HR diagram called?
1. 1 answer
2. 648 views
The decomposition of hydrogen peroxide in the presence of potassium iodide is believed to occur by the following mechanism:step
1. 0 answers
2. 854 views