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    Everything is already answered I just need to know if I am on the right track, please help I am really struggling with chemistry and I absolutely need to know how to do these problems correctly, so if I am wrong can you please tell me were my error is.

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    Which of the following salts would give you the lowest concentration of lead ions in solution if you placed 1 mole of the salt in a liter of water?

    a. PbSO4 Ksp= 1.8 x 10-8

    b. PbCO3 Ksp= 1.5 x 10-13

    c. PbSeO4 Ksp= 1.5 x 10-7

    d. PbCrO4 Ksp= 1.8 x 10-14

    Answer is D

    Question 2
    Which of the following salts would give you the lowest concentration of sulfate ions in solution if you placed 1 mole of the salt in a liter of water?

    a. BaSO4 Ksp= 1.1 x 10-10

    b. CaSO4 Ksp= 2.4 x 10-5

    c. SrSO4 Ksp= 2.8 x 10-7

    d. PbSO4 Ksp= 1.8 x 10-8

    Answer is C

    Question 3
    Which of the following salts would give you the highest concentration of calcium ions in solution if you placed 1 mole of the salt in a liter of water?

    a. CaCO3 Ksp= 3.8 x 10-9

    b. CaCrO4 Ksp=7.1 x 10-4

    c. CaSO4 Ksp= 2.4 x 10-5

    d. CaHPO4 Ksp= 2.7 x 10-7

    Answer is C

    Question 4
    Which of the following salts would give you the lowest concentration of calcium ions in solution if you placed 1 mole of the salt in a liter of water?

    a. CaCO3 Ksp= 3.8 x 10-9

    b. CaCrO4 Ksp=7.1 x 10-4

    c. CaSO4 Ksp= 2.4 x 10-5

    d. CaHPO4 Ksp= 2.7 x 10-7

    Answer is A

    Question 5 (10 points)
    Which of the following salts would give you the highest concentration of hydroxide ions in solution if you placed 1 mole of the salt in a liter of water?

    a. Fe(OH)2 Ksp= 7.9 x 10-15

    b. Ca(OH)2 Ksp= 7.9 x 10-6

    c. Ni(OH)2 Ksp= 2.8 x 10-16

    d. Zn(OH)2 Ksp= 4.5 x 10-17

    Answer is B

    Question 6 (10 points)
    What mass of potassium bicarbonate (KHCO3) must be added to 500 mL of a 0.200 M carbonic acid solution to make a buffer with pH = 6.30?

    a. 8.73 g

    b. 4.55 g

    c. 24.07 g

    d. 8.33 g
    Answer is D

    Question 7
    Which of the following salts would give you the lowest concentration of hydroxide ions in solution if you placed 1 mole of the salt in a liter of water?

    a. Fe(OH)2 Ksp= 7.9 x 10-15

    b. Ca(OH)2 Ksp= 7.9 x 10-6

    c. Ni(OH)2 Ksp= 2.8 x 10-16

    d. Zn(OH)2 Ksp= 4.5 x 10-17
    Answer is C

    Question 8
    What mass of NH4Cl must be added to 500 mL of a 0.150 M NH3 solution to make a buffer with pH = 9.50?

    a. 1.14 g

    b. 2.54 g

    c. 6.97 g

    d. 2.31 g
    Answer is B

    Question 9
    What mass of NH4Cl must be added to 200 mL of a 0.200 M NH3 solution to make a buffer with pH = 9.30?

    a. 1.95 g

    b. 1.12 g

    c. 2.34 g

    d. 1.11 g

    Answer is A

    Question 10
    Which of the following salts would give you the highest concentration of phosphate ions in solution if you placed 1 mole of the salt in a liter of water?

    a. Ba3(PO4)2 Ksp= 1.3 x 10-29

    b. Ca3(PO4)2 Ksp= 1.0 x 10-25

    c. Pb3(PO4)2 Ksp= 3.0 x 10-44

    d. Sr3(PO4)2 Ksp= 1.0 x 10-31

    Answer is B

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    SOLUTION This solution is FREE courtesy of BrainMass!

    please see the attachment

    Which of the following salts would give you the lowest concentration of lead ions in solution if you placed 1 mole of the salt in a liter of water?

    a. PbSO4 Ksp= 1.8 x 10-8

    b. PbCO3 Ksp= 1.5 x 10-13

    c. PbSeO4 Ksp= 1.5 x 10-7

    d. PbCrO4 Ksp= 1.8 x 10-14

    Answer is D [Correct, Ksp = [Product+][Product-], lowest Ksp means this product is lowest]

    Question 2
    Which of the following salts would give you the lowest concentration of sulfate ions in solution if you placed 1 mole of the salt in a liter of water?

    a. BaSO4 Ksp= 1.1 x 10-10

    b. CaSO4 Ksp= 2.4 x 10-5

    c. SrSO4 Ksp= 2.8 x 10-7

    d. PbSO4 Ksp= 1.8 x 10-8

    Answer is C : [Wrong, Ksp = [Product+][Product-], lowest Ksp means this product is low]

    For a reaction AB <=> nA+ + mB-, Ksp = [A+]^n *[B-]^m, n and m are integers. If [A+] and [B-] are very low, Ksp will also be very low. (Same reasoning was applied to the first question) Correct answer is A

    Question 3
    Which of the following salts would give you the highest concentration of calcium ions in solution if you placed 1 mole of the salt in a liter of water?

    a. CaCO3 Ksp= 3.8 x 10-9

    b. CaCrO4 Ksp=7.1 x 10-4

    c. CaSO4 Ksp= 2.4 x 10-5

    d. CaHPO4 Ksp= 2.7 x 10-7

    Answer is C Correct answer is B. Reason is the same as above, but in reverse (high)

    Question 4
    Which of the following salts would give you the lowest concentration of calcium ions in solution if you placed 1 mole of the salt in a liter of water?

    a. CaCO3 Ksp= 3.8 x 10-9

    b. CaCrO4 Ksp=7.1 x 10-4

    c. CaSO4 Ksp= 2.4 x 10-5

    d. CaHPO4 Ksp= 2.7 x 10-7

    Answer is A Correct

    Question 5 (10 points)
    Which of the following salts would give you the highest concentration of hydroxide ions in solution if you placed 1 mole of the salt in a liter of water?

    a. Fe(OH)2 Ksp= 7.9 x 10-15

    b. Ca(OH)2 Ksp= 7.9 x 10-6

    c. Ni(OH)2 Ksp= 2.8 x 10-16

    d. Zn(OH)2 Ksp= 4.5 x 10-17

    Answer is B Correct

    Question 6 (10 points)
    What mass of potassium bicarbonate (KHCO3) must be added to 500 mL of a 0.200 M carbonic acid solution to make a buffer with pH = 6.30?

    a. 8.73 g

    b. 4.55 g

    c. 24.07 g

    d. 8.33 g
    Answer is D correct

    H2CO3 → HCO3- + H+ (pKa = 6.38)

    pH = pKa + log [salt]/[acid]

    6.3 = 6.38 + log [salt]/[acid] log [salt]/[acid] = -0.08

    [salt]/[acid] = 0.832

    [salt] = 0.832 * [acid] = 0.832 * 0.2 = 0.1664 M (number of moles of salt/liter of the solution)

    therefore, mass of KHCO3 = molar mass of KHCO3 * number of moles required *liter of solution

    = 0.1664*0.5 *100.12 = 8.33g

    Molar mass of KHCO3 = 39.1 + 1 + 12 + 3*16 = 100.1g/mol => (1 mole weigh 100.1 g)

    Question 7
    Which of the following salts would give you the lowest concentration of hydroxide ions in solution if you placed 1 mole of the salt in a liter of water?

    a. Fe(OH)2 Ksp= 7.9 x 10-15

    b. Ca(OH)2 Ksp= 7.9 x 10-6

    c. Ni(OH)2 Ksp= 2.8 x 10-16

    d. Zn(OH)2 Ksp= 4.5 x 10-17

    Answer is C. Wrong (correct is d)

    Question 8
    What mass of NH4Cl must be added to 500 mL of a 0.150 M NH3 solution to make a buffer with pH = 9.50?

    a. 1.14 g

    b. 2.54 g

    c. 6.97 g

    d. 2.31 g
    Answer is B incorrect. Answer is d

    pKa of NH4+ = 9.26

    pH = pKa + Log [base]/[acid]

    9.5 = 9.26 + log[base]/[acid]

     log[[0.15]/[acid]] = 0.24

     0.15/[acid] = 1.738
     [acid]= [NH4+] = 0.15/1.738 = 0.086306 M

    Molar mass of NH4Cl = 53.4 g/mol

    We have 0.086306 moles/litre of NH4+ in one litre of the solution.

    That is we have 0.086306 * 0.5 number of moles in 0.5 L.

    Therefore, mass of NH4Cl = molar mass (g/mol)* number of moles of NH4+ = 53.4*0.086306*0.5 = 2.304

    Question 9
    What mass of NH4Cl must be added to 200 mL of a 0.200 M NH3 solution to make a buffer with pH = 9.30?

    a. 1.95 g

    b. 1.12 g

    c. 2.34 g

    d. 1.11 g

    Answer is A answer is correct.
    Here also proceed as earlier.
    pH = pKa + log [base]/[acid]

    9.3 = 9.26 + log 0.2/[NH4+]

    log 0.2/[NH4+] = 0.04

    0.2/[NH4+] = 1.096

    [NH4+] = 0.2/1.096 = 0.1824 M

    moles of NH4+ = 0.1824 * 0.2 = 0.0365 mol

    Therefore, mass of NH4Cl = 53.4 * 0.0365 = 1.9489 g

    Question 10
    Which of the following salts would give you the highest concentration of phosphate ions in solution if you placed 1 mole of the salt in a liter of water?

    a. Ba3(PO4)2 Ksp= 1.3 x 10-29

    b. Ca3(PO4)2 Ksp= 1.0 x 10-25

    c. Pb3(PO4)2 Ksp= 3.0 x 10-44

    d. Sr3(PO4)2 Ksp= 1.0 x 10-31

    Answer is B Correct

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com December 24, 2021, 5:00 pm ad1c9bdddf>
    https://brainmass.com/chemistry/acids-and-bases/lowest-concentration-salt-water-21866

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