Chemistry

I have a test on monday and I NEED to ace it in order to raise my grade > . <
ldsfkjaslkf
right now, acids and bases are killing me

can somebody help me with these problems?

A buffer solution is prepared by mixing the weak base ammonia (Kb=1.77x10^-5) with ammonium chloride. The concentration of NH3 is 0.10M and that of NH4Cl is 050M. What is the pH of this solution?

If a 0.00100 mole sample of NaOH is added to 1.0L of the solution, what is the new pH of the solution?

To a new 1.0L sample of the buffer, 0.010 mole of HCl is added. What does it react with?

What happens to the pH of the same solution if another 0.10 mole of HCl is added?

  1. 👍 0
  2. 👎 0
  3. 👁 156
  1. The secret to acid/base problems is to recognize what you have produced in the problem and determine the pH from that.

    A buffer solution is prepared by mixing the weak base ammonia (Kb=1.77x10^-5) with ammonium chloride. The concentration of NH3 is 0.10M and that of NH4Cl is 050M. What is the pH of this solution?
    Use the Henderson-Hasselbalch equation.
    pH = pKa + log[(base)/(acid)]
    base is NH3. acid is NH4Cl. pKa for NH3 is pKw-pKb.


    If a 0.00100 mole sample of NaOH is added to 1.0L of the solution, what is the new pH of the solution?
    NaOH is a strong base, it will react with the acid of the buffer.
    NH4^+ + OH^- ==> NH3 + H2O
    Therefore, the NH4^+ decreases due to the added NaOH and the NH3 increases. Substitute those new concns of acid/base into the HH equation and solve the for the new pH.


    To a new 1.0L sample of the buffer, 0.010 mole of HCl is added. What does it react with?
    Here the HCl will react with the base, NH3.
    NH3 + HCl --> NH4Cl
    You can see the the NH3 concn will be decreased while the NH4^+ will be increased. Substitute those into the HH equation and solve for the new pH.


    What happens to the pH of the same solution if another 0.10 mole of HCl is added?
    Just redo the last one.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. statistics

    Consider the events of drawing an ace, then draw another ace, followed by a queen, one at a time without replacement (from a standard deck of cards). What is the probability of drawing an ace, then another ace, then a queen?

    asked by CJ on August 12, 2015
  2. statistics

    Six cards-ace, king, queen of hearts; ace, king of diamonds; and king of clubs-are all placed face down a table. One card is to be selected at random. Find the probability: a) of an ace, given that a diamond was turned b) of an

    asked by Anonymous on November 6, 2007
  3. Stats

    A professor believes that all Thursday sections are cursed and will always score lower on tests compared to Monday sections. To tests this he collects samples of test scores from these two sections. For Monday's section, the mean

    asked by Luis on April 15, 2015
  4. Statistics

    A standard pack of 52 cards consists of 4 suits, hearts, diamonds, clubs and spades. Each suit has 13 cards, from Ace to King. We deal randomly 5 cards from the deck of 52. 2 deals differing only by the order are considered the

    asked by Please Help on March 17, 2014
  5. Maths

    A standard pack of 52 cards consists of 4 suits, hearts, diamonds, clubs and spades. Each suit has 13 cards, from Ace to King. We deal randomly 5 cards from the deck of 52. 2 deals differing only by the order are considered the

    asked by Fung on March 16, 2014
  6. Math - Averages

    The test average for Louis' calculus class is found by taking the arithmetic mean of his four best test scores. If his first four test scores are 65,82,76 and 87, what score must he get on the fifth test to raise his test average

    asked by Venus on September 13, 2013
  7. Quick math question

    Can anyone give me a link to a free online algebra test for 9th graders. I have a test on Monday based on algebra to see if I can move on to Geometery and I need a test to see if I'm ready. Thanks

    asked by Katie on April 24, 2009
  8. math

    a business lady leaves her laundry every Monday, then picks it up the next monday as she drops off more. If she wears a clean blouse every day of the week, how many blouses must she have, in order to visit the laundry only on

    asked by lisa on March 5, 2010
  9. math

    The average of 5 numbers is 28. What would the 6th number have to be to bring the average up to 30? Anne’s average in math is 92. She wants to raise her average to 93 so she will make an A. she is taking a test on Friday. What

    asked by katherine on March 14, 2011
  10. Probability

    At a fair run by a local charity organization, it costs 50 cents to try one's luck in drawing an ace from a deck of 52 playing cards. What is the expected profit per customer if they pay $4 if and only if a person draws an ace. I

    asked by Martha on February 13, 2007

More Similar Questions