June 18, 2021, 10:47:54 PM
Forum Rules: Read This Before Posting


Topic: Prediction of precipitation  (Read 158 times)

0 Members and 1 Guest are viewing this topic.

Offline Win,odd Dhamnekar

  • Regular Member
  • ***
  • Posts: 94
  • Mole Snacks: +0/-5
  • Stock Exchange Trader, Investor,Chemistry Hobbyist
Prediction of precipitation
« on: June 10, 2021, 10:52:26 AM »
In all the following exercises M represents metal and X represents anion.


a) The salt, MX2 has a Ksp of 2.00e-6. If equal volumes of 0.0059M M(NO3)2 and 0.01M NaX are mixed, will solid form?

b)The salt, MX3 has a Ksp of 2.07e-10. If equal volumes of 0.0029M M(NO3)3 and 0.02M NaX are mixed, will solid form?

c)The salt, MX has a Ksp of 2.13e-6. If equal volumes of 0.0062M M(NO3)2 and 0.03M Na2X are mixed, will solid form?

My worked out answers:

a)Qion=0.00295*0.012=2.95e-7 which is less than the given Ksp 2.00e-6, hence solid won't form.

b)Qion=0.00145*(0.03)3=3.915e-8 which is greater than the given Ksp 2.07e-10, hence, solid will form.

c)Qion=0.0031*0.015= 465e-5 which is greater than the given Ksp 2.13e-6, hence solid will form.

What is your opinion about these answers? Are these answer correct? In my opinion, all  these three answers are correct.
Any science consists of the following process.
 1) See 2) Hear 3) Smell if needed 4) Taste if needed
5) Think 6) Understand 7) Inference 8) take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible, true or false or  any other required criteria]

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 1917
  • Mole Snacks: +275/-12
Re: Prediction of precipitation
« Reply #1 on: June 10, 2021, 04:35:08 PM »
Where do you get the value 0.03 in b? Or 0.01 in a?

Offline Win,odd Dhamnekar

  • Regular Member
  • ***
  • Posts: 94
  • Mole Snacks: +0/-5
  • Stock Exchange Trader, Investor,Chemistry Hobbyist
Re: Prediction of precipitation
« Reply #2 on: June 11, 2021, 02:12:23 AM »
In b) , Initial concentration of salt MX3 is 0.02M.After mixing equal volumes of metal(M) and anion(X), it will be 0.01. Then it will be multiplied by X's subscript in MX3=0.03.

Similar is the case for (a).
Any science consists of the following process.
 1) See 2) Hear 3) Smell if needed 4) Taste if needed
5) Think 6) Understand 7) Inference 8) take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible, true or false or  any other required criteria]

Offline mjc123

  • Chemist
  • Sr. Member
  • *
  • Posts: 1917
  • Mole Snacks: +275/-12
Re: Prediction of precipitation
« Reply #3 on: June 12, 2021, 01:51:19 PM »
You don't have MX3, you have M(NO3)3 and NaX. After mixing, you have 0.00145 M M3+ and 0.01 M X-.

You mustn't assume there are stiochiometric  amounts of M and X!

Sponsored Links