Dilution v.s Neutralization Problem

  • Thread starter Thread starter Lori
  • Start date Start date
  • Tags Tags
    Dilution
Click For Summary

Discussion Overview

The discussion revolves around the differences in solving two chemistry problems related to dilution and neutralization. Participants explore the appropriate methods for calculating volumes needed for neutralization reactions, comparing stoichiometric approaches with the M1V1 = M2V2 formula.

Discussion Character

  • Homework-related
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant describes two problems involving neutralization and dilution, questioning the differing techniques required for each.
  • Another participant suggests considering the chemical differences between nitric acid (HNO3) and sulfuric acid (H2SO4), hinting at the stoichiometric implications of their different molar ratios.
  • Some participants argue that stoichiometry is a more reliable method for solving titration problems, while the M1V1 = M2V2 formula is only applicable for reactions with a 1:1 molar ratio.
  • There is a discussion about the ease of using the M1V1 = M2V2 formula for dilution problems, with some participants expressing a preference for this method despite its limitations.
  • One participant acknowledges the distinction between the formulas, noting that for dilutions, the concentrations refer to the same substance.

Areas of Agreement / Disagreement

Participants express differing opinions on the appropriateness of using the M1V1 = M2V2 formula versus stoichiometry for neutralization problems. There is no consensus on which method is superior, as some find the formula easier while others emphasize the reliability of stoichiometry.

Contextual Notes

Participants highlight that the M1V1 = M2V2 formula may not be suitable for all neutralization reactions, particularly those that do not involve a 1:1 molar ratio. The discussion reflects varying levels of comfort with the mathematical approaches and their applications.

Lori

Homework Statement



So, i have two different problems, and I'm not sure why the technique for solving them is different! They look the same! My main problem is whether i should us M1V1 = M2V2 to solve for volume or to use stoic by using a balanced chemical equation...

the first problem is : What volume of 2.50 M HNO3 is needed to completely neutralize 34.6 ml of 1.22 M Ba(OH)2. [/B]
In this case, i used the stoic method to solve for the volume which got my the correct answer of : 33.9 ml. What i did was just convert Ba(OH)2 to the mols and use mole ratio to find vols of HNO3 and converted it to liters... However, using M1V1 = M1V2 does not work in this case.

the second problem is : 10.0g of Ca(OH)2 was added to enough water to make 435 ml Of solution. what volume of this solution should be added to 45 ml of 0.867 M sulfuric acid solution to completely neutralize the acid.?

In this problem, i used the M1V1 = M2V2 which yielded the correct answer! It was fast and simple since all i needed to do was plug into the formula. I didn't need a chemically balanced equation

Homework Equations


M1V1 = M2V2
M = mols/1 liter
 
Physics news on Phys.org
Can you think of an obvious chemical difference between HNO3 and H2SO4? (Hint: was your answer out by a factor of 2? If not, I am on the wrong track.)
 
mjc123 said:
Can you think of an obvious chemical difference between HNO3 and H2SO4? (Hint: was your answer out by a factor of 2? If not, I am on the wrong track.)
There aee 2 mols of H in the second acid right.
Is it because in the first problem, the mols of acid is not equal mols of base OH? So I'd have to use the stoic method?
 
Lori said:
My main problem is whether i should us M1V1 = M2V2 to solve for volume or to use stoic by using a balanced chemical equation...

Stoichiometry works always.

The formula you listed works only for reagents reacting 1:1. I hate it when people teach it as an approach to the titration problems, it is confusing and misguiding, you have just failed into this trap. Forget you ever saw the M1V1 = M2V2 formula, use stoichiometry and you won't ever have problems with any titration question.
 
Borek said:
Stoichiometry works always.

The formula you listed works only for reagents reacting 1:1. I hate it when people teach it as an approach to the titration problems, it is confusing and misguiding, you have just failed into this trap. Forget you ever saw the M1V1 = M2V2 formula, use stoichiometry and you won't ever have problems with any titration question.
I'm kinda aware of this but like I find it easier. So when can I use this formula? For dilutions right? Where m1v1 is initial and m1v2 is final
 
Lori said:
I'm kinda aware of this but like I find it easier. So when can I use this formula? For dilutions right? Where m1v1 is initial and m1v2 is final

Despite looking the same it is not the same formula. For dilutions you have concentration of the same substance on both sides of the equation.
 
Borek said:
Despite looking the same it is not the same formula. For dilutions you have concentration of the same substance on both sides of the equation.
Oh true. Totally forgot about it . That makes sense. Thanks!
 

Similar threads

Chemistry Moles of NaOH to Create Buffer Solution pH=6 in 0.42M Ethanoic Acid
  • · Replies 3 ·
Replies
3
Views
3K
Vinegar Concentration Calculation: % HC2H3O2 in a Diluted Solution
  • · Replies 1 ·
Replies
1
Views
2K
What is the Identity of the Acid Used to Neutralize Aluminum Hydroxide?
  • · Replies 7 ·
Replies
7
Views
2K
How Much HNO3 to Neutralize 0.200 M NaOH?
  • · Replies 1 ·
Replies
1
Views
2K
Chemistry Where Did the 400g in Enthalpy Change of Neutralization Come From?
  • · Replies 3 ·
Replies
3
Views
3K
Solving Dilution Problem w/o Original Volume
  • · Replies 9 ·
Replies
9
Views
4K
Neutralization by Acid-Base Titration Problems HELP
  • · Replies 1 ·
Replies
1
Views
10K
How to prepare 0.1M 200mL HCl Solution using 6M HCl
  • · Replies 2 ·
Replies
2
Views
10K
Find the Error: Calculating pH of 0.5L Diluted HA Solution
  • · Replies 1 ·
Replies
1
Views
2K
Chemistry Comparing methods of computing pH at equivalence point in titration
  • · Replies 4 ·
Replies
4
Views
2K