Find the molarity and ph of diluted HCl

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Discussion Overview

The discussion revolves around calculating the molarity and pH of a diluted hydrochloric acid (HCl) solution. Participants are addressing a homework problem that involves mixing a specific volume of distilled water with a certain number of drops of HCl, requiring clarification on how to approach the calculations involved.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Conceptual clarification

Main Points Raised

  • One participant expresses uncertainty about how to begin the calculations for molarity and pH.
  • Another participant questions the final volume of the solution and prompts for the calculation of moles of HCl based on the given concentration and volume.
  • A participant clarifies that the volume of HCl should be expressed in liters and points out the confusion regarding the use of drops versus milliliters.
  • Further clarification is provided on how to determine the final volume of the solution by summing the individual volumes of the components added.
  • One participant explains the definition of molarity as moles of substance per liter of solution and emphasizes the need to calculate moles of HCl added to proceed with the molarity calculation.
  • There is a note that HCl is essentially completely ionized in aqueous solution, which is relevant for the pH calculation.

Areas of Agreement / Disagreement

Participants have not reached a consensus on the calculations, and there are multiple competing views regarding the interpretation of volumes and the approach to finding molarity and pH.

Contextual Notes

There are unresolved aspects regarding the exact volumes involved in the calculations, particularly the conversion from drops to milliliters, and the final volume of the solution after mixing. The discussion also highlights the need for clarity on the definitions and relationships between moles, volume, and molarity.

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Homework Statement


To 25.000 mL of distilled water in a 50 mL beaker, you add exactly 19 drops of 0.100 M HCl and swirl to mix. If exactly 20 drops of HCl are required to make 1.000 mL


Homework Equations


Calculate molarity of the diluted HCl and pH of the diluted HCl



The Attempt at a Solution


i really don't know where to start.
i'd really appreciate the help i can get
 
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What is the final volume of the solution? How many moles of HCl are in 19/20 mL of 0.100 M HCl? What is the definition of molarity and how can you calculate pH if you know the molarity of the acid?
 
19/20 ml of HCL? you mean the drops
what about .025L or .001L isn't that the vol. for HCl
all i know is molarity is moles/volume
i'm still lost. since there's two volumes given and no moles to do the molarity equation
 
If you add 50 mL to 1 mL how many mL is the final solution? Now do that for 25 mL plus 19/20 mL... That's final volume.

Know how to calculate molarity? It's not moles/volume, btw.
 
Molarity means moles of substance of interest per liter of solution.

Use your given information to calculate moles of HCl added;
The volume of resulting solution is the sum of the volume of the individual volumes of everything added to make the solution. You want "Moles of HCl per liter of solution".

Note that for pH question, you want to know what pH means; and know that your HCl is essentially completely ionized in aqueous solution.
 

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