Why NaCl Instead of 2NaCl in Reactions?

  • Context: Chemistry 
  • Thread starter Thread starter simphys
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around the correct representation of the products in the reaction between sodium carbonate (Na2CO3) and hydrochloric acid (HCl). Participants are clarifying why the product should be NaCl instead of 2NaCl, focusing on balancing the equation and the implications of ionic dissociation in solution.

Discussion Character

  • Homework-related
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants question why the product is NaCl and not 2NaCl, suggesting that the number of sodium and chlorine atoms should match on both sides of the reaction.
  • One participant suggests that the discrepancy may be a simple typo, indicating that the correct representation should include 2NaCl.
  • Another participant argues that the answer given does not balance the number of sodium and chlorine atoms, implying it must be incorrect.
  • A later reply discusses the nature of ionic compounds, explaining that sodium chloride consists of sodium cations and chloride anions in a 1:1 ratio, which should be represented as NaCl rather than Na2Cl2.
  • Some participants emphasize the importance of balancing the equation correctly, noting that the equation provided is unbalanced and requires adjustment.

Areas of Agreement / Disagreement

Participants express differing views on whether the representation of the product as NaCl is correct or if it should be 2NaCl. There is no consensus on the correct form, and the discussion remains unresolved regarding the balancing of the equation.

Contextual Notes

Participants note the importance of balancing chemical equations and the potential for confusion regarding the representation of ionic compounds in solution. There are references to the need for clarity in distinguishing between molecular representations and the actual dissociation of ions in solution.

simphys
Messages
327
Reaction score
46
Homework Statement
An aqueous solution of Na2CO3 is added to dilute hydrochloric acid. The
resulting carbonic acid, H2CO3, breaks down to form CO2 gas and H2O. Complete and balance the molecular equation for this reaction
Relevant Equations
/
Hello,

Can I get some clarification on why it is NaCl and not 2NaCl as a product please?
Thanks in advance!

1663847665138.png


I had ##Na_2CO_3 + 2HCl## --> ##2NaCl + CO_2 + H_2O## instead. Why is this not correct?
I have this as shouldn't the number of chlorine and sodium atoms be the same in reactant and product side?
 
Physics news on Phys.org
simphys said:
Homework Statement:: An aqueous solution of Na2CO3 is added to dilute hydrochloric acid. The
resulting carbonic acid, H2CO3, breaks down to form CO2 gas and H2O. Complete and balance the molecular equation for this reaction
Relevant Equations:: /

Hello,

Can I get some clarification on why it is NaCl and not 2NaCl as a product please?
Thanks in advance!

View attachment 314453

I had ##Na_2CO_3 + 2HCl## --> ##2NaCl + CO_2 + H_2O## instead. Why is this not correct?
I have this as shouldn't the number of chlorine and sodium atoms be the same in reactant and product side?
That is what I get also. Perhaps we are missing something obvious, @Borek will spot it?
 
  • Like
Likes   Reactions: simphys
The 2 is missing, simple typo.
 
  • Like
Likes   Reactions: pinball1970 and simphys
The answer given does not have the same number of Na and Cl atoms on both sides of the reaction, so it must be wrong.
 
  • Like
Likes   Reactions: jim mcnamara and simphys
DrClaude said:
The answer given does not have the same number of Na and Cl atoms on both sides of the reaction, so it must be wrong.
What I assumed as well, thank you.
 
  • Like
Likes   Reactions: pinball1970
DrClaude said:
The answer given does not have the same number of Na and Cl atoms on both sides of the reaction, so it must be wrong.
hey @DrClaude (or anybode else :) )I didn't want to open another thread for this small question but I wanted to ask the following:
1663858641476.png

it's about question (a): I was wondering what the reason 'd be not to write ##Na_2Cl_2## instead of 2NaCl?
my possible explanation, because the ionic compounds dissociate in water(aq solution) where we get 2 Na+ions and 2 Cl- ions(and 1Ba(2+) and (SO4)2-) from one molecule of the compounds separately which then 'supposedly' form NaCl.
 
Last edited:
simphys said:
(a): I was wondering what the reason 'd be not to write Na2Cl2 instead of 2NaCl?
my possible explanation, because the ionic compounds dissociate in water(aq solution) where we get 2
Sodium Chloride is not any single molecule. The compound is sodium cations and chloride anions, ratio one-to-one. ONE such unit we symbolize NaCl. Two such units we can show as 2NaCl. If you try to say, Na2Cl2 this suggests you are saying The unit is like a molecule having two of each ion, which it is not.
 
  • Like
Likes   Reactions: Merlin3189
The key word in the question is BALANCE - your task is to work out how many of each compound there should be in the final balanced equation. It's NOT a typo in the question, it is an unbalanced equation for you to make balanced.

So your answer is correct.

The advice I always gave when lecturing was
Read the question
Read the question again
Answer the question that was asked
I've marked lots of exam papers where the student has not answered what I asked, but what they thought I had asked. Hence the read it again. I used to give students a list of things to do in an exam to get more marks without knowing anything extra, ie clues to what we looked for when marking any question.
 
Last edited:
  • Like
Likes   Reactions: pinball1970
  • #10
DrJohn said:
It's NOT a typo in the question, it is an unbalanced equation for you to make balanced.

Because of 2HCl on the left it doesn't look like a skeletal equation waiting to be balanced.
 
  • #11
DrJohn said:
The key word in the question is BALANCE - your task is to work out how many of each compound there should be in the final balanced equation. It's NOT a typo in the question, it is an unbalanced equation for you to make balanced.
Nobody has said it was a typo in the question, it's clearly a typo in the ANSWER.
 

Similar threads

Chemistry How do we interpret the steps in the algorithm to balance a redox equation?
  • · Replies 7 ·
Replies
7
Views
3K
How Do I Solve Double Displacement Reactions for Chemistry Homework?
  • · Replies 5 ·
Replies
5
Views
3K
Chemistry Why does a negative ΔH indicate an exothermic reaction?
  • · Replies 2 ·
Replies
2
Views
3K
Chemistry Ideal Gas Law and Partial Pressures
  • · Replies 16 ·
Replies
16
Views
4K
Chemical kinetics - reaction rate
  • · Replies 5 ·
Replies
5
Views
4K
Equilibrium reaction ICE method to ideal gas law
  • · Replies 4 ·
Replies
4
Views
3K
Calculate the "surface energy" of succesively smaller cubes
  • · Replies 3 ·
Replies
3
Views
3K
Reaction pathway of (di)chloramine and sodium carbonate
  • · Replies 1 ·
Replies
1
Views
3K
How Does Hess's Law Apply to Calculating ΔH in Neutralization Reactions?
  • · Replies 3 ·
Replies
3
Views
10K
Solubility of tartaric acid/sodium tartrate in high vs low pH
  • · Replies 5 ·
Replies
5
Views
3K