WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

25cm\(^3\) of a 0.2 mol dm\(^3\) solution of Na\(_2\)CO\(_3\) requires 20 cm\(^3\) of a solution...

Chemistry
JAMB 2002

25cm\(^3\) of a 0.2 mol dm\(^3\) solution of Na\(_2\)CO\(_3\) requires 20 cm\(^3\) of a solution of HCl for neutralization. The concentration of the HCl solution is

  • A. 0.5 mol dm3
  • B. 0.6 mol dm3
  • C. 0.2 mol dm3
  • D. 0.4 mol dm3
Post UTME Past Questions Agent
Your School's Whatsapp Group - Join Us now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Correct Answer: Option A
Explanation

First, write a balanced chemical equation or the reaction:

  Na\(_2\)CO\(_3\) +  2HCl →  2NaCl  +   H\(_2\)O +  CO\(_2\)

From the balanced equation, we can deduce that N\(_A\) = 2 , N\(_B\) = 1

We were also given from the question, C\(_A\) = ?  C\(_B\) = 0.2 mol/dm\(^3\)  V\(_A\) = 20cm\(^3\)  V\(_B\) = 25 cm\(^3\)

Using the relationship,   \(\frac{C_A  V_A}{C_B V_B}\) = \(\frac{N_A}{N_B}\)

C\(_A\) = \(\frac{C_B V_B N_A}{V_A N_B}\)

C\(_A\) =  \(\frac{0.2 X 25 X 2}{20 X 1}\)  =  0.5 mol/dm\(^3\)


Report an Error Ask A Question Download App
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Contributions ({{ comment_count }})

Please wait...

{{ settings.no_comment_msg ? settings.no_comment_msg : 'There are no comments' }}

Quick Questions

Post your Contribution

Please don't post or ask to join a "Group" or "Whatsapp Group" as a comment. It will be deleted. To join or start a group, please click here

{{ quote.posted_by.display_name }}
{{ settings.form_textarea_description }}
 
Your School's Whatsapp Group - Join Us now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
Post UTME Past Questions Agent
WAEC and NECO CBT Software for Computers and Laptops - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Your School's Whatsapp Group - Join Us now
Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts
WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now
Post UTME Past Questions Agent