Shweta Thakur posted an Question
June 30, 2020 • 18:10 pm 30 points
  • IIT JAM
  • Chemistry (CY)

Plz tell that for definition of enthalpy of neutralisation why can't we use i mole...as the actual definition is for 1 gram equivalentof acid and base

plz tell that for definition of enthalpy of neutralisation why can't we use I mole the actual definition is for 1 gram equivalent...

3 Answer(s) Answer Now
  • 0 Likes
  • 6 Comments
  • 0 Shares
  • comment-profile-img>
    Priyanshu kumar

    https://www.aplustopper.com/enthalpy-heat-neutralization/ for very detailed information go through this link shweta

    eduncle-logo-app

    sir but all enthalpies like enthalpy of combu. ,enthalpy of formation , are defined for 1mole but how this definition valid if we say that for neutralisation 1mol of h2so4 we have to take 1mole of naoh

    eduncle-logo-app

    this is not a general definition for neutralisation( in terms of mole)

    eduncle-logo-app

    read my explanation shweta in the previous comment

    eduncle-logo-app

    ok sir

  • Suman Kumar Best Answer

    Hope this helps 🙏

    eduncle-logo-app

    For HCl Gram equivalent=molar mass/ 1 as it's 1 mole will give 1 mole of H+

  • Suman Kumar

    It is defined as the energy released with the formation of 1 mole of water.

    eduncle-logo-app

    That's why we use equivalent.

    eduncle-logo-app

    For formation of water we need 1 mole of H+ & 1 mole of OH-.

    eduncle-logo-app

    For example 1 mole of H2SO4 release 2 mole of H+ so instead of mole we use gram equivalent.

    eduncle-logo-app

    So Gram equivalent= molar mass/2. That's why gram equivalent is useful.

    eduncle-logo-app

    Gram equivalent deals with no. of ions produced

    eduncle-logo-app

    so for this we can't used. definition in terms of mole right ??? because this vary for different acid and base example if we take1mol of h2so4 with 1 mol of naoh so its not a general definition that's why we use equivalent right

    eduncle-logo-app

    Absolutely Yes 😊

  • Suman Kumar best-answer

    The enthalpy of neutralization (ΔHn) is the change in enthalpy that occurs when one equivalent of an acid and one equivalent of a base undergo a neutralization reaction to form water and a salt. It is a special case of the enthalpy of reaction

  • comment-profile-img>
    Priyanshu kumar

    see the enthalpy of neutralisation say that 1 mole of acid or 1 mole equivalent is neutralised by 1 mole of base and vice versa....if there is strong acid and strong base same amount of heat is releesse that is -57.3 kj/mole

    eduncle-logo-app

    if you have problem in equivalent....see an equivalent is the number of moles of an ion in a solution multiplied by the valence of that ion. If 1 mol of NaCl and 1 mol of CaCl2 dissolve in a solution, there is 1 equiv Na, 2  equiv Ca, and 3 equiv Cl in that solution. (The valence of calcium is 2, so for that ion you have 1 mole and 2 equivalents.

    eduncle-logo-app

    also you find equivalent mass by (Molecular mass/ n- factor)...for acid n factor is basicity of that acid and if base then n factor is acidity of that base

    eduncle-logo-app

    read the above solution shweta you understand the concept behind this

    eduncle-logo-app

    as i have axplained above..see HCL have basicity of 1 as 1 H+ ions are produced and Basicity of H2So4 is 2 as 2 H+ ions are produced...so gram equiv of HCL = molar mass/1 and H2SO4 = Molar mass/2...similarly for base too...NAOH IS MONOACIDIC BASE, CA(OH)2 IS DIACIDIC BASE, AL(OH)3 IS TRIACIDIC BASE...so use n factor accordingly and get gram equiv

    eduncle-logo-app

    read shweta this explanation

    eduncle-logo-app

    ok

    eduncle-logo-app

    m asking about definition

    eduncle-logo-app

    yes as acid and base vary so gram equivalent weight here comes

    eduncle-logo-app

    yes sir

    eduncle-logo-app

    what is 1gram equivalent

    eduncle-logo-app

    now

    eduncle-logo-app

    when HCl acid is there then 1 grm equivalent = molar mass of HCL/1

    eduncle-logo-app

    when H2SO4 then Molar mass/2

    eduncle-logo-app

    i have explained this above

    eduncle-logo-app

    ok

    eduncle-logo-app

    sir

whatsapp-btn

Do You Want Better RANK in Your Exam?

Start Your Preparations with Eduncle’s FREE Study Material

  • Updated Syllabus, Paper Pattern & Full Exam Details
  • Sample Theory of Most Important Topic
  • Model Test Paper with Detailed Solutions
  • Last 5 Years Question Papers & Answers