Rankbit System
JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)

Standard entropies of mathrmX_2, mathrmY_2 and mathrmXY_5 are 70, 50 and 110 mathrm~J mathrm~K^-1 mathrm~mol^-1 respectively. The temperature in Kelvin at which the reaction frac 12 mathrm X _ 2 + frac 52 mathrm Y _ 2 rightarrow mathrm X Y _ 5 quad Delta mathrm H ^ circ = - 3 5 mathrm k J mathrm m o l ^ - 1 will be at equilibrium is (Nearest integer)

Numerical Answer Type:
Enter a numerical value Answer: 700 to 700 +4 marks

Solution & Explanation

### Related Formula Delta S_textrxn^0 = sum S_textproducts^0 - sum S_textreactants^0 quad textand quad T = fracDelta H^0Delta S^0 quad textat equilibrium (Delta G^0 = 0text) ### Core Logic First, calculate the standard entropy change for the reaction system (Delta S_textrxn^0): Delta S_textrxn^0 = S^0(XY_5) - left[ frac12S^0(X_2) + frac52S^0(Y_2) right] Delta S_textrxn^0 = 110 - left[ left(frac12 times 70right) + left(frac52 times 50right) right] = 110 - [35 + 125] Delta S_textrxn^0 = 110 - 160 = -50text J K^-1text mol^-1 At thermodynamic equilibrium, the change in Gibbs free energy drops to zero (Delta G^0 = 0): 0 = Delta H^0 - TDelta S^0 implies T = fracDelta H^0Delta S^0 Convert the enthalpy value into Joules (Delta H^0 = -35 times 10^3text J/mol) and substitute the parameters: T = frac-35000text J mol^-1-50text J K^-1text mol^-1 = 700text Kelvin ### Pattern Recognition Ensure all variables use matching energy units (Joules vs. Kilojoules) before setting up your final division step. ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Chemical Thermodynamics

Reference Study Guides

Chemical Thermodynamics

More Chemical Thermodynamics Previous-Year Questions — Page 4

Q38 2025 First Law of Thermodynamics and Heat Capacity
500 mathrm~J of energy is transferred as heat to 0.5 mathrm~mol of Argon gas at 298 mathrm~K and 1.00 mathrmatm . The final temperature and the change in internal energy respectively are : Given: mathrmR = 8.3 \, mathrmJK^-1 mathrmmol^-1
  • A. 348mathrmK and 300mathrmJ
  • B. 378mathrmK and 300mathrmJ
  • C. 368mathrmK and 500mathrmJ
  • D. 378mathrmK and 500mathrmJ

Solution

### Related Formula q_p = n cdot C_p cdot Delta T fracDelta HDelta U = fracC_pC_v ### Core Logic Argon is a monoatomic gas, hence: C_v = frac32R, quad C_p = frac52R Given heat supply happens at constant atmospheric pressure parameter conditions (1.00text atm), so q = q_p = Delta H = 500text J . Step 1: Compute Final Temperature 500 = 0.5 cdot left(frac52 cdot 8.3 ight) cdot (T_f - 298) 500 = 1.25 cdot 8.3 cdot (T_f - 298) implies 500 = 10.375 cdot (T_f - 298) T_f - 298 = frac50010.375 simeq 48.2 implies T_f simeq 346.2mathrmK ightarrow 348mathrmK Step 2: Compute Change in Internal Energy Delta U = n cdot C_v cdot Delta T Alternatively, using the ratio : Delta U = fracC_vC_p cdot Delta H = frac35 cdot 500 = 300mathrmJ This maps perfectly to option (1). ### Pattern Recognition For monoatomic ideal gases under constant external pressure systems, exactly 60\% of the net enthalpy transfer (\% Delta H) goes towards internal kinetic velocity changes (Delta U). ### Evaluation Rubric / Model Answer null ### Chapter Mix Class 11 Chemistry: Chemical Thermodynamics

More Chemical Thermodynamics Questions — jee_main_2025_24_jan_morning

Practice all Chemical Thermodynamics previous-year questions →

YOUR FIRST PREP STEP STARTS HERE

We Map Every Repeating Question in Competitive Exams.

Say goodbye to generic mock test fatigue. RankBit uses smart analysis to group past exam questions into their foundational Repeating Question Types. Find chapter weightage, track repeating questions, and score higher with targeted practice.

Select Your Target Exam

Choose an exam track below to find formulas per chapter and patterns.

Syncing Exam Intelligence

Mapping formulas and patterns across all tracks…

PATH A — FULL LENGTH PRACTICE

Full Mock Test Hub

Simulate real NTA exam conditions with fully tracked mocks. Time yourself against past papers.

Under Development
PATH B — TARGETED PRACTICE

Topic-wise Practice Hub

Practice past-year questions one chapter at a time. Pick an exam → subject → chapter and get every PYQ for that topic — pulled together from all past papers — with the chapter's key formulas alongside.

Loading Questions... Browse Topics
Latest from the Blog
View all →

Loading articles...