Where is double negative selection is found during T-cell formation?

TLS Online TPP Program

#Question id: 20248

#XL - P Chemistry

C (s) + O2 (g) →CO2, (g); DH = –94.3 kcal/mol

CO (g) + O2(g) → CO2 (g); DH = – 67.4 kcal/mol

O2(g) → 2O (g); ΔH = 117.4 kcal/mol

CO (g) → C (g) + O(g) ; ΔH = 230.6 kcal/mol

Calculate ΔH for C (s) → C (g) in kcal/mol.

TLS Online TPP Program

#Question id: 20249

#XL - P Chemistry

The difference between ΔH and ΔE on a molar basis for the combustion of n–octane at 25°C would be : 25ºC

TLS Online TPP Program

#Question id: 20250

#XL - P Chemistry

What is the work done against the atmosphere when 25 grams of water vaporizes at 373 K against a constant external pressure of 1 atm ? Assume that steam obeys perfect gas laws. Given that the molar enthalpy of vaporization is 9.72 kcal/mole, what is the change of internal energy in the above process ?

TLS Online TPP Program

#Question id: 20251

#XL - P Chemistry

In the reaction CS2 (l) + 3O2 (g) → CO2 (g) + 2SO2 (g) ΔH = –265 kcal

The enthalpies of formation of CO2 and SO2 are both negative and are in the ratio 4 : 3. The enthalpy of formation of CS2 is + 26 kcal/mol. Calculate the enthalpy of formation of SO2.

TLS Online TPP Program

#Question id: 20252

#XL - P Chemistry

The bond dissociation energy of gaseous H₂, Cl₂ and HCl are 104, 58 and 103 kcal mol^{– 1} respectively. The enthalpy of formation for HCl gas will be

TLS Online TPP Program

#Question id: 20253

#XL - P Chemistry

AB, A2 and B2 are diatomic molecules. If the bond enthalpies of A2, AB & B2 are in the ratio 1 : 1 : 0.5 and enthalpy of formation of AB from A2 and B2 is – 100 kJ/mol^–1. What is the bond enthalpy of A2.