EASY
11th CBSE
IMPORTANT
Earn 100

Calculate the enthalpy of formation of sucrose (C12H22O11) from the following data :-

C12H22O11+12O212CO2+11H2O, ΔH=5200.7 kJ mol-1.

C+O2CO2, ΔH=394.5 kJ mol-1.

H2+12O2H2O, ΔH=285.8 kJ mol-1.

Important Questions on Thermodynamics

HARD
11th CBSE
IMPORTANT

Calculate the standard enthalpy of formation of SO3 at 298 K using the following reactions and enthalpies.

S8(s)+8O2(g)8SO2(g),  Hο=-2775 kJ mol-1.

2SO2(g)+O2(g)2SO3(g),  Hο=-198 kJ mol-1.

EASY
11th CBSE
IMPORTANT

Calculate the enthalpy of formation of anhydrous Al2Cl6 from the following data:

i 2Als+6HClaqAl2Cl6aq+3H2g         +1004.2 kJ mol-1.ii H2g +Cl2g2HClg                                 +184 kJ mol-1.iii HClg+ aqHClaq                                    +73.2 kJ mol-1.iv Al2Cl6s+ aqAl2Cl6aq                                643.1 kJ mol-1.

EASY
11th CBSE
IMPORTANT

From the following thermochemical equations, calculate the standard enthalpy of formation of HCl (g).

A H2g  2Hg, H°=+436.0 kJ mol-1. B Cl2g  2Clg, H°=+242.7 kJ mol-1.C HClg  Hg + Clg, H°=+431.8 kJ mol-1.

EASY
11th CBSE
IMPORTANT
Calculate the enthalpy of formation of acetic acid if the enthalpy of combustion to CO2g and H2Ol is - 867.0 kJ mol-1 and enthalpies of formation of CO2g and H2Ol are respectively - 393.5 and - 285.9 kJ mol-1 
EASY
11th CBSE
IMPORTANT
The enthalpy of combustion of ethyl alcohol (C2H5OH) is 1380.7 kJ mol-1. If the enthalpies of formation of CO2 and H2O are 394.5 and 286.6 kJ mol-1 respectively. Calculate the enthalpy of formation of ethyl alcohol.
MEDIUM
11th CBSE
IMPORTANT

Calculate the enthalpy of combustion of benzene from the following data :­

i 6Cs+3H2gC6H6l, H=49.0 kJ mol-1 ii H2g+12O2gH2Ol, H=- 285.8 kJ mol-1 iii Cs+O2g CO2g, H=- 389.3 kJ mol-1

EASY
11th CBSE
IMPORTANT
The enthalpies of formation of methane, carbon dioxide and water (liquid) are -74.8, -393.5 and -286.2 kJ respectively. Calculate the enthalpy of combustion of methane at ordinary temperature.
EASY
11th CBSE
IMPORTANT

Calculate the enthalpy of reaction for COg+12O2gCO2g.

Given,

Cs+O2gCO2g, H=-393.5 kJ mol-1 and Cs+12O2gCOg, H=-110.5 kJ mol-1.