Heat of Reaction

Q. one mole of N2O4 at 300K is kept in closed container under one atmosphere .it is heated to600K when 20% by mass of N2O4 gas decomposes to NO2 gas the resul†an t pressure i

Q. 8.CaCO3(s)=CaO(s) +CO2(g).If Kp for the above reaction at 1200K is 1.5 atm.Some CaCO3 is taken in a 10 litre closed vessel, then the number of moles of CaO at equilibrium is (Take R=1/12 litreatmk-1mol-1) options :1)1.5 , 2)3.5, 3)0.015, 4)0.15

Q. In the equilibrium CaCO3(s)Cao (s)+CO2(g) at 1073 K, the pressure of CO2 isfound to be 2.5 x 10 Pa. The equilibriumconstant for the reaction at 1073 K will be.(a) 0.25(c)25(b) 2.5(d) 250

Q. A monoatomic ideal gas is given 200J of energy at cons†an t pressure. The increase in internal energy of gas will be

Q.

The enthalpy change for a given reaction at 298 K is $-xJmo{l}^{-1}$ (x being positive). If the reaction occurs spontaneously at 298 K, the entropy change at that temperature

1. Can be negative but numerically larger than x/298

2. Can be negative but numerically smaller than x/298

3. Cannot be negative

4. Cannot be positive

Q. If the heat of dissolution of $an.CuS{O}_4$ and $CuS{O}_4.5H_{2}O$ are (-15.89) kcal and 2.80 kcal respectively. Calculate the heat of hydration of $CuS{O}_4$:

1. -13.09 kcal
2. -18.69 kcal
3. 13.09 kcal
4. 18.69 kcal

Q. In a thermodynamic process two moles of a monatomic ideal gas obeys P oc V-2. If temperature of the gas increases from 300 K to 400 K, then find work done by the gas (where R universal gas constant) (1) 200 R (2) -200 R (4) -400 PR (3)-100 FR

Q. The variation of heat of reaction with temperature is given by:

1. Van't Hoff equation
2. Clausius-Clapeyron equation
3. Nernst equation
4. Kirchoff's equation

Q. ntCH3-CO-CH3(g)=CH3-CH3(g)+CO(g). Initial pressure of CH3COCH3 is 100mm.When equlibrium is set up mole fractionof CO is 1/3. Find the value of Kp.n

Q. The heat evolved when 0.25 mole of hydrochloric acid in solution is neutralized by 0.25 mole of Sodium hydroxide solution is :

1. 57.1 kJ
2. 14.3 kJ
3. 28.55 kJ
4. None

Q. If 50 atoms of carbo If 50 atoms of carbon reacts with 200 molecules of oxygen , find out the correct statement (1) O_2 is limiting reagent (2) 50 molecules of CO_{2 } are formed (3) 100 molecules of CO_2 are formed (4/) Both (1) and (2

Q. 45. The value of Cp – Cv is 1.00R for a gas semple in state A and is 1.08R in state B. Compare between pressures and temperatures of the two states.

Q. lattice energy is endothermic or exothermic process

Q. If 100 calories of heat are added to a system and a work of 50 calories is done on the system, calculate the energy change of the system

1. 150 calories

2. 50 calories

3. -50 calories

4. -150 calories

Q.

Consider the following data:

$\Delta f{H}^0(N_2{H}_4,l)=50kJ/mol$

$\Delta f{H}^0(N{H}_3,g)=-46kJ/mol$

$B.E.(N-H)=393kJ/mol$ and $B.E.(H-H)=436kJ/mol$, also ${\Delta }_{vap}H(N_2{H}_4,l)=18kJ/mol$

The N- N bond energy in $N_2{H}_4$ is

1. 45.45 kJ/mol

2. 190 kJ/mol

3. 226 kJ/mol

4. 154 kJ/mol

Q. 18 Identify the product and explain the mechanism of the reaction But-2-yne + NaNH2 →

Q. order of acidic strength: methyl benzene ethyl benzene 1methyl ethyl benzene 1, 1 dimethyl ethyl benzene

Q. 1 mole of a gas is changed from its initial value (15L, 2atm) to final state (4L, 10atm) respectively. If the change can be represented by a straight line in P-V curve. Calculate the maximum temperature attained by the gas.

Q. Calculate $\Delta H$ at $358K$ for the reaction,
$F{e}_2{O}_3\left(s\right)+3H_2\left(g\right)\to 2Fe\left(s\right)+3H_{2}O\left(l\right)$

Given that , $\Delta H_{298}=-33.29kJmo{l}^{-1}$ and $C_{P}forF{e}_2{O}_3\left(s\right),Fe\left(s\right),H_{2}O\left(l\right)$ and $H_2\left(g\right)$ are $103.8,25.1,75.3,and28.8J/Kmol$.

1. $-28.136kJ/mol$
2. $-58.136kJ/mol$
3. $28.136kJ/mol$
4. $58.136kJ/mol$

Q. 5.6 Litre of helium gas at STP is adiabatically compressed to 0.7 litre taking the initial temperature to be T the work done in the process is 9/8 RT Or 9/2 RT

Q.

For $H_{2}O\left(l\right)(1bar,373K)\to H_{2}O\left(g\right)(1bar,373K)$.The correct set of thermodynamic parameter is

1. ∆G = 0, ∆S = + ve

2. ∆G = 0, ∆S = -ve

3. ∆G = + ve, ∆S = 0

4. ∆G = - ve, ∆S = + ve

Q. For an exothermic reaction,

1. H of the product is less than that H of reactants
   where $H$ is the enthalpy of the product or reactant
2. H of the product is more than that H of reactants
   where $H$ is the enthalpy of the product or reactant
3. H of the product is equal to the H of reactants
   where $H$ is the enthalpy of the product or reactant
4. $\Delta H=\Delta H\left(products\right)-\Delta H\left(reactants\right)$ is always positive

Q. Calculate the heat evolved when 496 g of white phosphorus $P_4$ burns in air according to equation
$P_4\left(s\right)+5O_2\left(g\right)\to P_4{O}_{10}\left(s\right)$ $\Delta H=-3013kJ/mol$

1. $60226kJ$
2. $12052kJ$
3. $1252kJ$
4. $3052kJ$

Q. A non-ideal gas obeys the equation PV = RT + BP, where V is the molar volume and B is 10 L/mol. If one mole of the gas is expanded isothermally and reversibly at 27°C from 20 atm to 2 atm, calculate ΔU and ΔH ( jee advance 1997)

Q. If one mole each of a monoatomic and diatomic gases are mixed at low temperature then $C_p/C_v$ ratio for the mixture is :

1. $1.40$
2. $1.70$
3. $1.50$
4. $1.33$

Q. The enthalpy of solution of $BaC{l}_2\left(s\right)$ and $BaC{l}_2.2H_{2}O\left(s\right)$ are – 20.6 and 8.8 kJ $mo{l}^{-1}$ respectively, the enthalpy change for the hydration of $BaC{l}_2\left(s\right)$ is:

1. 29.4 kJ
2. – 11.8 kJ
3. – 29.4 kJ
4. + 11.8 kJ

Q. 10. Total planes in methane which contain maximum number of atoms? 1)4 2)6 3)10 4)12

Q. What is the product when ethyl bromide is reacted with Mg/dry eather followed by acetic acid a)ethanol b)butanoic acid c)ethane d)propanoic acid

Q. The enthalpy change for the reaction,
$\left(g\right)C_2{H}_4+3O_2\left(g\right)⟶2C{O}_2\left(g\right)+2H_{2}O\left(g\right)$ is called:

1. Enthalpy of formation

2. Enthalpy of sublimation

3. Enthalpy of combustion

4. Enthalpy of vaporization

Q. if entropy of methane , oxygen, carbon dioxide, and water are 186, 205, 214, 70 respectively and enthalpy of fusion of methane, carbon dioxide and water are -74.8, -393.5, -285.8 respectively, find the free energy change for the combustion of methane at 300K.