Q.1.
One gram atom of graphite and one gram atom of diamond were separately burnt to carbon dioxide. The amount of heat liberated were 393.5kJ and 39.4 kJ respectively. It follows that
-
27%
a) graphite has greater affinity for oxygen
-
18%
b) diamond has greater affinity for oxygen
-
27%
c) graphite is stable than diamond
-
27%
d) diamond is stable than graphite
Q.2.
If S + O2 → SO2; ΔH=-298.2 kJSO3 +H2O → H2SO4; ΔH=-130.2 kJH2 + ½O2 → H2O ; ΔH=-287.3 kJ SO2 + ½O2 → SO3 ; ΔH= -98.2 kJ Then enthalpy of formation of H2SO4 at 298K will be ... [ DPMT 1994]
-
38%
a) -814.4 kJ
-
38%
b) +320.5 kJ
-
25%
c) -650.3 kJ
-
0%
d) -933.7 kJ
Q.3.
Conversion of oxygen to ozone represented by the equation 3O2 → 2O3 is an endothermic reaction. Enthalpy change , ΔH accompanying the reaction.. [ KCET 1988]
-
27%
a) is negative
-
55%
b) is positive
-
9%
c) is zero
-
9%
d) depending on temperature
Q.4.
The compound with negative heat of formation is known as ..[ DPMT 1981]
-
9%
a) endothermic compound
-
64%
b) exothermic compound
-
27%
c) endoergonic compound
-
0%
d) none of the above
Q.5.
Heat of neutralization of NH4OH and HCl is ... [ Pb. PMT 1985]
-
27%
a) 13.7 kcal/mole
-
27%
b) < 13.7 kcal/mole
-
27%
c) > 13.7 kcal/mole
-
18%
d) zero
Q.6.
The bond dissociation energies of gaseous H2, Cl2 and HCl are 104, 58 and 103 kcal respectively. The enthalpy of formation of HCl gas would be.. [ MP PET 1998]
-
10%
a) -44 kcal
-
30%
b) -88 kcal
-
40%
c) -22 kcal
-
20%
d) -11 kcal
Q.7.
The work done in ergs for reversible expansion of one mole ideal gas from a volume of 1 litres to 20 litres at 25°C is ... [ CMC Vellore 1991]
-
20%
a) 2.303 ×298 ×0.082log2
-
30%
b) 298 ×107 ×8.31 ×2.303log2
-
50%
c) 2.303 ×298 × 0.082log0.5
-
0%
d) 2.303×298×2log2
Explanation
Q.8.
N2 + 2O2(g) → 2NO2 + X kJ2NO(g) + O2 (g) → 2NO2(g) + Y kJThe enthalpy of formation of NO is .. [ GUJ CET]
-
25%
a) ( 2X - 2Y)
-
25%
b) ( X - Y )
-
12%
c) ½ ( Y - X)
-
38%
d) ½ (X - Y)
Q.9.
A spontaneous change is one in which the system suffers ... [ NCERT 1981]
-
38%
a) An increase in internal energy
-
12%
b) A lowering of entropy
-
38%
c) A lowering of free energy
-
12%
d) No energy change
Q.10.
One mole of an ideal gas at 300K is expanded isothermally from an initial volume of 1 litre to 10 lites. The ΔE for this process is ... [ CBSE PMT 1998]( R=2 cal mole-1 K-1)
-
25%
a) 163.7 cal
-
25%
b) zero
-
50%
c) 1381.1 cal
-
0%
d) 9 li atom
Q.11.
Given that 2C (s) + 2O2(g) → 2CO2(g) ; ΔH=-787 kJH2(g) + ½O2(g) → H2O(l) ; ΔH=-286 kJC2H2(g) + 2.5 O2(g) → 2CO2(g) + H2O (l) ; ΔH=-1301kJHeat of formation of acetylene is ... [ KCET 1989]
-
14%
a) -1802 kJ
-
57%
b) + 1802 kJ
-
29%
c) -800 kJ
-
0%
d) +228 kJ
Q.12.
All the naturally occurring processes proceed spontaneously in a direction which leads to [ Pb. PMT 1985]
-
22%
a) decrease of entropy
-
22%
b) increase of enthalpy
-
44%
c) increase of free energy
-
11%
d) decrease of free energy
Q.13.
A solution of 500 ml of 0.2M KOH and 500 ml of 0.2M HCl is mixed and stirred; the rise in temperature is TThe experiment is repeated using 250ml each solution, the temperature rise is TWhich of the following is true? [ EAMCET 1987]
-
43%
a) T1=T2
-
57%
b) T1=2T2
-
0%
c) T1=4T2
-
0%
d) T2=9T1
Q.14.
Which of the following units represents largest amount of energy? [ CPMT 1980]
-
44%
a) Calorie
-
33%
b) Joule
-
11%
c) Erg
-
11%
d) Electron volt
Q.15.
A gas absorbs 250J of heat and expands from 1 litre to 10 litre at constant temperature aganst external pressure of 0.5 atm. The value of q , w and ΔE will be respectively
-
9%
a) 250 J, 455 J, 710 J
-
73%
b) 250J, -455J, -205 J
-
9%
c) -250 J, -455 J, - 205 J
-
9%
d) -250 J, 455 J, 205 J
Q.16.
The heat of combustion of CH4(g), C(graphite)., H2(g) are -20kcal, -40 kcal, -10kcal respectively. The heat of ofrmation of methane is... [ EAMCET 1998]
-
14%
a) -40 kcal
-
43%
b) +40 kcal
-
0%
c) -80 kcal
-
43%
d) +80 kcal
Q.17.
Enthalpy of a reaction at 27°C is 15kJ mol-The reaction will be feasible if entropy is ... [ Pb. CET 1988]
-
20%
a) 15 J mol-1K-1
-
20%
b) -50 J mol-1K-1
-
40%
c) greater than 50 J mol-1K-1
-
20%
d) less than 50 J mol-1K-1
Q.18.
Which of the following values of heat of formation indicates that the product is least stable? [ MP PMT 1991]
-
17%
a) - 94 kcal
-
50%
b) -231.6 kcal
-
0%
c) +21.4 kcal
-
33%
d) +64.8 kcal
Q.19.
The heat of combustion of yellow P and red P are -9.91 kJ/mol and -8.78 kJ/mol respectively. The heat of transiton of yellow P to red P is .. [ Pb. CET 1992]
-
25%
a) - 18.69 kJ
-
0%
b) +1.13 kJ
-
0%
c) +18.69 kJ
-
75%
d) - 1.13 kJ
Q.20.
Equal volumes of molar hydrocholic acid and sulphuric acid are neutralized by dil.NaOH solution and x kcal and y kcal of heat are liberated respectively. Which of the following is true? [ CBSE PMT 1994]
-
33%
a) x=y
-
50%
b) x=½ y
-
17%
c) x=2y
-
0%
d) none of these
Q.21.
The occurrence of reaction is impossible if ... [ AIIMS 1994] ΔG = ΔH - TΔS Answer: (c)
-
0%
a) Both ΔH and ΔS are positive
-
33%
b) ΔH is negative and ΔS is positive
-
33%
c) ΔH is positive and ΔS is negative
-
33%
d) Both ΔH and ΔS are negative
Q.22.
The mutual heat of neutralisation of 40g NaOH and 60g CH3COOH will be.. [ MP PMT 1988]
-
0%
a)57.1 kJ
-
60%
b) less than 57.1 kJ
-
40%
c) more than 57.1 kJ
-
0%
d) 13.7 kJ
Q.23.
For which one of the following reacts will there be a +ve ΔS? ..[ Hariyana CEET 1991]
-
0%
a) H2O(g) → HO(l)
-
20%
b) H2 + I2 → 2HI
-
80%
c) CaCO3(s) → CaO(s) + CO2(g)
-
0%
d) N2(g) + 3H2 → 2NH3(g)
Q.24.
H2(g) + I2(g) → 2HI(g) ; ΔH=12.4 kcal. According to this reaction heat of formation of HI will be ..[ MP PMT 1990]
-
25%
a) 12.4 kcal
-
25%
b) -12.4 kcal
-
50%
c) -6.20 kcal
-
0%
d) + 6.20 kcal
Q.25.
For a reaction2NH3(g) → N2(g) + 3H2(g)Which of the following statement is correct. .. [ PB.CET1990]
-
25%
a) ΔH=ΔU
-
50%
b) ΔH < ΔU
-
25%
c) ΔH > ΔU
-
0%
d) ΔH=0
Q.26.
The amount of energy released when 20 ml of 0.5 M NaOH are mixed with 100ml of 0.1M HCl is x kJ. The heat of neutralisation ( in kJ/mol) is [ manipal PMT 2002]
-
20%
a) -100x
-
0%
b) -50x
-
20%
c) + 100x
-
60%
d) + 50x
Q.27.
For a reaction to be spontaneous at all temperatures .. [ KCET 1990]
-
50%
a) ΔG and ΔH should be negative
-
0%
b) ΔH=ΔG=0
-
25%
c) ΔG and ΔH shlould be positive
-
25%
d) ΔH < ΔG
Q.28.
According to Kirchoff's equation which factor affects the heat of reaction? [ MP PMT 1990]
-
0%
a) Pressure
-
20%
b) Temperature
-
40%
c) Volume
-
40%
d) Molecularity
Q.29.
Which of the following reactions is endothermic? [ AFMC 1988]
-
25%
a) CaCO3 → CaO + CO2
-
25%
b) Fe + S → FeS
-
50%
c) NaOH + HCl → NaCl + H2O
-
0%
d) CH4 + 2O2 → CO2 + 2H2O
Q.30.
For an adiabatic process, which of the following is correct? [ CPMT 1990]
-
0%
a) PΔV=0
-
29%
b) q=+W
-
14%
c) ΔE=q
-
57%
d) q=0