NCERT Solutions
Board Paper Solutions
Ask & Answer
School Talk
Login
GET APP
Login
Create Account
Popular
Latest
Expert Answers
ALL
Nithyashrri Saravanan
Subject: Chemistry
, asked on 1/5/18
11. One mole of an anhydrous salt AB dissolves in water with the evolution of 21.0 J mol
^{-1}
of heat. If the heat of hydration of AB is -29.4 J mol
^{-1}
, then the heat of dissociation of hydrated salt AB is
$a)50.4Jmo{l}^{-1}b)8.4Jmo{l}^{-1}c)-50.4Jmo{l}^{-1}d)-8.4Jmo{l}^{-1}$
Answer
1
Hermoine
Subject: Chemistry
, asked on 12/4/18
Please help fast
Q. At 27
$\xb0$
C two moles of an ideal monoatomic gas occupies a volume V. The gas expands adiabatically to a volume 2 V. Calculate: (a) the final temperature of the gas, (b) the change in internal energy, (c) the work
done by the gas
ANS (a) 189 K, (b) - 2767 J. (c) 2767
Answer
1
Hermoine
Subject: Chemistry
, asked on 3/4/18
A sample of 4.0 mole 0 2 is originally confined in 20 L at 270 K is subjected to reversible adiabatic expansion against a constant pressure until the volume has been increased by a factor 3.0. Calculate q, W, dT, dE, dH and final pressure. Assume Cp /Cv = 1.40 for 02 gas
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 2/4/18
Solve
49.
If bond energy of C
$\equiv $
C, C-H, O=O, C=O & O-H bond is 800, 410, 500, 700 & 430 kJ / mol respectively, then calorific value (kJ/gm) of ethyne is
(1) 25.28
(2) 30.38
(3) 790
(4) 303
Answer
2
Aaradhya Kondawar
Subject: Chemistry
, asked on 2/4/18
Explain with reason.
$\mathbf{47}\mathbf{.}Forwhichofthefollowingprocess\u2206Sisnegative?\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\left(1\right)Boilingofegg\phantom{\rule{0ex}{0ex}}\left(2\right)C{l}_{2}(1atm,27\xb0C)\to C{l}_{2}(1.5atm,27\xb0C)\phantom{\rule{0ex}{0ex}}\left(3\right)Evaporationofwater\phantom{\rule{0ex}{0ex}}\left(4\right)PC{l}_{5}\left(g\right)\to PC{l}_{3}\left(g\right)+C{l}_{2}\left(g\right)$
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 1/4/18
Solve this:
Q5. The COP of a refrigerator is 5 is kept in a room having temperature at 27
$\xb0$
C temperature inside the refrigerator will be
(A) - 23
(B) - 27
(C) - 46
(D) - 54
Q6. The temperature of the gas before and after expansion
(A) T
_{before}
> T
_{after}
(B) T
_{before}
< T
_{after}
(C) T
_{before}
= T
_{after}
(D) needs more information
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
The enthalpy of solution of BaCl
_{2}
(s) and BaCl
_{2}
.2H
_{2}
O(s) is –x kJ mol
^{–1}
and y kJ mol
^{–1}
respectively then enthalpy of hydration of BaCl
_{2}
(s) to BaCl
_{2}
.2H
_{2}
O(s) is given by
(1) (x – y) kJ (2) (y – x) kJ (3) (x + y) kJ (4) –(x + y) kJ
Answer
4
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Q58 and Q59:
58. Which of the following is a spontaneous process takes place on initiation ?
(1) Dissolution of common salt in water.
(2) Reaction between methane and oxygen to form CO
_{4}
and water.
(3) Evaporation of water in an open vessel.
(4) All of these.
59. Select the correct statement.
(1) During hydration the physical state of the sold does not change.
(2) During dissolution , the physical state of solid changes.
(3) Enthalpy of formation of an atom is nearly half of the bond dissociation energy of gaseous diatomic molecule.
(4) All of these.
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Solve this:
60. Which of the following is not zero in cyclic process ?
(1)
$\u25b3$
S (2)
$\u25b3$
U (3) W (4)
$\u25b3$
T
Answer
2
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
$Solvethis:\phantom{\rule{0ex}{0ex}}Enthalpyofformationiszerofor\phantom{\rule{0ex}{0ex}}\left(1\right)Diamond\left(2\right)Graphite\left(3\right)Cl\left(aq\right)\left(4\right)Allofthese$
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Answer with explanation pls
81. For the reaction AB
_{2}
(g)
$\rightleftharpoons $
AB(g) + B(g) the initial pressure is 800 mm at certain temperature and the pressure becomes 100 mm at equilibrium. The value of K
_{p}
at the same temperature is.
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Select the correct statement
(1) Degree of dissociation of weak electrolyte decreases with increase in concentration.
(2) Catalyst catalyses the forward reaction only.
(3) Lower the value of equilibrium constant higher the probability to complete the reaction.
(4) All of these.
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
Answer with explanation pls
Answer
1
Aaradhya Kondawar
Subject: Chemistry
, asked on 29/3/18
$Solvethis:\phantom{\rule{0ex}{0ex}}65.Enthalpyofreactiondependson\phantom{\rule{0ex}{0ex}}\left(1\right)Physicalstateofreac\mathrm{tan}tsandproducts\phantom{\rule{0ex}{0ex}}\left(2\right)Amountofreac\mathrm{tan}tstaken\phantom{\rule{0ex}{0ex}}\left(3\right)Temperature\phantom{\rule{0ex}{0ex}}\left(4\right)Allofthese$
Answer
1
Abhishek Gupta
Subject: Chemistry
, asked on 27/3/18
Solve this:
Q59. What will be the heat of formation of KOH (s) if
${\mathrm{K}}_{\left(\mathrm{S}\right)}+{\mathrm{H}}_{2}{\mathrm{O}}_{\left(\mathcal{l}\right)}\to {\mathrm{KOH}}_{\left(\mathrm{aq}\right)}+\frac{1}{2}{\mathrm{H}}_{2\left(\mathrm{g}\right)};\u2206\mathrm{H}=-48\mathrm{Kcal}\phantom{\rule{0ex}{0ex}}{\mathrm{KOH}}_{\left(\mathrm{s}\right)}\to {\mathrm{KOH}}_{\left(\mathrm{aq}\right)};\u2206\mathrm{H}=-14\mathrm{Kcal}\phantom{\rule{0ex}{0ex}}{\mathrm{H}}_{2\left(\mathrm{g}\right)}+\frac{1}{2}{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to {\mathrm{H}}_{2}{\mathrm{O}}_{\left(\mathcal{l}\right)};\u2206\mathrm{H}=-68\mathrm{Kcal}$
(1) – 130 Kcal (2) – 102 Kcal
(3) – 112 Kcal (4) – 170 Kcal
Answer
1
1
2
3
4
5
Next
What are you looking for?

^{-1}of heat. If the heat of hydration of AB is -29.4 J mol^{-1}, then the heat of dissociation of hydrated salt AB is$a)50.4Jmo{l}^{-1}b)8.4Jmo{l}^{-1}c)-50.4Jmo{l}^{-1}d)-8.4Jmo{l}^{-1}$

Q. At 27$\xb0$C two moles of an ideal monoatomic gas occupies a volume V. The gas expands adiabatically to a volume 2 V. Calculate: (a) the final temperature of the gas, (b) the change in internal energy, (c) the work

done by the gas

ANS (a) 189 K, (b) - 2767 J. (c) 2767

49.If bond energy of C$\equiv $C, C-H, O=O, C=O & O-H bond is 800, 410, 500, 700 & 430 kJ / mol respectively, then calorific value (kJ/gm) of ethyne is(1) 25.28

(2) 30.38

(3) 790

(4) 303

$\mathbf{47}\mathbf{.}Forwhichofthefollowingprocess\u2206Sisnegative?\phantom{\rule{0ex}{0ex}}\phantom{\rule{0ex}{0ex}}\left(1\right)Boilingofegg\phantom{\rule{0ex}{0ex}}\left(2\right)C{l}_{2}(1atm,27\xb0C)\to C{l}_{2}(1.5atm,27\xb0C)\phantom{\rule{0ex}{0ex}}\left(3\right)Evaporationofwater\phantom{\rule{0ex}{0ex}}\left(4\right)PC{l}_{5}\left(g\right)\to PC{l}_{3}\left(g\right)+C{l}_{2}\left(g\right)$

Q5. The COP of a refrigerator is 5 is kept in a room having temperature at 27 $\xb0$C temperature inside the refrigerator will be

(A) - 23

(B) - 27

(C) - 46

(D) - 54

Q6. The temperature of the gas before and after expansion

(A) T

_{before}> T_{after}(B) T

_{before}< T_{after}(C) T

_{before}= T_{after}(D) needs more information

_{2}(s) and BaCl_{2}.2H_{2}O(s) is –x kJ mol^{–1}and y kJ mol^{–1}respectively then enthalpy of hydration of BaCl_{2}(s) to BaCl_{2}.2H_{2}O(s) is given by(1) (x – y) kJ (2) (y – x) kJ (3) (x + y) kJ (4) –(x + y) kJ

58. Which of the following is a spontaneous process takes place on initiation ?

(1) Dissolution of common salt in water.

(2) Reaction between methane and oxygen to form CO

_{4}and water.(3) Evaporation of water in an open vessel.

(4) All of these.

59. Select the correct statement.

(1) During hydration the physical state of the sold does not change.

(2) During dissolution , the physical state of solid changes.

(3) Enthalpy of formation of an atom is nearly half of the bond dissociation energy of gaseous diatomic molecule.

(4) All of these.

60. Which of the following is not zero in cyclic process ?

(1) $\u25b3$S (2) $\u25b3$U (3) W (4) $\u25b3$T

81. For the reaction AB

_{2}(g) $\rightleftharpoons $AB(g) + B(g) the initial pressure is 800 mm at certain temperature and the pressure becomes 100 mm at equilibrium. The value of K_{p}at the same temperature is.(1) Degree of dissociation of weak electrolyte decreases with increase in concentration.

(2) Catalyst catalyses the forward reaction only.

(3) Lower the value of equilibrium constant higher the probability to complete the reaction.

(4) All of these.

Q59. What will be the heat of formation of KOH (s) if

${\mathrm{K}}_{\left(\mathrm{S}\right)}+{\mathrm{H}}_{2}{\mathrm{O}}_{\left(\mathcal{l}\right)}\to {\mathrm{KOH}}_{\left(\mathrm{aq}\right)}+\frac{1}{2}{\mathrm{H}}_{2\left(\mathrm{g}\right)};\u2206\mathrm{H}=-48\mathrm{Kcal}\phantom{\rule{0ex}{0ex}}{\mathrm{KOH}}_{\left(\mathrm{s}\right)}\to {\mathrm{KOH}}_{\left(\mathrm{aq}\right)};\u2206\mathrm{H}=-14\mathrm{Kcal}\phantom{\rule{0ex}{0ex}}{\mathrm{H}}_{2\left(\mathrm{g}\right)}+\frac{1}{2}{\mathrm{O}}_{2\left(\mathrm{g}\right)}\to {\mathrm{H}}_{2}{\mathrm{O}}_{\left(\mathcal{l}\right)};\u2206\mathrm{H}=-68\mathrm{Kcal}$

(1) – 130 Kcal (2) – 102 Kcal

(3) – 112 Kcal (4) – 170 Kcal