Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Thermodynamics

Long Answer Type

241.

Define entropy and entropy change. What are the units of entropy?

151 Views

242.

What is the physical significance of entropy?

638 Views

Short Answer Type

243.

Account for the following:
(i) Why does real crystal have more entropy than an ideal crystal?

(ii) Why the entropy of a pure substance is taken as zero at absolute zero?

(iii) Why the entropy of the universe is continuously increasing?

412 Views

244.
Which of the following reaction will have a greater change in entropy? Explain.

$<pre>uncaught exception: Http Error #404 in file: /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/HttpImpl.class.php line 61 #0 [internal function]: com_wiris_plugin_impl_HttpImpl_0(Object(com_wiris_plugin_impl_HttpImpl), NULL, 'http://www.wiri...', 'Http Error #404') #1 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/php/Boot.class.php(769): call_user_func_array('com_wiris_plugi...', Array) #2 [internal function]: _hx_lambda->execute('Http Error #404') #3 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/haxe/Http.class.php(532): call_user_func_array(Array, Array) #4 [internal function]: haxe_Http_5(true, Object(com_wiris_plugin_impl_HttpImpl), Object(com_wiris_plugin_impl_HttpImpl), Array, Object(haxe_io_BytesOutput), true, 'Http Error #404') #5 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/php/Boot.class.php(769): call_user_func_array('haxe_Http_5', Array) #6 [internal function]: _hx_lambda->execute('Http Error #404') #7 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/HttpImpl.class.php(27): call_user_func_array(Array, Array) #8 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/haxe/Http.class.php(444): com_wiris_plugin_impl_HttpImpl->onError('Http Error #404') #9 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/haxe/Http.class.php(458): haxe_Http->customRequest(true, Object(haxe_io_BytesOutput), NULL, NULL) #10 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/HttpImpl.class.php(40): haxe_Http->request(true) #11 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php(80): com_wiris_plugin_impl_HttpImpl->request(true) #12 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/service.php(19): com_wiris_plugin_impl_TextServiceImpl->service('mathml2accessib...', Array) #13 {main}</pre>$

Entropy increases in both the reactions. This is because the number of gaseous particles increases in both the cases.
In reaction (i), all the products are molecules whereas, in reaction (ii), one-half of the particles are atoms which have no possibility of molecular vibrations. Hence reaction (i) has a greater change in entropy.

90 Views

245.

Predict the change in entropy for the system in which the following physical changes occur:
(i) Dissolving cream in a cup of coffee.
(ii) The beating of an egg for an omellete.
(iii) The formation of a rain drop in a cloud.
(iv) The crystallization of a metal alloy from the molten state.

104 Views

246.

In the following changes, state whether order has increased or decreased and consequently the direction of change of entropy of the system:

$left parenthesis straight i right parenthesis space straight H subscript 2 straight O left parenthesis straight l right parenthesis space space space space rightwards arrow space space space straight H subscript 2 straight O left parenthesis straight s right parenthesis left parenthesis ii right parenthesis space Dry space ice space left parenthesis solid space CO subscript 2 right parenthesis space space rightwards arrow space space space CO subscript 2 left parenthesis straight g right parenthesis left parenthesis iii right parenthesis space Steam space space rightwards arrow space space space water$

97 Views

247.

In the following changes, state whether order has increased or decreased and consequently by the direction of change of entropy of the system:

$left parenthesis straight i right parenthesis space Cr to the power of 3 plus end exponent space plus space 6 straight H subscript 2 straight O left parenthesis aq right parenthesis space space rightwards arrow space space Cr left parenthesis straight H subscript 2 straight O right parenthesis subscript 6 superscript 3 plus end superscript left parenthesis ii right parenthesis space CO subscript 2 plus straight H subscript 2 straight O space rightwards arrow from Photosynthesis to Light of space space Carbohydrates space plus space straight O subscript 2 left parenthesis iii right parenthesis space Proteins space left parenthesis helical space form right parenthesis space space rightwards arrow with denaturation on top space Proteins space left parenthesis random space coil space form right parenthesis left parenthesis iv right parenthesis space Normal space egg space rightwards arrow space space hard space boiled space egg.$