### Chemistry - Energetics

#### Question - 1

Which one of the following statements is wrong?

• A The brach of chemistry which deals with energy changes involved in chemical reactions, is called chemical energetics.
• B Renewable source of energy is also called non-convetional source of energy.
• C Non-renewal source of energy is also called non-convetional source of energy.
• D Coal, lignite, natural gas, crude petroleum oil, uranium etc. are renewable sources of energy.

#### Question - 2

For an exothermic reaction $\Delta$H is

• A zero
• B negative
• C positive
• D non-predictable

#### Question - 3

Which one of the following is an intensive property?

• A enthalpy
• B mass
• C temperature
• D volume

#### Question - 4

Carbon and carbon monoxide burn in oxygen to give carbon dioxide according to the equations :

$C(s)+{ O }_{ 2 }(g)\rightarrow { CO }_{ 2 }(g);\Delta H=-394kJ\quad \quad ...(i)$

$2CO(g)+{ O }_{ 2 }(g)\rightarrow { 2CO }_{ 2 }(g);\Delta H=-569kJ\quad \quad ...(ii)$

The heat of formation of carbon monoxide would be

• A - 109.5 kJ
• B + 109.5 kJ
• C + 108.5 kJ
• D - 108.5 kJ

#### Question - 5

A gas absorbs 100 calories of heat energy and is compressed from 10.0 litres to 5.0 litres by applying an external pressure at 2.0 atm. The change in internal energy for the gas is

• A 312 cal
• B 342 cal
• C 426 cal
• D 562 cal

#### Question - 6

What is $\Delta$E for system that does 500 cal of work on surroundings and 300 cal of heat is absoubed by the system?

• A - 200 cal
• B -300 cal
• C + 200 cal
• D + 300 cal

#### Question - 7

Given the reaction at 975$?$ and 1 atm $Ca{ CO }_{ 3 }\rightleftharpoons Cao(s)+{ CO }_{ 2 }(g);\Delta H=176kJ$ then $\Delta$E  is equal to

• A 162 kJ
• B 165.6 kJ
• C 180 kJ
• D 186.4 kJ

#### Question - 8

The enthalpy of neutralisation of sodium hydroxide and sulphuric acid is - 57 kJ mol-1 and with ethanoic acid is - 55.0 kJ mol-1. Which one of the following is the best explanation for this difference?

• A Ethenoic acid is monobasic acid, but sulphuric acid is a dibasic.
• B Ethenoic acid is only partly ionised, hence neutralisation is incomplete.
• C Ethenoic acid is a weak acid and hence requires less than sodium hydroxide for nrutralisation.
• D Some heat is used to ionise the ethanoic acid completely.

#### Question - 9

Enthalpy of an element in its standard state at 25$?$ and 1 atm pressure is always

• A zero
• B positive
• C negative
• D maximum

#### Question - 10

In which of the following reactions would $\Delta$E be equal to $\Delta$H?

• A ${ N }_{ 2 }{ O }_{ 4 }(g)\rightleftharpoons { 2NO }_{ 2 }(g)$
• B ${ 2SO }_{ 2 }(g)+{ O }_{ 2 }\rightleftharpoons { 2SO }_{ 3 }(g)$
• C ${ H }_{ 2 }(g)+{ I }_{ 2 }(g)\rightleftharpoons 2HI(g)$
• D ${ H }_{ 2 }(g)+\frac { 1 }{ 2 } { O }_{ 2 }(g)\rightleftharpoons { H }_{ 2 }O(l)$