Enthalpy - class-XII
Description: enthalpy | |
Number of Questions: 37 | |
Created by: Priya Bakshi | |
Tags: thermodynamics enthalpy changes chemical thermodynamics chemistry |
Heat of reaction at constant pressure is called
The relationship between enthalpy and internal energy change is
An athelete is given 100 g of glucose $(C _6H _{12}O _6)$ of energy equivalent to 1560 kJ. He utilises 50 percent of this gained energy in the event. In order to avoid storage of energy in the body, Determine the weight of water he would need to perspire. (The enthalpy of evaporation of water is 44 kJ/mole.)
Enthalpy of the system is given as :
Under which of the following condition is the relation $\Delta H = \Delta U + P\Delta V$ valid for a closed system at
In the hydrogenation of ethylene,$\Delta n$ is equal to:
For the reaction,
$C(s)+O {2}(g)\rightarrow CO _{2}(g);$
$\Delta n$ value is _________.
the $\triangle { H } _{ 1 }\quad $ and $\triangle { H } _{ 2 }\quad $ $(in kJ mol^-1)$ and the $\triangle {egH } $ $(in kJ mol^-1)$ of a few 3 elements are given below:
Which of the element is likel;y to be:
Elements | $\triangle { H } _{ 1 }\quad $ | $\triangle { H } _{ 2 }\quad $ | $\triangle {egH } $ |
---|---|---|---|
I | 520 | 7300 | -60 |
II | 419 | 3051 | -48 |
III | 1681 | 3374 | -328 |
IV | 1008 | 1846 | -295 |
V | 2372 | 5251 | +48 |
VI | 738 | 1451 | -40 |
What is abbreviated as '$H$'?
Which of the following statements are correct?
Enthalpy of the system is given as
Which of the following reactions have same heat of reaction at constant $P$ and constant volume as well?
For which reaction will $\Delta H = \Delta U$?
In which of the following reactions, $\Delta H > \Delta U$?
Enthalpy of the system is given as:
Match List I with List II and select the answer from the given codes.
List I List II
B. $N _2(g) + 3H _2(g)\longrightarrow 2NH _3(g)$ 2. $\Delta H = \Delta U$
C. $NH _4HS(s)\longrightarrow NH _3(g) + H _2S(g)$ 3. $\Delta H =\Delta U - 2RT$
D. $PCl _5(g)\longrightarrow PCl _3(g) + Cl _2(g)$ 4. $\Delta H = \Delta U + 2RT$
E. $2SO _2(g) + O _2(g)\longrightarrow 2SO _3(g)$ 5. $\Delta H = \Delta U - RT$
$H _2(g) + I _2(g)\longrightarrow 2HI(g)$
For this reaction, relate $\Delta H$ and $\Delta U$.
Heat of reaction at constant pressure and heat of reaction at constant volume for the gaseous reaction $N _2 + 3H _2 \longrightarrow 2NH _3$ differ $(\Delta H- \Delta U)$ by the amount:
If $\Delta E$ is the heat of reaction for
${C} _{2}{H} _{5}OH\left(l\right) + 3{O} _{2}\left(g\right) \longrightarrow 2C{O} _{2}\left(g\right) + 3{H} _{2}O\left(l\right)$
at constant volume, the $\Delta H$ (heat of reaction at constant pressure), at constant temperature is:
For gaseous reactions, if $\Delta H$ is the change in enthalpy and $\Delta U$ that in internal energy, then
At constant pressure:
For the combustion reaction at $298\,K$
$2Ag(s) +1/2O _2(g)\longrightarrow 2Ag _2O(s)$ Which of the following alternative is correct?
Hess's law is based on:
Select the correct option(s):
Enthalpy change of a reaction will be equal to:
In an isothermal process:
Two reactions are given below:
Which of the following is abbreviated as $H$?
A mixture of 2 mole of carbon monoxide and one mole of oxygen in a closed vessel is ignited to get carbon dioxide. If $\Delta H$ is the enthalpy change and $\Delta U$ is the change in internal energy, then:
Predict $\Delta H>\Delta U$ or $\Delta H<\Delta U$.
Water is boiled under a pressure of 1.0atm. When an electric current of 0.50A from a 12V supply is passed for 300 second through a resistance in thermal contact with it, it is found that 0.789g of water is vapourized. The molar internal energy change at boiling point (373.15K) is
A piston exerting a pressure of 1.0 atmosphere rests on the surface of water at $100^{\circ}C$. The pressure is reduced to smaller extent and as a result 10 g of water evaporates and absorbs 22.2 kJ of heat. The change in internal energy is:
Enthalpy is_________.
Statement I : An exothermic reaction has a positive $\displaystyle \Delta H$ value
Because
Statement II : Heat must be added to the reaction for the reaction to occur