Answer: conversion of ice to steam
Explanation: Endothermic process is one in which energy is absorbed by the system.
Conversion of ice to steam is change of solid phase to gaseous phase, thus energy is required to break the strong inter molecular forces of attraction in solids to convert it into gaseous phase.
Conversion of steam to ice, conversion of steam to water and conversion of water to ice releases energy and are examples of exothermic processes.
To calculate the <span>δ h, we must balance first the reaction:
NO + 0.5O2 -----> NO2
Then we write all the reactions,
2O3 -----> 3O2 </span><span>δ h = -426 kj eq. (1)
O2 -----> 2O </span><span>δ h = 490 kj eq. (2)
NO + O3 -----> NO2 + O2 </span><span>δ h = -200 kj eq. (3)
We divide eq. (1) by 2, we get
</span>O3 -----> 1.5O2 δ h = -213 kj eq. (4)
Then, we subtract eq. (3) by eq. (4)
NO + O3 -----> NO2 + O2 δ h = -200 kj
- (O3 -----> 1.5 O2 δ h = -213 kj)
NO -----> NO2 - 0.5O2 δ h = 13 kj eq. (5)
eq. (2) divided by -2. (Note: Dividing or multiplying by negative number reverses the reaction)
O -----> 0.5O2 <span>δ h = -245 kj eq. (6)
</span>
Add eq. (6) to eq. (5), we get
NO -----> NO2 - 0.5O2 δ h = 13 kj
+ O -----> 0.5O2 δ h = -245 kj
NO + O ----> NO2 δ h = -232 kj
<em>ANSWER:</em> <em>NO + O ----> NO2 δ h = -232 kj</em>
3.0x10-4..............................
Explanation: This is a reaction of oxidation of 
in the presence of acidified 
. Acidified is a strong oxidizing agent.
To balance out the 
on the reactant side, we write 
on the product side.
Balancing out the following reaction gives us:
