One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant.
<span>all the ones that phase down are exothermic - freezing, deposition, condensation.
all the ones that phase up are endothermic - melting, sublimation, vaporization
endothermic is to gain heat, exothermic is to release heat</span>
Answer : The value of 'R' is 
Solution : Given,
At STP conditions,
Pressure = 1 atm
Temperature = 273 K
Number of moles = 1 mole
Volume = 22.4 L
Formula used : 
where,
R = Gas constant
P = pressure of gas
T = temperature of gas
V = volume of gas
n = number of moles of gas
Now put all the given values in this formula, we get the values of 'R'.
Therefore, the value of 'R' is .
The name of the acid that is formed when hydrogen sulfide is dissolved in water would be hydrosulfuric acid. It has the same chemical formula as hydrogen sulfide which is H2S. It is classified as a weak acid which partially ionizes into hydrogen sulfide ions and hydronium ions. It is a very toxic substance and is distinguished by its strong odor which is compared to an egg that is rotting. It can be found in high concentrations in the crust of the Earth, in volcanic emissions and in many fossil fuels. To produce this acid, the gas hydrogen sulfide is dissolved into the water. However, this acid is not produced since it does not have any industrial application.
