Chapter 8, Problem 8.87AQAP

Interpretation Introduction

Interpretation:

“The volume of ${\text{H}}_{\text{2}}$ gas that can be produced at $0^{0}C$ and $\text{1}\text{atm}$ (STP) from $\text{25}\text{g}$ of Zinc should be calculated

Concept Introduction:

► Here, we have used the concept of stoichiometry where when reactants undergo a reaction, they form product in certain ratio based on the number of moles associated with the elements which participated in the reaction.

Thus, in stoichiometric calculation we come across chemical formula and chemical equation.

► A chemical equation directly states that the substance and the number of moles of each substance involved in the chemical reaction.

► The number of moles is related to the mass of the substance by the following relation

$\text{n =}\frac{\text{m}}{\text{M}}$

where $\text{n}$ is the number of moles

$\text{m}$= mass of the substance

$\text{M}$ is the molar mass of the substance

► STP is the standard temperature and pressure for one mole of a gas

The volume of gas at STP is $22.4L$

► Molar mass is the number of times a molecule of the substance is heavier than $\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$12th$}\right.$ the mass of an atom of $\text{carbon}-12$.

Given:

Mass of $\text{Zn = 25}\text{g}$

At STP, ${\text{T = 0}}^{\text{0}}\text{C }$

$\text{P = 1}\text{atm}$

$\text{n =1}\text{mol}$