La densidad del LiH es 0.82 g / cm^3. a) Calcule la densidad del hidrógeno en el LiH y el númer

La densidad del LiH es 0.82 g / cm^3. a) Calcule la...

La densidad del $\mathrm{LiH}$ es $0.82 \mathrm{~g} / \mathrm{cm}^3$. a) Calcule la densidad del hidrógeno en el LiH y el número de átomos de $\mathrm{H}$ en $5.0 \mathrm{~cm}^3$ de $\mathrm{LiH}$. b) ¿Cuántos litros de $\mathrm{H}_2$ a $20^{\circ} \mathrm{C}$ y $740 \mathrm{~mm} \mathrm{Hg}$ se requieren para preparar $5.0 \mathrm{~cm}^3$ de $\mathrm{LiH}$ ?

La densidad del $\mathrm{LiH}$ es $0.82 \mathrm{~g} / \mathrm{cm}^3$.
a) Calcule la densidad del hidrógeno en el LiH y el número de átomos de $\mathrm{H}$ en $5.0 \mathrm{~cm}^3$ de $\mathrm{LiH}$.
b) ¿Cuántos litros de $\mathrm{H}_2$ a $20^{\circ} \mathrm{C}$ y $740 \mathrm{~mm} \mathrm{Hg}$ se requieren para preparar $5.0 \mathrm{~cm}^3$ de $\mathrm{LiH}$ ?

Key Concepts

Density

Density is a fundamental physical property that expresses the mass of a substance per unit volume. In chemical problems, it is used to relate the volume of a material to its mass, which is essential when converting between physical dimensions and chemical quantities.

Stoichiometry

Stoichiometry involves the quantitative relationships between reactants and products in a chemical reaction. It allows for computing the proportion of each element in a compound based on its chemical formula, enabling the determination of the number of moles and mass of individual components from the whole compound.

Molar Mass

The molar mass is the mass of one mole of a substance, typically expressed in grams per mole. It serves as a conversion factor between the mass of a substance and the number of moles, facilitating calculations involving chemical reactions and composition.

Avogadro's Number

Avogadro's number is a constant that represents the number of atoms, ions, or molecules in one mole of a substance. It is crucial for translating between the macroscopic scale of grams and the microscopic scale of individual particles in chemical calculations.

Ideal Gas Law

The ideal gas law (PV = nRT) is a fundamental equation in physical chemistry that relates the pressure, volume, temperature, and number of moles of a gas. It is used to predict how gases will behave under varying conditions of pressure and temperature, making it essential for solving problems involving gaseous reactants or products.

Transcript

00:01 Hi everyone of now in order to solve this numerical first write the given data given data now how to write the given data now what they gave is you know density 078 gram for cmq then volume 5 cmq so you know you know you have to find density is equal to mass upon volume and therefore mass is equal to density into volume that is equal to 0 .78 into 5 so 3 .9 gram is the mass 3 .9 gram is the mass 3 .9 gram is the mass now, you know, in order to find out number of hydrogen atom, i should find out first mass of hydrogen atom.

01:46 Then so first find mass of hydrogen atom, mass of hydrogen atom, mass of hydrogen.

02:04 So mass of hydrogen that is equal to mass of lithium hydride into atomic mass of hydrogen.

02:15 Mass of hydrogen divided by atomic mass of lithium hydride.

02:31 Atomic mass of lithium hydride.

02:38 Now we just calculated a mass of lithium hydride as a 3 .9 gram into atomic mass of hydrogen 1 .08 divided by atomic mass of lithium hydrideide.

02:54 That is 7 .949 so this comes the numerator comes 3 .932 divided by 7 .949 now you know you have to find out density of lithium hydride now density of lithium hydride now density of lithium hydride is equal to mass of hydrogen.

03:31 Divided by volume of lithium hydride.

03:38 Now volume of lithium hydrate they have given 5.

03:41 So, you know, this is coming.

03:48 0 .4946 gram.

03:52 So 0 .4946 divided by 5.

04:00 So density is 0 .098 gram per cm cube.

04:13 So therefore n7 can write density of lithium hydride that is equal to 0.

04:21 0 .98 gram per cm cube gram per cm cube.

04:31 So i will do the bracket for this.

04:33 Now, you have to find out number of hydrogen atoms, number of hydrogen atoms.

04:51 So, number of hydrogen atoms, number of hydrogen atoms...