Density is the ratio of a substance ___ to its volume A. Force B. Mass C. Thickness D. Weight

Use standard enthalpies of formation to calculate ΔH∘rxn for the following reaction______.2H2S(g)+3O2(g)→2H2O(l)+2SO2(g) ΔH∘rxn

Ahat [919]

Answer:

-1,103.39KJ/mol

Explanation:

We use the subtract the standard enthalphies of formation of the reactants from that of the products. It must be taken into consideration that the enthalpy of formation of elements and their molecules alone are not taken into consideration. Hence, what we would be considering are the standard enthalpies of formation of H2S, H2O and SO2.

In places where we have more than one mole, we multiply by the number of moles as seen in the balanced chemical equations.

The standard enthalpies of the molecules above are as follows:

H2S = -20.63KJ/mol

H2O = -285.8KJ/mol

SO2 = -296.84KJ/mol

O2 = 0KJ/mol

ΔrH⦵ = [2ΔfH⦵(H2O) + 2 ΔfH⦵(SO2)] − [ΔfH⦵(H2S) + 3

 ΔfH⦵(O2)]

ΔrH⦵ =[(2 × -285.8) + (2 × -296.84)]

-[ 3 × -20.63)]

= (-571.6 - 593.68 + 61.89) = -1,103.39KJ/mol

6 0

4 years ago

Select correct examples of linear molecules for five electron groups. Select correct examples of linear molecules for five elect

Shalnov [3]

Explanation:

Formula to calculate hybridization is as follows.

Hybridization = $\frac{1}{2}[V+N-C+A]$

where,

V = number of valence electrons present in central atom

N = number of monovalent atoms bonded to central atom

C = charge of cation

A = charge of anion

So, hybridization of $BeCl_{2}$ is as follows.

Hybridization = $\frac{1}{2}[V + N - C + A]$

= $\frac{1}{2}[2 + 2]$

= 2

Hybridization of $BeCl_{2}$ is sp. Therefore, $BeCl_{2}$ is a linear molecule. There will be only two electron groups through which Be is attached.

Similarly, hybridization of $XeF_{2}$ is calculated as follows.

Hybridization = $\frac{1}{2}[V + N - C + A]$

= $\frac{1}{2}[8 + 2]$

= 5

Therefore, hybridization of $XeF_{2}$ is $sp^{3}d. Therefore, [tex]XeF_{2}$ is also a linear molecule. Though there are three lone pair of electrons present on a xenon atom and it is further attached with fluorine atoms through two electron pairs. Hence, there are in total five electron groups.

Thus, we can conclude that out of the given options $XeF_{2}$ is the correct examples of linear molecules for five electron groups.

7 0

3 years ago

Can matter be created or destroyed? Yes or No

anzhelika [568]

Answer:

No

Explanation:

The same amount of matter is present before and after chemical and physical changes. Matter cannot be created or destroyed

5 0

3 years ago

Read 2 more answers

Submit Quiz Previous Page 1 of 4 Next Drag and drop each description to match the subatomic particle. Protons Neutrons Drag and

Pavel [41]

Answer:

Protons:

Positively charged particle

The number of these is the atomic number

All atoms of a given element have the same number of these

Neutrons:

Neutral particles

Isotopes of a given element differ in the number of these

The mass number is the number of these added to the number of protons

Explanation:

Protons (positively charged), neutrons (neutral) and electrons (negatively charged) are smaller than an atom and they are the main subatomic particles. The nucleus of an atom is composed of protons and neutrons, and the electrons are in the periphery at unknown pathways.

The Atomic number (Z) indicates the number of protons ( $P^{+}$ ) in the nucleus. Every atom of an element have the same atomic number, thus the same number of protons.

The mass number (A) is the sum of the number of protons ( $P^{+}$ ) and neutrons (N) that are present in the nucleus: A= Z + N

Isotopes are atoms of the same element which nucleus have the same atomic number (Z), and different mass number (A), it means the same number of protons ( $P^{+}$ ) and a different number of neutrons (N). For example, the oxygen in its natural state is a mixture of isotopes:

99.8% atoms with A= 16, Z=8, and N=8

0.037% atoms with A=17, Z=8, and N=9

0.204% atoms with A=18, Z=8, and N=10

3 0

4 years ago

Open the Balancing Chemical Equations interactive and select Introduction mode. Then choose Separate Water. Adjust the coefficie

aleksklad [387]

Explanation:

1. Water decomposition

Decomposition reactions are represented by-

The general equation: AB → A + B.

Various methods used in the decomposition of water are -

Electrolysis
Photoelectrochemical water splitting
Thermal decomposition of water
Photocatalytic water splitting

Water decomposition is the chemical reaction in which water is broken down giving oxygen and hydrogen.

The chemical equation will be -

$H_2O + H_2 + O_2$

Hence, balancing the equation we need to add a coefficient of 2 in front of $H_2O$ on right-hand-side of the equation and 2 in front of $H_2$ on left-hand-side of the equation.