I need these done please

The absorbance of an equilibrium mixture containing FeSCN2 was measured at 447 nm and found to be 0.347. What is the equilibrium

Ksenya-84 [330]

Answer:

The concentration is $C = 1.11 mol/L$

Explanation:

From the question we are told that

The absorbance is $A = 0.347$

The length is $l = 447 nm = 447 *10^{-7} \ cm$

Generally absorbance is mathematically represented as

$A = \epsilon* C * l$

where $\epsilon$ is the molar absorptivity of FeSCN2 with a value $\epsilon = 7.0*10^3 L/cm/mol$

and $C$ is the equilibrium concentration of FeSCN2

So

$C = \frac{A}{\epsilon * l }$

substituting values

$C = \frac{0.347}{7.0*10^{3} * 447 *10^{-7} }$

$C = 1.11 mol/L$

5 0

2 years ago

Be sure to answer all parts. Carbon dioxide (CO2) is the gas that is mainly responsible for global warming (the greenhouse effec

Elena L [17]

Answer:

1.60x10⁶ billions of g of CO₂

Explanation:

Let's calculate the production of CO₂ by a single human in a day. The molar mass of glucose is 180.156 g/mol and CO₂ is 44.01 g/mol. By the stoichiometry of the reaction:

1 mol of C₆H₁₂O₆ -------------------------- 6 moles of CO₂

Transforming for mass multiplying the number of moles by the molar mass:

180.156 g of C₆H₁₂O₆ ----------------- 264.06 g of CO₂

4.59x10² g ---------------- x

By a simple direct three rule:

180.156x = 121203.54

x = 672.77 g of CO₂ per day per human

So, in a year, 6.50 billion of human produce:

672.77 * 365 * 6.50 billion = 1.60x10⁶ billions of g of CO₂

5 0

2 years ago

When substances combine to form mixtures they keep their properties. O True O False

Gnesinka [82]

Answer:

True

Explanation:

8 0

3 years ago

Read 2 more answers

Sighting along the C2-C3 bond of 2-methylbutane, the least stable conformation (Newman projection) has a total energy strain of

natima [27]

Answer:

21 KJ/mol

Explanation:

For this question, we have to start with the linear structure of 2-methylbutane. With the linear structure, we can start to propose all the Newman projections keep it in mind that the point of view is between carbons 2 and 3 (see figure 1).

Additionally, we have several energy values for each interaction present in the Newman structures:

-) Methyl-methyl gauche: 3.8 KJ/mol

-) Methyl-H eclipse: 6.0 KJ/mol

-) Methyl-methyl eclipse: 11.0 KJ/mol

-) H-H eclipse: 4.0 KJ/mol

Now, we can calculate the energy for each molecule.

Molecule A

In this molecule, we have 2 Methyl-methyl gauche interactions only, so:

(3.8x2) = 7.6 KJ/mol

Molecule B

In this molecule, we have a Methyl-methyl eclipse interaction a Methyl-H eclipse interaction and an H-H eclipse interaction, so:

(11)+(6)+(4) = 21 KJ/mol

Molecule C

In this molecule, we have 1 Methyl-methyl gauche interaction only, so:

3.8 KJ/mol

Molecule D

In this molecule, we have three Methyl-H eclipse interaction, so:

(6*3) = 18 KJ/mol

Molecule E

In this molecule, we have 1 Methyl-methyl gauche interaction only, so:

3.8 KJ/mol

Molecule F

In this molecule, we have a Methyl-methyl eclipse interaction a Methyl-H eclipse interaction and an H-H eclipse interaction, so:

(11)+(6)+(4) = 21 KJ/mol

The structures with higher energies would be less stable. In this case, structures B and F with an energy value of 21 KJ/mol (see figure 2).

I hope it helps!

3 0

3 years ago

10. (a) Describe how the structure of an alloy is different to a pure metal

Oxana [17]

1.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element that reacts with water to produce a lilac flame

2.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element used as an inert atmosphere

3.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element that has a valency of 3

4.Write a balanced chemical equation for the reaction between potassium and water. (Non-anonymous question). .
(1 Point)

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5.For each of the following, give the name of an element from Period 4 (potassium to krypton), which matches the description.
Elements may be used once, more than once or not all.. Single line text.
(1 Point)
an element with a fixed valency of 2 that not is not in group 2

Help

4 0

3 years ago