Does Radiant Energy contain Kinetic, or potential energy or both?

A standard solution of FeSCN2+ is prepared by combining 9.0 mL of 0.20 M Fe(NO3)3 with 1.0 mL of 0.0020 M KSCN . The standard so

Xelga [282]

Answer : The equilibrium concentration of $SCN^-$ in the trial solution is $4.58\times 10^{-8}M$

Explanation :

First we have to calculate the initial moles of $Fe^{3+}$ and $SCN^-$ .

$\text{Moles of }Fe^{3+}=\text{Concentration of }Fe^{3+}\times \text{Volume of solution}$

$\text{Moles of }Fe^{3+}=0.20M\times 9.0mL=1.8mmol$

and,

$\text{Moles of }SCN^-=\text{Concentration of }SCN^-\times \text{Volume of solution}$

$\text{Moles of }SCN^-=0.0020M\times 1.0mL=0.0020mmol$

The given balanced chemical reaction is,

$Fe^{3+}(aq)+SCN^-(aq)\rightleftharpoons FeSCN^{2+}(aq)$

Since 1 mole of $Fe^{3+}$ reacts with 1 mole of $SCN^-$ to give 1 mole of $FeSCN^{2+}$

The limiting reagent is, $SCN^-$

So, the number of moles of $FeSCN^{2+}$ = 0.0020 mmole

Now we have to calculate the concentration of $FeSCN^{2+}$ .

$\text{Concentration of }FeSCN^{2+}=\frac{0.0020mmol}{9.0mL+1.0mL}=0.00020M$

Using Beer-Lambert's law :

$A=\epsilon \times C\times l$

where,

A = absorbance of solution

C = concentration of solution

l = path length

$\epsilon$ = molar absorptivity coefficient

$\epsilon$ and l are same for stock solution and dilute solution. So,

$\epsilon l=\frac{A}{C}=\frac{0.480}{0.00020M}=2400M^{-1}$

For trial solution:

The equilibrium concentration of $SCN^-$ is,

$[SCN^-]_{eqm}=[SCN^-]_{initial}-[FeSCN^{2+}]$

$[SCN^-]_{initial}$ = 0.00050 M

Now calculate the $[FeSCN^{2+}]$ .

$C=\frac{A}{\epsilon l}=\frac{0.220}{2400M^{-1}}=9.17\times 10^{-5}M$

Now calculate the concentration of $SCN^-$ .

$[SCN^-]_{eqm}=[SCN^-]_{initial}-[FeSCN^{2+}]$

$[SCN^-]_{eqm}=(0.00050M)-(9.17\times 10^{-5}M)$

$[SCN^-]_{eqm}=4.58\times 10^{-8}M$

Therefore, the equilibrium concentration of $SCN^-$ in the trial solution is $4.58\times 10^{-8}M$

5 0

3 years ago

Fumaric acid, which occurs in many plants, contains, by mass, 41.4% carbon, 3.47% hydrogen, and 55.1% oxygen. The molecular mass

lukranit [14]

Answer:

Explanation:

C = 41.4/12 = 3.43

H = 3.47/1 = 3.47

O = 55.1/16 =3.44

CHO is the skeletal formula (divide each by the lowest number above). The results are close enough to 1 to be 1.

(CHO)_x = 116

C + H + O = 29

(29) _ x = 116

x = 116/29

x = 4

So there area 4 carbons 4 hydrogens and 4 oxygens.

The correct formula is C4H4O4

3 0

3 years ago

How many elements are in Li2SO4?how many elements are in li2s 04 how many elements are in li2s 04

Free_Kalibri [48]

Answer:

3

Explanation:

the three elements involved in this compound are Li, S, O.

lithium, sulfur, and oxygen. Which create the ionic compound, "Lithium Sulfate."

7 atoms total, since there are two lithium, four oxygen, and one sulfate atom. this is a white inorganic salt.

6 0

3 years ago

During a chemical reaction, the______

WINSTONCH [101]

Answer:

limiting reagent :)

Explanation:

5 0

3 years ago

Read 2 more answers

The Lewis dot model of a molecule is shown.

Katen [24]

Answer:

Carbon has a total of four bonded pairs of electrons around it.

Explanation:

Since there are four "lines" around the C (which stands for Carbon), we can conclude that Carbon has a total of four bonded pairs of electrons around it.

3 0

3 years ago