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If the molar absorptivity constant for the red dye solution is 5.56×104 M-1cm-1, calculate the molarity of the red dye solution

Shtirlitz [24]

Explanation:

a) Using Beer-Lambert's law :

Formula used :

$A=\epsilon \times c\times l$

where,

A = absorbance of solution = 0.945

c = concentration of solution = ?

l = length of the cell = 1.20 cm

$\epsilon$ = molar absorptivity of this solution = $5.56\times 10^4 M^{-1} cm^{-1}$

$0.945=5.56\times 10^4 M^{-1} cm^{-1}\times 1.20 \times c$

$c=1.4163\times 10^{-5} M=14.16 \mu M$

( $1\mu M=10^{-6} M$ )

14.16 μM is the molarity of the red dye solution at the optimal wavelength 519nm and absorbance value 0.945.

b) $c=1.4163\times 10^{-5} mol/L$

1 L of solution contains $1.4163\times 10^{-5}$ moles of red dye.

Mass of $1.4163\times 10^{-5}$ moles of red dye:

$1.4163\times 10^{-5}\times 879.86g/mol=0.01246 g$

$(w/v)\%=\frac{\text{Mass of solute (g)}}{\text{Volume of solvent (mL)}}\times 100$

$red(w/v)\%=\frac{0.01246 g}{1000 mL}\times 100=0.001246\%$

c) In order to dilute red dye solution by 5 times, we will need to add 1 L of water to solution of given concentration.

Concentration of red dye solution = $c=1.4163\times 10^{-5} M$

Concentration of red solution after dilution = c'

$c=c'\times 5$

$1.4163\times 10^{-5} M=c'\times 5$

$c'=2.83\times 10^{-6} M$

The final concentration of the diluted solution is $2.83\times 10^{-6} M$

8 0

3 years ago

Consider the following reaction: NaHCO3 + HC2H3O2 → NaC2H3O2 + H2O + CO2 How many mol of CO2 would be produced from the complete

Assoli18 [71]

Answer:

0.208mole of CO2

Explanation:

First, let us calculate the number of mole of HC3H3O2 present.

Molarity of HC3H3O2 = 0.833 mol/L

Volume = 25 mL = 25/100 = 0.25L

Mole =?

Mole = Molarity x Volume

Mole = 0.833 x 0.25

Mole of HC3H3O2 = 0.208mole

Now, we can easily find the number of mole of CO2 produce by doing the following:

NaHCO3 + HC2H3O2 → NaC2H3O2 + H2O + CO2

From the equation,

1mole of HC2H3O2 produced 1 mole of CO2.

Therefore, 0.208mole of HC2H3O2 will also produce 0.208mole of CO2

6 0

3 years ago

Read 2 more answers

what is the products of the reaction between 2-methylbut-2-ene and HCL 1b. write the IUPAC names of the product of the reaction;

zzz [600]

Answer:

Explanation:

2 - chloro-2-methylbutane

8 0

3 years ago

Help on science please

Otrada [13]

the Orange side will grow higher bc people on the blue side will eventually become over 65

6 0

3 years ago

If the equilibrium concentrations of products are much greater than those of reactants in this system, what would be the magnitu

miss Akunina [59]

Answer:

K > 1.

Explanation:

∵ The equilibrium constant K = [products]/[reactants].

Since, [products] > [reactants].

<em>∴ The equilibrium constant K > 1.</em>

5 0

3 years ago