Oxygen (

Calculate the weight percent of ascorbic acid in a tablet of Vitamin C from the following data:A 80 mg sample of a crushed Vitam

Lina20 [59]

Answer:

The Answer is 88%

Explanation:

The balanced ionic equation of the reaction

$IO^{3- }+ 8 I^- + 6 H^+ => 3 I^{3- }+ 3 H_2O$

$I^{3-} + 2 S_2O_3^{2-} => 3 I^- + S_4O_6^{2-}$

$C_6H_8O_6 + I^{3- }+ H_2O => C_6H_6O_6 + 3 I^- + 2 H^+$

Looking at the above reactions

The original number of moles of $I^{3-}$ = 3 × number of moles of $IO^{3-}$

= 3 × volume × concentration of $KIO_3$

Note: The formula for number of moles is volume × concentration

$=3 * \frac{40}{1000} * 0.00653 =0.000784$ mol

The number of moles of $I^{3-}$ left after its reaction with ascorbic acid

= $\frac{1}{2}$ x moles of $S_2O_3^{2-}$

= $\frac{1}{2}$ x volume x concentration of $S_2O_3^{2-}$

$= \frac{1}{2} * \frac{15}{1000} * 0.0510 =0.000383 \ mol$

Note: The division by 1000 is to convert mill liter to liter

Moles of ascorbic acid = moles of $I^{3-}$ reacted

$= initial \ moles \ of \ I^{3-} \ - remaining \ moles \ of \ I^{3-}$

$=0.000784 - 0.000383$

$=0.000401 \ mols$

$Mass = moles \ * molar \ mass$

Hence

Mass of ascorbic acid = moles of ascorbic acid × molar mass of ascorbic acid

$= 0.000401* 176.12 = 0.07055\ g$

$= 70.55\ mg$

Weight% of ascorbic acid = mass of ascorbic acid/mass of sample x 100%

= 70.55/80 × 100%

= 88.1%

3 0

4 years ago

Correct possible values of l for n = 4?

Kamila [148]

Answer:

0,1,2,3

Explanation:

for the given value of n , l = 0 to n-1

so if n = 4

l = 0 to 4-1

6 0

3 years ago

Two mineral samples have the same size. The heavier one has a higher _____________. *

Simora [160]

Answer:

Density

Explanation:

D= m/v

5 0

3 years ago

The enthalpy of combustion for octane (C8H18(l)), a key component of gasoline, is -5,074 kJ/mol. This value is the Delta. Hrxn f

Inessa [10]

Combustion can be defined as the reaction of a compound with oxygen. The enthalpy of combustion of octane is $\Delta H_{\rm rxn}$ for $\rm C_8H_{18}\;+\;25\;O_2\;\rightarrow 8\;CO_2\;+\;9\;H_2O$ .

<h3>What is the enthalpy of reaction?</h3>

The enthalpy of reaction is the amount of heat energy absorbed or lost by the molecules in the chemical reaction.

The enthalpy of combustion is the amount of heat energy released by the compound in the reaction with oxygen.

The reaction in which heat is liberated with the reaction of a compound with oxygen has an enthalpy of combustion, equivalent to the enthalpy of reaction.

The combustion of octane can be given as:

$\rm C_8H_{18}\;+\;25\;O_2\;\rightarrow 8\;CO_2\;+\;9\;H_2O$

Thus, the reaction has combustion energy equivalent to the enthalpy of the reaction is $\rm C_8H_{18}\;+\;25\;O_2\;\rightarrow 8\;CO_2\;+\;9\;H_2O$ . Thus, option B is correct.

Learn more about enthalpy of reaction, here:

brainly.com/question/1657608

6 0

3 years ago

"the number of quantum numbers needed to describe the state of an atomic electron is"

Blababa [14]

To completely describe an electron in an atom, four quantum numbers are needed: energy (n), angular momentum (ℓ), magnetic moment (mℓ), and spin (ms). The first quantum number describes the electron shell, or energy level, of an atom.

5 0

4 years ago