Experiment 26 Results only PDF

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Experiment 26...

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Results:

Figure 1. ln Ksp Vs. 1/T (K-1) 0

0

0

0

0

0

0

0

0

0

-1

Ln (Ksp)

-2

f(x) = − 8051.1 x + 22.88 R² = 0.99

-3

-4

-5

y = -8051.1x + 22.88 R² = 0.9903

-6

-7

1/T(K-1)

Sample of Calculations: Volume of HCl added ( mL )=buret reading , final (mL)−buret reading ,initial (mL) 22.8− 0=22.8 Temperature , T ( K )=℃+273.15 57 + 273.15 =330.15

1 −1 1 ( K )= T Temperature ( K ) 1 =3.03 × 10−3 330.15 1 −1 (K ) T 1000

0.174 × Moles of HClused ( mol )=

0.174 ×

1 ( K −1) 3.03 × 10−3 =3.9672 1000

Moles of HClused (mol ) 2 ¿ Moles of B4 O 5 (OH )4

2−¿ ( mol ) =

3.9672 =1.9836 2 B 4 O 5 ( OH ) 4 ¿ ¿3 Solubility product , K sp =4 ׿ ¿ 4 × ( 1.9836 )3=2.50 × 108 ln ( K sp) =ln (K sp ) ln ( 2.50 ×108) =19.336

( )

kJ = ∆H° mol

−∆ H ° ×−8.314 R 1000

−8.05 × 105 ×−8.314 =66.936 1000 ∆S

( molJ × K )= ∆RS ×8.314

43.603 ×8.314 =556.506 H° ∆ G , ( kJ ) at 298 K = ¿

kJ ( mol )−298 × ∆ S ( molJ × K) 1000

66.936 −298 × 556.506 =−98.90 1000

Conclusion: The objective of the experiment was to standardize a hydrochloric acid solution, to determine the solubility product of borax as a function of temperature and the standard free energy, standard enthalpy, and standard entropy changes for the dissolution of borax in an aqueous solution. In the experiment, the 3 temperatures used as the experimental conditions, were cold, hot, and room temperature. In my experiment, the molar solubility of borax of the hot, room, and cold samples respectably read, 0.39672. 0.13224, 0.07656. As the temperature increased, the solubility of the solution increased. In the experiment, when the solution was submerged in the hot environment, it allowed the particles of borax to diffuse thoroughly into the solvent. In the Gibbs free energy equation, temperature plays in important role in determining free energy and spontaneity. At low temperatures, the reaction has a higher probability of being spontaneous and at higher temperatures the reaction had a lower possibility of being spontaneous (non-spontaneous)....