What is the name of the element with the atomic number 79

If you have 100 ml of a 0.10 m tris buffer (pka 8.3) at ph 8.3 and you add 3.0 ml of 1.0 m hcl, what will be the new ph?

sukhopar [10]

The new pH is 7.69.

According to Hendersen Hasselbach equation;

The Henderson Hasselbalch equation is an approximate equation that shows the relationship between the pH or pOH of a solution and the pKa or pKb and the ratio of the concentrations of the dissociated chemical species. To calculate the pH of the buffer solution made by mixing salt and weak acid/base. It is used to calculate the pKa value. Prepare buffer solution of needed pH.

pH = pKa + log10 ([A–]/[HA])

Here, 100 mL of 0.10 m TRIS buffer pH 8.3

pka = 8.3

0.005 mol of TRIS.

∴ $8.3 = 8.3 + log \frac{[0.005]}{[0.005]}$

inverse log 0 = $\frac{[B]}{[A]}$

$\frac{[B]}{[A]} = 1$

Given; 3.0 ml of 1.0 m hcl.

pka = 8.3

0.003 mol of HCL.

$pH = 8.3 + log \frac{[0.005-0.003]}{[0.005+0.003]}\\pH = 8.3 + log \frac{[0.002]}{[0.008]}\\\\pH = 8.3 + log {0.25}\\\\pH = 8.3 + (-0.62)\\pH = 7.69$

Therefore, the new pH is 7.69.

Learn more about pH here:

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8 0

1 year ago

VA 19.75-g sample was heated by 12.35 calories. The specific heat of the sample is 0.125 cal/g°C. What was the initial temperatu

SOVA2 [1]

Answer:

31.9 °C

Explanation:

The formula for the heat q absorbed by an object is

q = mCΔT where ΔT = (T₂ - T₁)

Data:

q = 12.35 cal

m = 19.75 g

C = 0.125 cal°C⁻¹g⁻¹

T₂ = 37.0 °C

Calculations

(a) Calculate ΔT

q = mCΔT

12.35 cal = 19.25 g × 0.125 cal°C⁻¹g⁻¹ × ΔT

12.35 = 2.406ΔT °C⁻¹

ΔT = 12.35/(2.406 °C⁻¹) = 5.13 °C

(b) Calculate T₂

ΔT = T₂ - T₁

T₁ = T₂ - ΔT = 37.0 °C - 5.13 °C = 31.9 °C

The original temperature was 31.9 °C.

6 0

2 years ago

Of the following substances, ________ has the highest boiling point. Of the following substances, ________ has the highest boili

kolezko [41]

Answer:

Of the following substances, PCl₃ has the highest boiling point

Explanation:

The given substances and their boiling point from online resources are;

Krypton, Kr, boiling point = -153.4°C

Chlorine gas, Cl₂, boiling point = -34.6°C

Borane, BH₃, (transient compound), boiling point of the dimer it forms B₂H₆ = -164.85°C

Methane, CH₄, boiling point = -161.6°C

Phosphorus trichloride, PCl₃, boiling point = 76.1°C

Therefore, given that PCl₃ is a volatile liquid at room temperature, while the other substances are gases and that PCl₃ has the highest boiling point of all the substances of 76.1°C, the substance with the highest boiling point is PCl₃.

5 0

2 years ago

What is the amount in grams of EDTA needed to make 315.1 mL of a 0.05 M EDTA solution. The molar mass of EDTA is 374 g/mol

statuscvo [17]

Answer:

58.92 g EDTA

Explanation:

315.1 mL = .3151 L

M = Moles / Liter

.3151 L x 0.5 mol EDTA x 374 g EDTA = 58.92 g EDTA

1 L EDTA 1 mol EDTA

4 0

1 year ago

Unlock all of them pls pls pls pls pls pls pls pls pls pls pls pls

ladessa [460]

What do you mean by unlock all of them? Please explain

7 0

2 years ago