Th ph value of milk is close to

Which of the following is a true statement?

sergejj [24]

Answer:

C

Explanation:

Wind is geological therefore it is geological weathering

5 0

2 years ago

Heating a solution of alcohol and water, then collecting the alcohol vapors and condensing them into a liquid with higher alcoho

Sindrei [870]

Answer:

Distillation.

Explanation:

If we are heating a mixture of two miscible liquids and collecting the vapors it means we are separating the two mixtures from each other based on their boiling point differences.

This technique of separation of two liquids based on the difference in boiling point is known as Distillation.

Alcohol will evaporate easily as compared to water as water has stronger influence of hydrogen bond making the inter-molecular forces stronger.

4 0

3 years ago

"How much NH4Cl, when present in 2.00 liters of 0.200 M ammonia, will give a solution with pH = 8.20? For NH3, Kb = 1.8 x 10-5"

Andru [333]

Answer:

245.66g of NH₄Cl is the mass we need to add to obtain the desire pH

Explanation:

The mixture of NH3/NH4Cl produce a buffer. We can find the pH of a buffer using H-H equation:

pH = pKa + log [A⁻] / [HA]

Where [A⁻] is the molar concentration of the base, NH₃, and [HA] molar concentration of the acid, NH₄⁺. This molar concentration can be taken as the moles of each chemical

First, we need to find pKa of NH₃ using Kb. Then, the moles of NH₃ and finally replace these values in H-H equation to solve moles of NH₄Cl we need to obtain the desire pH.

pKa NH₃/NH₄⁺

pKb = - log Kb

pKb = -log 1.8x10⁻⁵ = 4.74

pKa = 14 - pKb

pKa = 14 - 4.74

pKa = 9.26

Moles NH₃

2.00L ₓ (0.200mol NH₃ / L) = 0.400 moles NH₃

H-H equation:

pH = pKa + log [NH₃] / [NH₄Cl]

8.20 = 9.26 + log [0.400 moles] / [NH₄Cl]

-1.06 = log [0.400 moles] / [NH₄Cl]

0.0087 = [0.400 moles] / [NH₄Cl]

[NH₄Cl] = 0.400 moles / 0.0087

[NH₄Cl] = 4.59 moles of NH₄Cl we need to add to original solution to obtain a pH of 8.20. In grams (Using molar mass NH₄Cl=53.491g/mol):

4.59 moles NH₄Cl ₓ (53.491g / mol) =

<h3>245.66g of NH₄Cl is the mass we need to add to obtain the desire pH</h3>

3 0

3 years ago

When a saturated solution of NH4Br dissolved in 100 grams of water is cooled from 60°C to 30°C, how much NH4Br will precipitate?

stepladder [879]

Answer:

$m_{precipitated}=24.8g$

Explanation:

Hello,

In this case, since at 60 °C, 108 grams of ammonium bromide are completely dissolved in 100 grams of water for a saturated solution, once it is cooled to 30 °C, wherein only 83.2 grams are completely dissolved in 100 grams of water, the following mass will precipitate:

$m_{precipitated}=108g-83.2g\\\\m_{precipitated}=24.8g$

Best regards.

8 0

3 years ago

Water molecules that remain in a fixed position with very little motion would be characteristic of

Dominik [7]

Ice because the molecules have less movement in solids

6 0

3 years ago