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3 years ago

ASAP for brainlist first correct question

Chemistry

1 answer:

Ghella [55]3 years ago

8 0

The second law of thermodynamics states that in a reversible process, the entropy of the universe is constant, whereas in an irreversible process, such as the transfer of heat from a hot object to a cold object, the entropy of the universe increases

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Which of the following is a chemical property of a base

zavuch27 [327]

Answer:

where is the chosices to choose from

Explanation:

5 0

4 years ago

What is the pH of a buffer solution upon mixing 15.0 mL of 0.40 M HCl and 20.0 mL of 0.50 M NH? Kb (NH3) = 1.8 x 10 E. 7.00 A. 9

vladimir2022 [97]

<u>Answer:</u> The pH of resulting solution is 9.08

<u>Explanation:</u>

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ ........(1)

<u>For HCl:</u>

Molarity of HCl = 0.40 M

Volume of solution = 15.0 mL

Putting values in equation 1, we get:

$0.40M=\frac{\text{Moles of HCl}\times 1000}{15.0mL}\\\\\text{Moles of HCl}=0.006mol$

<u>For ammonia:</u>

Molarity of ammonia = 0.50 M

Volume of solution = 20.0 mL

Putting values in equation 1, we get:

$0.50M=\frac{\text{Moles of ammonia}\times 1000}{20.0mL}\\\\\text{Moles of ammonia}=0.01mol$

The chemical reaction for hydrochloric acid and ammonia follows the equation:

$HCl+NH_3\rightarrow NH_4Cl$

Initial: 0.006 0.01

Final: - 0.004 0.006

Volume of solution = 15.0 + 20.0 = 35.0 mL = 0.035 L (Conversion factor: 1 L = 1000 mL)

To calculate the pOH of basic buffer, we use the equation given by Henderson Hasselbalch:

$pOH=pK_b+\log(\frac{[salt]}{[base]})$

$pOH=pK_b+\log(\frac{[NH_4Cl]}{[NH_3]})$

We are given:

$pK_b$ = negative logarithm of base dissociation constant of ammonia = $-\log (1.8\times 10^{-5})=4.74$

$[NH_4Cl]=\frac{0.006}{0.035}$

$[NH_3]=\frac{0.004}{0.035}$

pOH = ?

Putting values in above equation, we get:

$pOH=4.74+\log(\frac{0.006/0.035}{0.004/0.035})\\\\pOH=4.92$

To calculate pH of the solution, we use the equation:

$pH+pOH=14\\pH=14-4.92=9.08$

Hence, the pH of the solution is 9.08

3 0

3 years ago

What is the Epicenter (it's about earthquakes)

Archy [21]

Answer

The location below the earth's surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. Sometimes an earthquake has foreshocks. These are smaller earthquakes that happen in the same place as the larger earthquake that follows.

Explanation:

5 0

3 years ago

If helium had exactly the same mass as four hydrogen atoms, the luminosity o f the sun would be

Katena32 [7]

<span>Hydrogen has an atomic mass of about 1 and It contains one proton, orbited by a single electron. Helium has an atomic mass of approximately 4 and contains of 2 protons and 2 neutrons, orbited by 4 electrons. But all of this is irrelevant because luminosity is related to gravity, and that mass would identical, luminosity would be near identical. *insert luminosity relation equation here*</span>

7 0

3 years ago

24.50 g of Na react with H20 to make sodium hydroxide and H2 gas. How much sodium

Alenkasestr [34]

Answer:

hay 4,240 gr

Explanation:

<h2>2Na + 2 H20 - --- 2 NO(OH) -+ H2</h2><h2>n pued o es criibr</h2><h2>eo</h2>

3 0

3 years ago