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3 years ago

What is the best description of the Bohr model of the atom?

1 answer:

4 0

The best description of the Bohr model of the atom is that the atom consists of a nucleus with electrons orbiting at specific energy levels. Absorbed photons cause electrons to jump between energy levels. The answer is letter C.

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The strongly polar, hydrogen-bonding properties of water make it an excellent solvent for ionic (charged) species. By contrast,

trapecia [35]

Answer:

hello your question is incomplete attached below is the complete question

Pyridinium ion is more soluble in 0.1 M HCL (aqueous solution) and this is because the Pyridine ion reacts with NaOH and after the reaction it comes out neutral.

N-acetyltyrosine methyl ester is more soluble in 0.1 M HCL while

B-napthol is more soluble in 0.1 M NaOH because it forms phenoxide ion

Explanation:

Pyridine ion is more soluble in 0.1 M HCL (aqueous solution) and this is because the Pyridine ion reacts with NaOH and after the reaction it comes out neutral.

N-acetyltyrosine methyl ester is more soluble in 0.1 M HCL while

B-napthol is more soluble in 0.1 M NaOH because it forms phenoxide ion

attached below is the remaining part of the solution

7 0

4 years ago

You have 0.21 moles of Al how many atoms do you have

ZanzabumX [31]

Number of atoms : 1.26 x 10²³

<h3>Further explanation </h3>

The mole is the number of particles(molecules, atoms, ions) contained in a substance

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

0.21 moles of Al, so n = 0.21

Number of atoms :

$\tt N=0.21\times 6.02\times 10^{23}\\\\N=1.26\times 10^{23}$

8 0

3 years ago

Many chemistry problems result in equations of the form

Gnom [1K]

Answer:

When this equation is solved, the two values of the unknown are 0.0643 and -0.082

Explanation:

Given

$1.77 * 10^{-2} = \frac{x^2}{0.298 - x}$ --- the actual equation

Required

The values of x

We have:

$1.77 * 10^{-2} = \frac{x^2}{0.298 - x}$

Cross Multiply

$1.77 * 10^{-2} * (0.298 - x)= x^2$

Multiply both sides by 100

$1.77 * (0.298 - x)= 100x^2$

Open bracket

$0.52746 - 1.77x= 100x^2$

Rewrite as:

$100x^2 + 1.77x - 0.52746 =0$

Using quadratic formula:

$x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}$

Where:

$a = 100; b = 1.77; c = -0.52746$

So, we have:

$x = \frac{-1.77 \± \sqrt{1.77^2 - 4*100*- 0.52746 }}{2*100}$

$x = \frac{-1.77 \± \sqrt{214.1169}}{2*100}$

$x = \frac{-1.77 \± 14.63}{200}$

Split

$x = \frac{-1.77 + 14.63}{200}\ or\ x = \frac{-1.77 - 14.63}{200}$

$x = \frac{12.86}{200}\ or\ x = \frac{-16.40}{200}$

$x = 0.0643\ or\ x = -0.082$

3 0

3 years ago

Starting with 0.250L of a buffer solution containing 0.250 M benzoic acid (C 6H 5COOH) and 0.20 M sodium benzoate (C 6H 5COONa),

Zigmanuir [339]

Answer:

pH = 4.05

Explanation:

The pH of the benzoic buffer can be determined using H-H equation:

pH = pKa + log [A⁻] / [HA]

Where pKa is -logKa = 4.187

pH = 4.187 + log [Sodium Benzoate] / [Benzoic Acid]

Where [] can be understood as moles of each specie.

Thus, to find pH of the buffer we need to calculate moles of benzoic acid and sodium benzoate.

Initial moles:

Initial moles of benzoic acid and sodium benzoate are:

Acid: 250mL = 0.250L ₓ (0.250 moles / L) = 0.0625 moles of benzoic acid

Benzoate : 250mL = 0.20L ₓ (0.250 moles / L) = 0.050 moles of sodium benzoate

Moles after reaction:

Now, 0.0250L×(0.100mol/L) = 0.0025 moles of HCl are added to the buffer reacting with sodium benzoate, C₆H₅COONa, producing more benzoic acid, as follows:

HCl + C₆H₅COONa → C₆H₅COOH + NaCl

That means after reaction moles of both species are:

Benzoic acid: 0.0625 mol + 0.0025mol (Moles produced) = 0.065 moles

Sodium Benzoate: 0.050mol - 0.0025mol (Moles that react) = 0.0475 moles

Replacing in H-H equation:

pH = 4.187 + log [0.0475] / [0.065]

pH = 4.05

5 0

3 years ago

How do you change Celsious to Faranheight (or however u write them)

Minchanka [31]

Multiply by 1.8 and then add 32.

5 0

3 years ago

Read 2 more answers