Question 1 Which of the following is a false

The radius of a single atom of a generic element X is 169 picometers (pm) and a crystal of X has a unit cell that is body-center

Virty [35]

The volume of the unit cell is 2.67 x 10⁻²⁸ m³.

<h3>What is the volume of a unit cell of a body-centered cubic crystal?</h3>

In a body-centered cubic unit cell, the volume occupied by the particles of the substance is about 68% of the total unit cell.

Assuming that a single atomic a sphere, the volume is:

Volume(atom) = 4/3 x π x r³

Volume(atom) = 4/3 x π x (169 x 10⁻¹²)³

Volume(atom) = 2.02 x 10⁻²⁹ m³

There are a total of 9 atoms in a body-centered unit cell, so the total volume occupied by atoms is:

2.02 x 10⁻²⁹ x 9

= 1.82 x 10⁻²⁸ m³

Volume of cell = (1.15 x 10⁻²⁸ ) / 0.68

Volume of cell = 2.67 x 10⁻²⁸ m³

Therefore, the volume of the unit cell is 2.67 x 10⁻²⁸ m³.

Learn more volume of unit cells at: brainly.com/question/1594030

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8 0

2 years ago

What is the pH at the equivalence point in the titration of a 25.7 mL sample of a 0.370 M aqueous nitrous acid solution with a 0

expeople1 [14]

Answer:

pH = 8.24

Explanation:

Nitrous acid (HNO₂) reacts with KOH, thus:

HNO₂ + KOH → KNO₂ + H₂O

Moles of HNO₂ are:

0.0257mL ₓ (0.370mol / L) = 0.00951moles.

In equivalence point, the complete moles of nitrous acid reacts with KOH producing potassium nitrite. There are needed:

0.00951mol ₓ (1L / 0.491mol) = 0.01937L ≡ 19.4mL of 0.491M KOH to reach equivalence point.

Total volume in equivalence point is: 19.4mL + 25.7mL = 45.1mL

Potassium nitrite is in equilibrium with water, thus:

NO₂⁻ + H₂O ⇄ HNO₂ + OH⁻

Where equilibrium constant, Kb, is defined as:

Kb = 1.41x10⁻¹¹ = $\frac{[OH^-][HNO_2]}{[NO_2]}$

In equilibrium, molarity of each compound are:

[NO₂⁻]: 0.00951mol/0.00451L - X = 0.211M - X

[HNO₂]: X

[OH⁻]: X

Where X is reaction coordinate

Replacing in Kb:

1.41x10⁻¹¹ = $\frac{[X][X]}{[0.211 -X]}$

0 = X² + 1.41x10⁻¹¹X - 2.97x10⁻¹²

Solving for X:

X = -1.72x10⁻⁶ FALSE ANSWER. There is no negative concentrations.

X = 1.72x10⁻⁶. Right answer.

That means:

[OH⁻]: 1.72x10⁻⁶M

As pOH is -log [OH⁻] and pH = 14-pOH:

pOH = 5.76; pH = 8.24

3 0

3 years ago

How man grams of cl2 are consumed to produce 12.0 g of KCl

Korvikt [17]

Answer:

5.71 g

Explanation:

Step 1: Write the balanced equation

2 K + Cl₂ ⇒ 2 KCl

Step 2: Calculate the moles corresponding to 12.0 g of KCl

The molar mass of KCl is 74.55 g/mol.

12.0 g × 1 mol/74.55 g = 0.161 mol

Step 3: Calculate the moles of Cl₂ needed to produce 0.161 moles of KCl

The molar ratio of Cl₂ to KCl is 1:2. The moles of Cl₂ needed are 1/2 × 0.161 mol = 0.0805 mol

Step 4: Calculate the mass corresponding to 0.0805 moles of Cl₂

The molar mass of Cl₂ is 70.91 g/mol.

0.0805 mol × 70.91 g/mol = 5.71 g

8 0

3 years ago

Sometimes people do not want to change their belief regardless of the evidence.

bagirrra123 [75]

Answer:

True

Explanation:

Ex. People against vaccines tend to believe crazy theories over facts because they think they'll end up brainwashing them.

6 0

2 years ago

Which order is correct in listing the bond lengths from shortest to longest? A. single, double, triple B. triple, double, single

Alex787 [66]

A I believe would be the answer

3 0

3 years ago

Question 1Which of the following is a false​

Question 1Which of the following is a false