Please give me the correct answer 100 percent please any answer will be good

vazorg [7]

Answer: The correct answer is the option: B. An element with eight valence electrons is chemically unstable.

Explanation:

Hello! Let's solve this!

We will analyze each of the options:

A. The group number of the element provides a clue to the number of valence electrons: it is correct, since it provides the number of valence electrons.

B. An element with eight valence electrons is chemically unstable: this is not correct, since elements with eight electrons in the valence shell cannot react because they already have the last complete shell. Therefore, they are chemically stable.

C. The points must be placed one at a time on each side of the chemical symbol: it is correct, because that is the way to make the point diagram.

D. An atom is chemically stable if all the points are paired: this is correct since this verifies that the point diagram has been done well.

We conclude that the correct answer is the option: B. An element with eight valence electrons is chemically unstable.

Hope this helps..... Stay safe and have a Merry Christmas!!!!!!!!! :D

7 0

3 years ago

"acid is responsible for the odor in rancid butter. a solution of 0.25 m butyric acid has a ph of 2.71. what is the ka for"

Salsk061 [2.6K]

Answer:- The Ka for the acid is $1.53*10^-^5$ .

Solution:- In general, monoprotic acid could be represented by HA. The dissociation equation for the ionization of HA is written as:

HA(aq)\rightarrow H^+(aq) + A^-(aq)

Now, we make the ice table for this equation as:

HA(aq)\rightarrow H^+(aq) + A^-(aq)

I 0.25 0 0

C -X +X +X

E (0.25 - X) X X

where, I stands for initial concentration, C stands for change in concentration and E stands for equilibrium concentration.

X is the change in concentration and from ice table it's same as the concentration of hydrogen ion that is calculated from given pH.

$Ka = [H^+][A^-]\frac{1}{HA}$

Where, Ka is the acid ionization constant. Let's plug in the values.

$Ka = \frac{X^2}{0.25-X}$

Let's calculate the value of X first using the equation:

$pH = -log[H^+]$ [/tex]

on taking antilog ob above equation we get:

$[H^+]=10^-^p^H$

$[H^+]=10^-^2^.^7^1$

$[H^+]$ = 0.00195

So, X = 0.001195

Let's plug in this value of X in the equation:-

$Ka=\frac{(0.00195)^2}{0.25-0.00195}$

$Ka=1.53*10^-^5$

So, the value of Ka for butyric acid is $1.53*10^-^5$ .

8 0

3 years ago

Read 2 more answers

Balancing Chemical Equation<br> C=H2=CH4

svlad2 [7]

Answer:

C + 2H2 ⇒ CH4

Explanation:

In order to balance a chemical equation you need to make sure that the number of atoms on both sides are equal

C + H2 = CH4

C = 1

H = 2

Products:

C = 1

H = 4

H2 = 2 × 2 = 4

C + 2H2 ⇒ CH4

Hope this helps.

4 0

3 years ago

What amount of sucrose (C12H22O11) should be added to 5.83 mol water to lower the vapor pressure of water at 50 °C to 72.0 torr?

Triss [41]

Answer:

The amount of sucrose that must be added is 1.66 moles

Explanation:

Colligative property of lowering vapor pressure has this formula:

Vapor pressure of pure solvent (P°) - Vapor pressure of solution = P° . Xm

We have both vapor pressure (pure solvent and solution9, so let's determine the ΔP

ΔP = 92.6 Torr - 72 Torr = 20.6 Torr

Let's add the data in the formula

20.6 Torr = 92.6 Torr . Xm

Xm = Mole fraction of solute → (mol of solute/ mol of solute + mol of solvent)

Mol of solvent = 5.83 mol (data from the problem)

Therefore Xm = 20.6 Torr / 92.6 Torr → 0.222

Let's find out the moles of solute (our unknown value)

0.22 = moles of solute / moles of solute + 5.83 moles of solvent

0.222 (moles of solute + 5.83 moles of solvent) = moles of solute

0.222 moles of solute + 1.29 moles of solvent = moles of solute

1.29 moles of solvent = moles of solute - 0.222 moles of solute

1.29 moles = 0.778 moles of solute

1.29 / 0.778 = moles of solute → 1.66 moles

3 0

3 years ago

Convert a density of 7.2 g/ml into the unit kg/L

aivan3 [116]

Unit conversion is a multi-step process, in which division or multiplication by a numeral factor is involved.

Density = $7.2 g/mL$ (given)

Since, $1 g = 0.001 kg$ and

$1 mL = 0.001 L$

Now, converting $7.2 g/mL$ to $kg/L$ :

$7.2 \frac{g}{mL}\times \frac{1 kg}{1000 g}\times \frac{1000 mL}{1 L}$

= $7.2 kg/L$ .

Hence, density is $7.2 kg/L$ .

6 0

3 years ago