True or false this model represents an ion

Answer:

C. mg and Ca

Explanation:

These chemical elements are collectively called as the Alkaline Earth Metals. Calcium and Magnesium are two of the six elements that fall into this category. The outer electronic structure of all these elements is similar due to which they all have similarity in their chemical and physical properties. They are all shiny, though fairly soft but still harder than alkali metals. Further, these are usually white or silvery coloured elements.They react with water to form hydrogen gas and metal hydroxide and with oxygen, they form oxides.

Answer:

L× W×H

Answer:

The correct answer is L x W x H :)

Answer:

THe sun evapored the water and the wind helped dry it to.

Explanation:

Answer:

The answer is B(scale)

Explanation:

Since the question asked about a range, the scale would be the most logical answer since scales are used to measure.

Answer:

the answer is C.

Explanation:

Answer:

Explanation:

A solution with a pH value of 7 is neutral i.e neither acidic nor alkaline. A solution with a pH less than 7 is said to be acidic, while one with a pH value more than 7 is alkaline. Acidity increases as the value decrease below 7, while alkalinity increases as the value increase about 7.

Given that H2A is a diprotic weak acid have pKa values of 5.0 ad 9.0, it will undergo dissociation in the solution as:

NOTE: These reactions are reversible reactions.

[tex]\mathbf{H_2A \to H^+ + HA^- \ \ \ pKa = 5.0}[/tex]

[tex]\mathbf{HA^- \to H^+ +A^{2-} \ \ \ pKa = 9.0}[/tex]

Thus;

The primary species is HA⁻

The secondary species is A²⁻

Answer:

The actual concentration of the hydrochloric acid is 1.2M

Explanation:

The formula to be used here is that of concentration (popularly used during titration);

CₐVₐ/CbVb =nₐ/nb

where Cₐ is the concentration of acid (supposed to be 1.0 M but unsure)

Vₐ is the volume of acid (100 ml)

Cb is the concentration of base (1.3 M)

Vb is the volume of base (89.13 ml)

nₐ is the volume of acid

nb is the volume of base

The equation for the reaction described in the question is

HCl + NaOH ⇒ NaCl + H₂O

we can see from the above equation the ratio of the number of moles for both the acid and the base is 1:1

Thus;

Cₐ × 100/1.3 × 89.13 =1/1

Cₐ = 1.3 × 89.13/100

Cₐ = 1.2M

The actual concentration of the hydrochloric acid is 1.2M

Answer:

✔️Ionic bonds form between metal atoms and nonmetal atoms.

✔️The less electronegative atoms transfers one or more electrons to the more electronegative atom

✔️The metal atom forms a cation and the nonmetal atom forms an anion.

✔️The attraction between ions with an opposite charge forms an ionic bond.

Explanation:

Ionic bond refers to the bond formation which occurs when there is complete and permanent transfer of electrons from one metal atom to another non-metal atom. The metals, which are electropositive (less electronegative) loose their electrons while the non-metals, which are less electropositive (more electronegative) gain the electrons.

When the metal atom looses electrons, they form cations(become positively charged) while non-metal atom forms anions (become negatively charged). When the opposite charges attract each other, they form ionic bond.

Answer:

✔️ Ionic bonds form between metal atoms and nonmetal atoms.

✔️ The less electronegative atoms transfers one or more electrons to the more electronegative atom.

✔️ The metal atom forms a cation and the nonmetal atom forms an anion.

✔️ The attraction between ions with an opposite charge forms an ionic bond.

Answer:

Theories

Explanation:

It is theories because it was a generalistee abstract or thinking generalising the principle of fact about Earth tectonic plates ,it was formulated and concluded as plate tectonic theories after many findings. The theories conclude that the Earth has an outer layer called lithosphere and lies overly a plastic layer called asthenosphere. The lithosphere is divided into several plates and they move close to each other where they diverge, converge or slip over one another.

Answer:

The ball's kinetic energy is transforming to potential energy.

Explanation:

the ball is stopping resulting in potential energy

Answer:

See explanation

Explanation:

Coal is primarily used for electricity generation. The burning of coal leads to emission of gases such as oxides of carbon, oxides of sulphur, oxides of nitrogen and water vapour. All these go straight into the atmosphere.

Petroleum is primarily used as transportation fuels. The burning of petroleum oils mostly leads to the emission of oxides of carbon and sulphur together with water vapour into the atmosphere.

Answer:

Will be more acidic

Explanation:

The equilibrium of NH3 in water is:

NH3(aq) + H2O(l) ⇄ NH4⁺(aq) + OH⁻(aq).

Where equilibrium constant, Kb, is:

Kb = 1.85x10⁻⁵ = [NH4⁺] [OH⁻] / [NH3]

From 0.10M NH3, the reaction will produce X of NH4⁺ and X of OH⁻ and Kb will be:

1.85x10⁻⁵ = [X] [X] / [0.10M]

1.8x10⁻⁶ = X²

X = 1.34x10⁻³ = [OH⁻]

As pOH = -log[OH⁻] = 2.87

And as pH = 14 - pOH

pH of the 0.10M NH3 is 11.13

Now, to find the pH of the NH4Cl and NH3 we need to use H-H equation for bases:

pOH = pKb + log [NH4⁺] / [NH3]

Where pKb is -log Kb = 4.74 and [] are moles of both compounds.

Moles of [NH4⁺] = [NH3] = 60mL, 0.060L*0.22M = 0.0132moles:

pOH = 4.74 + log [0.0132] / [0.0132]

pOH = 4.74

pH = 14 - 4.74 = 9.26

That means the pH of the resulting solution will be more acidic

Answer:

C

Explanation:

It will be the same. That's what moving down a column means. The properties are going to be quite similar.

Answer:

[tex]p_2=5.17torr[/tex]

Explanation:

Hello.

In this case, by using the Clausius-Clapeyron Equation which allows us to relate the vapor pressure, temperature and heat of vaporization as shown below:

[tex]ln(\frac{p_1}{p_2} )=\frac{\Delta _vH}{R}(\frac{1}{T_2}-\frac{1}{T_1} )[/tex]

Whereas [tex]p_1[/tex] is 760 torr due to the normal conditions. In such a way, for computing the vapor pressure of benzaldehyde at 53.5 °C (326.65 K), we proceed as shown below:

[tex]\frac{p_1}{p_2} =exp[\frac{48800J/mol}{8.314\frac{J}{mol*K}}(\frac{1}{326.65K}-\frac{1}{451.0K} )]\\\\\frac{p_1}{p_2}=147.0[/tex]

Thus, the vapor pressure at the final T is:

[tex]p_2=\frac{p_1}{147.0}=\frac{760torr}{147.0}\\ \\p_2=5.17torr[/tex]

Best regards!

Answer:

a) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = pKa?

Step 1: Data given

Volume of HC2H3O2 = 1.0 L

Molarity of HC2H3O2 = 1.8 M

Ka = 1.8*10^-5

ph = pK = -log(1.8*10^-5) = 4.74

Step 2:

Use the Henderson-Hasselbalch equation.

pH = pKa + log(A-/HA)

4.74 = 4.74 + log(A-/HA)

0 =  log(A-/HA)

A-/HA = 1

Consider X = moles of NaOH added (and moles of A- formed)

Remaining moles of HA = 1.8 - X

moles of A- = X

HA = 1.8 - X

X/(1.8-X) = 1

X =0.9

We have to add 0.9 mole NaOH to 1.0 L of 1.8 M HC2H3O2

To control we can do the following equation:

4.74 = 4.74 + log(0.9/0.9) = 4.74

b) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = 4.00?

Step 1: Data given

Volume of HC2H3O2 = 1.0 L

Molarity of HC2H3O2 = 1.8 M

Ka = 1.8*10^-5

ph = 4

Step 2:

Use the Henderson-Hasselbalch equation.

pH = pKa + log(A-/HA)

4 = 4.74 + log(A-/HA)

-0.74 =  log(A-/HA)

A-/HA = 0.182

Consider X = moles of NaOH added (and moles of A- formed)

Remaining moles of HA = 1.8 - X

moles of A- = X

HA = 1.8 - X

X/(1.8-X) = 0.182

X =0.277

We have to add 0.277 mole NaOH to 1.0 L of 1.8 M HC2H3O2

To control we can do the following equation:

4 = 4.74 + log(0.277/1.523)

c) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = 5.00

Step 1: Data given

Volume of HC2H3O2 = 1.0 L

Molarity of HC2H3O2 = 1.8 M

Ka = 1.8*10^-5

ph = 5

Step 2:

Use the Henderson-Hasselbalch equation.

pH = pKa + log(A-/HA)

5 = 4.74 + log(A-/HA)

0.26 =  log(A-/HA)

A-/HA = 1.82

Consider X = moles of NaOH added (and moles of A- formed)

Remaining moles of HA = 1.8 - X

moles of A- = X

HA = 1.8 - X

X/(1.8-X) = 1.82

X =1.16

We have to add 1.16 mole NaOH to 1.0 L of 1.8 M HC2H3O2

To control we can do the following equation:

5 = 4.74 + log(1.16/0.64) = 5

Explanation:

Answer:

23 * 10^ 9 atoms of oxygen

Explanation:

From the molecular formula of dinitrogen tetraoxide;

molar mass of dinitrogen tetraoxide = 92 g/mol

hence;

92 g of dinitrogen tetraoxide contains 4 atoms of oxygen

x g of dinitrogen tetraoxide will contain 1 * 10^ 9 atoms of oxygen

x = 92 * 1 * 10^ 9/4

x =23 * 10^ 9 atoms of oxygen

Answer:

d) The rate of forward reaction equals the rate of the reverse reaction

Explanation:

A dynamic equilibrium is attained when the rate of forward reaction is the same as reverse reaction. It occurs majorly in a reversible reaction. Thus, no change occurs in the reaction.

The process can be control by the immediate removal of the product as it is formed. This ensure that the reaction stops when all reactants are used up.

Answer:

c. 3

Explanation:

Dicholorination of tertiary alkane ( i.e. isobutane) is a halogenation reaction which makes it possible to replace the alkyl functional group with halogenated chlorine.

When Isobutane is subjected to free radicals chlorination, three distinct dichlorination can be formed.

The mechanism of the formation of these products can be seen in the image attached below.

Answer:

O The sound waves are reflected.

Explanation:

When sound waves released by a bat hits an object, the sound waves are reflected back.

Bats used sound reflection for echolocation to determine the position of nearby objects.

Also, they use it to determine the shape and size of objects.

Answer:

B

The sound waves are reflected.

Explanation:

Explanation:

My physiological make-up that governs the attributes I have and my climate, i.e. the conditions I have, are the variables influencing my limits. Biological make-up also regulates my prospects when they depend on my attributes, i.e. my ability and my environment , i.e. the conditions under which I am. This has been shown by experiments on twins, that our limits and opportunities are controlled by both genetics and environment.

Answer:

Object B has a density of 2.5 g/cm³ which is greater than object A by 1 g/cm³

Explanation:

Since we know that the formula for density is d=m/v, we can divide each mass by its corresponding volume to find the densities

12/8=1.5

20/8=2.5

So we know that object B has a greater density than object A by 1 g/cm³ (gram per cubic centimeter). Also the standard unit for density is kilograms per cubic meter but I used gram per cubic centimeter since they were the given units. 1cm=100m, 1000g=1km

Answer:

D

Explanation:

Answer:

D

Explanation:

So. Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else.... When the heat waves hits the cooler thing, they make the molecules of the cooler object speed up.

Answer:

See explanation

Explanation:

Friedel-Crafts alkylation frequently undergo polysubstitution because the process  leads to the addition of an electron donating alkyl group, which activates the benzene ring to further alkylation. The acyl group rather deactivates the ring towards electrophilic substitution.

When benzene is reacted with t-butyl chloride, the chief disubstituted product is the para rather than ortho isomer because the increased bulk of the tert-butyl group hinders attack at the ortho-sites.

Answer:

mixture

Explanation:

Kool-Aid  is a mixture of sugar, water, dye, and flavoring.

Answer:

74.3kJ are transeferred

Explanation:

In the bomb calorimeter, the burning of C₈H₁₈ is producing heat that is been absorbed for the calorimeter and the water.

Heat absorbed calorimeter:

837J/°C * (33.8°C-15.0°C) = 15735.6J

Heat absorbed water:

C*m*ΔT

C specific heat of water (4.184J/g°C), m is mass of water (745g), and ΔT change in temperature (33.8°C - 15°C = 18.8°C)

4.184J/g°C*745g*18.8°C = 58601.1J

Heat released by the reaction:

15735.6J + 58601.1J = 74336.7J

Answer:

A high-pressure area, high, or anticyclone, is a region where the atmospheric pressure at the surface of the planet is greater than its surrounding environment. Winds within high-pressure areas flow outward from the higher pressure areas near their centers towards the lower pressure areas further from their centers.

Explanation:

Answer: It’s D

Explanation:

Cuz I said so

Answer: d. Shearing

Explanation:

Answer:

- 0.454 °C

Explanation:

From the given information:

The mass of KCl = 10 grams

The molar mass of KCl = 74.55 g/mol

The molality can be calculated as:

[tex]Molality \ m = \dfrac{mass \ of \ KCl \times 1000}{molar \ mass \ of \ KCl \times 1100.0}[/tex]

[tex]Molality \ m = \dfrac{10 \ g \times 1000}{74.55 \ g/mol \times 1100.0}[/tex]

Molality m = 0.1219 M

For freezing point depression;

[tex]\Delta T_R = i \times k_f \times m[/tex]

The van't Hoff's Factor (i) for KCl  = 2

The molar depression of freezing point constant [tex]k_f[/tex] = 1.86° C/m

∴

[tex]\Delta T_R = 2 \times 1.86 \times 0.1219[/tex]

[tex]\mathbf{\Delta T_R = 0.454^0\ C }[/tex]

However, the freezing point of water is known to be = 0°C

Therefore, the freezing point of the solution

= 0 °C - 0.454 °C

= - 0.454 °C

Answer:

Explanation:

From the given information:

The equation for the reaction can be represented as:

[tex]2SO_2 + O_2 \to 2SO_3[/tex]

The I.C.E table can be represented as:

                     2SO₂              O₂                   2SO₃

Initial:             14                  2.6                     0

Change:        -2x                -x                      +2x

Equilibrium:   14 - 2x          2.6 - x                2x

However, Since the amount of sulfur trioxide gas to be 1.6 mol.

SO₃ = 2x,

then x = 1.6/2

x = 0.8 mol

For 2SO₂; we have 14 - 2x

= 14 - 2(0.8)

= 14 - 1.6

= 12.4 mol

For O₂; we have 2.6 - x

= 2.6 - 1.6

= 1.0 mol

Thus;

[SO₂] = moles / volume = ( 12.4/50) = 0.248 M ,

[O₂] = 1/50 = 0.02 M ,  

[SO₃] = 1.6/50 = 0.032 M

Kc = [SO₃]² / [SO₂]² [O₂]

= ( 0.032²) / ( 0.248² x 0.02)

= 0.8325

Recall that; the equilibrium constant for the reaction [tex]2SO_2 + O_2 \to 2SO_3[/tex] = 0.8325;

If we want to find:

[tex]SO_2 + \dfrac{1}{2}O_2 \to SO_3[/tex]

Then:

[tex]K_c = (0.8325)^{1/2}[/tex]

[tex]\mathbf{K_c = 0.912}[/tex]

Since no temperature is given to use in the question, it will be impossible to find the final temperature of the mixture.