_____ chemical reactions need a certain amount of activation energy to get started.
A: only exothermic
B: only endothermic
C: All
D: most

Explanation:

96.485 columbs=1 faraday will

deposit 64/2g= 32 g cu ion

therfore it will require

96,485 ×2/32 =? coulombs or 1/16 of

Faraday= 1 / 16 mole of electrons .

Answer: The phenomenon of osmosis can be seen in the surrounding as the when the raisins are put into water overnight. The water enters the raisins and it swells.

The osmosis can be defined as the biological phenomenon by which the water or any other liquid enters from an area of its higher concentration to an area of its lower concentration via semi permeable membrane.

Diffusion can take place in between gases and in between gases and liquid.

Exchange of gases in the lungs is an example of diffusion in liquids and burning an incense stick in the room is an example of diffusion in gases.

Answer:

234.9 grams

Explanation:

Hope this helps

Answer:

The outermost shell of helium for example is filled with only two electrons. Hydrogen and lithium become stable by acquiring the electronic configuration of the nearest inert gas, which is helium. This is the duplet (or duet) rule.

Explanation:

Answer:

B and BBr3

Explanation:

1) 3HBr + B = BBr3 + H2 (double all equation because H2)

2) 6HBr + 2B = 2BBr3 + 3H2

Answer:

The answer is 17.75%.

Explanation:

We are given [tex]NH_{3}[/tex] (ammonia) as a chemical formula. We want to find the percent composition of the formula.

We are given the atomic masses of each element: [tex]H = 1.008 amu[/tex] and [tex]N = 14.01 amu[/tex]. Then, we need to find out how many atoms are present of each element in the compound.

N has one atom (no subscript present). H has three atoms (subscript of 3 is present).

Now, we simply multiply the masses of each element by the number of atoms present of that element.

[tex]H = 1.008amu * 3atoms = 3.024amu[/tex]

[tex]N = 14.01amu * 1 atom = 14.01 amu[/tex]

Then, we add up those products to get the mass of the formula.

[tex]3.024amu + 14.01amu = 17.034amu[/tex]

Finally, we divide the masses of each element by the mass of the formula to get the percentages of each element present in the compounds.

For hydrogen:

[tex]\frac{3.024amu}{17.034 amu} =0.1775[/tex]

[tex]0.1775 * 100 = 17.75[/tex]

Hydrogen atoms account for 17.75% of the compound.

For nitrogen:

[tex]\frac{14.01amu}{17.034amu} = 0.8225[/tex]

[tex]0.8225 * 100 = 82.25[/tex]

Nitrogen atoms account for 82.25% of the compound.

For an extra step, add up the percentages to make sure you get within 100 ± 0.01. Otherwise, you may have rounded incorrectly or miscalculated somewhere within your work.

Hope this helps!

vice versa: atoms are elements, so elements are made of atoms specifically 1 atom or multiple of the same kind

Answer:

Na2SO3 + H2O2 = Na2SO4 + H2O

The ionic equation of hydrogen peroxide reacting with sodium sulphide is Na₂SO₃ + H₂O₂ = Na₂SO₄⁻ + H₂O⁺.

A chemical equation known as an ionic equation expresses the constituents in an aqueous solution as dissociated ions. The ionic equation is written by using charge in them.

An example is  "NaCl" is "Na⁺ + Cl⁻".

To write an ionic equation, we should write by dissolving all soluble ionic chemicals into their corresponding ions. To demonstrate that an ion is present in the solution, it should be displayed with its charge and an (aq).  There is also a use of coefficient.

The reaction should be written as:

HS₂O₄ → 2H+ + (SO₄)²⁻

NaOH → Na+ + (OH)-

Na₂SO₄ → 2Na+ + (SO₄)²⁻

H2O exists in the molecular form

So we get 2H+ + (SO₄)²⁻ + 2Na+ + 2(OH)- →2Na+ + (SO₄)²⁻ + 2H₂O

Thus, the ionic equation is Na₂SO₃ + H₂O₂ = Na₂SO₄ + H₂O.

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Answer:

A. 1s²2s²

B. 1s²

C. 1s²

D. 1s²2s²2p⁶

Explanation:

The valency electron is the outer electron of an element. The valency electron resides in the outermost region of the shell.

Using the general configuration for the first 20 elements 2 8 8 2 the valency electrons can be identified.

A. 1s²2s²2p⁶3s² . The valency electron here are 2p⁶ and 3s² . Removing the valency electron we have 1s²2s²

B. 1s² 2s² 2p⁶. After removing the valency electron the configuration will be 1s².

C.1s²2s². After removing the valency electron the configuration will be 1s²

D.1s²2s²2p⁶3s¹. Removing the valency electron the electron configuration will be 1s²2s²2p⁶

Answer:

B

Explanation:

Option be is the only molecular structure with 4 carbon molecules and 10 hydrogen molecules

Answer:

higher temperatures increase the speed of solubility

Explanation:

This is because if the temperature of liquid is high and you place a solute inside it dissolves faster than a low temperature

Higher temperature increases the speed of solubility affect the speed with which the solute dissolves. Therefore, option A is correct.

The term solubility is defined as the maximum amount of a substance that will dissolve in a given amount of solvent at a specific temperature.

Based on the concentration of solute dissolves in a solvent, solutes are divided into highly Soluble, sparingly Soluble or insoluble substance.

When a solvent is heated, the molecules gain kinetic energy. Because of the increased rapid motion, the solvent molecules collide with the solute more frequently and with greater force. Both factors accelerate the solute's dissolution.

This is because if the temperature of the liquid is high and a solute is placed inside, the solute dissolves faster than if the temperature is low.

Thus, option A is correct.

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Answer:

Hydrogen bonding

Explanation:

Hydrogen bonding is the intermolecular force that would affect melting point the most. Therefore, the correct option is option B.

The electro - magnetic forces of attraction but rather repulsion that act between atoms or other types of nearby particles are examples of intermolecular forces, which mediate interaction between molecules. When compared to intramolecular forces, which include covalent bonds and other forces that hold molecules together, these forces are weaker.

The intermolecular force, which depends on the kinetic energy between atoms as well as the tiny electrically charged positive and negative charges on various sections of a molecule, is the total of all the forces connecting two nearby molecules. Hydrogen bonding is the intermolecular force that would affect melting point the most.

Therefore, the correct option is option B.

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Answer:

64.9 L

Explanation:

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Monomers and polymers

Most large biological molecules are polymers, long chains made up of repeating molecular subunits, or building blocks, called monomers.

The long chains formed by the process of polymerization are called monomers.

In biological macromolecules, polymerization is the chemical process through which relatively tiny and smaller molecules, known as monomers, unite to form a very big chainlike or network of molecules known as a polymer.  

These monomers undergo reactions with one another to form larger molecules known as polymers. The types of monomers in biological macromolecules include:

Each of these individual monomers is critical to the survival and evolution of life.

Therefore, we can conclude that the long chains formed by the process of polymerization are called monomers.

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Answer:

a. 0.02 moles  of NH₃, 0 moles of O₂, 0.08 moles of NO, 0.12 moles of H₂O

b. [tex]P_{NH_3}[/tex] = 12,576.5 Pa, [tex]P_{NO}[/tex] = 50,306.05 Pa, [tex]P_{H_2O}[/tex] =  74,459.1 Pa

c. The total pressure is 138,341.64 Pa

Explanation:

a. NH₃ + O₂  → NO + H₂O

The balanced chemical equation is first found to be

4NH₃ + 5O₂  → 4NO + 6H₂O

Therefore, we have;

4 moles of NH₃ reacts with 5 moles of O₂ to form 4 moles of NO and 6 moles H₂O

Dividing by the reactant with the highest number of moles which is 5 moles of oxygen gives;

4/5 moles  of NH₃ reacts with 5/5 moles of O₂ to form 4/5 moles of NO and 6/5 moles H₂O

Which is the same as 4/5 moles  of NH₃ reacts with 1 mole of O₂ to form 4/5 moles of NO and 6/5 moles H₂O

Multiplying by 0.100 gives;

0.1×4/5 moles  of NH₃ reacts with 0.1 mole of O₂ to form 0.1×4/5 moles of NO and 0.1×6/5 moles H₂O

The quantity of each gas in the container upon completion of the reaction is therefore;

(0.1 - 0.1×4/5) = 0.02 moles  of NH₃

0 moles of O₂

0.08 moles of NO

0.12 moles H₂O

b. Given that the temperature = 105°C, we have;

PV = nRT

P = nRT/V

Where:

n = Total number of moles = 0.02 + 0.08 + 0.12 = 0.22 moles

R = Universal gas constant = 8.3145 J/(mol·K)

T = Temperature = 105°C = 378.15 K

V = Volume = 5 litre = 0.005 m³

P = 0.22×8.3145×378.15/0.005 = 138,341.64 Pa

From Dalton's law of partial pressure, we have;

Partial pressure Pₓ = Xₓ × P

Where:

Xₓ = Mole fraction

Which gives for ammonia NH₃ with 0.02 moles;

Mole fraction = 0.02/0.22 = 1/11

[tex]P_{NH_3}[/tex] = 1/11 × 138,341.64  = 12,576.5 Pa

For the 0.08 moles of NO, we have

Mole fraction = 0.08/0.22 = 4/11

[tex]P_{NO}[/tex] = 4/11 × 138,341.64  = 50,306.05 Pa

For the 0.12 moles H₂O

P = 0.12×8.3145×378.15/0.005 = 74,459.1 Pa

Mole fraction = 0.12/0.22 = 6/11

[tex]P_{H_2O}[/tex] = 6/11 × 138,341.64  = 74,459.1 Pa

c. The total pressure = 12,576.5 Pa + 50,306.05 Pa + 74,459.1 Pa = 138,341.64 Pa.

Answer:

Vibration.

Explanation:

Answer:

vibration best describes it

Explanation:

Answer:

3,5-dimethyl-2-octene

Explanation:

The parent chain will be choosen based on the highest value. In this case, if we count from top to bottom, we'll get seven carbon, however if we count from the second carbon, going left and then down, we'll get eight carbon. So the parent chain is octene

The double bond is located at the second carbon and the methyl groups are located on carbon 3 & 5. Since there are two methyl groups, we add di- in front of methyl to indicate two methyl groups present.

Note: The functional group has to be prioritise and it needed to be a part of the parent chain. In this case, the functional group is the double bond. (alkene)

Answer:

0.54 J/goC

Explanation:

Recall that we define the heat transferred as ;

H= mcθ

Where;

H= heat transferred = 112300J

m= mass of the metal= 240g or 0.24 Kg

c= specific heat capacity of the metal = the unknown

θ= change in temperature = (880°C-13°C) = 867°C

Substituting values and making the specific heat capacity the subject of the formula;

c= H/mθ

c= 112300/ 240×867

c= 0.54 J/goC

Hence, the specific heat capacity of the metal is 0.54 J/goC.

Answer:

Troposphere

Explanation:

The troposphere is the lowest layer in the atmosphere, and where all the weather occurs. After the troposphere, there's the stratosphere, mesosphere, thermosphere, and exosphere.

I hope this helps!

Answer:

Troposphere is the lowest layer of the earths atmosphere.

Explanation:

Answer:

The different objects that make up a circuit are called components. A circuit must have a power source, such as a battery, and the current flows through a conductor, such as a wire.

Explanation:

I hope that was useful.

Answer: The total pressure of the mixture is 2.76 atm

Explanation:

According to Dalton's law, the total pressure is the sum of individual pressures.

[tex]p_{total}=p_A+p_B+p_C...[/tex]

Given : [tex]p_{total}[/tex] =total pressure of gases = ?

[tex]p_{O_2}[/tex] = partial pressure of oxygen = 0.00461 atm

[tex]p_{N_2}[/tex] = partial pressure of nitrogen = 1.78 atm

[tex]p_{Ar}[/tex] = partial pressure of argon = 0.975 atm

putting in the values we get:

[tex]p_{total}=0.00461atm+1.78atm+0.975atm[/tex]

[tex]p_{total}=2.76atm[/tex]

Thus the total pressure of the mixture is 2.76 atm

Answer:

10⁻³⁶ s

Explanation:

There is much speculation, but many scientists believe the universe started expanding about 10⁻³⁶ s  after the Big Bang.

Answer:

Oxygen Doesn't change

However, Li is oxidized (0 to +1), Na is reduced (+1 to 0)

Explanation:

On reactant side, Oxygen has -2 oxidation charge because we know common oxidation states such as oxygen -2, hydrogen +1 etc.

So NaOH, O is -2, H is +1, so Na has to be +1 to equal total charge of compound

In product side, LiOH, again O has to be -2, H is +1, so Li +1 as well..

We see that oxygen oxidation state doesn't change. However, for Li it becomes oxidized going from 0 to +1 whereas, Na is reduced going from +1 to 0.

Answer:

114

Explanation:

bottom number minus top number. just did the test

Answer:

1x10^-8 M

Explanation:

Since the solution turns blue, it mean the solution is a base.

Now, to know which option is correct, we need to determine the pH of each solution. This is illustrated below:

1. Concentration of Hydrogen ion, [H+] = 1x10^-2 M

pH =..?

pH = - log [H+]

pH = - log 1x10^-2

pH = 2

2. Concentration of Hydrogen ion, [H+] = 5x10-2 M

pH =..?

pH = - log [H+]

pH = - log 5x10^-2

pH = 1.3

3. Concentration of Hydrogen ion, [H+] = 5x10 M

pH =..?

pH = - log [H+]

pH = - log 5x10

pH = - 1.7

4. Concentration of Hydrogen ion, [H+] = 1x10-8 M

pH =..?

pH = - log [H+]

pH = - log 1x10^-8

pH = 8

A pH reading shows if the solution is acidic or basic. A pH reading between 0 and 6 indicates an acidic solution, a pH reading of 7 indicates a neutral solution while a pH reading between 8 and 14 indicates a basic solution.

From the above calculations, the pH reading indicates a basic solution when the hydrogen ion concentration was 1x10^-8 M.

Answer:

this option is the correct they move to an area with lower oxygen concentration because gas molecules can pass through semi-permeable and do not need transport proteins for the movement

Explanation:

i hope this will help you

can confirm that

They move to an area with a lower oxygen concentration

if the correct answer :)))

Explanation:

ape-x

Answer:

They are all alkali earth metals.

Explanation:

Their valence shell each has 2 electrons. Also, they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. They form alkaline solutions, hydroxides, when reacting with water and their oxides are found in the earth’s crust.

Answer:

magnesium (Mg)

Explanation: