why helium is duplet ??​

Answer:

-169°C to -104°C

Explanation:

Ethene, also known as ethylene exists in solid, liquid and gaseous states. Ethene is an aliens with condensed structural formula C2H4. Athens is a colourless gas. It is flammable and is also a sweet smelling gas in its pure form. It is the monomer in the production of polyethylene which is of great importance in the plastic industry. In agriculture, it is used to induce the ripening of fruits. It can be hydrated in order to produce ethanol.

The liquid range of ethene refers to the temperatures at which ethene is found in the liquid state of matter. It is actually the difference between the melting point and the boiling points of ethene. Hence the liquid range of ethene is -169°C to -104°C

Answer:

B - Poor crop production

Explanation:

I just did the quiz on Edge 2021

Answer:

b

Explanation:

Answer:

Explanation:

1) Chemical change :

It is permanent change.

Heat or energy is given out during the process

Physical change :

It is a temporary change.

Heat or energy in not given out during the process.

2) Condensation of water vapour is a physical change.

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Answer:

i. The difference between physical and chemical change is that a physical change merely changes the shape and size of the substance while a chemical change produces altogether new substance.

ii condensation of water vapour is a physical change

Explanation:

Answer:

You have 1680 grams of urea. It means (in it) there are 787 grams of nitrogen, 112 grams of hydrogen, 336 grams of carbon, and 448 grams of oxygen.

Explanation:

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:

Answer:

it is Ph of solution that tells you the acdic and basic nature of solution

if PH is lower than 7 the soution is acidic and if PH is larger than 7  the solution is basic

Explanation:

Answer:

A. Ph

Explanation:

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: When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The overall chemical reaction follows:

[tex]CaO(s)+CO_2\rightarrow CaCO_3(s)[/tex]     [tex]\Delta H^o_{rxn}=?[/tex]

The intermediate balanced chemical reaction are:

(1) [tex]Ca(s)+CO_2(g)+\frac{1}{2}O_2(g)\rightarrow CaCO_3(s)[/tex]    [tex]\Delta H_1=-812.8kJ[/tex]  

(2) [tex]2Ca(s)+O_2(g)\rightarrow 2CaO(s)[/tex]     [tex]\Delta H_2=-1269kJ[/tex]

The expression for enthalpy of the reaction follows:

[tex]\Delta H^o_{rxn}=[1\times (\Delta H_1)]+[\frac{1}{2}\times (-\Delta H_2)][/tex]

Hence, when the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.

Answer:

A. is halved and has its sign changed.

Explanation:

just took the test on edge

Answer:

B and BBr3

Explanation:

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

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

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.

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:

234.9 grams

Explanation:

Hope this helps

Answer:

210

Explanation:

according to vectors since they are in two different direction u minus them

F1 =10 F2=220

F1 has a forward direction

while f2 goes backward

Answer:

-210N

Explanation:

you say acting force minus opposing force 10N-220N= -210N

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.

To learn more about an ionic equation, refer to the below link:

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Answer: Water, alcohols, aldehydes, and ketones.

Explanation:

Answer:

Examples of Partially Miscible and Immiscible Liquids: Illustrations of immiscible liquids are cooking oil and water, milk and oil, gasoline and water, and liquid metals and water. There are as well partially miscible liquids such as honey and water, butanol and water, and potassium chloride and water.

Explanation:

Hope it helps

Answer:

114

Explanation:

bottom number minus top number. just did the test

Answer:

Fabric is made of cotton.

Explanation:

Hope that helps :)

Answer:

Hey mate your answer is

cotton

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Answer:

The entropy of this reaction (ΔS) = -187.9 J/K

Explanation:

.Step : Data given

ΔS = -187.9 J/K

ΔH = -198.4 kJ

T = 297.0 K

Step 2: The balanced equation

2SO2(g) + O2(g) → 2SO3(g)

Step 3: Calculate the entropy

ΔG = ΔH - TΔS

⇒ΔG = the gibbs free energy

⇒ΔH = the change in enthalpy of the reaction = -198.4 kJ

⇒with T = the temperature = 297.0 K

⇒with ΔS = the change of entropy =  -187.9 J/K

ΔG = -198400 kJ -297*(-187.9kJ/mol)

ΔG = -198400+55806.3

ΔG = - 142593.7 kJ = the gibbs free energy

The entropy of this reaction (ΔS) = -187.9 J/K

Answer:

C. -187.9 J/K

Explanation:

Entropy is just ΔS, which it gives you in the question as -187.9 J/K.

Answer:

64.9 L

Explanation:

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Answer:

acid rain

Explanation:

When sulfur dioxide combines with water and air, it forms sulfuric acid, which is the main component of acid rain. Acid rain can: cause deforestation.

Answer:

this is the answer

Explanation:

If someone tells Atomic mass of oxygen is 16, then it means that One the mass of an atom of a oxygen expressed in atomic mass units is 16 It is approximately equivalent to the number of protons and neutrons in the atom of oxygen (the mass number) or to the average number allowing for the relative abundances of different isotopes of oxygen.

Atomic mass Of oxygen is 15.99u or 15.99 amu.

And the mass no. Of oxygen is 16 because total no. Of protons and neutrons (in oxygen 16) is 16.

8 protons+ 8neutrons

So we can say that mass no. And atomic mass are different things.

Then, the atomic mass of oxygen is not 16 rather 15.99amu or 15.99u

Answer:

B

Explanation:

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

Answer:

112mL

Explanation:

We'll begin by calculating the number of mole in 0.640g of SO2.

This is illustrated below:

Molar mass of SO2 = 32 + (16x2) = 64g/mol

Mass of SO2 = 0.640g

Number of mole of SO2 =.?

Mole = mass /molar mass

Number of mole of SO2 = 0.640/64

Number of mole of SO2 = 0.01 mole

Next, we shall determine the number of mole of O2 required for the reaction. This is illustrated below:

2SO2(g) + O2(g) —> 2SO3(g)

From the balanced equation above,

2 moles of SO2 reacted with 1 mole of O2.

Therefore, 0.01 mole of SO2 will react with = (0.01 x 1)/2 = 0.005 mole of O2.

Therefore, 0.005 mole of O2 is required for the reaction.

Finally, we shall determine the volume of O2 required for the reaction as follow:

Note: 1 mole of a gas occupy 22.4L (22400mL) at stp.

1 mole of O2 occupy 22400mL at stp.

Therefore, 0.005 mole of O2 will occupy = 0.005 x 22400 = 112mL

Therefore, 112mL of O2 is required for the reaction.

Answer:

the answer is C

Explanation:

i did the test on edg and got it right

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.

To learn more about the solubility, follow the link;

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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.