How many moles are in 25.0 mL of C2H6O? The density of C2H6O is 0.785 h/mL.
Hint: use formula: mass = density x volume. )

Answer:

3) 2000 times the mass of an electron and a unit positive charge

Explanation:

The  proton is approximately 2000 times massive than electron.

Neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.

Symbol of proton= P+  

Symbol of neutron= n0  

Mass of proton=1.672623×10-27 Kg

Mass of neutron=1.674929×10-27 Kg

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.

Symbol= e-

Mass= 9.10938356×10-31 Kg

It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.

15.0 g

We are given;

We are required to calculate the remaining mass after three half lives

N = N₀ × 0.5^n

where, N is the remaining mass, N₀ is the original mass and n is the number of half lives.

Therefore;

N = 120.0 g × 0.5^3

  = 15.0 g

Thus, the remaining mass of Thallium-208 is 15.0 g

Alternatively;

120.0 g → 60.0 g (120 × 0.5) → 30.0 g (60 × 0.5) → 15.0 g (30 × 0.5)

For the Thallium-208 sample, after each half-life, the amount of the substance was reduced by half. After three half-lives, 15.0 g of the original 120.0g sample will remain.

In the concept of radioactive decay, each half-life is the period of time it takes for half of a substance to decay. We can determine how much of a radioactive isotope is left after a certain number of half-lives, such as the time span of three half-lives in this case, by reducing the original amount by half for each half-life period.

Let's apply this principle to your question. You start with a 120.0 g sample of Thallium-208. After the first half-life, half of the sample will have decayed, leaving 60.0 g. After the second half-life another 50% decays, leaving 30.0 g. Lastly, after the third half-life, the amount remaining is halved again, hence we have 15.0 g of Thallium-208 remaining.

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Answer:

Explanation:

Given data:

1) How many particles of water are there in 14 moles?

Answer:

84.308 × 10²³ particles

Explanation:

Given data:

Number of moles = 14 mol

Number of particles = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

One moles = 6.022 × 10²³ particles

14 mol × 6.022 × 10²³ particles / 1 mol

84.308 × 10²³ particles

2) How many moles of forks do you have if there are 1.4 x 1027 forks?

Answer:

0.23 × 10⁴ moles

Explanation:

Given data:

Moles of fork = ?

Number of moles of fork = 1.4 x 10²⁷forks

Solution:

one mole = 6.022 × 10²³ fork

1.4 x 10²⁷forks × 1 mol / 6.022 × 10²³ fork

0.23 × 10⁴ moles

3) How many molecules are in 23 moles of oxygen?

Answer:

138.506 × 10²³ molecules

Explanation:

Given data:

Number of moles = 23 moles

Number of molecules = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

one mole = 6.022 × 10²³ molecules

23 mol × 6.022 × 10²³ molecules / 1 mol

138.506 × 10²³ molecules

4) How many atoms in 3.00 moles of water?

Answer:

18.066 × 10²³ atoms

Explanation:

Given data:

Number of moles = 3.00 moles

Number of atoms = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

one mole of water = 6.022 × 10²³ atoms of water

3 mol × 6.022 × 10²³ atoms / 1 mol

18.066 × 10²³ atoms

5) How many molecules of methane do you have in 0.99 moles of methane?​

Answer:

6 × 10²³ molecules

Explanation:

Given data:

Number of moles of methane  = 0.99 moles

Number of molecules = ?

Solution

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

one mole of methane = 6.022 × 10²³molecules of methane

0.99 mol × 6.022 × 10²³  molecules / 1 mol

6 × 10²³ molecules

Answer:

See every answer with its explanation below

Explanation:

1. Write the molecular equation

         ↑                       ↑                               ↑                                   ↑

     solid nickel     aqueous nitric        aqueous nickel(III)     hydrogen gas

                             acid                         nitrate

2. Balance the molecular equation:

3. Type of reaction

This is a replacement reaction because the nickle is taking the place of hydrogen in the nitric acid and the hydrogen is released. It is also a redox reaction because nickel is being oxidized and hydrogen is being reduced.

The balanced half-reactions are:

         2Ni⁰ → 2Ni³⁺ + 2×(3e⁻)    

         Each nickle atom loses 3 electrons increasing its oxidation state from 0 to +3.

         6H⁺ + 6e⁻ → 3H₂⁰

         Each H⁺ gains 1 electron reducing its oxidation state from +1 to 0.

Answer:

C

Explanation:

acids are corrosive since they tend to destroy every single thing they do get a big example is the acidic rain which tends to corrode iron sheet thus making them to appear worn out and full of rust

Answer:

It's C.

Explanation:

c:  eat away at other materials.

Answer:

The phenomenon of marble cancer is due to (d) acid rain.

Explanation:

The marble cancer is the corrosion of the buildings and statues made up of marble due to the action of sulphuric acid and nitric acid.

[tex]SO_{2}[/tex] and [tex]NO_{x}[/tex] are produced due to pollution.

When these oxides mix with the rain drops in the cloud, they form sulphuric acid and nitric acid. When these acids come in contact with the marble, they cause corrosion.

Hence, acid rain causes the phenomenon of marble cancer.

Answer:

Mass = 595  × 10⁻⁸ g

Explanation:

Given data:

Number of atoms of uranium = 15.0 × 10¹⁵ atoms

Mass of uranium = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

1 mole of uranium = 6.022 × 10²³  atoms of uranium

1 mole × 15.0 × 10¹⁵ atoms / 6.022 × 10²³  atoms of uranium

2.5  × 10⁻⁸ moles

Mass of uranium:

Mass = number of moles ×  molar mass

Mass = 2.5  × 10⁻⁸ moles  × 238 g/mol

Mass = 595  × 10⁻⁸ g

Answer:

5.54 × 10¹⁷ atoms

Explanation:

Given data:

Mass of sand = 55.2 μg (55.2 ×10⁻⁶ g)

Molar mass of sand = 60 g/mol

Number of atoms = ?

Solution:

Number of moles = mass/ molar mass

Number of moles = 55.2 ×10⁻⁶ g / 60 g/mol

Number of moles = 0.92 × 10⁻⁶ mol

Number of atoms:

one mole = 6.022 × 10²³ atoms

0.92 × 10⁻⁶ mol ×  6.022 × 10²³ atoms / 1mol

5.54 × 10¹⁷ atoms

Answer:

0.241  × 10³⁰ molecules

Explanation:

Given data:

Mass of Cr(HCO₃)₃ = 9.273 × 10⁷ g

Number of molecules = ?

Solution:

Number of moles = 9.273 × 10⁷ g/ 235 g/mol

Number of moles = 0.04× 10⁷  mol

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For 0.04× 10⁷  moles of Cr(HCO₃)₃:

0.04× 10⁷  moles × 6.022 × 10²³ molecules / 1 mol

0.241  × 10³⁰ molecules

Answer:

chlorine (Cl), bromine (Br), fluorine (F)

Explanation:

as of writing this explanation, pokimane has been banned on twitch

Answer:

8.86 g

Explanation:

Molar mass gold = 196.97 g/mol

196.97 g/mol * 0.0450  mol ≈ 8.86 g

The mass of gold that participated in the chemical reaction is 8.86 g.

Molar mass gold = 196.97 g/mol

196.97 g/mol * 0.0450  mol ≈ 8.86 g

A chemical reaction occurs when one or more chemicals are converted to one or more other chemicals. Example: Iron and oxygen combine to form rust. Vinegar and baking soda combine to form sodium acetate, carbon dioxide, and water.

A chemical reaction is a process in which one or more substances are present. H. Convert the reactants to one or more other substances d. H. The products are converted to each other to form new substances with properties different from the molecules of the reactants. This is called the product.

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Answer:

C) nonmetal

Explanation:

Given;

The sample is in liquid state and do not conduct electricity.

We have given four types of classification.So for first,

A) Ionic

Ionic compounds are found in solid state at room temperature and it conducts electricity when dissolved in water. Hence the sample could not be ionic.

B)Metal

Metals are found in solid state at room temperature  except mercury and it conducts electricity very well. Mercury also conducts electricity.So the sample is not a metal.

C)Nonmetal

Non metals are found in solid state  except bromine which is in liquid state  at room temperature and it does not conducts electricity.

Here the property of nonmetal matches with the sample, so the sample is a nonmetal and it could be Bromine.

D)Salt

Salt is an ionic compound  found in solid state at room temperature and it conducts electricity when dissolved in water. Hence the sample could not be salt.

Answer:

C for k12

Explanation:

Answer:

Zn(s) → Zn⁺²(aq) + 2e⁻

Explanation:

Let us consider the complete redox reaction:

Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)

This is a redox reaction because, both oxidation and reduction is simultaneously taking place.

Here Zn(s) is undergoing oxidation from OS 0 to +2

And H in HCl (aq) is undergoing reduction from OS +1 to 0.

Therefore, for this reaction;

Oxidation Half equation is:

Zn(s) → Zn⁺²(aq) + 2e⁻

Reduction Half equation is:

2H⁺ + 2e⁻ → H₂(g)

Final answer:

The correct oxidation half-reaction for the reaction of zinc with hydrochloric acid is Zn(s) → [tex]Zn^2^+(aq) + 2e^-[/tex] Zinc is oxidized by losing two electrons to form zinc ions.

Explanation:

The oxidation half-reaction in the chemical reaction involving zinc and hydrochloric acid is represented by the equation:

Zn(s) → [tex]Zn^2^+(aq) + 2e^-[/tex]

This equation indicates that zinc metal (Zn) is losing two electrons, thus being oxidized to zinc ions ([tex]Zn^2^+[/tex]), which go into solution. The loss of electrons is shown by the electrons being products in this half-reaction. The correct choice for the oxidation half-reaction in the provided list is Zn(s) → [tex]Zn^2^+(aq) + 2e^-[/tex].

The enthalpy change for the given reaction is -62.1 kJ. By applying Hess's Law, we can calculate the enthalpy of formation (ΔH°f) for HCl(g). Using the given enthalpy values, we find that ΔH°f for HCl(g) is -62 kJ/mol.

The reaction given is:

SO2Cl2(g) + 2 H2O(ℓ) → H2SO4(ℓ) + 2 HCl(g)

We know that the enthalpy change, ΔH°, for the reaction is -62.1 kJ. We can use the given enthalpy of formation (ΔH°f) values to calculate the enthalpy of formation of HCl(g).

By applying the Hess's Law, we can determine the enthalpy changes based on the given data.

ΔH°f HCl(g) = ΔH°f SO2Cl2(g) + ΔH°f H2SO4(ℓ) - 2ΔH°f H2O(ℓ)

Substituting the given values, we have: ΔH°f HCl(g) = -364 kJ/mol + (-814 kJ/mol) - 2(-286 kJ/mol) = -62 kJ/mol

Therefore, the value of ΔH°f for HCl(g) is -62 kJ/mol.

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The heat of formation, or ΔH°f, for hydrogen chloride (HCl(g)) is −92.3 kJ/mol. This was found using Hess's Law and the given standard heats of formation.

The question is asking us to determine the heat of formation, or ΔH°f, for hydrogen chloride (HCl(g)) using the provided standard heats of formation and the heat of the reaction. This falls under the topic of thermodynamics in chemistry.

According to Hess's Law, the total enthalpy change for a reaction is the sum of the enthalpy changes for each step, regardless of the number of steps. So, the ΔH° for the reaction is the sum of the heats of formation of the products minus the sum of the heats of formation of the reactants. Mathematically, that's ΔH° = [ΔH°f(H2SO4) + 2*ΔH°f(HCl)] - [ΔH°f(SO2Cl2) + 2*ΔH°f(H2O)].

The only unknown in this equation is ΔH°f(HCl), which we can solve for:

ΔH°f(HCl) = {[ΔH° + ΔH°f(SO2Cl2) + 2*ΔH°f(H2O)] - ΔH°f(H2SO4)} / 2. Substituting the given values into this equation gives ΔH°f(HCl) = {-62.1 kJ + (-364 kJ) + 2*(-286 kJ) - (-814 kJ)} / 2 = −92.3 kJ/mol. So, the heat of formation for HCl(g) is −92.3 kJ/mol.

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Answer:

answer is b

Explanation:

when you boil water steam come from the pan

Answer:

(1) C C3H7OH = 9.200 M

(2) C C3H7OH = 11.647 m

Explanation:

mixture:

∴ 70% = (g C3H7OH/g mix)×100

∴ 30% = (gH2O/g mix)×100

∴ δ mix = 0.79 g/mL

assuming:

⇒ V mix = (100g)×(mL/0.79g) = 126.582 mL mix = 0.1266 L mix

⇒ g C3H7OH = 70g

⇒ g H2O = 30g

∴ Mw C3H7OH = 60.1 g/mol

∴ Mw H2O = 18 g/mol

(1) Molar concentration (M):

⇒ C C3H7OH = ((70 g)(mol/60.1 g))/(0.1266L) = 9.200 M

(2) molal concentration (m):

⇒ C C3H7OH = ((70 g)(mol/60.1g))/(0.100 Kg) = 11.647 m

The answer is D) "Genes usually have two alleles and carry instructions for proteins that express traits. Alleles are alternative forms of the instructions."

Hope this helped!

The covalent bond between 2 atoms where each atom contribute 3  electrons is called a triple bond. In a triple bond, two are pi bonds and one is a sigma bond.

Covalent bonds are formed between  two non-metals  through sharing of electrons. Two electron deficient atoms shares their valence electrons each other to achieve octet and forms covalent bonds.

Covalent bonds can be single, double or triple bonds. Single bonds are sigma bonds. Double bonds are formed through one sigma bond and one pi bond formed through sideways overlapping.

In a single bond each atoms shares one electron. In double bond each atom shares two electrons and in triple bonds, 3 electrons are shared by each atom. Hence, option D is correct.

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Answer:

D. Sound waves

Explanation:

The following options are missing:

A. radio wave

B. X-rays

C. Light waves

D. Sound waves

There are two kinds of waves: longitudinal and transverse.

In longitudinal waves, the vibrations are parallel to the direction of wave travel. Examples of longitudinal waves include: sound waves  and ultrasound waves.

In transverse waves, the vibrations are at right angles to the direction of wave travel. All electromagnetic waves (e.g. light waves, microwaves, radio waves and X-rays) are transverse waves.

A longitudinal wave is a type of wave in which the disturbance or movement of the particles is parallel to the direction of the wave propagation. Sound waves and seismic P-waves are examples of longitudinal waves. In contrast to transverse waves where the disturbance is perpendicular to the direction of wave propagation.

In physics, a common example of a longitudinal wave is a sound wave in air or water. In these waves, the periodic variations in pressure or disturbances are parallel to the direction of wave propagation. Other examples of longitudinal waves are seismic waves generated by earthquakes, specifically the compressional or P-waves, which move particles in the same direction as the wave itself.

In contrast, in transverse waves, such as those created on the strings of musical instruments, the disturbance or movement of the particles is perpendicular to the direction of wave propagation. It's important to note that some waves, like ocean waves and seismic waves, can consist of both transverse and longitudinal wave components.

To further clarify, consider a toy spring. If you create a disturbance by stretching and then compressing the spring in a horizontal direction, similar to how particles move in response to a sound wave, this represents a longitudinal wave.

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Answer: Its already balanced.

Explanation:

Answer:

the sodium nitrate in this investigation is

a) the solute

b) undergoing chemical change

generally, solute is the substance which is added in solvent.

The substance which is taken in relatively more volume is the solvent.

so, here sodium nitrate (NaNO₃) is the solute which is dissolved in water (H₂O) , which is solvent.

The reaction between them is :

NaNO₃ + H₂O ⇒ Na⁺ (aq) + NO₃⁻ (aq) ;     (aq) denotes aqueous;

so, here sodium nitrate undergoes chemical change into aqueous sodium ions(Na⁺) and aqueous nitrate ions(NO₃⁻).

Answer:

A :) It adds 1 more unit of mass to the atomic weight of the atom.

Explanation:

I just completed it on apex

Answer:

A

Explanation:

The volume of the can of dog food is approximately 74.8 cubic inches.

To calculate the volume of the can of dog food, we use the formula for the volume of a cylinder, which is V = (pi x [tex]r^2[/tex] x h), where V is the volume, pi is approximately 3.14159, r is the radius of the base, and h is the height of the cylinder.

First, we need to find the radius of the base. We know the area (A) of the circular base is 12.5 in2, and the area of a circle is given by A = pi x [tex]r^2[/tex]. We can solve for r:

A = pi x [tex]r^2[/tex]

12.5 = 3.14159 x [tex]r^2[/tex]

[tex]r^2[/tex] = 12.5 / 3.14159

[tex]r^2[/tex] = 3.981

r = [tex]\sqrt{3.981}[/tex]

r = 1.994 inches approximately.

Now that we have the radius, we can calculate the volume of the can:

V = pi x [tex]r^2[/tex] x h

V = 3.14159 x [tex](1.994 in)^2[/tex] x 6 in

V = 74.8 in3 (rounded to one decimal place).

Thus, the volume of the can of dog food is approximately 74.8 cubic inches.

Answer:

the answer is D

Explanation:

the reason how ik this is that i already did this test so yea

The example of an exothermic reaction among the provided options is D, where a firework explodes and releases both heat and light, a hallmark of exothermic processes.

An exothermic chemical reaction is a process that releases energy in the form of heat or light. When chemical bonds are formed in a new substance, energy is generally released, indicating an exothermic process. Among the options given, option D, where a firework explodes in the sky and releases heat and light, is a classic example of an exothermic reaction. This option perfectly illustrates the concept as fireworks, upon detonation, release energy in the form of heat and light due to the combustion reactions occurring within them. This reaction releases energy in the form of heat and light, making it an exothermic reaction. Exothermic reactions involve the release of energy, while endothermic reactions involve the absorption of energy.

Color change is most indicative of acid-base type of chemical reaction.

Chemical reactions are defined as reactions which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical reaction.

There are several characteristics of chemical reactions like change in color, change in state , change in odor and change in composition . During chemical reaction there is also formation of precipitate an insoluble mass of substance or even evolution of gases.

There are three types of chemical reactions:

1) inorganic reactions

2)organic reactions

3) biochemical reactions

During chemical reactions atoms are rearranged and reactions are accompanied by an energy change as new substances are formed.

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Answer:

Explanation:

1. Amount of heat absorbed by the water

Where:

2. Standard heat of formation of compound X: ΔHf

Reaction:

From tables (at 25ºC):

- 2,450 kJ/mol = 4 (-393.5 kJ/mol) + 3 (-393.5 kJ/mol) - ΔHf C₄H₆

ΔHf C₄H₆ = 2,450 kJ/mol - 2,754.5 = 304.5 kJ/mol ≈ 305 kJ/mol

Answer:

central vacuole

Explanation:

Answer:

Particles are far apart from each other because there are very weak forces of attraction between them. They move fast in all directions. Because of this, gases don't have a definite shape or volume and fill any container. Because there is lots of free space between particles, gases can easily be compressed.

Explanation:

The ability to be crushed is a physical property and therefore is the answer.

Answer:

the ability to be crushed

Explanation:

Chemical change are effects that is accompanied by changes in the chemical composition of a substance. When chemical changes occur the new substance are chemically different from the formal substance. A new chemical matter is usually formed after the change occur . Example of chemical changes are rusting of iron, toxicity, combustion(substance burning in the presence of oxygen), ability of substance to react with oxygen.

Physical changes are changes that does not alter the chemical composition of the new substance . Example of physical changes are steam condensing into liquid, sugar dissolving in water and crushing a solid substance. The changes are usually physical changes. The overall substance does not change in chemical composition.  

Answer:

T₂ = 51826.1 K

Explanation:

Given data:

Initial Volume = 2.3 L

Final volume = 400 L

Initial temperature = 25 °C (25+ 273 = 298 K)

Final temperature = ?

Solution:

V₁/T₁ = V₂/T₂

T₂ = V₂ T₁/V₁

T₂ =  400 L . 298 K / 2.3 L

T₂ = 119200 K. L / 2.3 L

T₂ = 51826.1 K

To find the temperature in Kelvin for a balloon to expand, we can use Charles's Law. Converting the initial temperature of 25 degrees Celsius to Kelvin gives us 298 K. By setting up the equation, we find that the balloon needs to be heated to approximately 5172.17 K.

To find the temperature in Kelvin at which a 2.3 L balloon expands to a volume of 400 L, we can use Charles's Law. Converting the initial temperature of 25 degrees Celsius to Kelvin gives us 298 K. Setting up the equation, we have:

V₁ / T₁ = V₂ / T₂

Substituting the given values, we have:

2.3 L / 298 K = 400 L / T₂

Cross multiplying and solving for T₂, we find:

T₂ = (400 L * 298 K) / 2.3 L = 5172.1739 K

Therefore, the balloon will need to be heated to approximately 5172.17 K in order to expand to a volume of 400 L.

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