The phase change from a solid to a liquid is __________

The reaction that does not occur in a beaker is;

- CH4(g) + 2O2(g) → CO2(g) + 2H2O(ℓ) + 213 kcal

In a beaker, it is unlikely that all of these conditions will be met for a combustion reaction to occur. For example, there may not be enough fuel present in the beaker to sustain a combustion reaction, or there may not be enough oxygen to support the reaction.

Additionally, an ignition source such as a spark or flame is usually necessary to initiate the reaction, which is unlikely to be present in a beaker.

Learn more about combustion:https://brainly.com/question/15117038

#SPJ1

The two geologic events which occur very slowly as a result of tectonic forces and movement are convection in the mantle and plate subduction.

This is a term which is referred to as the process in which there is collision between two of Earth's tectonic plates, where one plate sinks into the mantle underneath the other plate.

This is caused by geologic events which occur very slowly as a result of tectonic forces while on the other hand, mountains and volcanoes occur abruptly which is therefore the reason why options A and C were chosen as the correct choice.

Read more about Subduction here https://brainly.com/question/1358208

#SPJ1

Answer: A and C

Explanation:

Answer:

All of the above are chemical properties

The Mesopotamians discovered copper (Cu) in 9000 BC.

The basic mechanism that naturally creates freshwater within the hydrologic cycle is through the processes of evaporation, precipitation, infiltration, and runoff.

1. Evaporation: Water from the Earth's surface (e.g., oceans, lakes, and rivers) is heated by the sun and turns into water vapor, rising into the atmosphere.

2. Condensation: The water vapor cools as it rises, condensing into clouds.

3. Precipitation: When the clouds become heavy enough, the water droplets combine and fall back to the Earth's surface as precipitation (e.g., rain, snow, or hail).

4. Infiltration: Precipitation that reaches the ground can infiltrate the soil, becoming part of the groundwater system.

5. Runoff: Precipitation that does not infiltrate the soil will flow over the land surface as runoff, eventually entering rivers, lakes, and oceans.

This continuous movement of water through the various stages is known as the hydrologic cycle. Note that reverse osmosis is not part of this natural process; it is a human-engineered method used for water purification.

More on hydrologic cycle: https://brainly.com/question/13334963

#SPJ11

Answer:

-1300. kJ  

Explanation:

We have two equations:

1. P₄(s)       +3O₂(g) ⟶ P₄O₆(s);                 ΔH₁  = -1640.1 kJ

2. P₄O₁₀(s)               ⟶ P₄(s)      + 5O₂(g); ΔH₂ =  2940.1 kJ

From these, we must devise the target equation:

3. P₄O₆(s)  + 2O₂(g) ⟶ P₄O₁₀(s);               ΔH = ?

The target equation has P₄O₆(s) on the left, so you reverse Equation 1.

When you reverse an equation, you reverse the sign of its ΔH.

4. P₄O₆(s)                 ⟶ P₄(s)       +3O₂(g); ΔH₁  =  1640.1 kJ

Equation 4 has P₄ on the right. That is not in the target equation.

You need an equation with P₄ on the left, so you reverse Equation 2.  

5. P₄(s)      + 5O₂(g)  ⟶ P₄O₁₀(s);               ΔH₂ = -2940.1 kJ

Now, you add equations 4 and 5, cancelling species that appear on opposite sides of the reaction arrows.

When you add equations, you add their ΔH values.

You get the target equation 3:

4. P₄O₆(s)                      ⟶ P₄(s)        + 3O₂(g);      ΔH₁ =   1640.1 kJ

5. P₄(s)       + 2(5)O₂(g) ⟶ P₄O₁₀(s);                       ΔH₂ = -2940.1 kJ

3. P₄O₆(s)   + 2O₂(g)     ⟶ P₄O₁₀(s);                       ΔH   = -1300.  kJ

ΔH for the reaction is -1300. kJ

The boiling point elevation is a colligative property. From the calculations, the boiling point of the ethanol - sugar solution is 78.65°C.

The term colligative properties refers to those properties that depend on the number of solute particles present.

Number of moles of sugar = 20 g/342.3 g/mol = 0.058 moles

Boiling constant of ethanol = 1.22 °C⋅kg/mol

Molality of the solution = 0.058 moles/250 * 10^-3 = 0.232 m

Since sugar is a molecular substance, the Van't Hoff factor is 1

The normal boiling point of pure ethanol is 78.37 °C

ΔT = K m i

ΔT = 1.22 °C⋅kg/mol * 0.232 m * 1

ΔT = 0.28°C

Boiling point of solution =  78.37 °C + 0.28°C = 78.65°C

Learn more about boiling point: https://brainly.com/question/2153588

A.  by increasing the temperature

B.  by increasing the surface area of the solute

C.  by increasing the pressure

D.  by decreasing the temperature

E.  by decreasing the surface area of the solute

He (helium) exhibits the weakest intermolecular forces. This is because He is a noble gas with a full electron shell, making it stable and non-reactive. H2O, NH3, and HCl all have polar bonds and stronger intermolecular forces such as hydrogen bonding (H2O and NH3) or dipole-dipole interactions (HCl).

Of the given options, the gas He exhibits the weakest intermolecular forces. This is because He is a noble gas and exists as a single atom, making it non-polar and lacking any dipole-dipole or hydrogen bonding intermolecular forces. On the other hand, H2​O and NH3​ are polar molecules and exhibit hydrogen bonding intermolecular forces, making them stronger than He. HCl also exhibits intermolecular forces due to its polarity, but it is stronger than H2​O and NH3​ because it has stronger dipole-dipole forces. In 100 words, the intermolecular forces are attractive forces between molecules. The strength of these forces determines the physical properties of substances, such as boiling and melting points. The weakest intermolecular forces are found in non-polar molecules, such as He, which have no dipole-dipole or hydrogen bonding. Polar molecules, such as H2​O and NH3​, exhibit stronger intermolecular forces due to their polarity and ability to form hydrogen bonds. HCl, another polar molecule, has stronger intermolecular forces than H2​O and NH3​ because it has stronger dipole-dipole forces.

To know more about intermolecular forces visit:

https://brainly.com/question/31797315

#SPJ11

Answer:

28 kg

Explanation:

When diluting a strong acid with water, it is recommended to add the acid to the water and not the other way around. The statement is true.

This is because adding water to the acid can cause a rapid and exothermic reaction, leading to splattering and potential injury.

When the acid is added to the water, the heat generated is absorbed by the water, reducing the potential for splattering. Additionally, adding the acid to water allows for better mixing and reduces the risk of creating concentrated acid pockets that can be dangerous.

Overall, it is important to follow safe laboratory practices when working with acids and to consult with a trained professional if you are unsure about the proper procedures.

To know more about the dilution, here

brainly.com/question/28392867

#SPJ4

The coefficients of the species shown when the equation n2 + Br- + N2H4 → N2 + Br- + NH3 are balanced properly under basic conditions are 1, 2, and 2 for N2, Br-, and N2H4, respectively.

To balance the equation, start by balancing the nitrogen atoms by placing a coefficient of 2 in front of N2 and N2H4. This gives the equation 2N2 + Br- + N2H4 → 2N2 + Br- + NH3. Next, balance the hydrogen atoms by placing a coefficient of 2 in front of NH3. The equation then becomes 2N2 + Br- + N2H4 → 2N2 + Br- + 2NH3. Finally, balance the charge by adding OH- to the reactants side of the equation.

The final balanced equation is 2N2H4 + 6OH- + Br- → 4NH3 + 2N2 + 3H2O + Br-. Therefore, the coefficients for the species shown are 1 for Br-, 1 for N2, and 2 for N2H4.

To learn more about hydrogen atoms here

https://brainly.com/question/30886690

#SPJ11

Explanation:

The given intermediate chemical reactions do not lead to a single overall chemical equation for smog. Instead, they represent a combination of various reactions that contribute to the formation of different components of smog, such as nitrogen oxides (NOx) and ozone (O3).

The first reaction given is:

N2 + 3O2 + 2O3 + 2O → 8NO + 4NO2 + 2O3

This reaction represents the formation of nitrogen oxides and ozone from the reaction of nitrogen and oxygen with ozone and oxygen radicals. Nitrogen oxides and ozone are major components of smog.

The second reaction given is:

N2 + 3O2 + O3 + O → 9NO + 3NO2 + 2O3

This reaction also represents the formation of nitrogen oxides and ozone, but with a different stoichiometry.

The third reaction given is:

N2 + 3O2 → 2NO + O2

This reaction represents the direct formation of nitrogen oxides from the reaction of nitrogen and oxygen.

The fourth reaction given is:

N2 + 2O2 → 2NO2

This reaction represents the direct formation of nitrogen dioxide from the reaction of nitrogen and oxygen.

Overall, the formation of smog is a complex process that involves the interaction of various chemical reactions and environmental factors. Therefore, there is no single overall chemical equation that describes the formation of smog.

The solubility of a substance is influenced by many factors, including temperature, pressure, and the type of solvent used. Knowing the solubility of a substance can be useful in a variety of applications, such as:

Learn more about solubility: https://brainly.com/question/23946616

#SPJ4

Answer:

carbon dioxide

Explanation:

because we breath in oxygen and breath out Carbon

Answer:

Explanation:

relation between energy wavelength and frequency.....

we know that energy of photon is

E=hf  but

v=fλ

f=v/λ when v=c(speed of light) then f=c/λ

putting the value of f in the equation of photon

E=hc/λ this equation gave a relation between wavelength frequency and energy in electromagnetic  waves

among electromagnetic waves UV rays are most dangerous because exposure to these radiation cause serious problems in living organism

Among electromagnetic waves, UV rays are most dangerous because exposure to these radiation cause serious problems in living organism. The relation that we use in case of electromagnetic wave is E=hc/λ

Electromagnetic wave is a wave which contain two component one is electric component and other is magnetic component. The electric and magnetic component are perpendicular to each other. There are so many wave that comes under electromagnetic wave like infrared wave , radio wave

There is a relation between energy of wave. frequency of wave, and wavelength of wave

Mathematically,

E=hc/λ

where,

E = energy of electromagnetic wave

h is planks constant having value 6.67×10⁻³⁴js

c is speed of light that is 3×10⁸m/s

λ  is the wavelength of electromagnetic wave

Thus the relation that we use to find the energy of electromangetic wave is E=hc/λ

To know more about electromagnetic wave, here:

https://brainly.com/question/12289372

#SPJ6

Answer:

The statement “Decomposers are those organisms that recycle matter in the ecosystem” describes decomposers.

Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition.

4Na + O₂ → 2Na₂O is balanced equation.

Hence, Option (B) is correct answer.

The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.

Now check all the options one by one:

Option (A): 2H₂ + O₂ → 4H₂O

Reactant Side               Product Side

H = 4                               H = 8

O = 2                               O = 4

Here number of atoms of H on the reactant side is 4 and number of atom on product side is 8. H atoms are not balanced in this equation. Hence the given equation is not balanced.

Option (B): 4Na + O₂ → 2Na₂O

Reactant Side               Product Side

Na = 4                            Na = 4

O = 2                              O = 2

Here all the atom on reactant side and product side are equal. Hence the given equation is balanced.

Option (C):  Fe₂O₃ + H₂ → 2Fe + 3H₂O

Reactant Side               Product Side

Fe = 2                              Fe = 2

O = 3                                O = 3

H = 2                                H = 6

Here number of atoms of H on the reactant side is 2 and number of atom on product side is 6. H atoms are not balanced in this equation. Hence the given equation is not balanced.

Option (D): CH₄ + O₂ → CO₂ + H₂O

Reactant Side               Product Side

C = 1                                C = 1

H = 4                               H = 2

O = 2                               O = 3

Here H atoms on the reactant and product side is not equal and O atoms are also not equal on the reactant side and product side. Hence, the given equation is not balanced.

Thus from the above conclusion we can say that The balanced equation from the given options is 4Na + O₂ → 2Na₂O

Hence, Option (B) is correct answer.

Disclaimer: The question was given incomplete on the portal. Here is the complete question.

Question: Which of the following equations is balanced?

(A) 2H₂ + O₂ → 4H₂O

(B) 4Na + O₂ → 2Na₂O

(C) Fe₂O₃ + H₂ → 2Fe + 3H₂O

(D) CH₄ + O₂ → CO₂ + H₂O

Learn more about the Balanced Chemical Equation here: https://brainly.com/question/26694427

#SPJ1

Answer:  A. \(0.00301J/g^0C\)

Explanation:

The quantity of heat required to raise the temperature of a substance by one degree Celsius is called the specific heat capacity.

\(Q=m\times c\times \Delta T\)

Q = Heat absorbed  = 4.56 J

m = mass of substance = 123 g

c = specific heat capacity = ?

Change in temperature ,\(\Delta T=T_f-T_i=12.32^0C\)

Putting in the values, we get:

\(4.56J=123g\times c\times 12.32^0C\)

\(c=0.00301J/g^0C\)

The specific heat of a 123 g substance that requires 4.56 J of heat in  order to increase its temperature by 12.32 °C is \(0.00301J/g^0C\)

Answer:

A: Elements!!!

Explanation: Everything starts at an element!

The anode half-reaction in this redox reaction is the oxidation of aluminum (Al) metal to form aluminum ions (\(Al^{3+}\)):

2Al(s) → 2\(Al^{3+}\)(aq) + 6e-

This reaction involves the loss of electrons, which are represented on the right-hand side of the equation as part of the aluminum ions.

The ionic equation for the entire redox reaction would be:

2Al(s) + \(3Cd_{2}\)+(aq) → 2\(Al^{3+}\)+(aq) + 3Cd(s)

In this equation, the aluminum and cadmium ions are represented by their respective aqueous phases (\(Al^{3+}\)(aq) and \(Cd^{2+}\)(aq)), while the solid metals are represented by their respective phases (Al(s) and Cd(s)).

Learn more about redox reaction

https://brainly.com/question/2671074

#SPJ4

When reading the label on a reagent container, the three most important pieces of information include:

This is referred to a chemical which is added to a mixture thereby resulting in a chemical reaction occurring and have different properties which is why the label has to contain their features.

It is therefore best to check the label for properties such as name and concentration so as to enable individuals use it for the right type of reactions and is also important in prevention of the risk of accident by individuals.

Read more about Reagent here https://brainly.com/question/6959208

#SPJ1

Explanation:

Solution — 1 molecule of O2 = 2 oxygen atoms So, 1 mole of O2 = 2 mole oxygen atoms = 2 × 6.022 × 1023 = 12.044 ×1023 oxygen atoms.

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 1.2044 ×10²⁴ oxygen atoms are there in a 2 moles of oxygen atoms.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

number of mole of O\(_2\)= 2 mole

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

substituting all the given values in the above equation, we get

number of  oxygen atoms = 2 × 6.022 × 10²³

number of  oxygen atoms= 1.2044 ×10²⁴ oxygen atoms.

Therefore,  1.2044 ×10²⁴ oxygen atoms are there in a 2 moles of oxygen atoms.

To know more about mole, here:

https://brainly.com/question/15209553

#SPJ2

"Calcium ions are reduced" at the cathode during the electrolysis of molten calcium chloride.

During electrolysis, an electric current is passed through a molten or dissolved compound to split it into its constituent elements.

In the case of calcium chloride, when it is melted and electrolyzed, calcium ions (\(Ca^{2+}\)) and chloride ions (\(Cl^{-}\)) are present.

At the cathode, the positively charged calcium ions are attracted to the negative electrode and gain electrons, reducing them to elemental calcium.
Therefore, the reduction of calcium ions is the main answer to what happens at the cathode during the electrolysis of molten calcium chloride.

For more information on electrolysis kindly visit to

https://brainly.com/question/31885436

#SPJ11

Answer:

that the polar bear will come out again in 2 years

The valence shell electrons in a molecule are depicted in an extremely simplified manner by a Lewis Structure. It is used to demonstrate how the electrons in a molecule are positioned around particular atoms. Electrons are shown as "dots" or, in the case of a bond, as a line connecting the two atoms.

The significance of Lewis's structure is the second. For forecasting the geometry, polarity, and reactivity of (in)organic compounds, Lewis structures are crucial. Lastly, how to depict the Lewis structure. For each available valence electron, a dot is placed around an atom to represent that electron in the Lewis structure for that particular element.

Conclusion. A Lewis structure is created using the octet rule, which states that atoms must share electrons in order for each to have eight electrons in its outer shell. Typically, a symbol on the side of an element symbol designates a single electron.

To know more about Lewis Structure visit:

https://brainly.com/question/20300458

#SPJ4

Answer:  No, the samples are not of equal masses.

Explanation:  Mass is volume X density

A:  (2ml)*(18.4g/ml) = 36.8 g

B:  (5ml(*(35.5g/ml) = 177.5 g

Answer: For example, if electricity is passed through molten lead bromide, the lead bromide is broken down to form lead and bromine. This is what happens during electrolysis: Positively charged ions move to the negative electrode during electrolysis. ... Negatively charged ions move to the positive electrode during electrolysis.

Explanation:

hope this helps you find what your looking for