Students in Mr. Clark’s science class were trying to explain why we see the different phases of the moon. Which student’s explanation is correct?



A.


Student A explained that we see the different phases because the moon revolves around the earth.



B.


Student C explained that we see the different phases because the moon revolves around the sun.



C.


Student B explained that we see the different phases because the moon is very large.



D.


Student D explained that we see the different phases because the moon is covered with many craters

There are 516.682 grams in a sample of 7.9 moles of zinc.

To determine the number of grams in a sample of 7.9 moles of zinc, we need to use the molar mass of zinc. The molar mass of zinc is 65.38 g/mol.

Therefore, to calculate the number of grams in 7.9 moles of zinc, we can multiply 7.9 moles by 65.38 g/mol. The calculation is as follows:

7.9 moles x 65.38 g/mol = 516.682 g

Therefore, there are 516.682 grams in a sample of 7.9 moles of zinc. It's important to remember to always use the molar mass of the element or compound when converting between moles and grams.

To know more about moles refer here: https://brainly.com/question/31563792#

#SPJ11

There are seven sequential steps of scientific research.

The scientific method is a process used when conducting experiments and exploring observations. Some areas of science rely more heavily on this method to answer questions, as they are more easily tested than other areas.

This method aims to discover the relationships between cause and effect in various situations and applications. The 7 steps of scientific research are -

Therefore, there are seven sequential steps of scientific research.

Learn more about Scientific research, here:

https://brainly.com/question/30547498

#SPJ2

Answer:

3.7996 g

Explanation:

From the number of molecules we can find the number of moles of Fluorine gas (F2) and multiply by Fluorine Gas' molecular weight. Fluorine gas is F2,

F = 18.998g/mol.

F2 (g) = 18.998*2 =37.996g F2(g)/mol

1 mol = 6.02 x 10^23 molecules

[tex]\frac{6.02*10^{22} molecules}{6.02*10^{23}molecules / mole }\\\\ = 0.1 mole[/tex]

0.1 mol x 37.996g F2 (g) / mol

3.7996 g F2

The limiting reagent is F₂, the number of OF₂ molecules formed is 2 and the number of F₂ atoms/molecules in excess is 2.

Since there are two oxygen molecules and four fluorine molecules, fluorine is in excess.

The balanced equation is O₂ + 2 F₂ → OF₂, which shows that 1 molecule of O₂ reacts with 2 molecules of F₂ to form 2 molecules of OF₂. Therefore, since there are only 2 molecules of F₂ available, the limiting reagent is F₂.

As F₂ is the limiting reagent, only 1 molecule of O₂ will react with 2 molecules of F₂ to form 2 molecules of OF₂. Therefore, the number of OF₂ molecules formed is 2.

The number of atoms/molecules in excess is the difference between the number of atoms/molecules available and the number of atoms/molecules used in the reaction. In this case, since F₂ is in excess, the number of F₂ molecules in excess is 2.

Find out more on limiting reagents here: https://brainly.com/question/14222359

#SPJ1

Image transcribed:

Use the References to access important values if needed for this question.

The illustration to the left represents a mixture of oxygen (red) and fluorine (green) molecules.

If the molecules in the above illustration react to form OF₂ according to the equation

O₂ + 2 F₂ →  OF₂,

the limiting reagent is _______, the number of OF₂ molecules formed is ______ and

the number of ______ atoms/molecules in excess is ________.

The correct answer is iron(III) chloride.

The molar mass of iron (Fe) is approximately 55.8 g/mol, and the molar mass of chlorine (Cl) is approximately 35.5 g/mol.

To determine the compound, we can calculate the empirical formula, which gives the simplest whole-number ratio of atoms in the compound.

Assuming a 100 g sample of the compound, we have:

34.4 g Fe

65.6 g Cl

Converting these masses to moles:

34.4 g Fe / 55.8 g/mol Fe = 0.616 mol Fe

65.6 g Cl / 35.5 g/mol Cl = 1.85 mol Cl

Dividing by the smaller number of moles to get the simplest whole-number ratio:

Fe:Cl = 0.616 mol : (1.85 mol / 0.616 mol) = 0.616 mol : 3 mol

So the empirical formula is FeCl3, which is iron(III) chloride.

Therefore, the correct answer is iron(III) chloride (FeCl3).

To know more about molar mass refer to-

https://brainly.com/question/22997914

#SPJ11

2 moles of solute dissolved in 1 liter of solution has the greatest concentration.

Concentration refers to the quantity of solute that is dissolved in a specific amount of solution, and it is commonly measured in units such as moles per liter or grams per liter.

To determine which solution has the greatest concentration, we need to calculate the number of moles of solute present in each solution and then compare the values.

a. Concentration = 2 moles / 1 liter = 2 M

b. Concentration = 0.3 moles / 0.6 liters = 0.5 M

c. Concentration = 2 moles / 10 liters = 0.2 M

d. Concentration = 0.1 moles / 0.5 liters = 0.2 M

Comparing the concentrations, we see that solution (a) has the greatest concentration of 2 M, while the other solutions have concentrations of 0.5 M or lower.

To know more about concentration of solution, click here

https://brainly.com/question/24316606

#SPJ9

In redox reactions, electrons are transferred from one species to another. If the response is spontaneous, strength is released, that could then be used to do beneficial work.

To harness this strength, the response have to be break up into separate 1/2 of reactions: the oxidation and reduction reactions. The reactions are placed into one of a kind bins and a twine is used to pressure the electrons from one aspect to the other. In doing so, a Voltaic/ Galvanic Cell is created. An electrode is strip of metallic on which the response takes region. In a voltaic cell, the oxidation and discount of metals takes place on the electrodes. There are electrodes in a voltaic cell, one in every 1/2 of-cell. The cathode is wherein discount takes region and oxidation takes region on the anode. Through electrochemistry, those reactions are reacting upon metallic surfaces, or electrodes. An oxidation-discount equilibrium is mounted among the metallic and the materials in solution. When electrodes are immersed in an answer containing ions of the equal metallic, it's far referred to as a 1/2 of-cell.

To learn more about redox reaction check the link below-

https://brainly.com/question/21851295

#SPJ4

The volume of the gas at 2.00 atm and 200.0 K is 18.75 L.

We can use the combined to solve this problem:

(P1 * V1) / (T1) = (P2 * V2) / (T2)

where P is pressure, V is volume, and T is temperature.

Plugging in the given values:

(0.250 atm * 300 L) / (400.0 K) = (2.00 atm * V2) / (200.0 K)

Simplifying:

V2 = (0.250 atm * 300 L * 200.0 K) / (2.00 atm * 400.0 K)

V2 = 18.75 L

Therefore, the volume of the gas at 2.00 atm and 200.0 K is 18.75 L.

Gas laws refer to a set of principles that describe the behavior of gases under different conditions, including pressure, temperature, and volume.

There are several gas laws, including Boyle's law, Charles's law, Gay-Lussac's law, and the ideal gas law.

To know more about combined gas law refer to-

https://brainly.com/question/30458409

#SPJ11

In a reaction mechanism, the rate-determining step is the slowest step with the highest activation energy. The correct answer is option c.

This is because the rate of the overall reaction is determined by the speed of the slowest step, as it limits the rate at which the reaction can occur. The activation energy is the minimum energy required for a reaction to occur, and the higher the activation energy, the slower the reaction rate will be.

Identifying the rate-determining step is important for understanding and controlling the rate of a chemical reaction.

By knowing which step is the slowest, chemists can focus on optimizing conditions for that step to increase the overall reaction rate. This can involve adjusting the temperature, pressure, and concentrations of reactants, as well as adding catalysts to lower the activation energy of the rate-determining step.

Overall, understanding the rate-determining step is critical for designing and optimizing chemical reactions in fields ranging from industrial chemistry to drug discovery.

The correct answer is option c.

To know more about activation energy refer to-

https://brainly.com/question/28384644

#SPJ11

The appropriate term for the following mixtures are;

A mixture is a substance made when two or more substances are combined, but they are not combined chemically.

The components of a mixture can be easily separated because each component keep their original properties or identity.

A homogenous mixture is a gaseous, liquid or solid mixture that has the same proportions of its components throughout a given sample e.g. juice while heterogenous mixture is a mixture in which the composition is not uniform throughout the mixture e.g. smoke.

Learn more money mixtures at: https://brainly.com/question/30587533

#SPJ1

Answer:

Its in my screenshot

Explanation:

An enzyme can speed up a certain chemical reaction by all of the above ways mentioned. Option E is correct.

Enzymes are biological catalysts that increase the rate of chemical reactions without being consumed in the process. Enzymes work by binding to their substrates in a specific manner, which allows for the formation of an enzyme-substrate complex. The active site of the enzyme provides a suitable environment for catalysis, with the presence of acidic or basic residues, which can act as proton donors or acceptors to facilitate the reaction.

Additionally, enzymes can stabilize the highest energy part of the reaction, which is called the transition state. By stabilizing the transition state, the enzyme can lower the activation energy required for the reaction to occur. Enzymes can also expel water or unwanted reactants from the active site to prevent non-specific reactions from occurring. All of these mechanisms work together to speed up a certain chemical reaction and make it occur more efficiently. Option E is correct.

To know more about the Enzyme, here

https://brainly.com/question/12776461

#SPJ4

An element is made up of only one type of atom.

A compound is made up of different atoms that are chemically joined together.

A mixture is made up of two or more different atoms or compounds that are not chemically joined together, but rather are physically mixed together.

Elements are substances that are composed of the same type of atoms and which cannot be split by an ordinary chemical process. For example, sodium, chlorine, oxygen, etc.

Compounds are substances that are comprised of two or more elements chemically combined together. For example, common salt.

Mixtures are substances that are composed of two or more substances physically combined together. For example, salt and water to form a salt solution.

Learn more about compounds and mixtures at: https://brainly.com/question/24647756

#SPJ1

The amount of Ca(OH)₂ produced = 5.2 g which is calculated in the below section.

NUMBER OF MOLES of HCl = Molarity of solution x Volume of Solution

# of moles of HCl = (0.40 mol/L ) x 350 mL

                              = (0.40 mol/L ) x 0.350 L

                              = 0.14 mol

The mass of HCl that makes 0.14 mol of HCl

Mass of HCl= # of moles x molar mass of HCl

Mass of HCl = 0.14 mol x 36.5 g/ mol

Mass of HCl = 5.11g

As per Stoichiometry , 1g of HCl reacts with 1.015 g of Ca (OH)₂

So, 5.11g of HCl can react with 5.11 x 1.015  g

                                                 = 5.1865 g or 5.2 g of Ca(OH)₂

To learn more about number of moles check the link below-

https://brainly.com/question/29367909

#SPJ4

The answer is 120.0 g of sodium hydroxide are produced. The correct answer is option c.

The balanced equation for the reaction is:

[tex]2 Na + 2 H2O → 2 NaOH + H2[/tex]

From the equation, it can be seen that 2 moles of NaOH are produced for every 2 moles of Na that react. Therefore, the number of moles of NaOH produced can be calculated as follows:

moles of NaOH = moles of Na = mass of Na / molar mass of Na

molar mass of Na = 22.99 g/mol

moles of NaOH = 68.97 g / 22.99 g/mol = 3.00 mol

So, 3.00 moles of NaOH are produced. To convert to grams, we can use the molar mass of NaOH:

molar mass of NaOH = 40.00 g/mol

mass of NaOH = moles of NaOH x molar mass of NaOH

mass of NaOH = 3.00 mol x 40.00 g/mol = 120.00 g

Therefore, the answer is (c) 120.0 g of sodium hydroxide are produced.

To know more about  sodium hydroxide refer to-

https://brainly.com/question/29327783

#SPJ11

The reaction involves 3 moles of [tex]O_2[/tex] and [X] mol [tex]H_3PO_4[/tex]. The number of moles  [tex]H_3PO_4[/tex]  is not given, The number of moles  [tex]H_3PO_4[/tex] that can form during the reaction.  

The number of moles of  [tex]H_3PO_4[/tex] that can form during a reaction, we need to know the number of moles of reactants and the number of moles of products involved in the reaction, as well as the ratio of the coefficients of the reactants and products.

In this case, the reaction is:

[X] mol  [tex]H_3PO_4[/tex] + 3 mol  [tex]O_2[/tex]  → 3 mol  [tex]H_2O[/tex]. + 3 mol [tex]P_4O_{10[/tex]

We can start by solving for the number of moles of  [tex]H_3PO_4[/tex] that can form:

[X]  mol  [tex]H_3PO_4[/tex] + 3 mol  [tex]O_2[/tex]  → 3 mol  [tex]H_2O[/tex]. + 3 mol  [tex]P_4O_{10[/tex]

[X] mol  [tex]H_3PO_4[/tex] + 3 mol  [tex]O_2[/tex]  → 3 mol  [tex]H_2O[/tex]. + 3 mol  [tex]P_4O_{10[/tex]

1 mole  [tex]H_3PO_4[/tex] can form 3 moles of  [tex]H_2O[/tex]., so:

[X] mol  [tex]H_3PO_4[/tex] * 3 mol  [tex]H_2O[/tex]/mol  [tex]H_3PO_4[/tex] = 3 mol  [tex]H_2O[/tex].

Therefore, 1 mole of  [tex]H_3PO_4[/tex] can form 3 moles of [tex]H_2O[/tex].

The number of moles of  [tex]H_3PO_4[/tex] that can form during the reaction, we need to know the number of moles of reactants and the number of moles of products involved in the reaction, as well as the ratio of the coefficients of the reactants and products.

The reaction involves 3 moles of  [tex]O_2[/tex]  and [X] mol  [tex]H_3PO_4[/tex]. The number of moles of  [tex]H_3PO_4[/tex] is not given, so we cannot determine the number of moles of  [tex]H_3PO_4[/tex] that can form during the reaction.  

Learn more about moles Visit: brainly.com/question/29367909

#SPJ4

Limiting reactant: O2  and Amount of product formed: 47.7 g P2O3

To determine the limiting reactant and the amount of product formed, we need to first calculate the amount of product that can be formed from each reactant, assuming they completely react.

From the balanced chemical equation:

[tex]P4 + O2 → P2O3[/tex]

The stoichiometry of the reaction shows that 1 mole of P4 reacts with 5 moles of O2 to form 2 moles of [tex]P2O3[/tex]. Therefore, we need to calculate the number of moles of each reactant:

Number of moles of P4 = 65.1 g / 123.9 g/mol = 0.525 mol

Number of moles of O2 = 34.2 g / 32.0 g/mol = 1.069 mol

Next, we can calculate the amount of product that can be formed from each reactant:

From P4: (0.525 mol P4) x (2 mol P2O3 / 1 mol P4) x (109.9 g/mol P2O3) = 115.6 g P2O3

From O2: (1.069 mol O2) x (2 mol P2O3 / 5 mol O2) x (109.9 g/mol P2O3) = 47.7 g P2O3

Therefore, we can see that the amount of P2O3 that can be formed from O2 is lower than that of P4. This indicates that O2 is the limiting reactant, and P4 is in excess.

The maximum amount of product that can be formed is 47.7 g P2O3. This is the amount of product that would be formed if all the O2 was consumed. Therefore, the answer is:

Limiting reactant: O2

Amount of product formed: 47.7 g P2O3

To know more about Limiting reactant refer to-

https://brainly.com/question/14225536

#SPJ11

To produce 1000 grams of water, approximately 612.72 grams of propane are used in the combustion reaction.

To determine how much propane is used to produce 1000 grams of water, we must first understand the combustion reaction involving propane.

Propane (C3H8) is a hydrocarbon that undergoes combustion in the presence of oxygen (O2) to produce water (H2O) and carbon dioxide (CO2). The balanced chemical equation for this reaction is:

C3H8 + 5O2 → 3CO2 + 4H2O

From the balanced equation, we can see that 1 mole of propane (C3H8) produces 4 moles of water (H2O).

Next, we need to convert the mass of water (1000 grams) into moles, using the molar mass of water (18.015 g/mol):

1000 g H2O × (1 mol H2O / 18.015 g H2O) = 55.56 moles H2O

Now, using the stoichiometry from the balanced equation, we can find the moles of propane needed:

55.56 moles H2O × (1 mol C3H8 / 4 moles H2O) = 13.89 moles C3H8

Finally, we need to convert moles of propane into grams, using the molar mass of propane (44.097 g/mol):

13.89 moles C3H8 × (44.097 g C3H8 / 1 mol C3H8) = 612.72 grams

So, to produce 1000 grams of water, approximately 612.72 grams of propane are used in the combustion reaction.

To know more about propane, visit:

https://brainly.com/question/25008296#

#SPJ11

The formula for heat capacity, which is Q = m x c x ΔT. Q represents the amount of heat absorbed, m is the mass of the object, c is the specific heat capacity, and ΔT is the change in temperature.

In this case, we know the mass of the wood is 1500.0 grams and the specific heat capacity is 1.8 g/JxC. We also know that the wood absorbed 67,500 Joules of heat. Finally, we know the final temperature of the wood is 57C. We can use this information to solve for the initial temperature.

First, we need to rearrange the formula to solve for ΔT. ΔT = Q / (m x c)
ΔT = 67,500 J / (1500.0 g x 1.8 g/JxC)
ΔT = 25°C

Next, we can use the final temperature and ΔT to solve for the initial temperature. The initial temperature can be found by subtracting the change in temperature from the final temperature.

Initial temperature = final temperature - ΔT
Initial temperature = 57°C - 25°C
Initial temperature = 32°C

Therefore, the initial temperature of the wood was 32°C.

In summary, heat capacity is a measure of an object's ability to absorb heat. Temperature is a measure of the average kinetic energy of the particles in an object. In this problem, we used the formula for heat capacity to solve for the initial temperature of a piece of wood. We found that the initial temperature was 32°C, given that the wood absorbed 67,500 Joules of heat and its final temperature was 57°C.

To know more about  heat capacity refer here

https://brainly.com/question/28921175#

#SP

111900g  is the weight of an object that has the area of 74.6 m² and exerts a pressure of 1500 N/m².

Weight being a force The SI unit for weight is Newton (N), which also happens to be the same as the SI unit for force. When we look at how weight is expressed, we can see how it depends on both mass as well as the acceleration caused by gravity; while the mass might not vary from one location to another, the acceleration caused by gravity does.

Pressure = thrust/ area

              = weight/ area

1500  = weight/ 74.6

weight = 111900g

To know more about weight, here:

https://brainly.com/question/30176113

#SPJ1

The first step in this investigation will be to select several substances to test. It is important to choose substances that have similar chemical composition but differ in physical properties.

Once the substances have been selected, the next step is to measure the single property across each of the substances. This can be done through a variety of methods, such as using a thermometer to measure boiling points or a microscope to measure surface tension.

After the data has been collected, it should be compared and analyzed to determine how the property is related to the strength of the electrical forces in the substance. By comparing the data and making inferences, it is possible to determine how properties of substances can indicate the strength of the electrical forces within those substances.

Know more about Thermometer here

https://brainly.com/question/24189042#

#SPJ11

Based on the stoichiometry, sodium oxide is the limiting reactant because it produces less product compared to the calcium chloride. Therefore, 0.998 g of calcium oxide is the maximum amount of product that can be formed.

To determine the theoretically possible mass of solid product and the limiting reactant, we need to first write the balanced chemical equation for the reaction between calcium chloride and sodium oxide:

[tex]CaCl2 + Na2O → CaO + 2NaCl[/tex]

The stoichiometric ratio of calcium chloride to sodium oxide in the equation is 1:1, which means that for every 1 mole of calcium chloride that reacts, 1 mole of sodium oxide is required. We can use this ratio to calculate the moles of each reactant:

moles of [tex]CaCl2[/tex] = 1.98 g / 110.98 g/mol = 0.0178 mol

moles of [tex]Na2O[/tex] = 3.75 g / 61.98 g/mol = 0.0604 mol

According to the balanced equation, for every mole of calcium chloride that reacts, 1 mole of calcium oxide is produced. Therefore, the theoretical yield of calcium oxide can be calculated based on the moles of calcium chloride:

moles of [tex]CaO[/tex] = 0.0178 mol

mass of [tex]CaO[/tex] = moles of[tex]CaO[/tex] x molar mass of [tex]CaO[/tex]

mass of [tex]CaO[/tex] = 0.0178 mol x 56.08 g/mol

mass of [tex]CaO[/tex]= 0.998 g

Similarly, we can calculate the maximum amount of product that can be formed based on the moles of sodium oxide:

moles of [tex]NaCl[/tex]= 2 x moles of [tex]Na2O[/tex] = 0.1208 mol

mass of[tex]NaCl[/tex] = moles of [tex]NaCl[/tex] x molar mass of[tex]NaCl[/tex]

mass of [tex]NaCl[/tex]= 0.1208 mol x 58.44 g/mol

mass of [tex]NaCl[/tex] = 7.06 g

To know more about stoichiometry refer to-

https://brainly.com/question/30215297

#SPJ11

If the unknown solution reacts with potassium carbonate to form a white precipitate, then it contains strontium ions, indicating that the unknown solution is strontium nitrate.

On the other hand, if the unknown solution reacts with potassium sulfate to form a white precipitate, then it contains magnesium ions, indicating that the unknown solution is magnesium nitrate.

Therefore, based on the observations, if a white precipitate is observed when the unknown solution is mixed with potassium carbonate and no precipitate is observed when the unknown solution is mixed with potassium sulfate, the unknown solution is most likely strontium nitrate.

If no precipitate is observed when the unknown solution is mixed with both potassium carbonate and potassium sulfate, the unknown solution is most likely magnesium nitrate.

Therefore, we can determine the identity of the unknown solution by observing the reaction with potassium carbonate and potassium sulfate.

For more question on carbonate

https://brainly.com/question/30594488

#SPJ11

Gay-Lussac's Laws, also known as the Pressure-Temperature Law and Volume-Temperature Law, are a set of gas laws that explain the relationship between pressure, volume, and temperature in a given gas sample.

According to Gay-Lussac's Laws, if the pressure of a gas is increased while the volume remains constant, the temperature of the gas will also increase. Similarly, if the volume of a gas is decreased while the pressure remains constant, the temperature of the gas will increase as well.

In terms of a concept map, Gay-Lussac's Laws can be placed in the center with arrows pointing to both Boyle's Law and Charles's Law, which are two other gas laws that are also related to pressure, volume, and temperature.

Boyle's Law states that the pressure of a gas is inversely proportional to its volume, while Charles's Law states that the volume of a gas is directly proportional to its temperature.

To connect these three gas laws, the arrows can be labeled with key terms such as "pressure," "volume," and "temperature," with each gas law demonstrating how changes in one variable will affect the others.

The concept map can also include real-world examples of each gas law, such as how a tire pressure gauge can be used to demonstrate Boyle's Law, or how a hot air balloon can be used to demonstrate Charles's Law.

To know more about Gay-Lussac's Laws, visit:

https://brainly.com/question/2683502#

#SPJ11

To solve this problem, we need to use the ideal gas law which states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature. Rearranging this equation, we can solve for n by dividing both sides by RT.

n = PV/RT
Now, we can plug in the given values:
n = (4.2 atm)(128 L)/(0.0821 L*atm/mol*K)(382 K)

n = 16.4 moles
Therefore, 16.4 moles of gas occupy 128L at a pressure of 4.2 atm and a temperature of 382K.

It's important to note that the ideal gas law is only applicable to ideal gases, which follow certain assumptions such as having no intermolecular forces and having particles with negligible volume. Real gases can deviate from these assumptions, especially at high pressures and low temperatures. However, for most practical purposes, the ideal gas law provides a good approximation of gas behavior.

To know more about ideal gas law refer here

https://brainly.com/question/28257995#

#SPJ11

To answer this question, we need to use the equation for molarity, which is:
Molarity = moles of solute / volume of solution in liters
We can rearrange this equation to solve for the volume of solution:

Volume of solution = moles of solute / molarity
First, we need to calculate the number of moles of HCl in 32.0 g. The molar mass of HCl is 36.5 g/mol, so:
32.0 g / 36.5 g/mol = 0.8767 mol HCl

Next, we need to calculate the volume of solution needed to make a 4.80 m solution. Using the equation above:
Volume of solution = 0.8767 mol / 4.80 mol/L = 0.1826 L or 182.6 mL
Finally, we need to calculate how much water needs to be added. We started with 32.0 g of HCl and added water to make a total volume of 182.6 mL. The volume of water added is therefore:

Volume of water added = 182.6 mL - 32.0 g / 1 g/mL = 150.6 mL
Converting to liters:
Volume of water added = 150.6 mL / 1000 mL/L = 0.1506 L

Therefore, the answer is 0.18 L of water should be added to 32.0 g of HCl to make a 4.80 m solution.

To know more about Molarity refer here

https://brainly.com/question/8732513#

#SPJ11

Aluminum has a heat of fusion of 0.9 j/g. if you have 23.9g of aluminum, 21.51 J of energy would be required to melt this amount of aluminum at 660.3°c.

To calculate the energy required to melt 23.9 g of aluminum, we need to use the following formula:

Q = m * ΔHfus

where Q is the energy required, m is the mass of aluminum, and ΔHfus is the heat of fusion of aluminum.

Substituting the given values, we get:

Q = 23.9 g * 0.9 J/g = 21.51 J

Therefore, 21.51 J of energy would be required to melt 23.9 g of aluminum at 660.3°C.

To know more about the heat of fusion refer here :

https://brainly.com/question/14053504#

#SPJ11

Answer:

Backbone help us to be straight ,walk ,sleep etc

Explanation:

Backbone is the part of human body which is located back of our body.

It effort helps us to be straight do various work

The spine or the backbone is the central structure of the vertebrate body and it serves a few imperative capacities:

To know more about backbone,

https://brainly.com/question/30052045

The pH of the final solution will be equal to 7.

When 100 mL of 0.40 M hydrofluoric acid (a weak acid) is mixed with 100 mL of 0.40 M lithium hydroxide (a strong base), the reaction can be represented as:

HF + LiOH → LiF + H₂O

As both solutions have equal concentrations and volumes, they will completely neutralize each other. The product, LiF, is a soluble salt and will dissociate into Li+ and F- ions in water.

Since the number of moles of H+ and OH- ions is the same in the reaction, they will react to form water (H₂O), resulting in a neutral solution with a pH of 7. The formation of water from equal amounts of H⁺ and OH⁻ ions indicates that the solution is neither acidic nor basic, thus leading to a pH of 7.

To know more about weak acid click on below link:

https://brainly.com/question/22104949#

#SPJ11

Student 1 and Student 3 both provide incorrect explanations for the increase or decrease in entropy during dissolution reactions. Option A is correct.

Student 1 suggests that the entropy increased for ammonium nitrate but decreased for sodium hydroxide, based on the number of species introduced to water, which is not a valid explanation. Student 3 suggests that the entropy decreased for both ammonium nitrate and sodium hydroxide due to the salts becoming more ordered, which is also incorrect.

On the other hand, Student 2 provides the correct scientific reasoning. According to the second law of thermodynamics, dissolution reactions always result in an increase in entropy. As the solid dissolves, the molecules become more dispersed in the solvent, which increases the number of micro-states and hence the entropy. Option A is correct.

To know more about the Entropy, here

https://brainly.com/question/23132859

#SPJ4

Answer:2.18 g.

Explanation:To find the mass of sodium sulfate reacted, we use the balanced chemical equation to know that 1 mole of sodium sulfate reacts with 1 mole of barium sulfate. From the given mass of barium sulfate formed, we calculate the number of moles of barium sulfate. Since the stoichiometry of the reaction is 1:1, the number of moles of sodium sulfate reacted is the same as the number of moles of barium sulfate formed. We then use the molar mass of sodium sulfate to calculate the mass of sodium sulfate reacted. The final answer is 2.18 g.