if a neutral atom of oxygen (O) has 8 protons, 8 electrons and 7 neutrons, what is the mass number of this atom?
A.8
B.15
C.16
D.23

Answer:

Answers are in the image.

Explanation:

In dehydration reaction of alcohols, alcohols lose water to generate alkene proceeds by heating the alcohols in the presence of a strong acid, such as sulfuric or phosphoric acid (HX), at high temperatures. The most substituted alkene are formed preferentially

The products and mechanism are in the images.

I hope it helps!

The statement is likely false. The entropy of a substance generally increases with its molecular complexity and size, suggesting C₂H₅OH(l) would have higher entropy than CH₃OH(l). Additionally, the physical state (solid, liquid, gas) impacts entropy, but in this case, both substances are liquids.

The statement that 1 mole of CH₃OH(l) has a greater entropy than 1 mole of C₂H₅OH(l) is likely false. Entropy, a measurement of disorder or randomness in a system, generally increases with the complexity and size of a molecule. For example, a larger molecule with more atoms (like C₂H₅OH, also known as ethanol) typically has more potential arrangements or microstates, leading to a higher entropy than a smaller, less complex molecule (like CH₃OH, also known as methanol).

Furthermore, it should be noted that the physical state can significantly impact entropy. In general, gases have higher entropy than liquids, which in turn, have higher entropy than solids due to the increased disorder and freedom of movement in these states. However, as both substances in this case are in the liquid state, the primary factor influencing the entropy is likely the size and complexity of the molecule.

https://brainly.com/question/38613023

#SPJ12

The statement 1 mole of CH3OH(l) has a greater entropy than 1 mole of C2H5OH(l) is False.

To understand why this statement is false, let's consider the factors that affect the entropy of a substance. Entropy is a measure of the disorder or randomness in a system. In general, for liquids, the larger the molecule, the more ways there are for the molecules to arrange themselves, leading to higher entropy.

CH3OH, methanol, has a molar mass of approximately 32.04 g/mol, while C2H5OH, ethanol, has a molar mass of approximately 46.07 g/mol. Since ethanol has a larger molecule than methanol, it is expected to have a higher entropy due to the increased number of possible arrangements of its molecules in the liquid state.

Furthermore, experimental data supports this expectation. The standard molar entropy (S°) for methanol (CH3OH) at 298 K is about 126.8 J/(mol·K), while the standard molar entropy for ethanol (C2H5OH) at 298 K is about 160.7 J/(mol·K). Therefore, ethanol has a higher entropy than methanol in the liquid state.

In conclusion, 1 mole of C2H5OH(l) actually has a greater entropy than 1 mole of CH3OH(l), making the original statement false.

The percent yield of the alcohol fermentation reaction can be calculated by using the stoichiometry of the reaction and the ideal gas law. This involves converting the given mass of glucose to moles, calculating the expected moles of CO₂, and comparing this to the actual moles of CO₂ collected.

In your question, you're interested in the percent yield of alcohol fermentation - a biological process where yeast converts glucose to ethanol and CO₂. The starting amount of glucose and the amount of collected CO₂ are given, both of which can be used to calculate percent yield. Use the molecular weight of glucose to convert its initial given mass to moles. From there, you can calculate expected moles of CO₂ using the stoichiometry of the proposed alcohol fermentation reaction: 1 mole of glucose yields 2 moles of CO₂.

Furthermore, the actual moles of CO₂ collected can be calculated using the ideal gas law (PV=nRT), where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature in Kelvin. Finally, percent yield can be calculated by taking the actual yield (from the collected volume of CO₂) divided by the theoretical yield (from the stoichiometry of the reaction), and multiplying by 100% to obtain a percentage.

https://brainly.com/question/6947990

#SPJ11

A 12-carbon activated fatty acid requires 5 cycles of the β-oxidation pathway to be fully converted into acetyl-CoA molecules.

The β-oxidation pathway is a critical metabolic process that breaks down fatty acids into acetyl-CoA molecules.

To calculate the number of repetitions needed to fully convert a 12-carbon activated fatty acid into acetyl-CoA molecules, we can use the formula: [tex]\frac{n}{2} -1[/tex], where n is the number of carbon atoms in the fatty acid.

For a 12-carbon fatty acid:

Therefore, a 12-carbon activated fatty acid requires 5 repetitions of the β-oxidation pathway to be fully converted into acetyl-CoA molecules.

Final answer:

The volume occupied by a mixture of 0.522 mol of N2 and 0.522 mol of O2 gases at 0.56 atm and 42.7°C is calculated to be approximately 48.18 liters using the ideal gas law.

Explanation:

The question is asking to calculate the volume occupied by a mixture of gases using the ideal gas law. For a mixture of 0.522 mol of N2 and 0.522 mol of O2 gases at 0.56 atm and 42.7°C, we first need to convert the temperature to Kelvin by adding 273.15 to the Celsius temperature, which gets us 315.85 K. We then use the ideal gas law equation PV = nRT, where P is the pressure in atm, V is the volume in liters, n is the amount of gas in moles, R is the ideal gas constant (0.0821 L·atm·K⁻¹·mol⁻¹), and T is the temperature in Kelvin. Since both gases are ideal and in the same conditions, there is no need for separate calculations; we can combine the moles of the gases as the total amount is the sum of the individual moles of N2 and O2.

The total moles of gases is 0.522 mol + 0.522 mol = 1.044 mol. Placing these values into the ideal gas law equation and solving for V (volume), we have V = (nRT)/P. The calculated volume is then:

V = (1.044 mol x 0.0821 L·atm·K⁻¹·mol⁻¹ x 315.85 K) / 0.56 atm = 48.18 L

The volume occupied by the mixture is approximately 48.18 liters.

Oxygen is essential for life, but too much can be harmful. Lack of oxygen leads to brain damage and death. The optimal level for supporting life is about 20% oxygen in the atmosphere.

Oxygen is a vital component for life and is necessary for the chemical reactions that keep our bodies alive. It is a key player in the production of ATP, which is the energy currency of cells. Lack of oxygen can lead to brain damage within minutes and death within a short period of time.

While oxygen is essential for life, too much of it can be harmful. Pure oxygen at high concentrations can be toxic and cause damage to cells. The atmosphere contains about 20% oxygen, which is the optimal level for supporting life.

It is incorrect to say that less oxygen on Earth would lead to longer life spans. In fact, organisms require a certain amount of oxygen to survive and thrive. Oxygen is necessary for the process of respiration, which generates energy for the body.

To determine if an unknown compound is an alcohol using its IR spectrum, look for a distinct broad O-H stretch in the 3300 to 3400 cm⁻¹ range indicative of hydrogen bonding, and a strong C-O stretch. These features differentiate alcohols from other compounds with similar functional groups.

If you examine the IR spectrum of an unknown and want to determine if it is an alcohol, look for two key features: the O-H stretch and the C-O stretch. Alcohols are characterized by a very broad, strong O-H stretch in the range of 3300 to 3400 cm⁻¹, which is indicative of hydrogen bonding within the alcohol.

Additionally, alcohols exhibit a strong C-O stretch typically around 1000 to 1300 cm⁻¹. Unlike ethers and epoxides, which also display a C-O stretch, alcohols can be distinguished by the presence of the broad O-H stretch.

The exact position and the breadth of the O-H absorption can vary based on the level of hydrogen bonding, thus providing further clues about the structure of the unknown alcohol. To confirm the identity, comparing the IR spectrum of the unknown sample against known standards can be very helpful.

Final answer:

When solid potassium nitrate is put into water, it dissociates into its constituent ions: K+ and NO3-. The compound potassium nitrate is a strong electrolyte.

Explanation:

When solid potassium nitrate (KNO3) is put into water, it undergoes dissociation into its constituent ions. The balanced chemical equation for this reaction is:

KNO3 (s) → K+ (aq) + NO3- (aq)

This reaction shows that potassium nitrate is a strong electrolyte as it completely ionizes in water, producing free moving ions and allowing for electrical conductivity.

The number of moles can simply be calculated by the product of Molarity and Volume in L, therefore:

number of moles = (2.26 moles / L)* 0.0152 L

number of moles = 0.0344 moles

The molar mass of KOH is 56.11 g/mol, therefore the mass is:

mass = 0.0344 moles * 56.11 g/mol

mass = 1.93 g

Final answer:

To find moles and mass of KOH in a 15.2 ml sample of 2.26 M solution, you first calculate moles (0.034392 mol) using molarity and volume, then convert moles to grams using KOH's molar mass, resulting in 1.929 grams.

Explanation:

The task is to calculate the moles and mass of solute present in a 15.2 ml sample of a 2.26 M KOH solution. First, to find the number of moles of KOH in the sample, we use the formula moles of solute = molarity × volume of solution (in liters). Since the molarity is given as 2.26 M and the volume is 15.2 ml (which is equivalent to 0.0152 liters), the calculation is:

moles of KOH = 2.26 M × 0.0152 L = 0.034392 mol

Next, to find the mass of the solute, we multiply the number of moles by the molar mass of KOH. The molar mass of KOH is approximately 56.11 g/mol. Thus, the mass of KOH in the sample is:

mass of KOH = 0.034392 mol × 56.11 g/mol = 1.929 g

Therefore, the 15.2 ml sample of 2.26 M KOH solution contains approximately 0.034392 moles and 1.929 grams of KOH.

The effective nuclear charge (Zeff) for a valence electron in an oxygen atom is calculated using the formula Zeff = Z - S, with Z being the atomic number (8 for oxygen) and S the shielding constant (2 for oxygen). Thus, Zeff for a valence electron in oxygen is 6.

To calculate the effective nuclear charge (Zeff) for a valence electron in an oxygen atom, we first need to know the electron configuration of an oxygen atom. Oxygen has an atomic number of 8, so its electron configuration is 1s2 2s2 2p4. The valence electrons are those in the highest energy level, so for oxygen, they are the four electrons in the 2p orbital.

Using the formula Zeff = Z - S, where Z is the atomic number and S is the shielding constant, we can estimate Zeff for oxygen. Oxygen's atomic number (Z) is 8, and the shielding constant (S) is approximately equal to the number of nonvalence electrons, which for oxygen is 2 (the two electrons in the 1s orbital).

Therefore, Zeff for a valence electron in an oxygen atom is calculated as follows:
Zeff = Z - S = 8 - 2 = 6

The Zeff of 6 means that valence electrons in an oxygen atom experience an effective charge of +6 from the nucleus.

https://brainly.com/question/34266530

#SPJ3

Answer is: Huge stadium with a positively charged marble at the center.

According to Rutherford model of the atom:

1) Atoms have their charge concentrated in a very small nucleus.

2) Major space in an atom is empty.

3) Atoms nucleus is surrounded by negatively charged particles called electrons.

4) An atom is electrically neutral.

The enthalpy change for the thermite reaction when 8.00 mol of Al reacts is -6812 kJ.

The enthalpy change for the thermite reaction can be calculated using Hess's law. The overall reaction can be broken down into three steps, each with its own known enthalpy change values. The enthalpy change for the reaction is the sum of the enthalpy changes for each step.

In this case, the enthalpy change for the reaction is -851.5 kJ/mol of Fe₂O₃. To calculate the enthalpy change when 8.00 mol of Al reacts, you can multiply the enthalpy change by the number of moles of Al consumed, which is 8.00 mol. This gives a total enthalpy change of -851.5 kJ/mol x 8.00 mol = -6812 kJ.

Therefore, the enthalpy change for the thermite reaction when 8.00 mol of Al reacts is -6812 kJ.

https://brainly.com/question/32882904

#SPJ3

For the recrystallization of naphthalene, ethanol is likely more effective than hexane due to its ability to form hydrogen bonds and its polar nature, allowing for better dissolution when heated and potentially higher recovery rates.

The effectiveness of a solvent in the recrystallization of naphthalene depends on the solubility of naphthalene in that solvent at different temperatures. For recrystallization, a solvent in which the desired compound is slightly soluble when cold but more soluble when hot is ideal. Ethanol is a polar solvent that can form hydrogen bonds and therefore, can dissolve a wide range of organic compounds, including naphthalene, more effectively when heated.

Whereas, hexane is nonpolar and might not be as effective at dissolving naphthalene, especially if the substance is more polar. Based on solubility profiles and hydrogen bonding capabilities, ethanol would likely be a more effective solvent for recrystallization of naphthalene compared to hexane.

To solve this, we must remember that the number of moles in each formula must a whole number.

So we are given two X’s:

X = 0.3

X = 0.39

We divide the two by the smallest X, so divide by 0.3:

X = 0.3 / 0.3 = 1

X = 0.39 / 0.3 = 1.3

However the second X is not a whole number yet, therefore multiply the two X’s by 3 to make them whole numbers:

X = 1 * 3 = 3

X = 1.3 * 3 = 4

So the X’s must be: X3 and X4 and based from the choices, the answer is:

X3Y and X4Y

The plausible sets of formulas for these two  compounds are:

A. X2Y and X3Y

B. XY3 and XY4

C. X3Y and X4Y

D. XY and X3Y

E. XY and X2Y

F. X2Y5 and X3Y5

G. X4Y2 and X3Y

I think the correct answers are A and F. and G:

If we look at the combining masses of X and Y in each of the two compounds, the first compound contains 0.25 g of X combined with 0.75 g of Y, therefore the ratio (by mass) of X to Y is 1 : 3. Whereas the second compound contains 0.33 g of X combined with 0.67 g of Y, therefore the ratio (by mass) of X to Y is 1 : 2.

Then, suppose prepared each of these two compounds, starting with the same fixed mass of element Y (I will choose 12 g of Y for an easy calculation) 

The first compound will then contain 4g of X and 12g of Y. Next the second compound will then contain 6g of X and 12g of Y. The ratio which combined the masses of X and the fixed mass (12 g) of Y = 4 : 6 or 2 : 3.

So, the ratio of Moles of X which combined with the fixed amount of Y in the two compounds is also 2 : 3. Then the two compounds given with the plausible formula must therefore contain the same ratio.

Grade:  9

Subject: Chemistry  

Chapter: compounds

Keywords: the generic elements X,  the generic elements Y,  two  compounds, XY, X3Y

Substituting 6M NaOH for 6M NH3 in testing the reference solution would result in a more basic solution and a higher pH.

When testing a reference solution, if 6M NaOH is substituted for the 6M NH3, a different observation would be made. NH3 is a weak base, while NaOH is a strong base. In this case, the pH of the solution would change significantly since NaOH completely dissociates in water, producing a high concentration of hydroxide ions. On the other hand, NH3 only partially reacts with water, resulting in a lower concentration of hydroxide ions. Therefore, substituting NaOH for NH3 would result in a more basic solution and a higher pH.

Answer: 81.8 g/mol

Explanation:

We’re being asked to calculate the molar mass of an unknown acid based on our interpretation of the titration curve.  

Recall that at the equivalence point of a titration:

[tex]moles\ acid=moles\ base[/tex]

We can use this equation to calculate the moles of the unknown acid. Since the unknown acid only has a single Ka value, it is a monoprotic acid, which means there will be one equivalence point for the titration.

Mole-to-mole comparison: A mole-to-mole comparison will then show that 1 mole of the unknown acid reacts with 1 mole of Na(OH).

Molarity of NaOH: The molarity of NaOH (the base) is given as 0.112 M or 0.112 mol/L NaOH.

As for the volume of NaOH (the base) added, we can interpret this from the graph:  

we can see that at the equivalence point, 25 mL of the vase was added.

Vbase is more or less 25.00 mL

Recall:  

1 mL = 10-3 L  

Solving for MMacid:  

Again, at the equivalence point of a titration:

[tex]moles\ acid=moles\ base=0.112*25*10^{-3}[/tex]

[tex]moles\ acid = 0.0028\ moles[/tex]

Molar mass is defined as the mass in grams of one mole of a substance.  

The units of molar mass are grams per mole, abbreviated as g/mol and uses the formula below:

[tex]molar\ mass=\frac{mass\ of\ compound\ in\ grams}{mole\ of\ compound\ in\ moles}[/tex]

[tex]=\frac{mass\ of\ acid}{moles\ acid}[/tex]

[tex]=\frac{0.229g}{0.0028mol}[/tex]

molar mass acid = 81.8 g/mol

The molar mass of the unknown acid is 81.8 g/mol.

An acid that donates a single hydrogen atom or proton is called monoprotic acid. The molar mass of the unknown acid in titration is 81.8 gm/mol.

The molar mass of any substance is the ratio of the mass of the substance in grams and moles of the same substance in mol. The molar mass is given by g/mol.

In titration, the moles of acid are equivalent to acid and can be used to determine the moles of the unknown acid from the base.

We know, that the molarity of base (NaOH) is 0.112 M, and the graph is used to know the volume to be 25 ml.

The moles of the base is calculated as:

[tex]\begin{aligned} \rm moles &=\rm molarity \times volume\\\\&= 0.112 \;\rm M \times 25 \times 10^{-3}\;\rm L\\\\&= 0.0028\;\rm moles\end{aligned}[/tex]

Hence, moles of acid is 0.0028 mol.

The molar mass of acid is calculated as:

[tex]\begin{aligned}\rm Molar \;mass &= \rm \dfrac{mass}{moles}\\\\&= \dfrac{0.229}{0.0028}\\\\&= 81.8\;\rm g/mol\end{aligned}[/tex]

Therefore, 81.8 g/mol is the molar mass of unknown monoprotic acid.

Learn more about molar mass here:

https://brainly.com/question/5813064

Option A. Smaller atoms and stronger bonds.

Smaller the size of the atoms, less will be the distance between positive charge nucleus of one atom and electrons (negative charge) of other atom. This results in strong interaction between them.

Also, stronger bonds are difficult to break, making the minerals harder. Thus, small atoms and strong bonds in minerals makes then harder than the minerals with weak bonds or larger atoms.

When a chemical process reaches equilibrium, the equilibrium constant (often represented by the letter K) sheds light on the interaction between the reactants and products. The reciprocal of the initial equilibrium serves as the equilibrium constant for the reverse equilibrium.

The ratio of the concentration of the products to the concentration of the reactants, each raised to their respective stoichiometric coefficients, is the equilibrium constant of concentration (denoted by Kc) of a chemical process at equilibrium.

Since the acid is diprotic, there are two equilibrium dissociation reactions for it. Consequently, there will also be two expressions for equilibrium constants, Ka₁ and Ka₂.

First reaction:

H₂SO₃ ⇄ 2H⁺ + HSO₃²⁻          ------>     Ka₁ = [H⁺][HSO₃²⁻]/[H₂SO₃]

Second reaction:

HSO₃²⁻ ⇆ H⁺ + SO₃²⁻             ------>     Ka₂ = [H⁺][SO₃²⁻]/[HSO₃²⁻]

To know more about equilibrium constants, visit;

https://brainly.com/question/31603248

#SPJ6

Actually the third shall is composed of 1 s orbital, 3 p orbitals, and 5 d orbitals. Each of these orbital holds 2 electrons therefore the total number of electrons are:

(1 + 3 + 5) * 2 = 18

There are 18 electrons that can fall in the 3rd shell. And there are 9 orbitals.

Answer:

Solar radiation

Explanation:

Umm.. i just guessed and got the question right so...sksksks

look at the picture below for the anwse

To prepare 350 mL of 0.100 M solution from a 1.50 M solution, we simply have to use the formula:

M1 V1 = M2 V2

So from the formula, we will know how much volume of the 1.50 M we actually need.

1.50 M * V1 = 0.100 M * 350 mL

V1 = 23.33 mL

So we need 23.33 mL of the 1.50 M solution. We dilute it with water to a volume of 350 mL. So water needed is:

350 mL – 23.33 mL = 326.67 mL water

Steps:

1. Take 23.33 mL of 1.50 M solution

2. Add 326.67 mL of water to make 350 mL of 0.100 M solution

Final answer:

To prepare 350 mL of a 0.100 M C12H22O11 solution from a 1.50 M C12H22O11 solution, measure 23.33 mL of the 1.50 M solution and dilute it with solvent to reach a total volume of 350 mL.

Explanation:

To prepare 350 mL of a 0.100 M C12H22O11 solution starting with 3.00 L of a 1.50 M C12H22O11 solution, we can use the equation C1V1 = C2V2, where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.

Plugging in the values, we have (1.50 M)(3.00 L) = (0.100 M)(350 mL). Solving for V1, we get V1 = (0.100 M)(350 mL) / (1.50 M) = 23.33 mL.

Therefore, you should measure 23.33 mL of the 1.50 M C12H22O11 solution and dilute it with enough solvent (such as water) to reach a total volume of 350 mL.

The pH of acid is between 0-7 on pH scale while for base pH range is from 7-14. Therefore, the pH of  0.000081M  HClO₄  is 4.09. pH is a unitless quantity.

pH is a measurement of amount of hydronium ion H₃O⁺ in a given sample. More the value of hydronium ion concentration, more will be the solution acidic.

On subtracting pH from 14, we get pOH which measures the concentration of hydroxide ion in a given solution. pH depend on the temperature. At room temperature pH scale is between 0 to 14. pH of neutral solution is 7.

The concentration of  HClO₄ is 0.000081M or 8.1x10⁻⁵M

Concentration of H₃O⁺ in HClO₄ =0.000081M or 8.1x10⁻⁵M

Mathematically,

pH=-log[H⁺]

Substituting the values

pH=-log[0.000081]

pH of HClO₄=4.09

Thus the pH of  0.000081M HClO₄ is 4.09.

To learn more about pH, here:

https://brainly.com/question/27945512

#SPJ2

To find the percentage of water vaporized, use the ideal gas law to calculate the initial and final amount of water in the flask. Then, subtract the final amount from the initial amount to find the mass of water vaporized. Finally, divide the mass of water vaporized by the initial mass of water and multiply by 100 to find the percentage.

To find the percentage of water vaporized, we need to calculate the initial and final amount of water in the flask. We know that the initial mass of water is 1.20 g. Using the ideal gas law, we can calculate the amount of water vapor at 65°C and the pressure of 187.5 mmHg. Then, we can subtract the final amount of water vapor from the initial amount to find the mass of water vaporized. Finally, we can divide the mass of water vaporized by the initial mass of water and multiply by 100 to find the percentage:

By following these steps, you should be able to calculate the percentage of water vaporized.

https://brainly.com/question/26562774

#SPJ11