How much heat is given off when 16 g liquid methanol (CH3OH) at its freezing point
changes to solid methanol? (methanol AH+ = 3.16 kJ/mol)

A. 0.79 kJ
B. 0.18 kJ
C. 1.58 kJ
D. 0.36 kJ

Answer:

We need more? What else is in the question? This is unanswerable.

Explanation:

Answer:

ΔH=9.2 KJ

Explanation:

2NO₂→N₂O₄  ΔH=-57 KJ/mol

N₂ + O₂→2NO ΔH=180.6 KJ/mol

2NO + O₂→2NO₂ ΔH= -114.4 (notice this was reversed and sign changed

_____________________________________________

N₂+2O₂→N₂O₄ ΔH= 9.2 KJ

By reversing the third equation, we can get the O₂ on the left side or the (reactant side) so that we can get a total of 2O₂ in the final equation on the bottom. Cross out 2NO₂ on the first equation on the reactant side and 2NO₂ in equation 2 on the product side. You also want to cross out 2NO in the third equation on both the reactant and product side. This leaves the same above the line as below the line.

Since you reverse equation 3, the change in enthalpy will change sign so you input -57, 180.6 and -114.4 to get 9.2 KJ

Hope that helps.

Answer:

name four agricultural inputs are subsidized by the government

0.297 kJ of heat is needed to raise the temperature of 10g of aluminum from 22 degrees Celsius to 55 degrees Celsius.

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.

It is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.

It is given by the formula -

                                                  Q = mcΔT

where, Q = amount of heat

m = mass

c = specific heat

ΔT = Change in temperature

Given,

mass = 10g

c = 0.901J/g⁰C

Initial temperature (T₁) = 22⁰C

Final Temperature (T₂) = 55⁰C

Q = mcΔT

= 10 × 0.901 × (55 -22)

= 297.33 J = 0.297 kJ

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Answer:

Positive charge.

Explanation:

Hello!

In this case, since elements belonging to groups 1A, 2A and 3A are mostly metals, we infer they have the capacity to lose electrons and therefore they become positively charged.

Some examples may be:

\(Na^+\\\\H^+\\\\Ca^{2+}\\\\Al^{3+}\\\\Sr^{2+}\)

Best regards!

Answer:

o s2- or o A13 + Ba2+ or something else

Carbon atoms may thus form bonds to as many as four other atoms. For example, in methane (CH 4​start subscript, 4, end subscript), carbon forms covalent bonds with four hydrogen atoms

__________________________________________________________

Complete question is;

Which statements regarding the Henderson-Hasselbalch equation are true?

1. If the pH of the solution is known as is the pKa for the acid, the ratio of conjugate base to acid can be determined.

2. At pH = pKa for an acid, [conjugate base] = [acid] in solution.

3. At pH > pKa for an acid, the acid will be mostly ionized.

4. At pH < pKa for an acid, the acid will be mostly ionized.

A. All of the listed statements are true. B. 1, 2, and 3 are true.

C. 2, 3, and 4 are true.

D. 1, 2, and 4 are true.

Answer:

B. 1, 2, and 3 are true.

Explanation:

The formula for the Henderson-Hasselbalch equation is:

pH = pka + log₁₀([A^(-)]/[HA])

Where;

PH is acidity of solution

ka is acid dissociation constant

A^(-) is concentration of conjugate base

HA is concentration of Acid

- For statement 1; If the pH of the solution is known as is the pKa for the acid, the ratio of conjugate base to acid can be determined;

pH = pka + log₁₀([A^(-)]/[HA])

pH - pka = log₁₀([A^(-)]/[HA])

10^(pH - pka) = ([A^(-)]/[HA])

Since we can find the ratio as seen, then the statement is true

- For statement 2: At pH = pKa for an acid, [conjugate base] = [acid] in solution;

We will substitute pH for pKa;

pH = pH + log₁₀([A^(-)]/[HA])

This give;

0 = log₁₀([A^(-)]/[HA])

10^(0) = [A^(-)]/[HA]

1 = [A^(-)]/[HA]

Thus; [A^(-)] = [HA]

Thus, the statement is true

- For statement 3: At pH > pKa for an acid, the acid will be mostly ionized;

This means that;

pH - pKa is greater than 0 and thus;

10^(pH - pKa) is greater than 1.

Thus;

[A^(-)]/[HA] > 1

[A^(-)] > [HA]

So more acid is ionized than base.

So the statement is true.

- For statement 4: At pH < pKa for an acid, the acid will be mostly ionized;

This means that;

pH - pKa is less than 0 and thus;

10^(pH - pKa) is less than 1.

Thus;

[A^(-)]/[HA] < 1

[A^(-)] < [HA]

So we have more base ionized than acid. So statement is false

Four quantities must be known for a complete physical description of a sample of a gas: temperature, volume, amount, and pressure. ... The height of the mercury column is proportional to barometric pressure, which is often reported in units of millimeters of mercury (mmHg), also called torr.

\(\implies\) The correct answer is (B) 0.00037

\(\bf{ \underline{Step \: 1)} :3.7 × 10^{-4 }we \: can \: write \: as \:37 × 10^{-5}}\)

\(\bf{ \underline{Step \: 2)} :37 × 10^{-5 } \: we \: can \: write \: as \: 37 × \frac{1}{10^5}}\)

\(\bf{ \underline{Step \: 3)} :37 × \frac{1}{10^5}\: we \: can \: write \: as \: (37 × \frac{1}{(10)(10)(10)(10)(10)}})\)

\(\bf{ \underline{Step \: 4)} :37 × \frac{1}{(10)(10)(10)(10)(10)} we \: can \: write \: as \: ( 37 × \frac{1}{100000}})\)

\(\bf{ \underline{Step \: 5)} :37 × \frac{1}{100000} \: we \: can \: write \: as \: \frac{37}{100000}}\)

\(\bf{ \underline{Step \: 6)} :\frac{37}{100000} \: we \: can \: write \: as \: 0.000037}\)

Answer:

Anything which occupy space and have mass between them are called matter.

Sedimentation, filtration, and coagulation are the treatments that will help remove contaminants from minerals or from the pipes carrying water from a source.

Sedimentation is a process in which suspended particles settle out of water. It is one of the most basic techniques for removing particles from water. As particles settle, they become trapped in the bottom of a container or settle to the ground in an outdoor setting

Filtration is a method of removing particles from a fluid. It is a physical or chemical separation method that separates solids from fluids (liquids or gases) by adding a medium through which only the fluid can pass.

Coagulation is the process of using chemicals to remove contaminants from water. By creating a chemical reaction, coagulation destabilizes particles and causes them to clump together. This helps to remove the contaminants from the water.

Disinfection is the process of eliminating or destroying pathogens that cause infection. Disinfection eliminates harmful microorganisms by destroying or inactivating them. The disinfectant is a chemical or physical agent that is used to destroy or inactivate harmful microorganisms.

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Answer:

B

Explanation:

Planting trees sequesters CO2

  all of the other choices produce more CO2 in the atmosphere

In order to find the result we will have to do some stoichiometry in this question, first we need to set up the reaction:

3 NO2 + H2O -> 2 HNO3 + NO, the reaction is already properly balanced, but there could be some stoichiometry questions in which you need to balance it first

Now, we have 60 grams of NO2, and we want to know how many grams of NO will be produced, let's check the molar ratio between the two compounds

If we have 3 moles of NO2 we will end up with 1 mol of NO, therefore the molar ratio is 3:1

The partial atmospheric pressure (atm) of hydrogen in the mixture is 0.59 atm.

Partial pressure of particular gas will be calculated as:

p = nP, where

Moles will be calculated as:

Moles of Hydrogen gas = 2.02g / 2.014g/mol = 1 mole

Moles of Chlorine gas = 35.90g / 70.9g/mol = 0.5 mole

Mole fraction of hydrogen = 1 / (1+0.5) = 0.6

Partial pressure of hydrogen = (0.6)(748) = 448.8 mmHg = 0.59 atm

Hence, required partial atmospheric pressure of hydrogen is 0.59 atm.

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Answer:

I think first molar mass of ch3o which is 31

Explanation:

Answer:

c i think

Explanation:

Answer:

heat energy released by the substance

The energy change that takes place during deposition is that heat energy is released by the substance. This statement is true about deposition.

Deposition is a phase transition that occurs when a gas is converted directly to a solid without passing through the liquid state. During deposition, energy is released by the gas particles and absorbed by the surface, resulting in a decrease in the energy of the gas particles and an increase in the energy of the surface particles.As a result, the substance releases heat energy as it changes from a gas state to a solid state.

Therefore, the correct option is:Heat energy released by the substance.

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The term that the scientist would use in this case is partial pressure. Option D

The pressure that one particular gas component within a mixture of gases exerts is referred to as partial pressure. It is the pressure that the gas would experience at the same temperature if it were the only thing in the entire volume.

When researching gas mixtures, such as in gas laws, gas phase equilibria, and gas collecting methods, partial pressures are extremely crucial for the gas.

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Answer:

By filtering

Explanation:

Take one cup of mixture of sand and water , filter using a cotton cloth ,

Answer:

i think a solution

Explanation:

sry dont get mad if im wrong

Answer:

Convection currents are the result of differential heating. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.

Answer:

If Jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy,work is being done. Work is said to be done when it transforms energy from one form to another or from one place to another.

Explanation:

Answer:

56.96 grams

Explanation:

To find the mass of 1.78 moles of O2, we need to use the molar mass of O2, which is the mass of one mole of O2.

The chemical formula for O2 is O-O or simply O2. The molar mass of O2 is the sum of the atomic masses of two oxygen atoms, which can be found on the periodic table.

The atomic mass of oxygen (O) is approximately 16.00 g/mol. So the molar mass of O2 is:

Molar mass of O2 = 2 x atomic mass of O

= 2 x 16.00 g/mol

= 32.00 g/mol

Therefore, the mass of 1.78 moles of O2 is:

Mass = number of moles × molar mass

= 1.78 mol × 32.00 g/mol

= 56.96 g

So the mass of 1.78 moles of O2 is 56.96 grams.

The new temperature : 11.56 °C

Boyle's law and Gay Lussac's law  

\(\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}\)

P1 = initial gas pressure (N/m² or Pa)  

V1 = initial gas volume (m³)  

P2 = final gas pressure  

V2 = final gas volume

T1 = initial gas temperature (K)  

T2 = final gas temperature  

V₁=4.39 L

T₁=44+273=317 K

P₁ = 729 torr = 0,959211 atm

V₂=3.78 L

P₂= 1 atm

\(\tt \dfrac{0.959211\times 4.39}{317}=\dfrac{1\times 3.78}{T_2}\\\\T_2=\dfrac{1\times 3.78\times 317}{0.959211\times 4.39}\\\\T_2=284.559~K=11.56~C\)

Answer:

66.48 g.

Explanation:

Bauxite ore contains aluminium oxide which is decomposed using electricity to produce aluminium metal and oxygen gas

The number of chlorine moles present in the vessel are 37.67 mol.

What are moles?

Moles are the number of substances present in a system which consists of entities like ions, atoms, or molecules as much as atoms in the weight of pure carbon which is 12 grams. It is the SI unit of amount of substance.

One mole of a substance is equal to the Avogadro Number which is equal to 6.022×10²³.

According to Ideal gas law,

PV=nRT where,

P= Pressure

V= Volume

n= number of moles

R= Ideal gas constant

T= temperature (in Kelvin)

n= PV/RT

⇒33.3×36.5/0.0821×393

⇒1215.45/32.2653

⇒37.670

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The ion with a +3 charge, 28 electrons, and an atomic mass of 71 is the aluminum ion (\(Al^{3+}\)).

Aluminum (Al) typically has an atomic number of 13, which means it has 13 protons and 13 electrons in its neutral state. However, in the given ion, \(Al^{3+}\), the ion has lost three electrons, resulting in a +3 charge. This means that the ion now has 13 protons and only 10 electrons remaining, giving it a net positive charge of +3.

The atomic mass of aluminum is 26.98 atomic mass units (amu). The given ion has an atomic mass of 71 amu, which suggests that the ion has gained additional particles. In this case, the ion has also gained three neutrons, resulting in a higher atomic mass.

The total number of particles (protons, neutrons, and electrons) in the ion can be calculated by adding the number of protons (13) and the number of neutrons (3), which equals 16. Since the ion has a net charge of +3, it only contains 10 electrons.

In summary, the ion with a +3 charge, 28 electrons, and an atomic mass of 71 is the aluminum ion (\(Al^{3+}\)), which has 13 protons, 10 electrons, and 3 neutrons.

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The mass of sulfur dioxide required is approximately 6.36 grams.

To determine the number of grams of sulfur dioxide (SO2) required to exert a pressure of 0.705 atm in a 2.50L tank at 0 °C, we can use the ideal gas law equation: PV = nRT.

First, we need to convert the temperature from Celsius to Kelvin by adding 273.15, so the temperature becomes 273.15 K. The ideal gas constant (R) is 0.0821 L·atm/(mol·K).Rearranging the ideal gas law equation to solve for the number of moles (n), we get n = PV / RT.

Plugging in the given values, n = (0.705 atm) * (2.50 L) / [(0.0821 L·atm/(mol·K)) * (273.15 K)]. Calculating this expression, we find that n is approximately 0.0993 moles.The molar mass of sulfur dioxide is 64.06 g/mol (32.06 g/mol for sulfur + 2 * 16.00 g/mol for oxygen).

Finally, we can calculate the mass of sulfur dioxide using the formula: mass = n * molar mass = 0.0993 moles * 64.06 g/mol. Thus, the mass of sulfur dioxide required is approximately 6.36 grams.

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The concentration of the H2SO4 solution is 0.080 M.

The concentration of 50.0 ml of a solution of H2SO4 can be found by titrating the acid with a standardized solution of Ba(OH)2. This can be achieved by first preparing a 0.20M solution of Ba(OH)2 by dissolving a known mass of the reagent in distilled water and diluting to the mark. The end point is reached when all the H2SO4 has reacted with Ba(OH)2 and no more acid is left to react with the reagent.When 40.0 ml of 0.20M Ba(OH)2 titrant was added, we can calculate the amount of moles of Ba(OH)2 that reacted with the H2SO4 and use this value to find the concentration of H2SO4. To do this, we can use the following balanced equation:H2SO4 + 2Ba(OH)2 → BaSO4 + 2H2OFrom the balanced equation, we can see that one mole of H2SO4 reacts with two moles of Ba(OH)2. Thus, the number of moles of Ba(OH)2 used in the titration is given by:(40.0/1000) L × (0.20 mol/L) = 0.008 molWe can use the number of moles of Ba(OH)2 used to calculate the number of moles of H2SO4 present in the original solution. Since one mole of H2SO4 reacts with two moles of Ba(OH)2, the number of moles of H2SO4 in the solution is given by:0.008 mol Ba(OH)2 × (1 mol H2SO4 / 2 mol Ba(OH)2) = 0.004 mol H2SO4.The concentration of H2SO4 is then given by dividing the number of moles of H2SO4 by the volume of the solution in liters:0.004 mol / (50.0/1000) L = 0.080 M.

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