A student investigated the enthalpy of combustion (deltaHc) of methanol under standard conditions using the apparatus shown in the diagram. The measurements the student recorded are shown in the table. Use this information to answer the questions below.

_Clamp stand
_
_ _I__Thermometer
_ I I Beaker
_ I-----I
_ I___I Water
_ I Wick
_ -----
_ I I
_ ----- Alcohol
_ I __I
______________

Alcohol mass before burning: 80.6g
Alcohol mass after burning: 75.9g
Water heated: 100g
Methanol Mr: 32
Initial temperature of water: 21.5 C
Final temperature of water: 32.4 C
Enthalpy of combustion of 1 mole of methanol:

The student wanted to know if the value obtained in part 1 is similar to that calculated using average bond enthalpy data.

a) Using the balanced equation and the data in the table below, calculate the theoretical enthalpy of combustion.

Note: you will need to include the enthalpy of vaporisation for the liquid components which are also given.

CH3OH(l) + 1.5O2(g) → CO2(g) + 2H2O(l)

Average Bond Enthalpies KJmol-1
C-H 412
C-C 348
C-O 358
O=O 496
C=O 743
O-H 463

Enthalpy of vaporisation KJmol-1
Methanol 35
Water 41

b) Suggest some reasons as to why this value is different to the one obtained in the practical. (What are the reasons that the the theoretical and actual enthalpy changes are different)

Answers

Answer 1

The Molar enthalpy of combustion of methanol obtained from the practical is -31.02 kJ/mol.

The molar enthalpy of combustion from bond energies, ΔH is -543 kJ/mol

The differences in the values could be due to:

Heat losses from the calorimeter to the surroundingsInaccurate measurements of mass and temperature changes

What is the enthalpy theoretical and actual enthalpy of combustion of methanol?

The actual enthalpy of combustion of methanol is calculated from the data obtained from the laboratory work.

The enthalpy of combustion is equal to the heat energy given off from the combustion of methanol.

Quantity of heat gained by water , q = -mcθ

where:

m = massc = specific heat capacityθ = temperature change

mass of water heated = 100 g

specific heat capacity of water = 4.18 J/g/°C

temperature change = 32.4°C - 21.5°C = 10.9°C

q = -(100 * 4.18 * 10.9) J

q = - 4556.2 J

moles of methanol reacted = mass/molar mass

mass of methanol = 80.6 - 75.9 = 4.7 g

molar mass of methanol = 32 g/mol

moles of methanol = 4.7/32 = 0.14687 moles

Molar enthalpy of combustion of methanol = -4556.2 J/0.14687 mole

Molar enthalpy of combustion of methanol = -31.02 kJ/mol

Calculating molar enthalpy of combustion from bond energies:

ΔH = sum of the bond energies of bonds broken - sum of the bond energies of the bonds formed

Sum of bond energies of bonds broken = (3 * 412) + 358 + 463 + (1.5 * 496) + 35 = 2836 kJ/mol

Sum of bond energies of bonds formed = (2 * 743) + 2(2 * 463) + 41 = 3379 kJ/mol

ΔH = 2836 kJ/mol - 3379 kJ/mol

ΔH = -543 kJ/mol

The value obtained from the practical is less than that from the bond energies

b. The possible reasons for the difference in value obtained from the practical is less than that from the bond energies include:

Heat losses from the calorimeter to the surroundingsInaccurate measurements of mass and temperature changes.

In conclusion, the molar enthalpy of combustion of methanol is negative since heat is given off during the reaction.

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Related Questions

The theory of what an atom looks like has evolved over time. From the ancient Greeks, to Dalton, to Rutherford—no idea was exactly the same. However, as more information is gathered, new ideas can build on the old. Sometimes new ideas can completely replace the old ones. Even today, there may be new advances that have changed our understanding of the atom that are not reflected in this course.

Answer one of the following prompts to begin your discussion:

You claim that the atomic model should not be continually changed. What reasoning would you give someone to help them understand your claim?
You claim that a new atomic model should always build on an old one. What reasoning would you give someone to help them understand your claim?
You claim that a new atomic model should completely replace an old one. What reasoning would you give someone to help them understand your claim?
You claim that the continuous evolution of the atomic model is beneficial, but you think it should be a mix of the old and the new. What reasoning would you give someone to help them understand your claim?

Answers

To being my discussion, I claim that a new atomic model should always build on an old one with the following reasons of mine. That is option B.

What is an atomic model?

An atomic model is a model that describes how the interior of an atom looks like. This first atomic model was developed by William Thomson.

To start my discussion, I claim that a new atomic model should always build on an old one with the following reasons of mine:

The modern scientists exploited the ideas of the ancient scientists to arrive at a better atomic model.

This method is proven the the works of Bohr in the Bohr atomic model which relied on quantum mechanics, built upon the Rutherford model to explain the orbits of electrons.

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Please help me with this reaction

Answers

The major product from the above organic reaction is I

In this reaction, methoxy ethane undergoes addition reaction with hydrogen bromide, Markownikoff's rule being involved in the reaction.

What are organic compounds?

Organic compounds are the compounds which contains carbon and hydrogen.

Generally, organic compounds are characterized by the following:

All organic compounds contains carbon Organic compounds are also combustible in nature They are mostly covalent bonded molecules They are all soluble in non-polar solvents.They can be isolatedThey can also be prepared in the laboratory

Below are some classes of organic compounds:

AlkanesAlkenesAlkynesAlkanolsAlkanoic acidAlkanalsEstersKetonesAmines

So therefore, the major product from the the above organic reaction is IV

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OMG PLEASE HELP!! THIS IS IMPORTANT!!

which statements describe the cell membrane? Check all that apply


A.) The cell membrane is very selective.

B.) The cell membrane lets anything enter the cell.

C.) The cell membrane lets anything leave the cell.

D.) The cell membrane is protective layer surrounding a cell.

E.) The cell membrane allows waste to leave the cell.

Answers

Answer:

The cell membrane is protective layer surrounding a cell.

Answer:

options D is correct

....hope it helps you

Urgent

During an experiment, distilled water was placed in a sealed container and the container was heated gradually. Describe this system when it reaches phase equilibrium.

Answers

We can achieve equilibrium state, when the concentration of product and reactants are equal to each other.

Describe this system when it reaches phase equilibrium?

In this type of system, when the same amount of liquid water is converted into gaseous form of water and the gaseous form of water into liquid form of water. This phase is known as equilibrium phase or state because same amount of reactants and products are produced .

So we can conclude that we can achieve equilibrium state, when the concentration of product and reactants are equal to each other.

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State which substance is undergoing oxidation and which substance is undergoing reduction in the following reaction:

Fe 3+ (aq) + SO3 2- (aq) ---> Fe 2+ (aq) + SO4 2- (aq)

Answers

Fe is undergoing oxidation while S is undergoing reduction

What is oxidation-reduction reaction?

Oxidation-reduction reaction can simply be defined as a special type of chemical reaction in which the oxidation states of substrate change. Oxidation is the

So therefore, Fe is undergoing oxidation while S is undergoing reduction

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Solve the following question

Answers

Answer:

140. J/g*K

Explanation:

To find the specific heat capacity, you need to use the following equation:

Q = mcΔT

In this equation,

-----> Q = energy/heat (J)

-----> m = mass (g)

-----> c = specific heat (J/mole*K)

-----> ΔT = change in temperature (K)

Before you can use the equation above, you need to (1) convert kg to grams, then (2) convert grams to moles (via molar mass), and then (3) convert Celsius to Kelvin. The final answer should have 3 significant figures.

1.11 kg C₄H₈O₂ x 1,000 = 1110 g

Molar Mass (C₄H₈O₂): 4(12.01 g/mol) + 8(1.008 g/mol) + 2(16.00 g/mol)

Molar Mass (C₄H₈O₂): 88.104 g/mol

1110 grams C₄H₈O₂                1 mole
------------------------------  x  -------------------------  =  12.6 moles C₄H₈O₂
                                           88.104 grams

34.5 °C + 273 = 307.5 K

52.3 °C + 273 = 325.3 K

Q = mcΔT                                                                   <----- Equation

3.14 x 10⁴ J = (12.6 moles)c(325.3 K - 307.5 K)         <----- Insert values

3.14 x 10⁴ J = (12.6 moles)c(17.8)                                <----- Subtract

3.14 x 10⁴ J = (224.28)c                                 <----- Multiply 12.6 and 17.8

140. = c                                                         <----- Divide both sides by 224.28

**this answer may be slightly off due to using different molar masses/Kelvin conversions**

Which of the following statements is correct?

Question 12 options:

In an acidic solution, [H+] > [OH-].


In a basic solution, [OH-] > [H+] .


In a neutral solution, [H+] = [OH-] .


All of the above statements are correct.

Answers

Answer:

All of the above statements are correct.

Explanation:

acid is a substance that acts as a proton donor, so will have more H+ ions;

basic/alkaline substances act as a proton acceptor, so will have more OH- ions according to bronsted lowry theory

and no to mention neutral means balanced so will have balanced concentration of ions to cancel their charges out.

Give the IUPAC name of 2,2,3-trimethyl butane and draw it's corrosponding structure.​

Answers

I hope this helps you ...

What is the half life of sodium-24 if after 12 days the sample has a mass of 1.2 g from an initial mass of 9.6 g?
Group of answer choices

A. 36 days

B. 12 days

C. 24 days

D. 4 days

Answers

As well as I think the answer is 24 days

How many grams of water will be produced if you start with 4.0 grams of hydrogen and an excess of oxygen given the following balanced chemical equation?

2H2 + O2 → 2H2O

Group of answer choices

A. 32.0 grams

B. 36.0 grams

C. 54.0 grams

D. 18.0 grams

Answers

Taking into account the reaction stoichiometry, 36 grams of water (option B) will be produced if you start with 4.0 grams of hydrogen and an excess of oxygen.

Reaction stoichiometry

In first place, the balanced reaction is:

2 H₂+ O₂  → 2 H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

H₂: 2 moles O₂: 1 moleH₂O: 2 moles

The molar mass of the compounds is:

H₂: 2 g/moleO₂: 32 g/moleH₂O: 18 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

H₂: 2 mole× 2 g/mole= 4 gramsO₂: 1 mole× 32 g/mole= 32 gramsH₂O: 2 moles× 18 g/mole= 36 grams

Mass of H₂O formed

You can see that by reaction stoichiometry 4 grams of H₂ form 36 grams of H₂O.

Summary

In summary, 36 grams of water (option B) will be produced if you start with 4.0 grams of hydrogen and an excess of oxygen.

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Based upon the ion charge of the following polyatomic ions, predict the formula for the following compounds.
sulfate = SO42
phosphate = PO43
hydroxide OH-
sodium hydroxide
O Na(OH)2
O Na(OH)3
O Na₂OH
O NaOH

Answers

Answer:

D.) NaOH

Explanation:

Sodium always forms the cation, Na⁺.

Hydroxide is always written as OH⁻.

The compound should have an overall charge of 0 (be neutral). As you can see, the charges perfectly balance out (+1 + (-1) = 0). Therefore, there only needs to be one atom of each ion. The ionic compound is thus NaOH.

3. Calculate the molarity of the HCI solution if 0.074 mol of HCl is dissolved in water to

make 2000 mL of the solution. Also calculate the pH of this solution. Hint: In case of

strong acids the [H3O+] is same as the molarity of acid solution.

Answers

Answer:

Molarity = 0.037 M

pH = 1.43

Explanation:

First, you need to calculate the molarity. After converting mL to L, you can plug the values into the molarity equation and simplify.

2,000 mL / 1,000 = 2 L

Molarity (M) = moles / volume (L)

Molarity = 0.074 moles / 2 L

Molarity = 0.037 M

You can plug the molarity of the hydrogen ion into the pH equation to find the pH. Remember that H₃O⁺ and H⁺ can be considered the same thing. Since HCl dissociates into just one H⁺ and one Cl⁻, the molarity of the HCl solution is the same as the molarity of the H⁺.

pH = -log[H⁺]

pH = -log[0.037]

pH = 1.43

Determine the acid dissociation constant (Ka) for a 0.200 M solution of hydrogen sulfate ion with
the pH of 1.35 if the reaction for the dissociation of this acid is
HSO 4 →→ H+ + SO 4-²
(Hint: [H+] = 10-PH; Ka = [product]/[reactant])

Answers

The acid dissociation constant(Ka) is 0.0095

The reaction for this dissociation of acid is

HSO4 ⇄H+ + SO4 -2

The dissociation constant can be determined from the following expression

[tex]Ka= \frac{[H+] [SO4]-2}{[HSO4}[/tex]  

[H+] = 10-PH

       = 10-1.35

[H+]  = 0.0447

[H+] = 0.0447 mol / L

From equation, [H+] = [SO4-2] = 0.0447 mol / L

[SO4-2] = 0.0447 mol / L

From the values of [H+], [SO4-2] and [HSO4] Ka can be calculated as follows,

Ka = 0.0447 * 0.0447 / 0.200

     = 0.0019 / 0.200

     = 0.0095

Hence the value of the acid dissociation constant (Ka) for the given reaction is  0.0095

                           

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Determine the mass % of a NaCl solution if 58.5 grams of NaCl was dissolved in 50 ml of water (assume the density of water to be 1 g/ml). [5]​

Answers

Considering the definition of percentage by mass and density, the percentage by mass of a NaCl solution is 53.917%.

Percentage by mass

The percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.

In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.

The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:

[tex]percentage by mass= \frac{mass of solute}{mass of solution}x100[/tex]

Density

Density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.

In other words, density is a quantity that allows us to measure the amount of mass in a certain volume of a substance. Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:

[tex]density=\frac{mass}{volume}[/tex]

Percentage by mass of a NaCl solution

In this case, you know:

mass of solute= 58.5 gramsvolume of water= 50 mLdensity of water= 1 [tex]\frac{g}{mL}[/tex]mass of solution= mass of solute + mass of water

Replacing in the definition of density, you get the mass of water:

[tex]1 \frac{g}{mL} =\frac{mass of water}{50 mL}[/tex]

Solving:

mass of water= 1 [tex]\frac{g}{mL}[/tex]× 50 mL

mass of water= 50 grams

Then, you get that the mass of solution is calculated as:

mass of solution= mass of solute + mass of water

mass of solution= 58.5 grams + 50 grams

mass of solution= 108.5 grams

So, the percentage by mass is calculated as:

[tex]percentage by mass= \frac{58.5 grams}{108.5 grams}x100[/tex]

percentage by mass= 53.917%

Finally, the percentage by mass of a NaCl solution is 53.917%.

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The value of the entropy change for the process N₂ (g) + 3H₂ (g) --> 2NH₃ (g) is ________.


positive


unchanged


zero


negative

Answers

Answer:

negative

Explanation:

Entropy is a measure of the "disorder" in a system.

In this reaction, the amount of disorder decreases. This is because one gas molecule (NH₃) has more order than two gas molecules (N₂ and H₂). Therefore, the entropy change should be negative.

72
Anteaters have very long noses that are adapted to help them survive. Although they have poor eyesight,
anteaters have an excellent sense of smell that helps them detect their surroundings. Anteaters are also good
swimmers and can use their noses like a snorkel held above the water.
How does an anteater's nose help it meet its needs?
A
Its nose can be used to fight off predators.
B
C
D
Its nose can be used as a paddle to help it swim.
Its sticky tongue can quickly catch insects to eat.
Its powerful sense of smell helps it find insects to eat.

Answers

Answer:

Its powerful sense of smell helps it find insects to eat.

What is the average dose of radiation that most people are exposed to every year not including dental or medical personnel dealing
with X-rays?
OA. 40 uSv
OB. 1000 u Sv
OC. 2400 u Sv
OD. 100,000 u Sv

Answers

C. The average dose of radiation that most people are exposed to every year not including dental or medical personnel dealing with X-rays is 2400 u Sv.

What is x-ray?

X-rays are a form of electromagnetic radiation, similar to visible light used for medical treatment and other forms of x ray inspection.

An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation.

The average dose of radiation that most people are exposed to every year not including dental or medical personnel dealing with X-rays is 2400 u Sv or 2.4 m u Sv.

Thus, the average dose of radiation that most people are exposed to every year not including dental or medical personnel dealing with X-rays is 2400 u Sv.

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A weak monoprotic acid is titrated with 0.100 MNaOH. It requires 50.0 mL of the NaOH solution to reach the equivalence point. After 25.0 mL of base is added, the pH of the solution is 3.52.

Estimate the pKa of the weak acid.
Express your answer using three significant figures.

Answers

pKa value =4.76Ka

=1.73×10 −5 !!    PH=4−PKa=14−4.76=9.24 for a weak monoprotic acid is titrated with 0.100 M NaOH. It requires 50.0 mL of the NaOH solution to reach the equivalence point. After 25.0 mL of the base is added, the pH of the solution is 3.52.

One way to describe an acid's potency is by its pKa value. The acid dissociation constant, or pKa, is the negative log of the pKa value. A stronger acid is indicated by a lower pKa value. In other words, a lower value means that the acid dissociates in water more completely.

The logarithm of Ka's negative value is denoted as pKa. The logarithmic inverse of the H+ concentration is pH. Acidity indication. An acid's pKa value tells you if it's a strong acid or a weak acid. The pH scale shows how acidic or alkaline a system is.

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In a calorimetry experiment 2.50 g of methane is burnt in excess oxygen. 30% of the

energy released during the combustion is absorbed by 500 g of water, the temperature of

which rises from 25°C to 68°C. The specific heat capacity of water is 4.184 J/g°C. What

is the total energy released per gram of methane burnt?

Answers

The total energy released per gram of methane in the experiment is 119941.33 J/g

How to determine the change in the temperature of waterInitial temperature of water (T₁) = 25 °CFinal temperature of water (T₂) = 68 °CChange in temperature (ΔT) = ?

Change in temperature (ΔT) = T₂ – T₁

Change in temperature (ΔT) = 68 – 25

Change in temperature (ΔT) = 43 °C

How to determine the heat absorbed by the water

The absorbed by the water can be obtained as illustrated below:

Mass of water (M) = s00 gChange in temperature (ΔT) = 43 °C Specific heat capacity of the water (C) = 4.184 J/gºC Heat (Q) =?

Q = MCΔT

Q = 500 × 4.184 × 43

Q = 89956 J

How to determine the energy released by methane in the experimentHeat absorbed by water = 89956 JPercentage of heat absorbed by water = 30%Heat released by methane =?

Heat absorbed by water = 30% of heat released by methane

89956 = 30% × heat released by methane

89956 = 0.3 × heat released by methane

Divide both sides by 0.3

Heat released by methane = 89956 / 0.3

Heat released by methane = 299853.33 J

How to determine the heat released per gram of methaneHeat released by methane (Q) = 299853.33 JMass of methane (m) = 2.5 gHeat per gram (ΔH) =?

Q = m × ΔH

Divide both sides by m

ΔH = Q / m

ΔH = 299853.33 / 2.5

ΔH =119941.33 J/g

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Calculate the molarity of a solution that has 18.0 g of glucose, C6H12O6, dissolved in 80.0 g of water.

Answers

Answer:

1.25 M

Explanation:

In this case, the solute is C₆H₁₂O₆ and the solvent is H₂O.To find the molarity, you need to (1) convert the mass C₆H₁₂O₆ to moles (via molar mass), then (2) convert grams H₂O to liters H₂O, and then (3) calculate the molarity.

(Step 1)

Molar Mass (C₆H₁₂O₆): 6(12.011 g/mol) + 12(1.008 g/mol) + 6(15.998 g/mol)

Molar Mass (C₆H₁₂O₆): 180.15 g/mol

18.0 g C₆H₁₂O₆           1 mole
------------------------  x  -----------------  =  0.0999 moles C₆H₁₂O₆
                                   180.15 g

(Step 2)

1,000 grams = 1 L

80.0 g H₂O                1 L
--------------------  x  -------------------  =  0.0800 L H₂O
                                 1,000 g

(Step 3)

Molarity = moles solute / volume solvent (L)

Molarity = 0.0999 moles / 0.0800 L

Molarity = 1.25 M

how did the boiling point of plain water compare to that of water with salt? Compared to water with sugar?

Answers

The boiling point of plain water is less than the boiling point of both salt and sugar water.

What is boiling point?

Boiling point can be defined as the point when the pressure exerted by the surroundings upon a liquid is equal to the pressure exerted by the vapour of the liquid.

The boiling point of plain water is 100°C which increases upon addition of solute substances such as salt and sugar.

But salts are usually made up of ionic bonds while sugar are made up of covalent bonds. This means that more energy would be required to boil salt solution due to its ionic bonds.

Therefore, the boiling point of salt water is highest following sugar water before plain water which is the lowest.

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Question 6
How many mole of potassium hydroxide are in 27.5 mL of 0.250 M
potassium hydroxide solution?

Answers

Answer:

0.00688 moles

Explanation:

The molarity ratio looks like this:

Molarity = moles / volume (L)

After you convert mL to L, you can plug the values into the equation and simplify to find moles.

27.5 mL / 1,000 = 0.0275 L

Molarity = moles / volume                         <----- Molarity ratio

0.250 M = moles / 0.0275 L                      <----- Insert values

0.00688 = moles                                       <----- Multiply both sides by 0.0275

Find q when 22.0 g of water is heated from 29.0°C to 100.0°C.

Answers

Answer:

6530 J

Explanation:

To find the value of "Q", you need to use the following equation:

Q = mcΔT

In this equation,

-----> Q = energy/heat (J)

-----> m = mass (g)

-----> c = specific heat capacity (J/g°C)

-----> ΔT = change in temperature (°C)

The specific heat capacity of water is 4.182 J/g°C. You can plug the given values into the equation and solve for "Q". The final answer should have 3 significant figures because the lowest number of sig figs among the given values is 3.

Q = ? J                             c = 4.182 J/g°C

m = 22.0 g                      ΔT = 100.0 °C - 29.0 °C = 71.0 °C

Q = mcΔT

Q = (22.0 g)(4.182 J/g°C)(71.0 °C)

Q = 6530 J

Approximately 6461.9 joules of heat are required to heat 22.0 g of water from 29.0°C to 100.0°C.

Given:

mass of water, m = 22.0 g

Specific heat capacity of water, c = 4.184 J/g°C

Change in temperature, ΔT= 100.0°C - 29.0°C = 71.0°C

The formula for the heat absorbed or released during a temperature change:

q = m × c ×ΔT

where:

q = heat (in joules, J)

m = mass of the substance (in grams, g)

c = specific heat capacity of the substance (in J/g°C)

ΔT = change in temperature (in °C)

For water, the specific heat capacity is approximately 4.184 J/g°C.

Putting the values into the formula and calculating q:

q = 22.0 g × 4.184 J/g°C ×71.0°C

q ≈ 6461.9 J

Thus, approximately 6461.928 joules of heat are required.

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How much heat is needed to melt 10.0 grams of ice at -10°C until it is water at 10°C?
Group of answer choices

A. +83.6 J

B. +3963 J

C. -3963 J

D. -83.6 J

Answers

Taking into account the definition of calorimetry, sensible heat and latent heat, the heat needed to melt 10.0 grams of ice at -10°C until it is water at 10°C is 3,969.5 J.

Calorimetry

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).

In this case, the amount of heat a body receives or transmits is determined by:

Q = c× m× ΔT

where:

Q is the heat exchanged by a body of mass m. c is a specific heat substance.ΔT is the temperature variation.Latent heat

Latent heat is defined as the energy required by a quantity of substance to change state.

When this change consists of changing from a solid to a liquid phase, it is called heat of fusion and when the change occurs from a liquid to a gaseous state, it is called heat of vaporization.

In this case, the heat Q that is necessary to provide for a mass m of a certain substance to change phase is equal to

Q = m×L

where L is called the latent heat of the substance and depends on the type of phase change.

This case

First, you  have to get the ice from -10°C to 0 °C, which is the melting point.  Then you have to melt the ice into liquid water. Now, you have to get the water from 0°C to 10°C.

-10°C to 0 °C

In this case, you know:

c= specific heat capacity of ice= 2.108 [tex]\frac{J}{gK}[/tex]m= 10 gΔT= Tfinal - Tinitial= 0 °C - (-10 °C)= 10 °C= 10 K because being a temperature difference, the difference is the same in °C and K.

Replacing in the definition of sensible heat:

Q1= 2.108 [tex]\frac{J}{gK}[/tex]× 10 g× 10 K

Solving:

Q1= 210.8 J

Heat needed to melt ice

In this case, you have to melt the ice into liquid water. Being the specific heat of melting of ice is 334 J/g, the heat needed to melt 10 grams of ice is calculated as:

Q2= 10 grams× 334 J/g

Solving:

Q2= 3,340 J

0°C to 10 °C

In this case, you know:

c= specific heat capacity of liquid water is 4.187 [tex]\frac{J}{gK}[/tex]m= 10 gΔT= Tfinal - Tinitial= 10 °C - 0 °C= 10 °C= 10 K because being a temperature difference, the difference is the same in °C and K.

Replacing in the definition of sensible heat:

Q3= 4.187 [tex]\frac{J}{gK}[/tex]× 10 g× 10 K

Solving:

Q3= 418.7J

Total heat required

The total heat required is calculated as:  

Total heat required= Q1 + Q2 + Q3

Total heat required= 210.8 J + 3,340 J + 418.7 J

Total heat required= 3,969.5 J

In summary, the heat needed to melt 10.0 grams of ice at -10°C until it is water at 10°C is 3,969.5 J.

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What is the chemical symbol of the terminal atom in the lewis structure of OH- ?

Answers

Answer:

kindly refer to the picture attached

Explanation:

Have a great day . keep smiling

↬ [tex]what \: is \: psi \:?[/tex]​

Answers

[tex] \large \underline{ \boxed{ \tt \red{Pounds \: per \: square \: inch}}}[/tex]

[tex] \: \: \: [/tex]

( PSI ) is a measurement of pressure in the Imperial system of measurement.

PSI is commonly used to measure the pressure of gasses (pneumatic pressure) or liquids (hydraulic pressure). PSI is also used as a measure of tensile strength, defined as resistance to pulling forces, and elastic modulus strength, defined as resistance to deformation, which controls the stiffness of materials.

[tex] \: \: \: [/tex]

hope helps ~

The Haber process is a method to produce ammonia from hydrogen and nitrogen gases. The reaction is:
N2(g) + 3 H2(g) <--> 2 NH3(g)
If hydrogen gas is added after the reaction has reached equilibrium, the reaction will:
Group of answer choices

A. Need more information

B. Stop. All of the nitrogen gas has been used up.

C. Shift to the left to produce more reactants

D. Shift to the right to produce more product

Answers

Answer:

D.) Shift to the right to produce more product

Explanation:

When more reactants are added to a reaction, the equilibrium will shift to the product side to restore the balance.

As such, when H₂ (a reactant) is added, the reaction will shift to the product side, resulting in an increase of NH₃.

Given the reaction: A + B <--> C + D
The concentrations at equilibrium are [A] = 1 M, [B] = 1 M, [C] = 2 M, and [D] = 2 M. What is the value of the equilibrium constant (K)?
Group of answer choices

A. 4.0

B. 2.0

C. 1.0

D. 0.25

Answers

Answer:

A.) 4.0

Explanation:

The general equilibrium expression looks like this:

[tex]K = \frac{[C]^{c} [D]^{d} }{[A]^{a} [B]^{b} }[/tex]

In this expression,

-----> K = equilibrium constant

-----> uppercase letters = molarity

-----> lowercase letters = balanced equation coefficients

In this case, the molarity's do not need to be raised to any numbers because the coefficients in the balanced equation are all 1. You can find the constant by plugging the given molarities into the equation and simplifying.

[tex]K = \frac{[C]^{c} [D]^{d} }{[A]^{a} [B]^{b} }[/tex]                                       <----- Equilibrium expression

[tex]K = \frac{[2 M] [2 M]}{[1 M] [1 M] }[/tex]                                     <----- Insert molarities

[tex]K = \frac{4}{1 }[/tex]                                                <----- Multiply

[tex]K = 4[/tex]                                                <----- Divide

If the temperature of a gas is increased from 20°C to 35°C, what is the new pressure if the original pressure was 1.2 atm? Assume that volume is constant.

A. 0.6 atm

B. 1.3 atm

C. 1.0 atm

D. 2.6 atm

Answers

The new pressure of the gas would be = 2.1 atm.

Calculation of gas pressure

The initial temperature of the gas(T1) = 20°C

The final temperature of the gas(T2)= 35°C

The volume= constant

The Original pressure (P1) = 1.2atm

The new pressure (P2) =?

Using the gas law P1/T1 = P2/T2

Make P2 the subject of formula;

P2= P1×T2/T1

P2= 1.2 × 35/20

P2= 42/20

P2= 2.1 atm

Therefore, the new pressure of the gas would be = 2.1 atm.

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Which of the following best describes how an ionic compound dissolves in water?
Group of answer choices

A. It separates into individual molecules and is a non-electrolyte.

B. It breaks into its individual ions and is an electrolyte.

C. It separates into individual molecules and is an electrolyte.

D. It breaks into its individual ions and is a non-electrolyte.

Answers

The correct answer choice which best describes how an ionic compound dissolves in water is that It breaks into its individual ions and is an electrolyte.

Option B is the correct answer

What is ionic bonding?

This is type of chemical bonding which involves the transfer of valence electron from a metallic element to a non-metallic element

So therefore, The correct answer choice which best describes how an ionic compound dissolves in water is that It breaks into its individual ions and is an electrolyte.

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