When a chemical reaction is run in aqueous solution inside a calorimeter, the temperature change of the water (and Ccal) can be used to calculate the enthalpy change for the reaction. Here, we will study the reaction of hydrochloric acid with sodium hydroxide in the calorimeter from problem 3. Equal volumes (50.0 mL) of 1.00 M sodium hydroxide and 1.00 M hydrochloric acid are mixed.
HCl+NaOH→NaCl+H2O
1. What is the total change in enthalpy (in Joules) for the reaction?
2. Where initial temperature is 21.2 °C and final temperature is 28.0 °C. Ccal is 1234.28 j

A. The mole of 6.00 g oxygen, O₂ is 0.188 mole

B. The mole of 450.0 g of iron(III) oxide, Fe₂O₃ is 2.92 moles

C. The mole of 45.5 g of calcium chloride, CaCl₂ is 0.41 mole

The mole present in 6.00 g oxygen, O₂ can be obtained as follow:

Mole = mass / molar mass

Mole of oxygen, O₂ = 6 / 32

Mole of oxygen, O₂ = 0.188 mole

The mole present in 450.0 g of iron(III) oxide, Fe₂O₃ can be obtained as follow:

Mole = mass / molar mass

Mole of Fe₂O₃ = 450/ 159.69

Mole of Fe₂O₃ = 2.92 moles

The mole present in 45.5 g of calcium chloride, CaCl₂ can be obtained as follow:

Mole = mass / molar mass

Mole of CaCl₂ = 45.5/ 111

Mole of CaCl₂ = 0.41 mole

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The sample that uses the substance that Jacob and Natalie should use to make a cold pack that will do the best job of keeping food cool is sample 2, because it absorbs the most energy (option B).

Endothermic refers to a chemical reaction that absorbs heat energy from its surroundings. This ensures that the temperature of the surroundings is cool or has a lower temperature.

According to this question, Jacob and Natalie are asked by their science teacher to design a warming or cooling device. They make use of certain substances, however, sample 2 has the lowest final temperature of -4°C.

This shows that sample 2 absorbs the most energy, hence, would be the best for keeping the food cool.

The incomplete question is as follows:

Jacob and Natalie are asked by their science teacher to design a warming or cooling device. They decide to design a cold pack that can be used to help keep food cool. Jacob and Natalie read about different substances that can be used inside cold packs and learn that most cold packs use endothermic reactions to cool objects.

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The VSEPR (Valence Shell Electron Pair Repulsion) theory describes the arrangement of electron pairs around a central atom in a molecule, and the VSEPR number represents the total number of electron pairs around the central atom, including both bonding pairs and lone pairs.The VSEPR number can be determined from the Lewis structure of the molecule, which shows the arrangement of atoms and lone pairs around the central atom. The first two digits of the VSEPR number correspond to the number of bonding pairs and lone pairs, respectively, around the central atom.To determine the third digit of the VSEPR number, you need to consider the shape of the molecule. The shape is determined by the repulsion between electron pairs, which is strongest between lone pairs and decreases in the order lone pair-lone pair > lone pair-bonding pair > bonding pair-bonding pair.The third digit of the VSEPR number indicates the shape of the molecule according to the following scheme:1: linear shape2: trigonal planar shape3: tetrahedral shape4: trigonal bipyramidal shape5: octahedral shapeThus, to determine the third digit of the VSEPR number, you need to determine the shape of the molecule based on the number of electron pairs and their relative positions. This can be done by applying the VSEPR theory and considering the repulsion between electron pairs. Alternatively, you can consult a table or chart that lists the shapes associated with different VSEPR numbers.

Answer:

Answer: Number of moles of KOH present in solution is 3.75.

Explanation:

0.1 moles

There are 0.1 moles of solute in 250 mL of 0.4 M solution.

1 Answer. 1 mol of NaOH

The vapor pressure is obtained as 3.7 atm.

The Clausius-Clapeyron equation is the equation that we could use to obtain the vapor pressure of a solution at any temperature. Of course we would always have two different temperatures to work with.

Hence;

ln(P1/P2) = ΔHvap/R (1/T2 - 1/T1)

P1 = initial pressure

P2 = final pressure

ΔHvap =  enthalpy of vaporization

T2 = final temperature

T1 = initial temperature

ln(1/P2) = 35.2 * 10^3/8.314 (1/338 - 1/307)

ln(1/P2) = 4234(0.00295 - 0.00326)

ln(1/P2) = -1.31

1/P2 = e^-1.31

P2 = 1/e^-1.31

P2 = 3.7 atm

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1.6moles

The formula for calculating the molarity of a solution is expressed according to the equation:

Given the following parameters

volume of solution = 400mL = 0.4L

molarity of the solution = 4M

Determine the moles present

Hence the number of moles present is 1.6moles

205.7 cm^3 (or 0.2057 L) of the concentrated tetraoxosulphate (VI) acid to prepare 8 dm^3 of a 0.5 mol/dm^3 solution of the compound.

To prepare 8 dm^3 of a 0.5 mol/dm^3 solution of tetraoxosulphate (VI) acid from a stock solution, you need to use:

(0.5 mol/dm^3) x (8 dm^3) x (98 g/mol) = 392 g of tetraoxosulphate (VI) acid

Since the acid is 97% pure, we know that:

(97/100) x (392 g) = 379.84 g of tetraoxosulphate (VI) acid is pure acid

We can use the specific gravity of the acid, which is 1.84 g/cm^3, to calculate the volume of the acid needed:

379.84 g / (1.84 g/cm^3) = 205.7 cm^3 of tetraoxosulphate (VI) acid

So, you would need to use 205.7 cm^3 (or 0.2057 L) of the concentrated tetraoxosulphate (VI) acid to prepare 8 dm^3 of a 0.5 mol/dm^3 solution of the compound.

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From the solution that we have in the question;

The equilibrium constant, denoted as K, is a value that quantitatively represents the ratio of the concentrations of products to reactants at equilibrium in a chemical reaction.

It is a fundamental concept in chemical equilibrium.

The value of the equilibrium constant provides valuable information about the position of equilibrium and the relative concentrations of species involved in a chemical reaction.

Kc = [X] [Y]/[XY]

\(0.25 = (0.1 + x)^2/(0.5 - x)\)

\(0.25(0.5 - x) = (0.1 + x)^2\)

\(0.125 - 0.25x =0.01 + 0.2x + x^2\\ x^2 + 0.45x - 0.115 = 0\)

x = 0.18 M

The equilibrium amount of X and Y=  0.28 M and the equilibrium concentration of XY = 0.32 M

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Based on the answer to the question that we have;

The ratio of the product to reactant concentrations in a chemical reaction at equilibrium is represented quantitatively by the equilibrium constant, abbreviated as K.

It is a cornerstone of the theory of chemical equilibrium.

A chemical reaction's equilibrium position and the relative concentrations of the species involved can both be learned from the equilibrium constant's value.

Kc = [X][Y]/[XY]

\(0.25 = (0.1 + x)^2/(0.5 - x)\\0.25(0.5 - x) = (0.1 +x)^2\\0.125 - 0.25x = 0.01 +0.2x +x^2\\= 0.18 M\)

The equilibrium concentration of;

XY =0.5 - 0.18

=0.32 M

Then the equilibrium amount of

X and Y is

0.1 + 0.18= 0.28 M.

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Answer:

Waterrrr

Explanation:

H2O

Answer:

Muscle contraction

Explanation:

According to the new study, exercise improves muscle health by renewing its cellular powerhouse: the mitochondria. Mitochondria are crucial to the good functioning of our bodies, as well as to our overall health and longevity. These tiny parts of the cell turn the food we eat into energy.

The equation for the equilibrium constant (K) of the reaction studied in this exercise can be written as follows: K = ([\(CI_20\), 2-] * [\(H_20\)(1)]) / ([\(C0_4^ 2\)-] * [Ht])

In this equation, the concentrations of the species involved in the reaction are represented by the square brackets [ ]. The subscripts indicate the stoichiometric coefficients of each species in the balanced chemical equation.

The reaction being studied involves the following species:

\(C0_4^ 2\)- (ag) + 2Ht (ag) = \(CI_20\), 2- (ag) + \(H_20\)(1)

In the equilibrium constant expression, the concentration of \(CI_20\), 2- is multiplied by the concentration of \(H_20\)(1) and divided by the product of the concentrations of \(C0_4^ 2\)- and Ht. The stoichiometric coefficients in the balanced equation are used as exponents for the concentrations of the respective species.

It is important to note that the concentrations used in the equilibrium constant expression should be in molar units (mol/L) or expressed as partial pressures for gases.

Additionally, the equilibrium constant is specific to a given temperature, and its value provides information about the relative amounts of reactants and products at equilibrium.

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The lower the first ionization energy, the higher the reactivity of the metal.

The metallic character increases as energy from ionization lower. The reactivity of a metal is not balanced with the energy of its first ionization. The higher the first energy of ionization, the higher the metal's reactivity. The lower the first energy of ionization, the higher the metal's reactivity.

Metallic character is inversely proportional to the ionization energy. The reduced ionization energy is the metallic character of the element.

So we can conclude that  Part of metallic character is the ease with which electrons are contrasted from an atom. Ionization Energy calculates the energy required to remove an electron.

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Answer:

I got

−

902 kJ

for the reaction as-written. How would you rewrite this into

kJ/mol NH

3

?

The standard molar enthalpy of formation is for the formation of

1 mol

of product from its elements as they exist in nature at

25

∘

C

and

1 atm

. For example...

1

2

N

2

(

g

)

+

3

2

H

2

(

g

)

→

NH

3

(

g

)

,

Δ

H

∘

f

(

NH

3

(

g

)

)

=

−

45.9 kJ/mol

But that also means formation of elements in their standard states must yield zero enthalpy change:

1

2

O

2

(

g

)

→

1

2

O

2

(

g

)

,

Δ

H

∘

f

(

O

2

(

g

)

)

=

0

That means we can simply derive from Hess's law and that fact to get:

Δ

H

∘

r

x

n

=

∑

P

n

P

Δ

H

∘

f

,

P

−

∑

R

n

R

Δ

H

∘

f

,

R

where

n

indicates the mols of product

P

or reactant

R

. Here we actually have just summed many formation reactions together that we know have

Δ

H

∘

r

x

n

=

Δ

H

∘

f

.

Here we have:

Δ

H

∘

r

x

n

=

[

4 mols NO

(

g

)

⋅

Δ

H

∘

f

,

N

O

(

g

)

+

6 mols H

2

O

(

g

)

⋅

Δ

H

∘

f

,

H

2

O

(

g

)

]

−

[

4 mols NH

3

(

g

)

⋅

Δ

H

∘

f

,

N

H

3

(

g

)

+

0 kJ/mol

]

where we have set a zero contribution

O

2

(

g

)

right off the bat.

=

[

4 mols NO

(

g

)

⋅

91.3 kJ/mol

+

6 mols H

2

O

(

g

)

⋅

−

241.8 kJ/mol

]

−

[

4 mols NH

3

(

g

)

⋅

−

45.9 kJ/mol

+

0 kJ/mol

]

=

[

−

1085.6 kJ

]

−

[

−

183.6 kJ

]

=

−

902 kJ

for the reaction as-written.

Explanation:

Two key criteria that engineers must prioritize are efficiency and safety. By emphasizing efficiency and safety during process development, engineers can create robust and reliable processes that not only maximize productivity but also prioritize the well-being of personnel and the environment.

When developing a process, engineers need to consider several important criteria. Two key criteria that engineers must prioritize are efficiency and safety.

Efficiency is crucial in process development to ensure optimal use of resources, time, and energy. Engineers strive to design processes that maximize productivity, minimize waste, and reduce costs. This involves optimizing reaction conditions, streamlining workflow, and implementing automation where possible. Efficiency considerations also extend to energy consumption, raw material utilization, and overall process sustainability.

Safety is another critical aspect that engineers must prioritize. They need to identify and mitigate potential hazards associated with the process, ensuring the safety of both personnel and the environment. This involves conducting thorough risk assessments, implementing safety protocols, and designing equipment and systems with safety features. Engineers must also consider the safe handling and storage of materials, as well as potential risks during transportation and disposal.

By emphasizing efficiency and safety during process development, engineers can create robust and reliable processes that not only maximize productivity but also prioritize the well-being of personnel and the environment.

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Answer:

before

Explanation:

Answer:

Does evaporation happen before of after condensation?

Explanation:

Condensation, the opposite of evaporation, occurs when saturated air is cooled below the dew point (the temperature to which air must be cooled at a constant pressure for it to become fully saturated with water), such as on the outside of a glass of ice water.

Or

Heat (energy) is necessary for evaporation to occur. Condensation, the opposite of evaporation, occurs when saturated air is cooled below the dew point (the temperature to which air must be cooled at a constant pressure for it to become fully saturated with water), such as on the outside of a glass of ice water.

The complete question is as follows: Which statement describes the way in which energy moves between a system reacting substances in the surroundings.

A) molecule Collisions transfer thermal energy between the system and its surroundings

B) The thermal energy of the system and it’s surroundings increase

C) The potential energy of the system and it’s surroundings increases

D) molecular collisions create energy that is then released into the surroundings

Answer: The statement, molecule Collisions transfer thermal energy between the system and its surroundings describes the way in which energy moves between a system reacting substances in the surroundings.

Explanation:

When there will occur an increase in kinetic energy of molecules then there will occur more number of collisions.

When kinetic energy between these molecules tends to decrease then they will release heat energy into their surroundings.

As a result, it means that molecule collisions transfer thermal energy between the system and its surroundings.

Thus, we can conclude that the statement molecule Collisions transfer thermal energy between the system and its surroundings describes the way in which energy moves between a system reacting substances in the surroundings.

Answer:  Soundwaves travel as longitudinal or transverse waves depending on the temperature of the medium.

Explanation: i think its C

Answer:

Division by zero is undefined because there is no other number to divide it by.

Explanation:

Unlike 2/2, 2/0 doesn't have anything to divide the 2 by which makes it undefined and impossible to solve.

The division by zero is undefined​, because whatever response we may give, we will then have to concur that the answer times 0 = 1, which is illogical because anything multiplied by zero is zero.

Since any attempt at definition results in a contradiction, the outcome of a division by zero cannot be defined. a=r*b. r*0=a. (1) (1) But because r*0=0 for all r, there is no solution to the equation unless a=0 (1).

Again, mathematicians have left zero divided by zero as an open problem because they are both equally valid and, to be honest, neither of them is consistent with the rest of mathematics.

Mathematically, it is impossible to divide a number by zero, just as in this illustration. Or, at the very least, there isn't currently a means to do that. Numerous attempts have been made to figure out how to divide by zero, as mathematicians are constantly looking for solutions to intriguing mathematical issues.

Thus, The division by zero is undefined​, because whatever response we may give, we will then have to concur that the answer times 0 = 1.

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Answer:

The number of molecules of water us 1.50× 10²⁵ molecules

Explanation:

From N=nL

where L =avogadro number ( 6.02× 10^²³ entities)

The number of the molecules of water =1

n (amount of substance)=25 moles

hence (N) = 25×1×6.02×10^²³

=1.50×10²⁵ molecules of H2O

From the specific heat capacity of mercury, the amount of heat energy required to raise the temperature of 4.0 g of mercury metal from 9.3 °C to 83.0 °C is 77.792 J.

The specific heat capacity of a substance is the amount of heat required to raise the temperature of a unit mass of the substance by one degree Celsius or kelvin.

The specific heat capacity of a substance is a constant that can be used to calculate the amount of heat required to raise the temperature of a given mass of a substance to any temperature.

The specific heat capacity of mercury is 0.140 J/g/k.

The formula for calculating specific heat capacity is given below:

Specific heat capacity, c = Δq/mΔT

where;

Δq = heat change

m = mass of the substance

ΔT = temperature change

The Heat required, Δq, will then be:

Δq = m * c * ΔT

Heat required, Δq = 4.0 * 0.140 * (83.0 - 9.3)

Heat required, Δq = 77.792 J

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The total kilojoules in two tablespoons is  836.8 kJ.

To determine the total kilojoules in two tablespoons of a substance, we need to know the specific substance and its energy content per tablespoon. Different substances have different energy values, so without this information, it is not possible to provide an accurate calculation.

The energy content of food or substances is typically measured in kilocalories (kcal) or kilojoules (kJ). 1 kilocalorie is equal to 4.184 kilojoules. The energy content of a substance is often listed on food labels or in nutritional databases.

For example, if we have the energy content of a substance as 100 kilocalories (kcal) per tablespoon, we can convert it to kilojoules by multiplying it by 4.184:

100 kcal * 4.184 kJ/kcal = 418.4 kJ

So, if we have two tablespoons of this substance, the total energy would be:

418.4 kJ/tablespoon * 2 tablespoons = 836.8 kJ

It's important to note that the energy content of a substance can vary depending on its composition, density, and other factors. Therefore, it is always recommended to refer to reliable sources such as food labels, nutritional databases, or consult a qualified professional to obtain accurate information regarding the energy content of specific substances.

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In the formation of the sodium chloride, there is the loss of one electron from the sodium atom to the chlorine atom.

An ionic bond is the kind of bond that is formed between a metal and a non metal. The metal is known to donate electrons to the non metal. In the actual sense, the compound that is formed is an ion pair because the metal is positively charged while the non metal is negatively charged.

In the case of the sodium chloride, we know that the both elements, sodium and chlorine are highly reactive. Hence the sodium atom would quickly loose electrons to the chlorine atom and then the sodium chloride compound is formed.

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x = 10, y = 20/6

Given

one number is three times of the other

their arithmetic mean is 10

Required

The numbers

Solution

Suppose the numbers you are looking for are x and y, then :

x = 3y (equation 1)

The arithmetic mean : the average of values

(x+3y)/2=10

x+3y = 20 (equation 2)

Substitute equation 1 into equation 2

3y+3y=20

6y=20

y = 20/6

from equation 1 :

x= 3 x 20/6

x = 60/6

x = 10

Answer: D) 2.37°C

Explanation:

\(4.39x10^5J(\frac{g°C}{4.184J} )(\frac{kg}{1000g})(\frac{1}{44.3kg} )\) \(=2.37°C\)

Answer:

Na3N

Explanation:

cuzdoodlikeimsosure

Due to its smaller quantity relative to iron(II) filings, sulphur acts as the limiting reagent in the reaction between iron(II) filings and iron. Since sulphur and iron(II) filings have a mole ratio of 1.74:1, we can determine the theoretical yield.

We calculate the amount of sulphur present in 0.742 mol by dividing the sulfur's mass (23.8 g) by its molar mass (32.06 g/mol). This is multiplied by the mole ratio, which results in a theoretical yield of 1.33 mol.

By dividing the moles of iron(II) filings (0.983 mol) by their molar mass (55.85 g/mol), one may calculate the theoretical yield of iron(II) filings, which is 54.6 g. Calculated as the difference between the original amount and the predicted yield (55.0 g - 54.6 g), the surplus iron(II) filings total 0.4 g.

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Answer:the 50 kg girl because she is 1/4th of the weight of the 200 kg man which would fall down faster causing him to have more kinetic energy and the little girl would have more more potential energy

Explanation: because in different …and ur stuck on question 10 of unit 4 guided notes

Answer:

Platinum is especially good for this because it is unreactive, and does not produce a color in the flame which will mask the presence of other metals.

Hope this answer is right!

Answer:

Hey mate, here is your answer

1. Platinum doesn't impart any color to the flame.

2. It is not oxidised under the high temperature of the flame from a bunsen burner.

3. It is almost chemically inert. Even at high temperatures, it remains unattacked by free radicals / acid radicals.

Therefore, platinum wire is crucial for a flame test. Also, a platinum wire should be thoroughly cleaned before using it for a new flame test.

A platinum wire is cleaned by dipping it into concentrated HNO3 and then placing it in the non luminous part of the bunsen flame. Otherwise, the perviously tested radicals will impart color to the flame, which may cause confusion.

Explanation:

Hope it helps you

Answer:

1) C) Ea = 40 kJ/mol; E = -30 kJ/mol.

2) B) Ea = 80 kJ/mol; E = 10 kJ/mol.

3) Ea = 40 kJ/mol; E = -30 kJ/mol.

4) B) Ea = 80 kJ/mol; E = 10 kJ/mol.

Explanation:

The activation energy Ea is the energy that reactants must possess in order to cross the 'energy barrier' between reactants and products.

The rate of reaction depends on the activation energy as we can see from the Arrhenius equation; k = Ae^-Ea/RT. The higher the activation energy, the slower the rate of reaction.

If this is the case, then the reaction with the lowest activation energy is the fastest in any given direction while the reaction with the highest activation energy is the slowest in any given direction, hence the answers above.

The regular payment necessary to repay the $60,000 loan over 14 years while paying interest at a rate of 4% per year compounded 6 times a year is $803.03.

Interest is the cost of borrowing money or the return earned from investing money. Interest is computed as a percentage of the principal, which is the amount of money borrowed or invested. When someone borrows money from a lender, the borrower must pay back the principal plus interest. When someone invests money, the investor earns interest on the money they have invested. Monthly, quarterly, yearly, or at maturity, interest payments are all possible. Interest rates can vary widely depending on the type of loan or investment, the creditworthiness of the borrower or investor, and prevailing economic conditions.

The periodic payment R required to amortize a loan of $60,000 over 14 years with interest charged at a rate of 4% per year compounded 6 times a year can be calculated using the formula below:
R = P × r/m[1 − (1 + r/m)^−mt]
R = 60,000 × 0.04/6[1 − (1 + 0.04/6)^−6*14]
R = 803.03

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