A student dissolves 15.0 g of ammonium chloride(NH4Cl) in 250. 0 g of water in a well-insulated open cup. She then observes the temperature of the water fall from 20.0 oC to 16.0 oC over the course of minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction:
NH4Cl(s) rightarrow NH4+(aq) + Cl-(aq)
You can make any reasonable assumptions about the physical properties of the solution. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
1. Is this reaction exothermic, endothermic, or neither?
2. If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case.
3. Calculate the reaction enthalpy deltaHrxn per mole of NH4CI.

Answer:

P4O10 + 6H2O → 4H3PO4         ΔH = 453 kJ

Explanation:

A thermochemical reaction is one in which the amount of heat gained/evolved is written as part of the reaction equation.

A thermochemical equation helps us to judge whether an equation is endothermic or exothermic. For an endothermic reaction, ΔH  is positive while for an exothermic reaction ΔH is negative.

Since, the reaction of one mole of P4O10(s)  with H2O(l) to form H3PO4(aq) evolves 453 kJ of energy for each mole of P4O10(s) that reacts. Then we can write;

P4O10 + 6H2O → 4H3PO4         ΔH = 453 kJ

Answer:

Avogadro's constant says that  

1

mole of any atom contains  

6.022

⋅

10

23

atoms. In this case you have  

3.40

⋅

10

22

atoms:

3.40

⋅

10

22

atoms

6.022

⋅

10

23

atoms

mol

=  

5.65

⋅

10

−

2

m

o

l

Step 2

The atomic mass of helium (He) will give you the weight of one mole of this molecule:  

1

mol =  

4.00

gram:

4.00

g

mol

⋅

5.65

⋅

10

−

2

mol

=  

0.226

g

So the  

3.40

⋅

10

22

helium atoms weigh  

0.226

gram

.

Explanation:

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Answer:

Caesar's enemies killed him.

Explanation:

On March 15, 44 B.C.E., Julius Caesar was stabbed to death in Rome, Italy. . A group of as many as 60 conspirators decided to assassinate Caesar at the meeting of the Senate on March 15, the ides of March.

Hope this helped!!!

Answer: 1:7

Explanation: 2 Tc^+7 + 7 O2^-2 -> Tc2 (O2)7

Also 2 Tc to 14 O

Given :

It takes 45.60 mL of a 0.225 M hydrochloric acid solution to react completely with 25.00 mL of calcium hydroxide in the given reaction.

2HCl(aq) + Ca(OH)2(aq) --> CaCl2(aq) + 2H2O(l)

To Find :

The molar concentration of the calcium hydroxide solution.

Solution :

From given equation 2 mole of hydrochloric acid react with 1 mole of calcium hydroxide.

So,

[tex]2M_1V_1 = M_2V_2\\\\2\times 0.225 \times 45.60 = M_2 \times 25 \\\\M_2 = \dfrac{20.52}{25}\\\\M_2 = 0.8208 \ M[/tex]

Therefore, molar concentration of the calcium hydroxide solution is 0.8208 M.

Answer:

Molar concentration of the calcium hydroxide solution = 0.2052 M

Explanation:

Volume of HCl = 45.60 mL  = 0.0456 L

Molar concentration of HCl = 0.225 M

Volume of Ca(OH)2 = 25.00 mL  = 0.025 L

No. of moles of HCl = (0.225 M)*(0.0456 L)   = 0.01026 mol

As we know

2 moles of HCl require 1 mole of Ca(OH)2, hence, .01026 moles of HCl will need 0.5*(0.01026) = 0.00513 moles of Ca(OH)2

Molar concentration of Ca(OH)2 = [(0.00513 mol)/(0.025 L)]   = 0.2052 M

The redox equation C6H12O6 + 6O2 -> 6H2O + 6CO2 represents the process of cellular respiration. Option C

Cellular respiration is a biochemical process that occurs in living organisms, including plants and animals, to convert organic compounds, such as glucose (C6H12O6), into usable energy in the form of adenosine triphosphate (ATP). It is the primary process by which cells derive energy to carry out their functions.

In the given equation, glucose (C6H12O6) is being oxidized, losing electrons, and releasing carbon dioxide (CO2) as a byproduct. This oxidation process results in the production of energy-rich molecules, such as ATP.

Additionally, oxygen (O2) is being reduced, accepting the electrons from glucose and combining with hydrogen (H) to form water (H2O). This reduction process allows for the transfer of electrons and the generation of energy.

The process of cellular respiration is essential for the survival and functioning of organisms, as it provides the necessary energy for various metabolic activities, growth, and maintenance of cellular processes.

It is a fundamental metabolic pathway found in both plants and animals, enabling them to extract energy from organic molecules through the oxidation of glucose or other fuel sources.

Therefore, option C, cellular respiration, is the correct answer that represents the process described by the given redox equation.

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The concept Charles's law is used here to determine the new volume. At the condition of constant pressure the new volume of the balloon is 459.54 mL.

At constant pressure, the volume of a given mass of gas is directly proportional to the temperature on Kelvin scale. Mathematically, the law can be expressed as follows:

V = constant × Temperature

V / T = Constant

V = Volume

T = Temperature

The Charles's law also explained that at -273°C, the volume of all the gases will become zero. This temperature is defined as the absolute zero.

For two different gases with volumes V₁ and V₂ and temperatures T₁ and T₂ is represented as:

V₁ / T₁ = V₂ / T₂

V₂ = V₁T₂ / T₁

222 × 62.1 / 30.0 = 459.54 mL

Thus the new volume of balloon is 459.54 mL.

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Answer:

1.5x1024

Explanation:

The true statements are

The false statements are.

The true statements reflect accurate concepts in relation to user intent and the dynamic nature of query meanings.

User intent refers to the purpose or goal the user has in mind when conducting a search.

Query meanings can evolve over time due to various factors such as changes in language usage,cultural shifts, or emerging   trends. The false statements, on the other hand,do not align with the actual understanding of these concepts.

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Answer: True

Explanation:

Titration is a quantitative technique where a solution of known concentration is used to determine the concentration of an unknown solution. The titrant (the known solution) is added from a burette to a known quantity of the the unknown solution until the reaction is complete.

By knowing the volume of titrant,  we can determine the concentration of the unknown.

Thus the statement Titrations provide a method of quantitatively measuring the concentration of an unknown solution is True .

Answer:

98.356 ohms is the answer

Answer:

The incorrect or the false options are -

(B) - If NH4NO3 is added, the pH becomes more basic.

(D) - If a small amount of HCl is added, the pH becomes slightly more basic.

 (E) - If NaOH is added, the OH- ions react with the [tex]NH_3[/tex].

Explanation:

The given solution the buffer basic .

Therefore , the options A ( If a small amount of NaOH is added, the pH becomes slightly more basic.) and C ( If HCl is added, the H+ ions react with the NH3.) All other B , D , E are false .

Answer:

They refer to energy that moves. Kinetic energy is energy that is currently moving. Potential refers to energy that has yet to move, or simply energy in wait

Explanation:

Answer:

I'm not 100% but a possible answer could be: No energy could either be created or destroyed

LMK if not but good luck!

Answer:it’s b

Explanation:I took. The test and got 100

Answer:

a- i know the other person said that it was b but i looked it but and it seems to be A. whoops-

Explanation:

Answer:

1.332 L

Explanation:

The reaction that takes place is:

First we calculate the number of NaOH moles, using the given volume and concentration:

Then we convert NaOH moles into H₂SO₄ moles, using the stoichiometric coefficients:

Finally we calculate the required volume of a 1.75 M solution of H₂SO₄, using the concentration and number of moles:

We can convert mL into L:

Answer:

D

Explanation:

Answer:

116.88554 grams

Explanation:

*sweating profusely*

i had to look it up

Answer:

187.01686400000003 grams

Explanation:

The volume of the balloon is 2.1L.

Volume is the amount of space the matter occupies. The SI unit of volume is cubic meter.

Using Boyles law equation,

P1V1 = P2V2

Where P1 and V1 are the initial pressure and volume of the gas

           P2 and V2 are the final pressure and volume of the gas

Given:

P1 = 3.5atm

V1 = 4.2L

P2 = 7.0atm

V2 = ?

Solve for V2 ,

V2 = P1V1/P2

V2 = (3.5atm x 4.2 L) / (7.0atm)

     = 2.1L

Hence, the volume of the balloon is 2.1L.

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Given :

Mass of roller coaster, m = 1000 kg.

Speed with which roller coaster is moving, v = 20.0 m/s.

To Find :

The kinetic energy if roller coaster.

Solution :

We know, kinetic energy of any object of mass m and speed v is given by :

[tex]K.E = \dfrac{mv^2}{2}\\\\K.E = \dfrac{1000\times 20^2}{2}\ J\\\\K.E = 200000\ J\\\\K.E = 200\ kJ[/tex]

Therefore, the kinetic energy of roller coaster is 200 kJ.

Answer:

due to the pollution the light months tended to stand out against the the wood that was dark due to the smoke the darker months population grew due to the fact that they were more harder to see for the predators

Answer:

The dark colored months became more common

Explanation:

Thats the answer !

Answer:

1500ml

Explanation:

molarity=3.65⋅g36.5⋅g⋅mol−1500⋅mL×10−3⋅L⋅mL−1=0.200⋅mol⋅L−1

Answer:

D. Mutation

Explanation:

Mutation is any change or alteration that occurs to the nucleotide sequence of a gene induced during DNA replication or by mutation-causing substances called MUTAGENS.

Mutation can be in the form of addition, removal, or substitution of nitrogenous bases in a DNA molecule. For example, in an original DNA sequence as follows: GAT ATC TGA, the following mutation can occur:

Addition: GAT ATC CTG A

Removal: GAT ATT GA

Substitution: GAT CTC TGA

Answer:

Explanation:

At the highest point of the first and tallest slope, your potential energy is at its most elevated it will at any point be on this ride. As you plunge, your potential energy diminishes until it's totally gone at the lower part of the slope." The more limited the slope the exciting ride climbs, the more prominent its active energy.

Another way of saying is that

A roller ride works utilizing gravity. the underlying slope must be sufficiently high that gravity can create sufficient force to finish the course.

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Answer:

Ternary

Explanation:

A ternary ionic compound is an ionic compound composed of three or more elements. Copper II Nitrate is a ionic compound and contains 3 elements thus making it Ternary

Answer:

81.5

Explanation:

smartworks

Answer:

The answer is C.

Explanation:

A P E X approved :)

Answer:Explanation:

250.ml of a 0.400 divide