A student dissolves 10.3 g of potassium chloride (KCI) in 200. g of water in a well-insulated open cup. She then observes the temperature of the water fall from 22.0 °C to 19.0 °C over the course of 6.8 minutes.

KCI(8) → K+ (aq) + Cl- (aq)

You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to the correct number of significant digits.

Required:
Is this reaction exothermic, endothermic, or neither?

Answers

Answer 1

Answer:

Endothermic.

Explanation:

Hello there!

In this case, it is possible to answer to the requested question "Is this reaction exothermic, endothermic, or neither?" by looking at the temperature change; thus, since the temperature is diminished from 22.0 °C to 19.0 °C, it is possible to realize that the dissociation reaction:

KCI(8) --> K+ (aq) + Cl- (aq)

Is endothermic as it absorbs heat and therefore the solution gets cooled down. Now for any calculation regarding the heat of reaction, it'd be necessary to assume that the solution has a specific heat equal to the water as the former is mostly composed by the latter and the amount of KCl does not modify the solution significantly.

Best regards!


Related Questions

assuming fixed shape when heated?​

Answers

Answer:

Assuming that the atmospheric pressure is standard, the temperature will rise steadily until it reaches 100°C

Pls someone help me with this question pls

Answers

Answer:

it c

Explanation:

because it's supposed to be untangled so nothing will happen to it because if it's Tangled bad stuff what happened to it and it will broke

I need help with level 15 in covalent bonding in playmada collisions app.

Answers

which level are u on now?

The speed of an electron is 1.68*10^8m/s what is the wavelength

Answers

Answer:

[tex]\lambda =4.33x10^{-12}m=4.33pm[/tex]

Explanation:

Hello there!

In this case, since the speed, wavelength and mass of an electron are related via the the Broglie wavelength:

[tex]\lambda =\frac{h}{m*v}[/tex]

Thus, by plugging in the mass of the electron and the Planck's constant, we obtain the following wavelength:

[tex]\lambda =\frac{6.626x10^{-34}J*s}{9.11x10^{-31}kg*1.68x10^{8}m/s}\\\\\lambda =4.33x10^{-12}m=4.33pm[/tex]

Best regards!

What mass of nitrogen (N2) is needed to produce 0.125 mol of ammonia (NH3)? Input a numerical answer only. N2 + 3H2 ---> 2NH:

Please help me ​

Answers

Given the following equation: I N2(g) + 3H2(g) → _2_NH3(e) a. ... Calculate the number of grams of NH3 produced by the reaction of 5.40 g of ... C. How many grams of nitrogen are needed to produce 15.3 g of NH3?
98 KB

Very sorry if this is wrong!

all metals rust please answer false or true​

Answers

Answer:

True

Explanation:

All metals do rust but at different rates. Gold, platinum, and silver can rust if but at different rates. It can take time for it to rust, if you clean your metals, it won't rust, it'll take awhile before it rusts if you keep cleaning them.

Hopefully this helps :3 sorry if wrong :( plz mark brainiest if correct :D your bootiful/handsome! Have a great day luv <3

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True or False?

Weak bases dissociate
completely into (OH)- and
metal cations.

Answers

Answer:

False

Explanation:

When weak bases dissociate, an equilibrium is established rather than dissociating 100%. So OH- and metal ions are partially ionized.


8. If 134 L of Nitrogen gas at STP is combined with 99 L of Chlorine gas at STP,
Which is the limiting reactant?
N2 + Cl2 → NCI3
.

Answers

Answer:

Cl₂ is the limiting reactant.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

N₂ + 3Cl₂ —> 2NCl₃

From the balanced equation above,

1 L of N₂ reacted with 3 L of Cl₂.

Finally, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

1 L of N₂ reacted with 3 L of Cl₂.

Therefore, 134 L of N₂ will react with = 134 × 3 = 402 L of Cl₂.

From the calculation made above, we can see that a higher volume (i.e 402 L) of Cl₂ than what was given (i.e 99 L) is needed to react completely with 134 L of N₂.

Therefore, Cl₂ is the limiting reactant and N₂ is the excess reactant.

Calculate the amount of copper in moles in a 27.5g pure copper sheet

Answers

The amount of copper in moles in the 27.5 g pure copper sheet is approximately 0.433 moles.

To calculate the amount of copper in moles in a pure copper sheet, we need to use the molar mass of copper and the given mass of the sheet.

The molar mass of copper (Cu) is approximately 63.55 g/mol. This value represents the mass of one mole of copper atoms.

Given that the mass of the pure copper sheet is 27.5 g, we can calculate the number of moles using the following formula:

moles = mass / molar mass

Substituting the values:

moles = 27.5 g / 63.55 g/mol

moles ≈ 0.433 mol

Therefore, the amount of copper in moles in the 27.5 g pure copper sheet is approximately 0.433 moles.

To arrive at this result, we divided the given mass of the sheet (27.5 g) by the molar mass of copper (63.55 g/mol). This calculation allows us to convert the mass of the sheet into the corresponding number of moles of copper.

The result tells us that the 27.5 g pure copper sheet contains approximately 0.433 moles of copper atoms. This conversion to moles is useful in various chemical calculations and allows for easier comparison and analysis of quantities on a molecular scale.

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List three forms of energy.

Answers

The different types of energy include thermal energy, radiant energy, chemical energy, nuclear energy, electrical energy, motion energy, sound energy, elastic energy and gravitational energy.

you could use any of these.

Answer: Chemical energy is energy stored in the bonds of atoms and molecules. ...

Mechanical energy is energy stored in objects by tension. ...

Nuclear energy is energy stored in the nucleus of an atom—the energy that holds the nucleus together.

Explanation:

How many milliliters of 0.100 M NaOH is needed to titrate 20.0 mL of 0.100 M HNO3 ?

Answers

Therefore, 50.0 m L of 0.200 M NaOH is required to completely neutralize 100.0 mL of 0.100 M HCl

HELPPPP ASAP!!! Plzzz

Answers

Answer:

420 miles

Explanation:

From the question given above, the following data were obtained:

Time = 3.5 hours

Speed = 120 mi/h

Distance =?

Speed is defined as the distance travelled per unit time. Mathematically, it is expressed as:

Speed = distance / time

With the above formula, we can obtain the distance travelled by the plane as follow:

Time = 3.5 hours

Speed = 120 mi/h

Distance =?

Speed = distance / time

120 = distance / 3.5

Cross multiply

Distance = 120 × 3.5

Distance = 420 miles

Thus, the distance travelled by the plane is 420 miles

How many grams of C5Hg would you need to measure out to have 0.172 mol?

Answers

We would need to measure out approximately 44.84 grams of C5Hg to have 0.172 mol.

To determine the grams of C5Hg needed to have 0.172 mol, we need to use the molar mass of C5Hg and the given amount in moles. The molar mass of a compound represents the mass of one mole of that compound.

The molar mass of C5Hg can be calculated by summing the atomic masses of all the atoms in the compound:

C5Hg: (5 * atomic mass of C) + (1 * atomic mass of Hg)

Using the atomic masses from the periodic table:

Atomic mass of C = 12.01 g/mol

Atomic mass of Hg = 200.59 g/mol

Molar mass of C5Hg = (5 * 12.01 g/mol) + (1 * 200.59 g/mol) = 60.05 g/mol + 200.59 g/mol = 260.64 g/mol

Now, we can calculate the grams of C5Hg needed for 0.172 mol using the mole-to-mass conversion:

Grams of C5Hg = Moles of C5Hg * Molar mass of C5Hg

Grams of C5Hg = 0.172 mol * 260.64 g/mol = 44.84 grams (rounded to two decimal places)

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what are the reasons that you cannot see many stars in the city nights?

Answers

Answer:

Because of the artificial lights influencing the dark night, turning it into a grey.

The solubility of a solid in a liquid generally increases with increase temperature.

True
Or
False

Answers

Answer:

False, Solubility increases with temperature for most solids.

Explanation:

which is the most fluorescent molecule?

Answers

I think neon....................

Explain how a neutral paper fragment can be attracted to a charged rod

Answers

Answer:

The particles in the neutral paper can shift, causing the paper to become polarized and attracted to the rod.

Explanation:

The neutral paper has an even distribution of its electrons throughout the paper. If a charged rod is brought near the neutral paper, this can cause the electrons in the paper to shift. If the rod is negative, the electrons will be repelled from the rod and cause the molecules in the paper to have a slight positive charge on the part of the paper closest to the rod. If the rod is positive, the electrons will be attracted to the rod and cause a slight negative charge on the side of the paper closest to the rod.

1. What organ system is responsible for controlling all of the body
functions?

Answers

Answer:

The human brain is the body's control center, receiving and sending signals to other organs through the nervous system and through secreted hormones. It is responsible for our thoughts, feelings, memory storage and general perception of the world. The human heart is a responsible for pumping blood throughout our body

what is bond stability??​

Answers

Answer:

Bond order is a counting method that gives an idea about numbers of electrons shared between atoms. A species with a higher bond order is more stable. A bond order equal to 2 is a double bond, and a bond order of 3 is a triple bond.

Explanation:

A scientist wants to display the numbers of gallons of fuel that were used up
in a one-hour period by three different types of motors. What type of visual
display should the scientist use?


Help please

Answers

Answer:

bar graph

Explanation:

What's the bond between two atoms of hydrogen?​

Answers

Answer:There is a iin dipole attraction between two hydrogen atom

Explanation:

The same atoms have the ion dipole attraction between them the same atoms repel each other

What are the benefits of Fluoride?

Answers

Answer:

The benefits of Fluoride are rebuild (remineralize) weakened tooth enamel.slow down the loss of minerals from tooth enamel.reverse early signs of tooth decay.prevent the growth of harmful oral bacteria

Answer:

Fluoride is often called nature's cavity fighter and for good reason. Fluoride, a naturally-occurring mineral, helps prevent cavities in children and adults by making the outer surface of your teeth (enamel) more resistant to the acid attacks that cause tooth decay.

If 5.32 mols N2 and 15.8 mols H2 react together, what mass NH3 can be
produced? Which is the limiting reactant?

Answers

Answer:

2.87 gram

N2 is the limiting agent

Explanation:

We will find out if there is sufficient N2 and h2 to produce NH3

a) For 2.36 grams of N2

Molar mass of N2 = 28.02

Number of moles of N2 in 2.36 grams = 2.36/28.02

Mass of NH3 = 17.034 g

Now NH3 produced form 2.36 grams of N2 =  

2.36/28.02 * 2 * 17.034 = 2.87 g NH3

b) For 1.52 g of H2  

NH3 produced = 1.52/2.016 * (2/3) * 17.034 = 8.56

N2 Is not enough to produce 2.87 g of NH3 and also H2 is not enough to make 8.56 g of NH3.  

N2 is the limiting agent as it has smaller product mass

True/False –Similar to liquids, gases cannot be compressed.

Answers

Answer:

False

Explanation:

A liquid has a definite shape and takes on the volume of its container. A gas has both the shape and the volume of its container. The particles in a gas cannot be compressed into a smaller volume. Liquids tend to contract when heated.

Hope this helps

I a doing an exam in science pls help.


What type of energy comes from the motion of tiny particles of matter?

Answers

Answer:

heat

Explanation:

Answer:

Thermal Energy

Explanation:

The trait that shows up in the first generation.
Recessive
Dominant
Ok

Answers

Answer:

Dominant

Explanation:

hope this help


The change in time for the first quarter is
seconds.
The change in time for the second quarte 1.39
seconds.
2.07
The change in time for the third quarter is
2.18
seconds.
The change in time for the fourth quarter is
second

Answers

Answer: The change in time for the first quarter is  1.39 seconds.

The change in time for the second quarter is 0.78 seconds.

The change in time for the third quarter is 0.64 seconds.

The change in time for the fourth quarter is 0.54 seconds.  

Explanation: took info from my data and completed lab

Step 5: Measure the Speed of the Toy Car on the Higher Track

Calculate the change in time for each quarter of the track. Record the change in time in Table E of your Student Guide.

Also added the other calculations -

Calculate the average time the car took to reach each checkpoint. Record the average time in Table D of your Student Guide.

The average time to the first quarter checkpoint is 1.39 seconds.  

The average time to the second quarter checkpoint is 2.18 seconds.

The average time to the third quarter checkpoint is 2.82 seconds.

The average time to the finish line is 3.36 seconds.

Calculate the speed of the car at each checkpoint by dividing the distance between each checkpoint, in meters, by the change in time. Record your answers in Table E of your Student Guide.

The speed at the first quarter checkpoint is 1.09 m/s.  

The speed at the second quarter checkpoint is 1.95 m/s.

The speed at the third quarter checkpoint is 2.37 m/s.

The speed at the finish line is 2.80 m/s.

Please make me Brainly..:)

Which term describes something that displays all the characteristics of life?
a.homeostasis
b.organism
c.stimulus
d.unicellular

Answers

A, it says on here good luckkkkkk

what role does the grass play in the food web?
A. Producer B. Primary Consumer C. secondary Consumer D. Decomposer​

Answers

Answer:

Producer

Explanation:

I took the test :)

Question 7 point
What is the name of the covalent compound with the formula P2N3?

Answers

List of covalent compounds
Binary molecular (covalent) compounds
compound systematic name
NO2 nitrogen dioxide
N2O3 dinitrogen trioxide
N2O4 dinitrogen tetroxide
N2O5 dinitrogen pentoxide
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