A calorimeter contains 31.0 mL of water at 13.5 ∘C . When 2.30 g of X (a substance with a molar mass of 76.0 g/mol ) is added, it dissolves via the reaction X(s)+H2O(l)→X(aq) and the temperature of the solution increases to 29.5 ∘C . Calculate the enthalpy change, ΔH, for this reaction per mole of X. Assume that the specific heat of the resulting solution is equal to that of water [4.18 J/(g⋅∘C)], that density of water is 1.00 g/mL, and that no heat is lost to the calorimeter itself, nor to the surroundings. Express the change in enthalpy in kilojoules per mole to three significant figures.

Answers

Answer 1

Answer:

-73.6kJ/mol

Explanation:

The solution is increasing its temperature from 13.5°C to 29.5°C, that means the enthalpy change is < 0

The released heat is determined using the calorimeter equation:

Q = -C×m×ΔT

Where Q is heat,

C is specific heat of the solution (4.18J/g°C)

m is mass of the solution (31.0mL = 31.0g + 2.30g = 33.3g)

And ΔT is change in temperature (29.5°C - 13.5°C = 16°C)

Replacing:

Q = -4.18J/g°C×33.3g×16°C

Q = -2227J are released

This heat is released when 2.30g are dissolved, that is:

-2227J / 2.30g × (76.0g / mol) = -73591J/mol =

-73.6kJ/mol


Related Questions

C. At an old gas station, gasoline leaks from an underground storage tank.
Classification:
Explanation:

Answers

To pevent gasoline leaks, regular maintenance checks and replacement of damaged underground tanks is required.

What causes gasoline leak?

Gasoline leaks occurs when tanks are rusty and corroded or where there are loose fitting of pipes and connection points.

Gasoline leak presents a serious environmental hazard as well as threat to life and properties.

Gasoline leaks can cause fire outbreaks which would destroy properties and endanger lives.

Gasoline leaks can also cause land and water pollution killing important aquatic and soil organisms.

Therefore, regular maintenance checks and replacement of damaged underground tanks will prevent gasoline leaks.

Learn more about gasoline leaks at: https://brainly.com/question/10338424

Answer:

To pevent gasoline leaks, regular maintenance checks and replacement of damaged underground tanks is required.

What causes gasoline leak?

Gasoline leaks occurs when tanks are rusty and corroded or where there are loose fitting of pipes and connection points.

Gasoline leak presents a serious environmental hazard as well as threat to life and properties.

Gasoline leaks can cause fire outbreaks which would destroy properties and endanger lives.

Gasoline leaks can also cause land and water pollution killing important aquatic and soil organisms.

Therefore, regular maintenance checks and replacement of damaged underground tanks will prevent gasoline leaks.

Explanation:

Give the person who answered this question for real brainliest, they deserve it :D

What is the main molecule that provides the energy to produce ATP?

Answers

Answer: glucose

Explanation:

glucose is the answer.

According to the rate law, how do concentrations affect rate?

A. The rate increases as concentrations decrease.

B. The rate increases as concentrations increase.

C. It is impossible to tell how the rate is affected.

D. The rate is independent of concentrations.

Answers

Answer:

Rate Laws. Typically, reaction rates decrease with time because reactant concentrations decrease as reactants are converted to products. Reaction rates generally increase when reactant concentrations are increased.

1. When solute dissolves in water​

Answers

Explanation:

The water molecules behave like tiny magnet attracted to metal ....As each solute molecule gradully breaks away,water molecules surround it, and it drifts it to solution. Is the solute is a solid,the prosses happens gradually

The correct formula for the ionic compound formed between Ca and I is CaI
True or False

Answers

It would be false because the correct formula would be CaI2, since calcium has a +2 charge and iodide has a -1 charge.

The statement "correct formula for the ionic compound formed between Ca and I is CaI" is false.

What is chemical formula?

Chemical formula is using of the elements and number to write a  compound or element using the chemical terms. The chemical formula re the short form of the name of the elements and compounds.

The chemical formulas or equation are written by using the balanced form of equation by using the number of moles and charge on the elements.

Ca and I are the chemical element of the periodic table, and they combine and written as calcium iodide, CaI₂, because they are ionic compound and iodine contain charge of two. Ionic compounds are the compounds that are formed when they lose to gain electrons to form a bond.

Thus, the statement is false.

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In Earth’s mantle there are convection currents. The convection currents flow in a _________ shape. As the hot magma ________________, the colder magma ___________________. These convection currents are a continuous_______________. This means that convection currents will _____________ stop because they have a constant source of heat energy. Convection currents move the lithosphere and cause many events on the surface including_____________ and _____________.

Words:
rises
eventually
system
earthquakes
triangular
circular
tornadoes
volcanoes
never
sinks

Answers

Answer:

4

5

2

6

3

1

6

7

.......

.

.

.

.

.

..

Distillation is a process used to separate a mixture to liquids based on different

Answers

boiling points

Explanation:

It is used to separate two immiscible liquids

9. The magnetic pattern of ocean-floor rocks on one side of an ocean ridge is ____. a. a mirror image of that of the other side
b. younger than on the other side
c. much different from the magnetic pattern found in rocks on land d. at right angles to the ocean ridge

Answers

Answer:

is this for quizzes

Explanation:

asdfghkl, dftyuil, cftyhjm

Answer:

The answer is A Mirror Image Of That Of The Other Side

HELP ASAP

Which of these correctly lists the order of the engineering process?
A. Produce a product, improve it, identify a problem, make a solution,
test the solution.

B. Make a solution, identify a problem, research the problem, test the
solution, improve the product, test and evaluate, research, make a
plan, do the plan.

C. Identify a need, research the background, make a plan, do the
work, evaluate the results, look for improvements.

Answers

Answer:

C. Identify a need, research the background, make a plan, do the

work, evaluate the results, look for improvements.

Answer:

B.make a solution, identify a problem, research the problem, test the solution, improve the product, test and evaluation, research, make a plan , do the plan

Explanation:

B

Select the Multiple Atoms tab. Select the Continuous option from the Electron Production control and also select the Spectrometer and Squiggles options. Now select hydrogen, run the experiment, and note the colors and wavelengths of the photons shown in the spectrometer readings. Do the same with neon. How would you differentiate hydrogen and neon using the spectrometer readings?

Answers

Answer:

hydrogen and neon can be distinguished based on their atomic spectra, neon has wavelengths in the range of 540 nm to 750 nm and the colors of light are observed as green, yellow, orange, and red.

hydrogens wavelengths are in the range of 410 nm to 660 nm. the colors obeserved are purple, dark blue, light blue, and red.

so they can be differentiated by their wavelengths and the colors of light they emit.

Question 22
When 85 g of CH4 are mixed with 320 g of O2 the limiting reactant is
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

Answers

Answer:

O2, oxygen.

Explanation:

Hello.

In this case, for the undergoing chemical reaction, we need to compute the moles of CO2 yielded by 85 g of CH4 (molar mass = 16 g/mol) and by 320 g of O2 (molar mass 32 g/mol) via the following mole-mass relationships:

[tex]n_{CO_2}^{by\ CH_4}=85gCH_4*\frac{1molCH_4}{16gCH_4} *\frac{1molCO_2}{1molCH_4} =5.3molCO_2\\\\n_{CO_2}^{by\ O_2}=320gO_2*\frac{1molO_2}{32gO_2} *\frac{1molCO_2}{2molO_2} =5molCO_2[/tex]

Considering the 1:2:1 among CH4, O2 and CO2. Therefore, since 320 g of O2 yield the smallest amount of CO2 we infer that the limiting reactant is O2.

Best regards.


PLEASE HELLLLOOPLPPPPP

Answers

Answer:

the answer is d.Class there u go i hope its riht

To separate a mixture of p-toluidine and p-nitrotoluene dissolved in ether:

a. extract the ether solution with aqueous HCl and treat the water layer with aqueous NaOH.
b. extract the ether solution with aqueous NaOH and treat the water layer with aqueous HCl.
c. extract the ether solution with water and treat the water layer with aqueous NaOH.
d. extract the ether layer with aqueous HCl and treat the ether layer with aqueous NaOH.
e. extract the ether solution with aqueous HCl and treat the ether layer with aqueous HCl.

Answers

Answer:

extract the ether solution with aqueous HCl and treat the water layer with aqueous NaOH.

Explanation:

p-toluidine is a basic compound, it can react with aqueous HCl to form p-Toluidine hydrochloride and is recovered subsequently.

An alkali such as NaOH can be used to recover the p-toluidine. The neutral compound, p-nitrotoluene, will remain in the ether layer and can be recovered by evaporating the solution.

Does photosynthesis take place in animals, plants, or both animals and plants?

only animals

only plants

both animals and plants

Answers

Only plants. the animals eat plants to get energy and the predators eat that animal to get their energy

What does the 2 in 2 CO represent?

Answers

Answer:

CO2 is the chemical formula for the compound carbon dioxide. C is the symbol for the element carbon, and O is the symbol for oxygen.

Explanation:

Carbon Dioxide has One Carbon and Two Oxygens.

What element is this

Answers

Answer:

the element is lithium answer

Arrange elements in decreasing order of the number of valence electrons

Answers

Answer:

It’s voice and a

Explanation:

Order these elements from LEAST to GREATEST atomic mass.
A) Li, He N.S
B) He, Li, N, S
C) N, He, Li, s
D) S, N, Li, Hs

Answers

Answer:

B) He, Li, N, S

Explanation:

mass of helium < mass of lithium < mass of nitrogen < mass of sulfur

Which statement identifies an accurate relationship between metals and nonmetals in the same period of the Periodic Table?
A
Metals generally have higher electronegativity than nonmetals in the same period.
B
Nonmetals generally have a lower, first-ionization energy than metals in the same period.
с
Metals generally have smaller radii than nonmetals in the same period.
D
Nonmetals generally have a higher electronegativity than metals in the same period.

Answers

Answer:

D.) Nonmetals generally have a higher electronegativity than metals in the same period.

Explanation:

A.) is incorrect because within the same period, nonmetals have the higher electronegativity values.

B.) is incorrect because ionization energy usually increases as one goes across the periodic table, meaning metals will generally have lower, first-ionization energies. This is because the protons in the atoms increase as you travel across the periodic table while the outer shell continues to occupy the same energy level. The more protons there are, the greater the attraction between the electrons and protons, making it more difficult to ionize the atom.

C.) is incorrect because within the same period, nonmetals will have the smaller radii. This is because as you go across a period, the protons in the atom increase. The more protons there are, the greater the pull they will have on their electrons. This shrinks the size of the atom.

D.) is correct because as you go across a period, the electronegativity increases. These atoms are more likely to attract electrons due to their higher proton count while simultaneously being a smaller size.

what is chemical bond

Answers

Answer:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds.

Explanation:

The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

A chemist has a 0.200 M solution of potassium hydroxide (molar mass = 56.1g/mol). What mass of KOH is dissolved in 3.20 L of the solution?

Answers

Answer:

35.904g

Explanation:

[tex]concentration = \frac{mole}{volume} \\ 0.200 = \frac{n}{3.20} \\ n = 0.640mol \\ n \frac{mass}{molar \: mass} \\ mass = n \times molar \: mass \\ molar \: mass = 56.1gmol {}^{ - 1} \\ mass = 56.1 \times 0.640 \\ mass = 35.904g[/tex]

If 0.200 mol of copper(II) sulfate is dissolved in 275 g of H2O, what is the percent by weight of the copper(II) sulfate in the solution

Answers

Answer:

I think its 0.200x159.6=31.92 if this is correct can u mark me brainliest

What is saturation

Give two examples each of acid and basic salt

Answers

Answer:

saturated refers to a point of maximum concentration, in which no more solute may be dissolved in a solvent.

Acid:sulfuric,nitric

Basic salt:Calcium carbonate (CaCO3)

Sodium acetate (NaOOCCH3)

Explanation:

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HEY I NEED ALL ANSWERS RIGHT NOW IT'S MISSING AND MY TEACHER ARE GRADING THEM NOW YOU WILL BE MARKED BRAINIEST

Answers

Molar mass of butane:-

4(12)+10=58u

Moles of Butane:-

100/58=1.7mol

#16

2mols of Butane produce 8mol CO_21mol of butane produces 4mol CO_2

Moles of CO_2

4(1.7)=6.8mol

Mass of CO_2:-

44(6.8)=299.2g

#17

2mols of butane need 13mol O_21mol of butane needs 6.5mol O_2

Moles of O_2

6.5(1.7)=11.05mol

Mass of O_2

11.05(32)=353.6g

1. What is contained in the nucleus of an atom?

Answers

Answer:

The atom consists of a tiny nucleus surrounded by moving electrons. The nucleus contains protons, which have a positive charge equal in magnitude to the electron's negative charge. The nucleus may also contain neutrons, which have virtually the same mass but no charge.

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Help I need to show work!

Question: The result of a reaction of propane and air gave 11.21 g CO2 and 33.0 grams water according
to the following equation: C3H3 + 5 02 + 3 CO2 + 4 H20
a) What type of reaction (name reaction) is this?
b. How many grams of carbon were produced?
C. How many grams of hydrogen were produced?

Answers

Answer:

a. Combustion.

b. [tex]m_C=3.057gC[/tex]

c. [tex]m_H=3.67gH[/tex]

Explanation:

Hello.

a. In this case, given the reaction by which propane is converted into carbon dioxide and water:

[tex]C_3H_8+5O_2 \rightarrow 3CO_2+4H_2O[/tex]

It is known as a combustion reaction since it is about a fuel (here propane) which is burnt by the oxygen contained in the air (21%).

b. Since the carbon dioxide contains all the carbon in the products based on the law of conservation of mass, the yielded grams are computed via a mole mass relationship:

[tex]m_C=11.21gCO_2*\frac{12gC}{44gCO_2}=3.057gC[/tex]

Since 44 grams of carbon dioxide contain 12 grams of carbon.

c. As well as b., all the hydrogen is  given off in form of water, thus, the required mass turns out:

[tex]m_H=33.0gH_2O*\frac{2gH}{18gH_2O}=3.67gH[/tex]

Since 18 grams of water contain 2 grams of hydrogen.

Best regards.

When a 16.8 mL sample of a 0.410 M aqueous hydrocyanic acid solution is titrated with a 0.408 M aqueous sodium hydroxide solution, what is the pH after 25.3 mL of sodium hydroxide have been added?
pH =

Answers

From the calculations and results obtained, the pH of the solution is 12.85. This implies that the solution is basic or we can say it is alkaline.

What is pH?

pH is a scale that shows the acidity or alkalinity of a solution.

Number of moles of hydrogen cyanide =  0.410 M *  16.8 /1000 L = 0.0069 moles

Number of moles of NaOH = 0.408 M  * 25.3/1000 L = 0.01 moles

Since the reaction is 1:1, hydrogen cyanide is the limiting reactant.

Number of moles of NaOH left over = 0.01 moles - 0.0069 moles  

= 0.0031 moles

Total volume = 16.8 mL + 25.3 mL = 42.1 mL  or 0.042 L

Molarity of left over hydroxide ions = 0.0031 moles /0.042 L

= 0.07 M

pOH = - log(0.07 M) = 1.15

pH = 14 - 1.15 = 12.85

Learn more about pH: https://brainly.com/question/15289741

Ionic compounds form

crystal structures.
molecular structures.
pure elements.
neutral elements.

Answers

Answer:

A,  crystal structures.

Explanation:

Answer:

A

Explanation:

Baking soda NaHCO3, is made from soda ash, a common name for sodium carbonate. The soda ash is obtained in two ways. It can be manufactured in a process in which carbon dioxide, ammonia, sodium chloride, and water are the starting materials. Alternatively, it is mined as a mineral called trona (top photo). Whether the soda ash is mined or manufactured, it is dissolved in water and carbon dioxide is bubbled through the solution. Sodium bicarbonate precipitates from the solution. As a chemical analyst you are presented with two samples of sodium bicarbonateâone from the manufacturing process and the other derived from trona. You are asked to determine which is purer and are told that the impurity is sodium carbonate. You decide to treat the samples with just sufficient hydrochloric acid to convert all the sodium carbonate and bicarbonate to sodium chloride, carbon dioxide, and water. You then precipitate silver chloride in the reaction of sodium chloride with silver nitrate. A 6.93 g sample of baking soda derived from trona gave 11.89 g of silver chloride. A6.78 g sample from manufactured sodium carbonate gave 11.77 g of silver chloride.

Required:
Which sample is purer, that is, which has the greater mass percent NaHCO3?

Answers

Answer:

Explanation:

From the given information:

mass of silver chloride AgCl = 11.89 g

molar mass of AgCl = 143.37 g/mol

We know that:

number of moles = mass/molar mass

number of moles of AgCl = 11.89 g/ 143.37 g/mol

number of moles of AgCl = 0.0829 mol

The chemical equation for the mineral called trona is:

[tex]\mathsf{Na_2CO_3.NaHCO_3.2H_2O}[/tex]

when being reacted with hydrochloric acid, we have:

[tex]\mathsf{Na_2CO_3.NaHCO_3.2H_2O + 3HCl \to 3NaCl + 2CO_2 +4H_2O}[/tex]

One mole of NaCl formed from one mole of trona sample = 0.0829 moles of AgCl

i.e. 0.0829 moles of NaCl can be formed from AgCl

mass of trona sample = number of moles × molar mass

mass of trona sample = 0.0829 × 226

mass of trona sample = 18.735 g

The mass in the percentage of NaHCO₃ = mass of NaHCO₃/ mass of trona

The mass in the percentage of NaHCO₃ = 6.93/18.735

The mass in the percentage of NaHCO₃ = 0.36989

The mass in the percentage of NaHCO₃ = 36.99%

Nonetheless, a 6.78 g samples manufactured from sodium carbonate in pure 100%

6.78 g sample manufactured from Na₂CO₃ is purer.

As you move down the periodic table atoms get bigger. This is because ____________.

Answers

Answer:

Because the atoms have more energy levels

Explanation:

Hope this helps:)....if not sorry for wasting your time and may God bless you:)

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