2
3 of 6 - SCH4U
Date: Name(s):
4. HCl is a corrosive colourless gas that dissolves readily in water.
Aqueous HCl reacts with NaOH to form water and NaCl. In a simple
calorimeter, a 100.00 mL sample of 0.415 mol/L HCl(aq) is mixed
with 50.00 mL of excess NaOH(aq). During the reaction, there is a
rise in temperature by 4.83 °C. Calculate the molar enthalpy change
(in kJ/mol) for the above reaction. SHOW ALL YOUR WORK.

Answers

Answer 1

Answer: The molar enthalpy change is 73.04 kJ/mol

Explanation:

[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]

moles of HCl= [tex]molarity\times {\text {vol in L}}=0.415mol/L\times 0.1=0.0415mol[/tex]

As NaOH is in excess 0.0415 moles of HCl reacts with 0.0415 moles of NaOH.

volume of water = 100.0 ml + 50.0 ml = 150.0 ml

density of water = 1.0 g/ml

mass of water = [tex]volume \times density=150.0ml\times 1.0g/ml=150.0g[/tex]

[tex]q=m\times c\times \Delta T[/tex]

q = heat released

m = mass  = 150.0 g

c = specific heat = [tex]4.184J/g^0C[/tex]

[tex]\Delta T[/tex] = change in temperature = [tex]4.83^0C[/tex]

[tex]q=150.0\times 4.184\times 4.83[/tex]

[tex]q=3031.3J[/tex]

Thus 0.0415 mol of HCl produces heat = 3031.3 J

1 mol of HCL produces heat = [tex]\frac{3031.3}{0.0415}\times 1=73043.3J=73.04kJ[/tex]

Thus molar enthalpy change is 73.04 kJ/mol


Related Questions

A plant takes root in a small crevice of rock, as the plant grows, its roots push on the edges of the rock, breaking it is a form of weathering?

1. True

2. False

Answers

Answer:
True

Step-by-step explanation:

Roots grow into cracks in the rocks, as the roots grow, they press on the sides of the crack, making it wider until it breaks apart (example - tree roots breaking up the sidewalk. Mechanical weathering is the process of breaking big rocks into little ones. This process usually happens near the surface of the planet. Temperature also affects the land. The cool nights and hot days always cause things to expand and contract. That movement can cause rocks to crack and break apart.

Identify the metals in period 3 on the periodic table

Answers

Answer:

Aluminum (Al) is the only metal in period 3 on the periodic table.

In an experiment to displace
from copper sulfate, 6.5g of Zinc was
added to an excess of copper(ii) sulfate
Solution. The copper was fitered off,
washed and dried. The mass of
Copper obtained was 48 g. Calculate
the percentage yield of copper?

Answers

The percentage yield of copper = 76%

Further explanation

Given

6.5g of Zinc

The mass of Copper: 4.8 g

Required

The percentage yield of copper

Solution

Reaction

Zn+CuSO₄⇒Cu+ZnSO₄

mol Zn :

= mass : Ar Zn

= 6.5 g : 65,38 g/mol

= 0.0994

From the equation, mol ratio of Zn : Cu = 1 : 1, so mol Cu = 0.0994

Mass Cu (theoretical) :

= mol x Ar Cu

= 0.0994 x 63,546

= 6.316 g

%yield = (actual/theoretical) x 100%

%yield = (4.8/6.316) x 100%

%yield = 76%

Write the name for CH2.

Answers

Methylene.........i think???.............

Please select the word from the list that best fits the definition How far something moves in a specific amount of time

Answers

Answer:

Speed

Explanation:

That is what I believe the word to the definition, How far something moves in a specific amount of time, but you'd have to providea picture of the list of words for me to be sure...

The electron structure of atoms in elements A and C are 2, 8, 1 and 2, 8, 18, 7, respectively. The formula for the compound formed between A and C will be AC. True or false? pls help me T^T

Answers

True but I don’t feel like explaining lol hope it helps!!

What is the name of a molecule which is composed of two
phosphorous atoms and four sulfur atoms?

Answers

Phosphorus sulfide this answer

The name of a molecule which is composed of two phosphorous atoms and four sulfur atoms is phosphorus sulphide.

What is molecule ?

According on the context, the word may or may not include ions that meet this requirement. A molecule is a collection of two or more atoms bound together by attractive forces known as chemical bonds.

A molecule is the smallest unit of any material that is composed of one or more elements and is capable of existing independently while maintaining all of the substance's physical and chemical characteristics. Further atom division occurs within molecules. For instance, the symbols for the oxygen atom and molecule are O and O2, respectively.

Thus, The name of a molecule which is composed of two phosphorous atoms and four sulfur atoms is phosphorus sulphide.

To learn more about molecule follow the link below;

https://brainly.com/question/19556990

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five more than one third of a number is nine .

Answers

Answer:

uh

Explanation:

5+x/3=9

=x/3=9-5

=x=12

calculate the percentage of calcium in calcium chlorate

Answers

Answer:

19.4%

Explanation:

Calcium Chlorate is Ca(ClO3)2

Now calculate the molar mass of Ca(ClO3)2

Ca = 40.1

Cl = 35.5

O = 16.0

But they are two chlorine atoms and six oxygen atoms. So you do this:

40.1 + 35.5(2) + 16.0(6) = 207.1 grams

Now find the molar mass of just calcium.

There is only one calcium atom.

So you do this.

40.1(1) = 40.1

Now divide the molar mass of calcium by the molar mass of calcium chlorate.

40.1 / 207.1 = 0.1936

0.1936 rounds to 0.194

Now multiply 0.194 * 100 and you will get 19.4

So the final answer is 19.4%.

Hope it helped!

Can you help me with this 19 points

Answers

Answer:

21

Explanation:

To find the total atoms.

Multiply 3 *2 and you will get 6

Then multiply 3 * 5 and you will get 15.

You do this because there is 3 as a coefficient and is before the chemical compound. Furthermore, that means the same thing as a parenthesis.

Last of all, add 15 + 6 and you will get 21.

Therefore, there are a total of 21 atoms.

Examine the chemical reaction and lab scenario.

2Fe2S3+9O2→2Fe2O3+6SO2

3.17 g of iron(III) sulfide (Fe2S3) reacts with an excess amount of oxygen at standard temperature and pressure. The theoretical yield of sulfur dioxide (SO2) is 3.81 g. However, during a lab, only 3.37 g are produced.

What is the percent yield of sulfur dioxide?

94.41% SO2

81.36% SO2

44.00% SO2

88.45% SO2

Answers

Explanation:

Percentage Yield

= (3.37g/3.81g) * 100% = 88.45%.

Therefore 88.45% SO2 is the percentage yield.

John rode his bike down the street to the east. He rode 100 meters in 25
seconds. What was his velocity?
A. 0.25 m/s east
B. 25 m/s east
C. 10 m/s east
D. 4 m/s east

Answers

Answer:

The answer is D.

Explanation:

Given that velocity also applies speed formula, S = D ÷ T where D represents distance and T is time :

S = D ÷ T

S = 100m ÷ 25s

S = 4m/s

V = 4m/s east

The difference between speed and velocity is that speed has only magnitude but velocity has magnitude and direction.

Find the number of grams in 3.45 x 10^21 molecules NiO

Answers

Answer:

Mass = 0.43 g

Explanation:

Given data:

Mass in gram = ?

Number of molecules of NiO = 3.45×10²¹

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

1 mole = 6.022 × 10²³ molecules

3.45×10²¹ molecules × 1 mol / 6.022 × 10²³ molecules

0.57×10⁻² mol

0.0057 mol

Mass in gram:

Mass = number of moles × molar mass

Mass = 0.0057 mol × 74.69 g/mol

Mass = 0.43 g

if a bike travels 23m at constant speed 5289s what is the bikes speed?

Answers

Answer:

0.004 m/s

Explanation:

Given data:

Distance traveled = 23 m

Time taken = 5289 s

Speed of bike = ?

Solution:

Formula:

speed = distance / time

b y putting values,

speed = 23 m/ 5289 s

speed = 0.004 m/s

A simplified version of the Periodic Table of the Elements is provided. What type of elements would you most likely find in the circles portion?

Answers

Answer:

Transition elements are present in this region.

Explanation:

What happens during chemical reactions?
O A. The total amount of energy changes
O B. Total mass increases in the products
O C. Energy is given off or absorbed
O D. Atoms are changed into new elements

Answers

Answer:

D. Atoms are changed into new elements.

Explanation:

atoms rearrange to form one or more different substances.

Hope that helps!!!

Sorry if its worng :(

Answer:

It's actually C. Energy is given off or absorbed.

Explanation:

"All chemical reactions involve changes in energy. This may be a change in heat, electricity, light, or other forms of energy. Reactions that absorb energy are endothermic. Reactions that release energy are exothermic."

-LibreTexts Chemistry

Chemistry
Definition in your own words
Will check if you got it from online.

Word: Solid

Answers

Answer:

A solid is a matter that has particles that are closely packed which as a result makes it vibrate but not flow.

Comparin
List three characteristics of chemical reactions
and three characteristics of nuclear reactions.
DONE

Answers

Answer:

Chemical reactions involve the loss, gain, or sharing of electrons, but do not involve changes to the nucleus of an atom. Nuclear reactions involve changes to the nucleus and produce a new particle. Chemical reactions involve low energy changes. Chemical reactions never involve a change in the mass of atoms.

List three characteristics of chemical reactions, I have five:

occur when bonds are broken and formed

atoms remain unchanged though they may be rearranged

involve only valence electrons

reaction rate is influenced by, temp, pressure, concentration, and catalyst

Three characteristics of nuclear reactions, I have five:

occur when nuclei emit particles

atoms are often converted into atoms of another element

may involve protons, neutrons, and electrons

reaction rate is not normally affected by temp, pressure or catalyst

Which of the following statements about tobacco use is not true?

a. Nicotine narrows blood vessels and puts added strain on the heart.

b. Smoking improves athletic performance.

c. Smoking can wreck lungs.

d. Nicotine in smokeless tobacco is addictive.

Answers

Explanation:

b and c statements are not true

if it helps you then plzz mark me brainliest

Answer:

B.) Smoking improves Athletic performance

Explanation:

describe some acidic oxides that can be prepared by the thermal decomposition of nitrates and carbonates​

Answers

The oxidation is the best thing

72.40% iron,27.60% Oxygen Empirical formula

Answers

Explanation:

Fe. O

72.40/ 56 27.60/16

____________________

1.29/1.29 1.725/1.29

_____________________

1. :. 1

Emperical formula = FeO

Empirical formula is the whole number ratios of elements in a compound. It can be found from the number of moles. The empirical formula of iron and oxygen of 72.4 % and 27.6 % respectively is Fe₂O₃.

What is empirical formula?

Empirical formula of a compound is the chemical formula derived from the number of moles each element present in it.  Whereas, molecular formula is derived from the actual masses of the elements present in the compound.

Empirical formula can be determined from the number of moles of the elements. It is given that the mass percentages of iron and oxygen are 72.40% and 27.60% respectively. This can be taken as 72.40 g and 27.60 g in a 100 g of compound.

Thus there is 72.40 g of iron. The atomic mass of Fe = 55.85 g/mol

Thus number of moles of Fe = 72.40 / 55.85

                                               = 1.295

The weight of oxygen in 100 g of compound is 27.60 g. Atomic mass of oxygen is 16 g/mol.

Thus number of moles of oxygen = 27.60 /16 = 1.725

Taking the ratios of these number of moles = 1.295 :1.725 = 2 :3

Hence, the ratios of iron to oxygen is 2:3 which means the empirical formula of the compound is Fe₂O₃.

To find more about empirical formula, refer the link below:

https://brainly.com/question/11588623

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true or false
1. Average atomic mass is the mass of any atom based on its nuclear particles in relation to units measured in amu which is 1/12th of a carbon atom.
2. When calculating the average atomic mass of an element, the average atomic mass value falls closest to that of the least percentage abundance (least common) isotope.

Answers

Answer:

true

Explanation:

calculating the average atomic

What are natural disasters that are NOT in Florida?

A: Tsunami
B: Earth quakes
C: Sand Storm
D: Hurricanes
E: Storm

Answers

c because florida has no sand whatsoever besides there beaches but it will not cause a hugs storm

2. How many moles are in 2.43 x 1024 particles of Carbon Monoxide

(CO)?

Answers

Answer:

= 14.63 × [tex]10^{45}[/tex] particles.

Explanation:

According to Avogadro's priciple:

1 mole of any substance is 6.02 × [tex]10^{23}[/tex] particles

∴ 2.43 x [tex]10^{24}[/tex] moles × 6.02 × [tex]10^{23}[/tex]

= 14.63 × [tex]10^{45}[/tex] particles.

I hope this was clear and easy to understand.

please help. calculate the partial pressure of oxygen gas Po2 at STP.

Answers

Answer:

0.21 atm

Explanation:

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

Partial pressure of N₂ (P₁) = 0.78 atm

Partial pressure of Ar (P₂) = 0.01 atm

Partial pressure of O₂ (P₃) =?

Since the system is at standard temperature and pressure (STP), the total pressure of the system is 1 atm.

Finally, we shall determine the partial pressure of O₂. This can be obtained as follow:

Partial pressure of N₂ (P₁) = 0.78 atm

Partial pressure of Ar (P₂) = 0.01 atm

Total pressure (Pₜ) = 1 atm

Partial pressure of O₂ (P₃) =?

Pₜ = P₁ + P₂ + P₃

1 = 0.78 + 0.01 + P₃

1 = 0.79 + P₃

Collect like terms

1 – 0.79 = P₃

P₃ = 0.21 atm

Therefore, the partial pressure of O₂ is 0.21 atm.

What is produced when an acid and an alkali react?
A. Water and a base
B. Water and Carbon dioxide
C. Salt and a base
D. Salt and water

Answers

The answer is D: Salt and Water
D. Salt and water is produced when an acid and an alkali react

How will you process the information in the table and on the map to
make predictions? Describe how you will use the inputs to develop
an output.
Help

Answers

Answer:

By measuring through scale

Explanation:

CAN YOU TELL THE NAME OF COUNTRY BECAUSE I AM FROM NEPAL

Is the cell wall factory part or worker? And please explain what the worker or factory part does. (Don’t tell me it’s on quizlet bc I can’t find it)

Answers

Cell wall is a worker because it allows water and sugar in and out (atp)

i need help with this

Answers

Answer:

It would be the last one because the way earth is tilted the sun rays would be pointing at the Northern Hemisphere more than the Southern Hemisphere

A force that does not have a high amount of effect

Answers

Answer:

yes

Explanation:

its not that hard to get

Pretty sure it’s a fictitious force
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