How many moles of KOH are in 21.0g of KOH?​

Answers

Answer 1

Answer:

HowHow many moles of KOH are in 21.0g of KOH?

Answer 2

Answer:

0.374 moles

Explanation:

I have included the dimensional analysis below, and by MM I mean Molar Mass of the atom.

Hope this helps!

How Many Moles Of KOH Are In 21.0g Of KOH?

Related Questions

the process of breaking food is to release energy is called _____​

Answers

Answer:

The process by which food is broken down to release energy is called respiration

I hope it helps.

Answer:

Respiration

Explanation:

hope this helps.

Hot air balloons are open at their lower and end. A basket is suspended from the balloon and can take several passengers as well as the pilot. A propane burner fixed to the basket is used to heat up the air in the balloon A hot balloon has a volume of 1500 m3 and its volume does not change when the enclosed air is heated.

1) Use the ideal gas equation, pV=nRT. to calculate how many molecules of the balloon contains at a temperature of 10 °C and a pressure 10.1 KP.
2) Calculate the mass of air it contains, assuming an average M of 29.​

Answers

(a) The number of molecules contained by the balloon at the given condition is 6,438.97 moles.

(b) The mass of air in the balloon is 186.73 kg.

The given parameters;

volume of the balloon, V = 1500 m³temperature, T = 10⁰C = 273 + 10 = 283 Kpressure, = P = 10.1 kPa = 10,100 Pa

The number of molecules contained by the balloon at the given condition is calculated as follows;

[tex]PV = nRT[/tex]

where;

R is ideal gas constant = 8.314 J/mol.Kn is the number of moles air in the balloon;

[tex]n = \frac{PV}{RT} \\\\n = \frac{10,100 \times 1500}{8.314 \times 283} \\\\n = 6,438.97 \ moles[/tex]

The mass of air in the balloon is calculated as;

[tex]n = \frac{m}{M} \\\\m = nM\\\\m = 6,438.97\ moles \ \times \ 29 \ g/mol\\\\m = 186.73 \ kg[/tex]

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Where did the atoms come from in the first place?

Answers

Answer:

All the carbon atoms in the human body were created in the stars. Elementary particles, such as protons, were formed during the "big bang"; that amazing moment about 14 billion years ago in which the universe got it's start.

Convert 1.36x10 to standard form​

Answers

Answer:

13.6 is the correct answer written in standard form.

Explanation:

1.36, move the decimal once to the right to get 13.6

Answer:

13.6

Explanation:

The standard form is 13.6

an alloy composed of tin, lead, and cadmium is analyzed. the mole ratio of sn:pb is 2.73:1.00, and the mass ratio of pb:cd is 1.78:1.00. what is the mass percent composition of pb in the alloy

Answers

This problem is describe the mole-ratio composition of an allow composed by tin, lead and cadmium. Ratios are given as Sn:Pb 2.73:1.00 and Pb:Cd is 1.78:1.00, and we are asked to calculate the mass percent compositon of Pb in the allow.

In this case, according to the given information, it turns out possible realize that the following number of moles are present in the alloy, according to the aforementioned ratios:

[tex]2.73mol Sn\\\\1.00molPb\\\\\frac{1.00molPb*1.00molCd}{1.78molPb}= 0.562molCd[/tex]

Next, we calculate the masses by using each metal's atomic mass:

[tex]m_{Sn}=2.73mol*\frac{118.7g}{1mol}=324.05g\\\\ m_{Pb}=1.00mol*\frac{207.2g}{1mol}=207.2g\\\\m_{Cd}=0.562mol*\frac{112.4g}{1mol}=63.2g[/tex]

Thus, the mass percent composition of each metal is shown below:

[tex]\%Sn=\frac{324.05g}{324.05g+207.2g+63.2g} *100\%=54.5\%\\\\\%Pb=\frac{207.2g}{324.05g+207.2g+63.2g} *100\%=34.9\%\\\\\%Cd=\frac{63.2}{324.05g+207.2g+63.2g} *100\%=10.6\%[/tex]

So that of lead is 34.9 %.

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If an atom should form from its constituent particles,
(a) matter is lost and energy is taken in.
(b) matter is lost and energy is released. .
(c) matter is gained and energy is taken in.
(d) matter is gained and energy is released.

Answers

Answer:

(b) matter is lost and energy is released

Explanation:

When atoms are being formed from its constituent components it weighs less this is called mass defect so the answer would be (b) matter is lost and energy is released.

the amount of solute dissolved in a solvent
A. Concentration.
B.alloy
C.mixture
D.solution

Answers

Answer:

solution

Explanation:

solvent +solute =solution

What is the use of GMO?

Answers

Some benefits of genetic engineering in agriculture are increased crop yields, reduced costs for food or drug production, reduced need for pesticides, enhanced nutrient composition and food quality, resistance to pests and disease, greater food security, and medical benefits to the world's growing population.

Insect resistance: Corn

Herbicide tolerance: Soybean

Describing Chemical Reactions
Project: Modeling the Conservation of Mass

Answers

Answer:

Step 1: Prepare for the project.

a) Read the entire Student Guide before you begin this project.

b) If anything is unclear, be sure to ask your teacher for assistance before you begin.

c) Gather the materials you will need to complete this project.

Step 2: Review the chemical reaction.

a) The chemical reaction that you will model is shown below. Calcium oxide (CaO) is a white

solid with a crystalline structure. It is made by heating limestone, coral, sea shells, or chalk,

which are composed mainly of calcium carbonate (CaCO3). During the heating process,

carbon dioxide (CO2) is released and calcium oxide (CaO) is produced. Commercially,

calcium oxide is called lime. One of the oldest uses of lime is to make mortar, a substance

used in construction to secure bricks, stones, and blocks together.

CaCO3  CaO + CO2

Step 3: Build a model of the reactant.

a) Use gumdrops and toothpicks to build a model of CaCO3.

b) Select one color of gumdrop for calcium, a second color for carbon, and a third color for

oxygen. Be sure to include a key of your chosen color scheme with your model.

c) Use the periodic table to help you determine the number of bonds each atom will form.

Step 4: Build models of the products.

a) Use gumdrops and toothpicks to build a model of CaO and a model of CO2.

b) Be sure to use the same colors of gumdrops for calcium, carbon, and oxygen as you did in

Step 3. Include a key of your chosen color scheme with your models.

c) Use the periodic table to help you determine the number of bonds each atom will form.

Step 5: Type one to two paragraphs that describe your models and explain the conservation of

mass in the chemical reaction.

a) Create a new blank document. Type your name at the top.

b) Type one to two paragraphs that describe your models and relate them to the law of

conservation of mass. Your document should:

i. identify the names of the reactants and products in the reaction.

ii. identify the number of molecules that make up the reactants and products.

iii. identify the type and number of atoms in each molecule of the reactants and products.

iv. explain what happens during the chemical reaction.

v. explain how mass is conserved during the chemical reaction.

Step 6: Evaluate your project using this checklist.

If you can check each criterion below, you are ready to submit your project.

 Did you create an accurate model of calcium carbonate (CaCO3)? Your model should include

the correct number of gumdrops for each element in calcium carbonate, consistent use of

colors for elements in calcium carbonate, and the correct number and placement of toothpicks

(bonds).

 Did you create an accurate model of calcium oxide (CaO)? Your model should include the

correct number of gumdrops for each element in calcium oxide, consistent use of colors for

elements in calcium oxide, and the correct number and placement of toothpicks (bonds).

 Did you create an accurate model of carbon dioxide (CO2)? Your model should include the

correct number of gumdrops for each element in carbon dioxide, consistent use of colors for

elements in carbon dioxide, and the correct number and placement of toothpicks (bonds).

Did you type one to two paragraphs that describe your models and relate them to the law of

conservation of mass? Your document should include the names of the reactants and

products in the reaction, the number of molecules that make up the reactants and products,

and the type and number of atoms in each molecule of the reactants and products. It should

also explain what happens during the chemical reaction and how mass is conserved during  the reaction

Step 7: Revise and submit your project.

a) If you were unable to check off all of the requirements on the checklist, go back and make  

b) When you have completed your project, submit your models to your teacher for grading.  

c) Submit your document through the virtual classroom. Be sure that your name is on it.

Step 8: Clean up your workspace.

a) Clean up your workspace. Return any extra materials to your teacher and throw away any  trash.

Explanation:

Dont need work pls help

Answers

The answer is a low is the correct answer

What element is a gas at room temp, has 6 valence electrons, and is non-reactive

Answers

Answer:

Noble gases

Explanation:

Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table in the figure below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn).18 Jun 2021

Find the volume of 0.170 M sulfuric acid necessary to react completely with 72.2 g sodium hydroxide.

Answers

The volume of sulphuric acid, H₂SO₄ needed for the complete reaction with 72.2 g of sodium hydroxide, NaOH is 5.31 L

We'll begin by calculating the number of mole in 72.2 g of NaOH. This can be obtained as follow:

Mass of NaOH = 72.2 g

Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol

Mole of NaOH =?

Mole = mass / molar mass

Mole of NaOH = 72.2 / 40

Mole of NaOH = 1.805 mole

Next, we shall determine the number of mole of H₂SO₄ needed to react with 1.805 mole of NaOH.

2NaOH + H₂SO₄ —> Na₂SO₄ + 2H₂O

From the balanced equation above,

2 moles of NaOH reacted with 1 mole of H₂SO₄.

Therefore,

1.805 mole of NaOH will react with = 1.805 / 2 = 0.9025 mole of H₂SO₄.

Finally, we shall determine the volume of H₂SO₄.

Mole of H₂SO₄ = 0.9025 mole

Molarity of H₂SO₄ = 0.170 M

Volume of H₂SO₄ =?

Volume = mole / Molarity

Volume of H₂SO₄ = 0.9025 / 0.170

Volume of H₂SO₄ = 5.31 L

Thus, the volume of H₂SO₄ needed for the reaction is 5.31 L

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Which of the following is NOT a type of evidence indicating that a chemical change has occurred? *

- fizzing/bubbling
- heat is released
- solubility
- sound is given off

Answers

Answer:

sound is given off

Explanation:

due to a number of scientific research sound that is given off of an object is not due to a chemical reaction.

4. A system contracts from an initial volume of 15.0 L to a final volume of 10.0 L under a constant external pressure of 0.800 atm. The value of w, in J, is?

Answers

The value of the work done in joule is 405.3 J.

We know that the work done is obtained using the relation;

w = PΔV

Where;

w = work done

P = pressure

V = volume

Now, substituting values,

w = 0.800( 15.0 -  10.0)

w = 4 atm L

Since;

1 L atm = 101.325 J

4 atm L  = 4 atm L × 101.325 J/1 L atm

= 405.3 J

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Identify the strongest intermolecular force that is likely to affect each of the samples described below.
A mixture of chlorine gas (Cl) and fluorine gas (F): V London dispersion forces
COMPLETE
Tweaks
Menu
A mixture of hydrogen sulfide (H2S) and hydrogen chloride (HCI): V dipole-dipole interactions
Search
Selection
COMPLETE
Guess
this
hydrogen bonding
A mixture of water (H2O) and ammonia (NH3):

Answers

Answer:

A mixture of chlorine gas (Cl2) and fluorine gas (F2):

✔ London dispersion forces

Explanation:

Part C
Describe the shape of the graph showed in part B.
(Is it like- a normal shape??)

Answers

This graph shows a straight line.

Answer:

The graph is a straight line that angles upward.

Mechanical waves travel fastest through
A -Solid
B -Liquid
C -Gas
D -Vacuum

Answers

Answer:

A-Solid

Explanation:

Waves travel faster in solids & slowest in gases

2. What pressure is required to compress 196.0 L of air at 1.00 atmosphere into a cylinder
whose volume is 26 0 L? (2 points)

Answers

Answer:

7.54 atm

Explanation:

The required pressure can be found by using the formula for Boyle's law which is

[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

From the question we have

[tex]P_2 = \frac{1 \times 196}{26} = \frac{196}{26} \\ = 7.538461...[/tex]

We have the final answer as

7.54 atm

Hope this helps you

4.What volume of hydrogen gas at STP is produced when 2.5 grams of zinc react with an
excess of hydrochloric acid?

Answers

Answer:

0.86

Explanation:

1mol of Zn has mass of 65.39g.The amount of Zn is 2.5g65.39g/mol=0.038mol.

The amount of H2 produced is the same as the amount of Zn consumed (0.038mol).

1mol of ideal gas will occupy 22.4L at STP.

The H2 will occupy 0.038mol×22.4L/mol=0.86L

.

Oil does not dissolve in water because

Answers

Answer:

Because oil have apolar molecules, while water have polar molecules

which two types of food are homogeneous mixtures
A. mustard
B. mayonnaise
C. tossed salad
D. trail mix

Answers


Answer: It’s most likely Mayonnaise and mustard.
Explanation: It’s definitely mayonnaise because it’s not possible to see the different substances and for mustard it depends on what type. Hope this helps. Good luck :)

So My friend has started her you know what and she scared to call her mom what should I do I'm sorry if this question is personal anything but I'm kind of confused cuz she's scared to call her mom her mom is gone so she needs some advice the best person who got the best answer will receive a brainly and 50 more points

Answers

Answer: so I was really scared to tell my mom and I was always thinking about how should I tell here but she should tell her mom an just said I think I started my thing  her mom wont get mad she got it to and every girl goes thru that so your not alone

Explanation; she does not have to tell her mom but her mom could helpo her and give her tips

Answer:

Tell her to calm down and tell her mum because her mom knows better and would be able to put her through better than anyone could have ever.

In this photograph, a soccer player is about to kick the ball. Use the situation to explain that when two objects interact, the force between them can cause energy to be transferred. In your response, identify the type of energy that each object has before they interact, the forces exerted when the objects interact, and the type of energy that each object has after they interact.

Answers

The explanation to the question is stated as follows:

Newton's first law of motion states that: a body will continue in its state of rest or uniform motion unless an external force acts on it. So then, the ball initially possesses potential energy because it was at rest. While the leg of the soccer player possesses kinetic energy because its in motion.

Thus, when the player hits the ball, a force known as push has been applied. This would ensure that the ball compels and moves in the direction of the applied force. Therefore after the interaction, the leg of the player now possesses potential energy, since it would come to rest after hitting the ball. While the ball would start moving, now possessing kinetic energy.

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5. Select the answer for both questions ​

Answers

Answer:

engey

Explanation:

what does cost-effective mean? im kind of confused on cost-effective and time-effective things and i keep getting mixed up :(

Answers

Cost-effective definition: producing good results without costing a lot of money. E.g: that machine is very cost effective, it made 200 shirts with only a dollar.

Time effective definition: how well time was used. E.g that machine is very time-effective, it made 200 pants in one hour!

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What instruments are used to measure moleculars vibration , rotation and translation?

Answers

Answer:

you hear

Explanation:

beautiful hear can be wonderful day in your life so to be rotations is not a big deal

A 14.0 L container at 323 K holds a mixture of two gases with a total pressure of 8.00 atm. If there are 1.50 mol of Gas A in the mixture, how many moles of Gas B are present

Answers

The number of moles of gas B present in the gas mixture is 2.72 moles.

The given parameters;

Volume of the gases, V = 14 LTemperature of the gases, T = 323 KTotal pressure of the gases, P = 8 atmNumber of moles of gas A = 1.5 moles

The total number of moles of the gases is calculated by applying ideal gas law;

PV = nRT

where;

R is ideal gas constant = 0.0821 L.atm./mol.K

n is the total mole of the gases

[tex]n =\frac{PV}{RT} \\\\n = \frac{8 \times 14}{0.0821 \times 323} \\\\n = 4.22 \ moles[/tex]

The number of moles of gas B is calculated as follows;

[tex]n_B = 4.22 - n_A\\\\n_B = 4.22 - 1.5\\\\n_B = 2.72 \ moles[/tex]

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Converting from the US customary system to the metric system, 16 fluid ounces is approximately equal to a) 1 gallon. O b) 160 milliliters. c) 480 milliliters. O d) 960 milliliters.

Answers

Answer:

473 ml.

Explanation:

In gallons it’s equal to 0.125

pls help me right now​

Answers

Answer:

LETTER

1. D. PURE SUBSTANCES CAN BE FURTHER BROKEN DOWN INTO SIMPLER SUBSTANCES.

2.A

PO PLEASE MARK A BRAINLIESTS ANG MARK A 5 STAR ANG HEART PO PLEASW

Problem 07.020 - Heat transferred from cold to hot reservoir Assume that heat in the amount of 100 kJ is transferred from a cold reservoir at 600 K to a hot reservoir at 1050 K contrary to the Clausius statement of the second law. What is the total entropy change

Answers

This problem is describing a system in which 100 kJ of energy is transferred from a cold reservior at 600 K to a hot one at 1050 K. This situation is opposed to the Clausius statement of the second law of thermodynamics, because it is widely known that heat is transferred from hot to cold systems.

However, we can calculate the total entropy change by using the following formula:

[tex]\Delta S =\Delta S _{Low}+\Delta S _{High}[/tex]

Which is broken down as follows:

[tex]\Delta S =\frac{-Q}{T_{Low}} + \frac{Q}{T_{High}}\\\\\\\Delta S =Q(\frac{-1}{T_{Low}} + \frac{1}{T_{High}})[/tex]

Since the heat is assumed to be equal for the both of them. Then, we plug in the given heat and temperatures to obtain:

[tex]\Delta S =100kJ(\frac{-1}{600K} + \frac{1}{1050K})\\\\\Delta S =-0.0714\frac{kJ}{K}[/tex]

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