4 Identify Give an example of a physical change and an example of a chemical change.

The percentage yield of oxygen obtained from the reaction, given that 400 g of potassium chlorate was heated is 73.4%

2KClO₃ —> 2KCl + 3O₂

Molar mass of KClO₃ = 122.5 g/mole

Mass of KClO₃ from the balanced equation = 2 × 122.5 = 245 g

Molar mass of O₂ = 32 g/mole

Mass of O₂ from the balanced equation = 3 × 32 = 96 g

SUMMARY

From the balanced equation above,

245 g of KClO₃ decomposed to produce 96 g of O₂

From the balanced equation above,

245 g of KClO₃ decomposed to produce 96 g of O₂

Therefore,

400 g of KClO₃ will decompose to produce = (400 × 96) / 245 = 156.7 g of O₂

Percentage yield = (Actual /Theoretical) × 100

Percentage yield = (115 / 156.7) × 100

Percentage yield = 73.4%

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Answer:

B. 73.40%

Explanation:

I AM JUST HIM

Answer:

Taste bufs

Explanation:

May be teenager or adult is the most probable answer because teenager and adult are fully developed species of human so they can have most sensitive taste bud

PLEASE MARK ME BRAINLIEST IF MY ANSWER IS CORRECT

Answer:

Cu (s)  and AlCl₃ (s)

Explanation:

This reaction can be classified as a single-displacement reaction, aka. a single-replacement reaction. These reactions involve one element swapping out another element in a compound. In this reaction, aluminum is taking the place of copper (ii) in the copper (ii) chloride compound. Aluminum takes the place of copper (ii) specifically because aluminum is more likely form a cation than anion. Copper (ii) serves as a cation in the compound.

Al (s) + CuCl₂ (s) --> Cu (s) + AlCl₃ (s)

The final products are copper (ii) metal and aluminum chloride. The metal of copper (ii) is produced instead of the cation in order to maintain the neutral charge balance of the reaction. The chorine has a subscript of 3 because aluminum usually forms cations of a +3 charge while chlorines form anions with a -1 charge.

The balanced equation is:

2 Al (s) + 3 CuCl₂ (s) --> 3 Cu (s) + 2 AlCl₃ (s)

Answer:

B

Explanation:

Answer:

C. cohesion

Explanation:

The cohesive force between liquid molecules are responsible for the phenomenon known as surface tension

When an acid reacts in a reaction, it donates hydrogen ion as the only positive ion.

According to Bronsted-Lowry's definition, an acid is a substance that donates hydrogen ions as the only positive ion in reactions.

Following this definition, it can be concluded that when an acid reacts with another substance, it donates one or more hydrogen ions.

A good example is shown in the equation below:

[tex]HCl + KOH --- > KCl + H_2O[/tex]

In the reaction above, HCl donated a hydrogen ion.

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Answer:

a

Explanation:

just took the quiz and this is correct.

Answer:

limiting reactant gives ................

Answer:

Limiting Reagent or Limiting Reactant

Explanation:

And to assess which reactant is which, we must usually have quantities of each reagent in a chemical reaction...and of course we should write a stoichiometric equation that is balanced with respect to mass and charge in order to assess the stoichiometric equivalence.

We could examine for instance, the combustion of methane gas, the which MAY have cooked your dinner … its combustion reaction is as shown...

[tex]CH_4(g) + 2O_2(g) rarr CO_2(g) + 2H_2O(g) + Delta[/tex]

And here conditions of COMPLETE combustion pertain; there is DIOXYGEN in excess, AND methane is the limiting reagent. A [tex]10*g[/tex] mass of methane represents a molar quantity of …

[tex](10.0*g)/(16.01*g*mol^-1)=0.623*mol[/tex]

And with respect to dioxygen we thus require...

[tex]0.623*mol*32.00*g*mol^-1=40*g[/tex]

...but this quantity (AND MORE) is available from the atmosphere....and the methane was the limiting reagent....

Answer:

Energy costs are high for many school districts. Therefore, unlimited free power generated by the sun can deliver huge cost savings when compared to grid-generated power. With a modestly sized solar array, cost savings are alike modest.

Explanation:

Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest halogen and is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour.

Answer:

Bromine is a nonmetal in group 7 or group 17, known as the halogens. It has 7 valence electrons.

So the correct answer is "nonmetal, 7 valence electrons"

The molarity of a solution that contains 4.9 g of [tex]H_2SO_4[/tex] in 400 ml of solution would be 0.12465 M

Define molarity of a solution.

Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution. Molarity is also known as the molar concentration of a solution.

Mathematically,

[tex]Molality = \frac{Moles \;solute}{olume \;of \;solution \;in \;litre}[/tex]

Mole of 4.9 g [tex]H_2SO_4[/tex]

= [tex]\frac{mass}{molar \;mass}[/tex]

= [tex]\frac{4.9 g}{98.08}[/tex]

= 0.0499

[tex]Molality = \frac{Moles \;solute}{ olume \;of \;solution \;in \;litre}[/tex]

[tex]Molality = \frac{ 0.0499}{0.4}[/tex]

= 0.12465 M

Hence, the molarity of a solution that contains 4.9 g of [tex]H_2SO_4[/tex] in 400 ml of solution would be 0.12465 M.

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Answer:

C

Explanation:

Actually, arranged to the size of smallest to least atom radius size = C

Atomic sizes generally get smaller as you go from L to R across a row of the periodic table.

Anders Celsius made the centigrade thermometer.

Answer:

Use a catalyst, use more reactants, have a larger reactant surface area, more pressure, higher temperature.

Explanation:

The isomer of the molecule in the depicted image would be A.

Isomers are molecules with the same chemical formula but different arrangements of their component atoms. Isomers also have different properties.

The original molecule in the image has a triple bond with 4 carbon atoms. Thus, its isomers must also have a triple bond with 4 carbon atoms.

The only option with a triple bond and 4 carbon atoms in the image is option A.

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Answer:

In this type of neutralization reaction, the acids and bases are the reactants, since they are the materials that will react to form a new solution. The products are water and salt since they have been created following the reaction.

Explanation:

Neutralization occurs when a strong acid and a strong base come together in a chemical reaction to form water and salt.

In chemistry, acids and bases are measured on the pH scale, which ranges from 0 to 14. Pure water sits in the middle, at a neutral 7. Anything below 7 is an acid, and anything above 7 is a base. Often, solutions are either too acidic or too basic, so a reaction must take place in order to achieve neutralization.

That neutralization leads to the formation of water and salt. In chemistry, salt doesn’t necessarily just mean table salt. It is also a broader term that categorizes the compound that is created in the reaction between an acid and a base.

Answer:

Engineering is all about solving problems using math, science, and technical knowledge. And engineers have solved a lot of problems in the world by designing and building various technologies. We have everything from machines that can breathe for you in hospitals to suspension bridges to computers we use every day. All of these things were once designed by engineers using the engineering design process.

Explanation:

Answer:

Students will have to use their brains to solve problems and challenges they will face to find a solution to cleaning up oil spills. Students will face failures after completing their solution, lots of research, and problems during the making of their solutions. What will work? What won't?

Explanation:

Hope this helps!

Answer:

Organisms that belong to the same species, form groups, and interact together in the same environment make the level of the population whereas a community has groups of different species living together in an environment. Species are the group of individuals that are genetically related to each other.

Answer:

4Fe+3O2- 2Fe2O3

the ratio: 3:2

x:3.95

x=5.92 moles of O2

Answer:

B. Wall applies equal reaction force on hand

Explanation:

This is newton's third law. You push something, that something pushes you back with same force. The direction is opposite, so if I push a wall, the wall pushes me back with same force just in opposite direction (so wall towards me). This is why option A is incorrect b/c it says force in same direction as wall. C and D talk about unequal force which is incorrect.

Answer:Wall applies equal reaction force on hand

Explanation:

Answer:

Six step guide to help you solve problems

Step 1: Identify and define the problem. State the problem as clearly as possible. ...

Step 2: Generate possible solutions. ...

Step 3: Evaluate alternatives. ...

Step 4: Decide on a solution. ...

Step 5: Implement the solution. ...

Step 6: Evaluate the outcome

Answer:

Gamma rays

Since they have high penetrating power.

Answer:

A

Explanation:

Balanced one

Moles of Pentyne

Moles of H_2O

1mol releases 241.8KJ

2mol releases 241.8(2)=483.6KJ

Remember the relationship

So

The pairs are

And so on

Answer:

Here are the following answers to the five questions:

(1) "Form only at boundaries between two continental plates."

(2) "A fault-block mountain"

(3) "Island arcs form when hot, fluid rock rises through thin spots in Earth's crust, whereas hotspot volcanoes form when two oceanic plate boundaries push against each other until subduction happens and the plates partially melt."

(4) "The fault plane runs from the top of the rock to the bottom of the rock at an angle greater than 45 degrees."

(5) "Segments of Earth's crust bent and doubled over, and moving wind and water gradually shaped the rock into gently sloping domes."

Explanation:

Answer:

solo esto se responderte

Explanation:

Algunos solutos (por ejemplo, cloruro de sodio (NaCl) en agua) exhiben una solubilidad bastante independiente de la temperatura. Unos pocos, como el sulfato de cerio (III) y el carbonato de litio, se vuelven menos solubles en agua a medida que aumenta la temperatura.

The three macroscopic properties of a gas in terms of the microscopic nature of atoms and the molecules making up the gas is explained by the kinetic theory of gases. The macroscopic properties like pressure, volume and temperature are used to study a gas.

The kinetic theory of gases is a theoretical model which describes the molecular composition of the gas in terms of a large number of submicroscopic particles which include atoms and molecules. Gas is a combination of large number of atoms or molecules.

The kinetic theory of gases considers that the atoms or molecules of a gas are constantly moving point masses which contain a huge inter-particle distance and may undergo perfect elastic collisions.

1. Since the particles are in motion, the average kinetic energy is proportional to the temperature of the gas. So when the inflated balloon is placed in a freezer, the balloon shrinks due to decrease in temperature.

2. When balloon is kept outside in the sun, it will burst due to expansion of gases.

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Answer:

C

water has undergone a phase change and the composition of a substance was not changed

19. For the reaction, 2S+ 30=2SO3, how many moles of so3 will be produced from 12.5 g 02 and excess S?

:

For the reaction: 2S(s) + 3O2 -> 2SO2(g) How many moles of SO3 will be produced from 2.0 mol O2 and excess S?

Answer:

Explanation:

19. For the reaction, 2S+ 30=2SO3, how many moles of so3 will be produced from 12.5 g 02 and excess S?

Answer:

Known for his law of gases, Boyle was a 17th-century pioneer of modern chemistry. Every general-chemistry student learns of Robert Boyle (1627–1691) as the person who discovered that the volume of a gas decreases with increasing pressure and vice versa—the famous Boyle's law.