Two students determine the percentage of lead in a sample as a laboratory exercise. The true percentage is 22.52%. The students results for three determinations are as follows: (1) 22.52, 22.48, 22.54 (2) 22.64, 22.58, 22.62 Calculate the average percentage for each set of data and state which set is the more accurate based on the average

Answer:

B

Explanation:

If AH and AS are both negative  will a low temperature make a reaction spontaneous.

A spontaneous reaction is a reaction that favors the formation of products at the conditions under which the reaction is occurring. A roaring bonfire (see figure below) is an example of a spontaneous reaction.

A fire is exothermic, which means a decrease in the energy of the system as energy is released to the surroundings as heat.

The products of a fire are composed mostly of gases such as carbon dioxide and water vapor, so the entropy of the system increases during most combustion reactions.

Therefore,  If AH and AS are both negative  will a low temperature make a reaction spontaneous.

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Answer:

170ml

Explanation:

multiply the volume value by 100000

The amount of heat energy absorbed when 200 grams of water are heated from 20 C to 60 C is 33,440 Joules.

To find the amount of heat energy absorbed when 200 grams of water are heated from 20 C to 60 C, we can use the equation Q = mcAT.
First, we need to find the value of m, which is the mass of the water in grams. In this case, it is given as 200 grams.
Next, we need to find the value of AT, which is the change in temperature in degrees Celsius.

This can be calculated by subtracting the initial temperature from the final temperature, which gives us 60 C - 20 C = 40 C.
The specific heat capacity of water, C, is given as 4.18 Joules per gram per degree Celsius.
Now we can plug in the values into the equation:
Q = mcAT
Q = (200 g) x (4.18 J/g°C) x (40°C)
Q = 33,440 J
Therefore, the amount of heat energy absorbed when 200 grams of water are heated from 20 C to 60 C is 33,440 Joules.

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With the compounds sample mass at  150g, and we are left to decipher the proportion of Carbon, Hydrogen, and Oxygen amount, The compound's empirical formula is mathematically given as

Ep=C5H12O4

Question Parameters:

A 150 g sample of a compound is comprised of 44.07% C, 8.98% H and the remainder is O by mass

Generally, the equation for the compound  is mathematically given as

CxHyOz

Where

Therefore

O percentage is

Po100-(44.07+8.98)

Po=46.95

For Cx we determine the minimum value

hence

x=1.25*4

x=5

For Hy

y=3.0*4

For  Oz

y= 1*4

y=4

In conclusion, the empirical formula is

C5H12O4

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The balanced equation  \(K_{2}Cr_{2}O_{7}\) oxidizes KI in the presence of \(H_{2}SO_{4}\)can be represented as

6 KI + \(K_{2}Cr_{2}O_{7}\) + 7 \(H_{2}SO_{4}\) → 4 \(K_{2}Cr_{2}O_{7}\) + \(Cr_{2}(SO_{4})_{3}\) + 3 \(I_{2}\)\(I_{2}\) + 7 \(H_{2}O\)

The balanced equation for the oxidation of KI (potassium iodide) by \(K_{2}Cr_{2}O_{7}\)(potassium dichromate) in the presence of \(H_{2}SO_{4}\)(sulfuric acid) can be represented as follows:

6 KI + \(K_{2}Cr_{2}O_{7}\) + 7 \(H_{2}SO_{4}\) → 4 \(K_{2}Cr_{2}O_{7}\) + \(Cr_{2}(SO_{4})_{3}\) + 3 \(I_{2}\)\(I_{2}\) + 7 \(H_{2}O\)

In this equation, \(K_{2}Cr_{2}O_{7}\) is the oxidizing agent, and KI is the substance being oxidized. The sulfuric acid (\(H_{2}SO_{4}\)) serves as a catalyst and provides the necessary acidic conditions for the reaction to occur.

The products of the reaction are potassium sulfate (\(K_{2}SO_{4}\)), chromium(III) sulfate (\(Cr_{2}(SO_{4})_{3}\)), iodine (), and water (\(H_{2}O\)).

Note that this equation represents a stoichiometrically balanced equation, ensuring that the number of atoms of each element is the same on both sides of the equation.

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concentration of sulfuric acid is 0.124mol/dm³

Given,

volume of sulfuric acid is 25 cm³

1 dm³ = 1000 cm3.

25.0 cm³ 0.250mol/dm3 NaOH solution contains (25/1000)×0.250 = 0.00625 mol NaOH.

2NaOH + H2SO4 → Na2SO4 + 2H2O

2 moles of NaOH neutralizes 1 mole of H2SO4.

Therefore, 0.00625 moles of NaOH neutralizes 0.00625/2 = 0.00312 moles of H2SO4.

So, the molarity of H2SO4 solution = (0.00312/25) × 1000 = 0.124 mol/dm³.

therefore concentration of sulfuric acid is 0.124 mol/dm³.

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The statement that accurately describes the photoelectric effect is Shining a HIGH frequency light over a metal will cause ELECTRONS to be ejected. That is option B.

Photoelectric effect is defined as the process by which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation.

The photoelectric effect can also be defined as the ejection of electrons from a metal plate when light falls on it.

Therefore, statement that accurately describes the photoelectric effect is Shining a HIGH frequency light over a metal will cause ELECTRONS to be ejected.

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Niels Bohr's 1913 model depicts that the atom has a small, positively charged nucleus which surrounded by electrons that travel in circular orbits around the nucleus.

The Bohr model, is a representation of the structure of atoms, especially that of hydrogen, The Bohr Model is a universal model in which the negatively charged electrons orbit a small, positively charged nucleus like the planets.

In the Bohr model, electrons are pictured as traveling in circles at dissimilar shells, depending on which element you have. The Bohr model is a proportional primitive model of the hydrogen atom, in contrast to the valence shell mode

So we can conclude that the Bohr Model is a structural model of an atom that shows electrons and the nucleus of an atom.

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Answer:

The conclusion

Explanation:

Answer:

Do you know the formula¿?

The decomposition of aspirin (acetylsalicylic acid,\(C_{9} H_{8} O_{4}\)) can occur through the hydrolysis reaction, resulting in the formation of acetic acid (\(CH_{3} COOH\)) and salicylic acid (\(C_{7} H_{6}O_{3}\)).

The decomposition of aspirin (acetylsalicylic acid, \(C_{9} H_{8} O_{4}\)) can occur through the hydrolysis reaction, resulting in the formation of acetic acid (\(CH_{3} COOH\)) and salicylic acid (\(C_{7} H_{6}O_{3}\)). To determine the moles of each product formed, we need to consider the balanced chemical equation for the reaction:

\(C_{9} H_{8} O_{4} = > C_{7} H_{6}O_{3} +CH_{3} COOH\)

From the equation, we can see that for every 1 mole of aspirin, 1 mole of salicylic acid and 1 mole of acetic acid are produced.

Therefore, the moles of salicylic acid and acetic acid formed will be equal to the number of moles of aspirin that decomposes. If we know the amount of aspirin in moles, we can directly calculate the moles of each product based on stoichiometry.

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Answer:

moringa tree has seeds that have unique properties towards water purification

Explanation:

the seeds of moringa tree have an extract which can separate unwanted particulates from the water sediment impurities.

they have the

anti-microbial treatment potentials

moringa also has various vitamins since it is a plant tissue

Answer:

spring tides is the correct answer of your question

Regarding electrons and their energy emitters or absorbers, A is the assertion that is untrue. The energy of an atom's electrons is not inversely related to the atom's radius.

In reality, the amount of protons and neutrons in the atom's nucleus as well as the forces holding the electrons in their orbits are what essentially determine an atom's radius. A particle's position within the electron shell of an atom or the amount of energy it has absorbed or given off through interactions with other particles or electromagnetic radiation determine the energy of an electron.

B. It is correct that the energy of the emitting electron increases as the wavelength of the radiation emits. This is due to the fact that longer wavelengths are associated with lower frequencies and energy levels. On the other hand, longer wavelengths equate to higher frequencies and more energy.
C. The opposite is also true: an electron's wavelength increases as its energy lowers. This is because higher frequencies and longer wavelengths are associated with higher energy levels. On the other hand, shorter wavelengths and higher frequencies are associated with higher energy levels.

D. This claim is also accurate. The energy of the emitting electron rises with the frequency of the radiation. This is because shorter wavelengths and higher energies are associated with higher frequencies.

In conclusion, A is the part of the statement about electrons and their energy emitters or absorbers that is untrue. The energy of an atom's electrons is not inversely related to the atom's radius.

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Answer:

fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, ... Most fans are powered by electric motors

A: begin to cool and daylight hours decrease.

Plants go through seasonal changes from summer to fall because of the changes in temperature and the length of daylight hours. As summer ends and fall begins, temperatures begin to cool down and the days become shorter. This change in temperature and daylight hours triggers physiological changes in plants, such as the slowing down of growth and the production of pigments like anthocyanins, which give leaves their characteristic red and orange colors in the fall. These changes allow the plant to prepare for the colder winter months and conserve energy for the upcoming spring growth season.

Answer:

a. begin to cool and daylight hours decrease

hope this helps ;)

Answer:

Bromine loses an electron.

Explanation:

Hello there!

In this case, according to the given chemical reaction, it will be possible for us to realize that as the reaction progresses, we see that the bromine, as it is initially negative, it increases the oxidation state as it loses an electron for which it is oxidized.

Moreover, no change is potassium is evidenced as it remains as the cation in the reaction; therefore, the answer is Bromine loses an electron.

Regards!

Answer:

The above answer is correct

Explanation:

I took the test

The density of 200 cm^3 of pure water is 200 g / 200 cm^3 = 1 g/cm^3, and  is the same as the density of 1 cm^3 of water.

b. A Corn syrup on top, water in middle, and olive oil on bottom because corn syrup has the highest density of 1.4 g/cm^3, followed by water with a density of 1 g/cm^3, and olive oil with a density of 0.85 g/cm^3.

So option A is correct.

Density is described as the substance's mass per unit of volume.

We were able to determine which substance will stay in its relative position using Archimedes' principle which states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces.

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Global warming brought on by rising carbon dioxide concentrations in the atmosphere is changing weather patterns and ocean temperatures. Changes in precipitation patterns are being brought on by the warming of the atmosphere.

Because it is one of the gases in the atmosphere that causes the greenhouse effect, which causes the Earth to warm, carbon dioxide is known as a greenhouse gas. Long-wavelength infrared radiation (heat) from the Earth is absorbed by carbon dioxide molecules in the atmosphere, and some of it is then radiated back downward.

Similarly, as air temperatures rise in response to rising carbon dioxide concentrations, more water vapor escapes into  the atmosphere—which then amplifies greenhouse heating

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Number many peaks are present in the ¹H-nmr spectrum of Eugenol are having 12 different hydrogen atom.

The Eugenol has contain the 12 different hydrogen atoms. in the ¹H-nmr spectrum  the peaks from right to left is 3:2:2:3:2. The three hydrogen atoms have two peaks of about the 6.7 pm. These hydrogen atoms are from the aromatic ring. the four hydrogen atoms have two peaks of around 6 pm.  the one peak is from the hydrogen atom in the OH group. the vinylic hydrogen atoms are 3 they have one peak.

Thus, Number many peaks are present in the ¹H-nmr spectrum of Eugenol are having 12 different hydrogen atom.

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Answer:

Invasive species are an organism that causes ecological or economic harm in a new environment where it's not native.

Explanation:

An invasive species can harm both the natural resources in the ecosystem as well it threaten the human use of these resources and invasive species can be introduced to a new area via the ballast water of oceangoing ships, intentional and accidental releases of aquaculture species, aquarium specimens or bait, and etc.

Invasive species is capable of causing extinctions to native plants and animals, reducing biodiversity, competing with native organisms for limited resources, and altering habitats. This can also result a huge economic impacts and fundamental disruptions of coastal and the great lakes of the ecosystems.

I hope it helps you.

According to the concept of molar concentration, molarity of the solution is 1.525 M.

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.

In the given problem, by substituting values in mentioned formula related to moles we get,7.32/4.80=1.525 M.

Thus , the molarity of solution is 1.525 M.

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Answer: it has 2 parts

Explanation:

Firstly, plant cells have a cell wall that surrounds the cell membrane, whereas animal cells do not. Plant cells also possess two organelles that animal cells lack: chloroplasts and a large central vacuole

0.26L is the volume of sodium hydroxide, NaOH, needed for the reaction to occur.

A measurement of three-dimensional space is volume. Several imperial or US customary units, as well as SI-derived units (such the cubic meter and liter), are frequently used to quantify it quantitatively (such as the gallon, quart, cubic inch).

Volume and length (cubed) have a symbiotic relationship. The capacity of such a container is typically regarded to be its volume.

Molarity₁×Volume₁=Molarity₂×Volume₂

0.95 × 0.42=1.5×Volume₂

Volume₂=(0.95 × 0.42)/1.5

             =0.26L

Therefore, 0.26L is the volume of sodium hydroxide, NaOH, needed for the reaction to occur.

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Answer:

True.

Explanation:

Typically, cars have built in radios for the reason of not using your phone. That's why you connect it with bluetooth to call, text, and use personal music instead of listening to the ones on the radio.

Answer:

True

Explanation:

It is to keep us safe. So, we answer calls without having to take our hands off the wheel. Although it is unsafe for that aswell. The best thing to do is have 0 things that would keep you from having your eyes on the road.

Answer:

i think its P6O15

Explanation:

Answer:

Yes it is B,D.

Explanation:

Each box represents an element and contains its atomic number, symbol, average atomic mass, and (sometimes) name. The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups.

Answer:

Number of moles = 0.21 mol

Explanation:

Given data:

Mass of NaOH = 8.45 g

Number of moles = ?

Solution:

Formula:

Number of moles = mass/molar mass

Molar mass of NaOH = 40 g/mol

by putting values in formula

Number of moles = 8.45 g / 40 g/mol

Number of moles = 0.21 mol