In an insulated cup of negligible heat capacity, so g of water at 40°C is mixed with 30. g of water at 20.-C. The final temperature of the mixture is closest to 22°C 27°C 30.°C D 33°C 38°C 21.

In the number 0.07080 grams, there are four significant figures. Significant figures are the digits in a number that carry meaning or contribute to its precision.

Significant figures are a way to express the precision or accuracy of a measured or calculated value. In the number 0.07080 grams, each digit contributes to the precision of the measurement. The nonzero digits "7", "0", and "8" are all significant because they provide meaningful information about the measurement. Zeros can also be significant depending on their position. The zero before the decimal point is not significant since it simply indicates the absence of any units greater than grams. However, the trailing zero after the decimal point is significant because it represents precision to the nearest hundredth of a gram.

Therefore, the number 0.07080 grams has four significant figures, indicating a higher level of precision in the measurement.

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The energy change associated with the transition from n = 2 to n = 5 in a hydrogen atom is determined using the formula:ΔE = -RH [(1/nf²) - (1/ni²)]where RH is the Rydberg constant, nf is the final energy level (n = 5), and ni is the initial energy level (n = 2).

The Rydberg constant (RH) is a fundamental physical constant relating to the electromagnetic spectra of atomic hydrogen, or the spectrum of a one-electron ion.

The Rydberg constant is defined as the wave number of the first spectral line of atomic hydrogen, i.e., 1.09678 × 107 m-1. Substituting the values into the formula: ΔE = -RH [(1/5²) - (1/2²)]ΔE = -2.179 × 10^-18 J = -13.6 eV.

Therefore, the energy change associated with the transition from n = 2 to n = 5 in a hydrogen atom is -2.179 × 10^-18 Joules or -13.6 electron-volts. This energy corresponds to the energy of the photon that is emitted or absorbed during the transition between the two energy levels.

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When mentos and diet coke are mixed, the diet soda explodes

Explanation:

Due to the fact that the mentos are dense, they sink to the bottom of the bottle which gives the diet coke its explosion.

Answers & Explanations:

What happens when Mentos and Diet Coke are mixed?

Mentos sinks rapidly through the liquid, causing a fast, large eruption.

What causes Mentos and Diet Coke to react that way?

The addition of the Mentos leads to the rapid nucleation of carbon dioxide gas bubbles in the Diet Coke, causing them to precipitate out of the solution.

Is the reaction Chemical or Physical?

The eruption is caused by a physical reaction.

How could we prove one way or the other?

We can prove it by using the equation:

[tex]CO_{2} (aq) = Co_{2}(g)[/tex]

To determine the volume of hydrogen gas needed to generate 446 liters of ammonia (NH3) at STP (Standard Temperature and Pressure), we can use the balanced chemical equation for the reaction of hydrogen and nitrogen to form ammonia:

3H2 + N2 -> 2NH3

Determine the number of moles of ammonia (NH3) needed:

Since we want to produce 446 liters of NH3, we divide that by the molar volume at STP:

446 L NH3 / 22.4 L/mol = 19.91 moles of NH3

Determine the number of moles of hydrogen gas (H2) needed:

According to the balanced equation, 2 moles of NH3 require 3 moles of H2.

Therefore, we use the mole ratio to find the number of moles of H2 needed:

(19.91 moles NH3) × (3 moles H2 / 2 moles NH3) = 29.86 moles H2

Determine the volume of hydrogen gas needed:

Since 1 mole of any gas at STP occupies 22.4 liters, we multiply the number of moles of H2 by the molar volume:

29.86 moles H2 × 22.4 L/mol = 668.864 liters of H2

Therefore, approximately 668.864 liters of hydrogen gas are needed to generate 446 liters of ammonia at STP.

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Answer:

I'm not sure if this is true but in science class I learned that stress can cause a risk of diseases

Explanation:

the more months of stress you have, the higher the risk

Explanation:

M&M's.

Reese's Peanut Butter Cups.

Hershey Bar.

Snickers.

Kit Kat.

Twix.

Twizzlers.

Skittles.

When Br2(l) boils at its normal boiling point, its entropy increases. Entropy is a measure of the disorder or randomness in a system, and boiling represents a transition from a more ordered liquid phase to a more disordered gaseous phase.

During boiling, the intermolecular forces holding the liquid Br2 molecules together are overcome, and the molecules gain enough energy to escape into the gas phase. In the gaseous phase, the molecules have greater freedom of movement and occupy a larger volume compared to the liquid phase. This increase in molecular motion and expansion of volume contributes to an increase in the disorder or randomness of the system, leading to an increase in entropy. The concept of entropy can also be understood from a statistical perspective. In the liquid phase, the molecules are more closely packed and have limited freedom of movement. However, in the gaseous phase, the molecules are dispersed and have a larger number of possible positions and velocities. This increased number of microstates in the gaseous phase corresponds to a higher probability distribution, which is a characteristic of higher entropy.

Therefore, when Br2(l) boils at its normal boiling point, its entropy increases as the system transitions from a more ordered liquid phase to a more disordered gaseous phase.

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Answer:

500mL.

Explanation:

The Cl-C-Cl bond angle in the CCl2O molecule (with carbon as the central atom) is slightly less than the ideal tetrahedral angle of 109.5 degrees. It is reduced to around 105 degrees due to the presence of two lone pairs on the oxygen atom. This distortion occurs because lone pairs exert greater electron repulsion compared to bonded pairs, resulting in a compressed bond angle.

The CCl2O molecule consists of a central carbon atom (C) bonded to two chlorine atoms (Cl) and one oxygen atom (O). In an ideal tetrahedral arrangement, the bond angle between the three atoms connected to the central atom would be 109.5 degrees. However, in the case of CCl2O, the presence of two lone pairs on the oxygen atom causes electron repulsion, which affects the bond angles.

Lone pairs of electrons occupy more space around the central atom than bonded pairs, and they exert greater repulsion. This repulsion pushes the chlorine atoms closer together, reducing the Cl-C-Cl bond angle. As a result, the bond angle in CCl2O is slightly less than the ideal tetrahedral angle, typically around 105 degrees. The presence of lone pairs on the oxygen atom introduces an asymmetry in the molecule, leading to the distortion in the bond angles from the ideal geometry.

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The reduction of iodate by hydrogen sulfite ions to give iodide and sulfate in basic aqueous solution is represented by the following equation:
IO3– + 3HSO3– + H2O → 3SO4^2– + I– + 2H+ + 2H2O

The balanced equation is:

2 IO3– + 6 HSO3– + 6 OH– → 6 SO4^2– + 2 I– + 9 H2O

To balance the given redox reaction, we follow these steps: Write the unbalanced chemical equation for the given reaction. Split the reaction into two half-reactions: oxidation and reduction.Balance the atoms that are not hydrogen or oxygen in each half-reaction. This is done by adding the appropriate coefficient to each species.Write balanced equations for each half-reaction.Combine the half-reactions to get a balanced overall equation.In the given reaction, iodate (IO3–) is reduced to iodide (I–) by hydrogen sulfite ions (HSO3–) to give sulfate (SO4^2–) in basic aqueous solution. The unbalanced chemical equation is:

IO3– + HSO3– → I– + SO4^2–

Step 2: We split the reaction into two half-reactions:'

Oxidation half-reaction: IO3– → I–

Reduction half-reaction: HSO3– → SO4^2–

Step 3: We balance the atoms that are not hydrogen or oxygen in each half-reaction. We see that the oxidation half-reaction is already balanced and we balance the reduction half-reaction as follows:

HSO3– → SO4^2– + 2 H+ + 2 e–

Step 4: We write balanced equations for each half-reaction.

IO3– + 6 H+ + 5 e– → I– + 3 H2O

HSO3– → SO4^2– + 2 H+ + 2 e–

Step 5: We combine the half-reactions to get a balanced overall equation.

IO3– + 6 HSO3– + 6 OH– → 6 SO4^2– + 2 I– + 9 H2O

Thus, the balanced equation is:

2 IO3– + 6 HSO3– + 6 OH– → 6 SO4^2– + 2 I– + 9 H2O

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The resulting solution formed by the dissolving of sodium acetate in water is basic because C2H3O2 is the conjugate base of a weak acid.

When sodium acetate (NaC2H3O2) is dissolved in water, it dissociates into sodium ions (Na+) and acetate ions (C2H3O2-). Acetate ions act as the conjugate base of acetic acid (CH3COOH), which is a weak acid.

In water, acetate ions can accept protons from water molecules through hydrolysis to a small extent, resulting in the formation of hydroxide ions (OH-) and acetic acid. This reaction is a weak base reaction:

C2H3O2- + H2O ⇌ CH3COOH + OH-

The presence of hydroxide ions (OH-) in the solution makes it basic. The basic nature of the solution is primarily due to the hydrolysis of the acetate ions, which generate hydroxide ions, rather than the sodium ions (Na+) which do not significantly affect the pH.

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Answer:

When a guy who shows a girl to much emotion, they get turned off.

Explanation:

2-bromo-2-methylbutane (less hindrance) will react faster by the Syl mechanism.

S_N2 reactions have a bimolecular mechanism, which means that the rate of reaction is proportional to the concentration of both the nucleophile and the electrophile. The S_N2 mechanism is very sensitive to steric effects since the nucleophile must approach the carbon bearing the leaving group from the side opposite the leaving group's location. As a result, a greater degree of hindrance at the carbon center decreases the rate of S_N2 reactions. The less steric hindrance, the faster the S_N2 reaction. So, let's see which member of each pair will react faster by the Syl mechanism:1-bromopropane (less hindrance) will react faster by the Syl mechanism.2-bromo-3-methylbutane (less hindrance) will react faster by the Syl mechanism.allyl bromide (less hindrance) will react faster by the Syl mechanism.1-bromo-2,2-dimethylpropane (more hindrance) will react slower by the Syl mechanism.tert-butyl chloride (more hindrance) will react slower by the Syl mechanism.2-bromo-2-methylbutane (less hindrance) will react faster by the Syl mechanism.

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Human use of land has negative impacts. Human activities contribute to the erosion and pollution of beaches. Deforestation of land can also lead to desertification and a loss of biodiversity.

Answer: mass of water is 81.1 g

Explanation: from reaction eguation you see there are equal amounts of water and Mg(OH)2. Then amount of water is 4.50 mol. Molar mass of water is 18.016 g/mol.

Mass m= n·M= 4.50 mol· 18.016 g/mol = 81.1 g

The number of grams of water reacting to form a mass of water is 81.1 g.

Mass is the quantity of matter in a physical body.

The given reaction is

MgO(s) + H₂O(1) → Mg(OH)₂(s)

The number of moles is equal in both sides

The moles of water is 4.50

The molar mass of water is 18.016 g/mol

mass × molar mass

4.50 × 18.016 = 81.1 g.

Thus, the number of grams of water reacting to make a mass of water is 81.1 g.

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The types of chemical bonds present in a mixture of water (water molecules) and oil (triglyceride molecules) are: Hydrogen bonds and van der Waals interactions.

Water molecules are polar and form hydrogen bonds with each other. These hydrogen bonds result from the attraction between the partially positive hydrogen atom of one water molecule and the partially negative oxygen atom of another water molecule.

Oil, on the other hand, primarily consists of nonpolar molecules such as triglycerides. Nonpolar molecules do not form hydrogen bonds but can interact through weak attractive forces known as van der Waals interactions. These interactions occur due to temporary fluctuations in electron distribution, resulting in induced dipoles that attract each other.

Therefore, in the mixture of water and oil, hydrogen bonds form between water molecules, while van der Waals interactions occur between oil molecules and potentially between water and oil molecules.

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Answer:

4.8x10⁻³ Liters are required

Explanation:

Molarity is an unit of concentration in chemistry defined as the ratio between moles of solute (In this case, silver nitrate) and liters of solution.

The 0.50M solution contains 0.50 moles of silver nitrate per liter of solution.

To provide 2.4x10⁻³ moles Silver nitrate are required:

2.4x10⁻³ moles * (1L / 0.50 moles) =

Answer:

Static electricity is a type of energy that is produced by friction.

Explanation:

Static electricity may be the result when there is an imbalance between the negative charges and the positive charges in the surroundings. They are non contact forces. They pull of push without actually touching the body. The charged particles interact by pulling or pushing the uncharged particles.

These charges are released when they come closer to some uncharged or other charged particles like the electrostatic charges. It is the charge build up in an area.

The statement "Reaction of heating potassium permanganate produces potassium manganate" is false.

The reaction of heating potassium permanganate (KMnO₄) does not produce potassium manganate (K₂MnO₄). Instead, it undergoes a thermal decomposition reaction, resulting in the formation of different products.

When heated, potassium permanganate decomposes into potassium manganate (K₂MnO₄), manganese dioxide (MnO₂), and oxygen gas (O₂).

The reaction can be represented as follows:

2 KMnO₄(s) → K₂MnO₄(s) + MnO₂(s) + O₂(g)

Therefore, heating potassium permanganate leads to the formation of potassium manganate, along with manganese dioxide and oxygen gas. The color change from purple to green observed during the reaction is due to the formation of potassium manganate.

However, it is important to note that potassium manganate is not the sole product of the reaction but one of the products alongside manganese dioxide and oxygen gas.

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Complete question :

Reaction of heating potassium permanganate produces potassium manganate. T/F

On completing and balancing the half-reaction of chromium (iii) forming from dichromate the number of electrons are either produced or consumed  are option (b): Three electrons are produced.

To determine the number of electrons produced or consumed in the half-reaction of chromium(III) forming from dichromate, let's first write the balanced half-reaction. The dichromate ion (Cr2O7^2-) is reduced to chromium(III) ion (Cr^3+) in this reaction. We can represent the reduction half-reaction as follows:

Cr2O7^2- ⟶ Cr^3+

To balance the half-reaction, we need to equalize the number of chromium atoms and oxygen atoms on both sides. Since there are two chromium atoms on the left side and only one on the right side, we add a coefficient of 2 in front of the chromium ion:

2Cr2O7^2- ⟶ 2Cr^3+

Now, let's examine the changes in oxidation state for chromium in this reaction. In dichromate (Cr2O7^2-), chromium has an oxidation state of +6, while in chromium(III) (Cr^3+), it has an oxidation state of +3. Therefore, the oxidation state of chromium decreases by 3 in this reduction half-reaction.

Reduction involves a gain of electrons. Since the oxidation state of chromium decreases by 3, it means that three electrons are gained by each chromium ion. Therefore, the correct answer is option (b): Three electrons are produced.

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Answer:

c. Six electrons are consumed

Explanation:

The first step is to ensure that the chromium atoms are balanced by adjusting the coefficients if needed. Do so by giving the Cr3+ ion a coefficient of 2.

Cr2O2−7 ⟶ 2Cr3+ (aq)

Next, balance the oxygen atoms by adding H2O molecules. The half-reaction has seven O atoms on the left and none on the right, so add 7H2O (l) to the right side.

Cr2O2−7 ⟶ 2Cr3+ (aq) + 7H2O (l)

Next, balance the hydrogen atoms by adding H+ ions. The half-reaction has 14 H atoms on the right side and none on the left, so add 14H+(aq) to the left side.

Cr2O2−7 + 14H+ (aq) ⟶ 2Cr3+ (aq) + 7H2O (l)

At this point, the charge can be balanced by adding electrons (e−). To do so, find the total charge on each side of the reaction. The left side has a total charge of (−2) + 14 × (+1) = 12+. The right side has a total charge of 2 × (+3) = 6+. Adding 6e− to the left side brings the charge down to 6+ to match the right side.

Cr2O2−7 + 14H+ (aq) +6e− ⟶ 2Cr3+ (aq) + 7H2O (l)

This gives us the answer to the question, which is that six electrons are consumed, since they are on the left side of the equation. Note that it does not make a difference whether the reaction is assumed to be in an acidic or a basic solution. The extra step taken for a basic solution is to add the same number of OH− ions to both sides of the reaction, which does not affect the number of electrons needed to balance the charges.

Answer:

5 g/cm^3

Explanation:√3V=1.91293cm

Answer:

The answer of this question is A

Answer: B is the right

Explanation:

Reactants in the reaction are [tex]H_2O_2[/tex](aq),[tex]I^-[/tex](aq); Products are[tex]IO^-[/tex](aq), [tex]H_2O[/tex](l), [tex]O_2[/tex](g); Intermediate are [tex]IO^-[/tex]aq); and catalysts are None.

The first step of the mechanism is the rate-determining step. In this step, a hydrogen atom from hydrogen peroxide is transferred to an iodine ion, forming an intermediate called iodosyl ion. The iodosyl ion is then unstable and decomposes to form oxygen gas and another iodine ion.

The overall reaction is:

[tex]H_2O_2(aq) + I^-(aq) - > IO^-(aq) + H_2O(l) + O_2(g)[/tex]

The reactants are hydrogen peroxide and iodine ion. The products are iodosyl ion, water, and oxygen gas. The intermediate is iodosyl ion. There is no catalyst in this mechanism.

The rate-determining step is the slowest step in the mechanism. This is the step that determines the overall rate of the reaction. In this case, the rate-determining step is the step in which the hydrogen atom is transferred from hydrogen peroxide to iodine ion.

The intermediate is a chemical species that is formed in one step of the mechanism and is consumed in another step. In this case, the intermediate is iodosyl ion. It is formed in the first step of the mechanism and is consumed in the second step.

The catalyst is a chemical species that speeds up the rate of a reaction but is not consumed in the reaction. There is no catalyst in this mechanism.

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In the given reaction, 6 moles of sodium react with aluminum oxide to produce 2 moles of aluminum and 3 moles of sodium oxide. When 5.52 g of sodium is reacted with excess aluminum oxide, 1.00 g of aluminum is produced.

To calculate the theoretical yield of aluminum, we need to determine the molar mass of sodium (Na) and aluminum (Al). With the molar masses, we can convert the given mass of sodium (5.52 g) to moles. Since the reaction has a 6:2 ratio between sodium and aluminum, we can use stoichiometry to calculate the moles of aluminum produced.

Next, we can convert the moles of aluminum to grams using the molar mass of aluminum. This gives us the theoretical yield of aluminum.

To calculate the percent yield, we divide the actual yield (1.00 g) by the theoretical yield and multiply by 100%.

Percent Yield = (Actual Yield / Theoretical Yield) * 100%

Substituting the values, we can calculate the percent yield.

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Carbon dioxide absorbs heat from the sun and traps it in the Earth's atmosphere. Since the heat cannot escape, it causes the Earth's temperature to increase. answer C is correct

Carbon dioxide absorbs heat from the sun and traps it in the Earth's atmosphere. Since the heat cannot escape, it causes the Earth's temperature to increase.

The connection between increasing carbon dioxide (CO2) and increasing temperature is based on the greenhouse effect, which is a fundamental principle of Earth's climate system. The greenhouse effect refers to the process by which certain gases in the atmosphere, including carbon dioxide, absorb and trap heat radiated from the Earth's surface.

When fossil fuels are burned, such as coal, oil, and natural gas, they release carbon dioxide into the atmosphere. Additionally, deforestation and other land-use changes also contribute to the increase in atmospheric CO2 levels. These activities have significantly enhanced the natural greenhouse effect.

Carbon dioxide molecules have the ability to absorb and re-emit infrared radiation. When sunlight reaches the Earth's surface, it warms the surface, which in turn emits heat energy in the form of infrared radiation. However, certain gases in the atmosphere, like carbon dioxide, act as a barrier to this outgoing heat radiation. They absorb a portion of the infrared radiation and re-emit it in all directions, including back towards the Earth's surface. This process traps heat in the atmosphere, similar to how a greenhouse traps heat, hence the term "greenhouse effect."

As the concentration of carbon dioxide and other greenhouse gases increases in the atmosphere, more heat is trapped, leading to an overall warming of the Earth's surface and lower atmosphere. This phenomenon is commonly referred to as global warming. The increased energy in the Earth's climate system disrupts weather patterns, alters ecosystems, and poses various risks to human societies.

Scientific studies and observations have established a strong correlation between the rise in atmospheric CO2 concentrations and increasing global temperatures over the past century. The Intergovernmental Panel on Climate Change (IPCC) and numerous scientific institutions worldwide have concluded that human activities, particularly the burning of fossil fuels, are the primary cause of the observed increase in atmospheric CO2 levels and the resulting global warming trend.

In summary, the connection between increasing carbon dioxide and increasing temperature lies in the greenhouse effect, where carbon dioxide absorbs and re-emits heat radiation, trapping it in the Earth's atmosphere and causing the Earth's temperature to rise.

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The compound CH3CH2COCH2CH2CH3 is named as 3-hexanone.

The given condensed structural formula represents a ketone called 3-hexanone. In the IUPAC nomenclature, the position of the carbonyl group (C=O) is indicated by the lowest possible number, which in this case is 3. The carbon chain consists of six carbon atoms (hexane) with a carbonyl group attached to the third carbon atom.

The compound 3-hexanone can undergo both oxidation and reduction reactions. As a ketone, it contains a carbonyl group that can be oxidized to form a carboxylic acid or reduced to form an alcohol. Therefore, it is not limited to only oxidation or reduction reactions.

The statement that the compound can be reduced to form 3-hexene is incorrect. Reduction of 3-hexanone would yield 3-hexanol, not 3-hexene. Reduction adds hydrogen to the carbonyl group, converting it to a hydroxyl group (-OH).

The compound with the condensed structural formula CH3CH2COCH2CH2CH3 is named 3-hexanone. It is a ketone that can undergo both oxidation and reduction reactions. However, it cannot be directly reduced to form 3-hexene; instead, reduction of 3-hexanone would yield 3-hexanol. The compound can be formed by the oxidation of 3-hexanol, where the alcohol group is converted to a carbonyl group.

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For the central boron atom:

The central boron atom:

A. Obeys the octet rule.

In the Lewis structure of BF3, boron (B) is the central atom bonded to three fluorine (F) atoms. Boron has an atomic number of 5 and its electronic configuration is 1s² 2s² 2p¹. In its ground state, boron has three valence electrons. In BF3, each fluorine atom shares one electron with boron to form a single bond, resulting in three single bonds between boron and fluorine.

Since boron only forms three single bonds and has no lone pairs of electrons, it satisfies the octet rule. The octet rule states that atoms tend to gain, lose, or share electrons to achieve a stable electron configuration with eight electrons in their valence shell, similar to the nearest noble gas. Therefore, the central boron atom in BF3 obeys the octet rule.

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Answer:

C. The Pressure

Explanation:

Pressure only affects the solubility of gases. It barely affects the solubility of solids and liquids.

The following reactions are redox reactions are,

a. 4K(s) + O2(g) → 2K2O(s)

b. Al(s) + 3Ag+(aq) → Al3+(aq) + 3Ag(s)

d. SO3(g) + H2O(l) → H2SO4(aq)

Redox (shorthand for reduction/oxidation reaction) reactions are chemical reactions in which the oxidation state of atoms is changed.

These reactions are the basis for batteries, fuel cells, and other energy storage devices, and they also play a crucial role in the metabolic processes of living organisms.

Example of a Redox reaction,

Al(s) + 3Ag+(aq) → Al3+(aq) + 3Ag(s)

In the above reaction, Al metal is oxidized (loses electrons) and Ag+ ions are reduced (gains electrons).

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