How many moles of helium are 8.84×1024 atoms of He?

Answer:

c.) increase the concentration of one of the solutions

Explanation:

Answer: It's equal to 10^(-2.3), or 0.00501 M, or 5.01 * 10^-3 moles/Liter

Explanation:

Well, pH = - log[H+]

Or, in words, pH is equal to -1 multiplied by the logarithm (base 10) of the hydrogen ion concentration.   So you have 2.3 = -log[H+].    We want to isolate the H+, so let's start simplifying the right hand side of the equation. First, we multiply both sides by -1.   -2.3=log[H+]   Now, the definition of a logarithm says that if the log (base 10) of [H+] is -2.3, then 10 raised to the -2.3 power is [H+]   So on each side of the equation, we raise 10 to the power of that side of the equation.   10^(-2.3) = 10^(log[H+])   and because 10^log cancels out...   10^(-2.3) = [H+]   Now we've solved for [H+], the hydrogen ion concentration!

A sample of lemon juice is found to have a pH of 2.3.  5.012×10−3 moles per liter is the concentration of hydrogen ions in the lemon juice.

The pH scale, which previously stood for "potential of hydrogen," is used to describe how acidic or basic an aqueous solution is. The pH values of acidic solutions are typically lower than those of basic or alkaline solutions.

The pH scale determines how acidic or basic water is. The range is 0 to 14, with 7 representing neutrality. A base is present when the pH is higher than 7. In reality, pH is a measurement of the proportion of free hydrogen and hydroxyl ions in water.

Lemon juice is 10,000–100,000 times more acidic than water, with a pH between 2 and 3. (1, 2, 3). The pH of food is a gauge of how acidic it is. Lemon juice is acidic because its pH ranges from 2 to 3.

pH = -log [ H+ ]

2.3 = -log [ H+ ]  

-2.3 = log [ H+ ]  

10^( -2.3 ) = 10^( log [ H+ ] )    

10^(-2.3) = [ H+ ]  

[ H+ ]  = 5.012×10−3 moles per liter.

Thus, A sample of lemon juice is found to have a pH of 2.3.  5.012×10−3 moles per liter is the concentration of hydrogen ions in the lemon juice.

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Answer:

C

Explanation: a is incorrect since the lower the ph = more acidic and b is incorrect because it produces hydronium ion and d I’m not sure what it is but I no that base recieve the protons

Concepts to understand before solving:

-Oxygen is ALWAYS reduced

-OIL- Oxidation Is Loss of electrons

-RIG- Reduction Is Gain of electrons

-the element that is oxidized is the reducing agent

-the element that is reduced is the oxidizing agent

A. 2H2 + O2 —> 2H2O

O is reduced, making it the oxidizing agent

H is oxidized, making it the reducing agent

B. 2KNO3 —> 2KNO2 + O2

O is reduced, making it the oxidizing agent

KNO is oxidized, making it the reducing agent

Answer:

Explanation:

        2 H₂O (l) ⇄ H₃O⁺ + OH⁺

        Kw = [H₃O⁺ ] [ OH⁺]

The Tyndall Effect is the effect of light scattering in colloidal dispersion, while showing no light in a true solution. This effect is used to determine whether a mixture is a true solution or a colloid.

The Tyndall Effect in chemistry refers to the scattering of light by particles in a colloid or very fine suspension, making the mixture appear cloudy or opaque. It is used to differentiate between solutions and colloids, and plays a significant role in light scattering phenomena and microscopy.

The Tyndall effect is a phenomenon associated with the scattering of light by particles in a colloid or in a very fine suspension. It can be used to differentiate between solutions and colloids as the particles in a colloid are large enough to scatter light, making colloidal mixtures appear cloudy or opaque. For instance, clouds are colloidal mixtures composed of water droplets that are much larger than molecules, but that are small enough that they do not settle out.

Similar effects of light scattering are observed in other phenomena like thin-film interference seen in oil slicks or the varying colors in a soap bubble. In microscopy, contrast agents or stains are frequently used along with light sources to create sharp images of structures or organisms up to about 1000x magnification. These substances can also be differentiated on the basis of their light absorption or reflection properties owing to the Tyndall effect.

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Answer:

Alkene.

Explanation:

C₂H₄ is the formula of ethene.

C forms four bonds.

Its structure is: CH₂=CH₂.

The bond between the two carbon atoms is double bond.

When the hydrocarbon contains a double bond, it is classified as an alkene.

0.131 mol of carbon dioxide gas, [tex]CO_2[/tex], are there in 2.94 L of this gas at STP.

The ideal gas equation, pV = nRT, is an equation used to calculate either the pressure, volume, temperature or number of moles of a gas.

We use the formula PV=nRT. The conditions STP are 1 atm of pressure and 273K of temperature:

PV=nRT

n=[tex]\frac{PV}{RT}[/tex]

n =  [tex]\frac{1 atm\; X \;2.94 L}{0,082 l atm/K mol X 273K}[/tex]

n=0.131 mol

Hence, 0.131 mol of carbon dioxide gas, [tex]CO_2[/tex], are there in 2.94 L of this gas at STP.

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Answer:

TRUE

Explanation:

Answer:

Explanation:

Beryllium especially, but Boron as well both exhibit metallic characteristics.

The outside ring of Beryllium contains 2 electrons. It would have to take on 6 electrons to have a ring of 8. The same statement can be made about Boron (except that it would need 5 electrons to make 8). It is easier for the atom to give up 2 or 3 than than to take on 5 or 6. It would not be easy to have a 5 or 6 minus charge on it.

Boron and beryllium are exceptions to the octet rule because they have less than eight electrons in their valence shell in some compounds, such as BF₃ and BeH₂, due to their position in Group III and the unique properties of their electrons.

Boron and beryllium are exceptions to the octet rule because they do not always complete an octet of electrons in their compounds. Boron, found in compounds like BF₃, tends to form compounds with only six valence electrons around the boron atom, rather than the eight suggested by the octet rule. Beryllium, on the other hand, often ends up with only four valence electrons as seen in the molecule BeH₂. These deviations from the octet rule occur because of the elements' positions in Group III of the periodic table, where elements commonly have fewer valence electrons than required to fulfill the octet. Thus, compounds of these elements are less predictable from the octet rule, which was primarily based on observations of the elements in Groups IV through VIII.

Incomplete octets are found in some compounds involving boron, aluminum, and beryllium, such as boron hydrides. The behavior of these elements is based on their tendency to form stable structures with fewer than eight electrons; boron atoms, for example, might follow a 'sextet rule' in some compounds but can achieve full octets in others like in its complex with ammonia, NH₃BF₃. Likewise, beryllium typically forms molecular compounds wherein it forms single covalent bonds without reaching an octet, due to its limited number of valence electrons and its small atomic size.

Decreasing the activation energy needed for the reaction.

Answer:

A. 29.9

Explanation:

Average atomic mass of P = ∑(Isotope mass)(its abundance)

∴ Average atomic mass of P = (P-29 mass)(its abundance) + (P-30 mass)(its abundance) + (P-31 mass)(its abundance) + (P-33 mass)(its abundance)

Abundance of isotope = % of the isotope / 100.

∴ Average atomic mass of P = (29)(0.327) + (30)(0.4803) + (31)(0.184) + (33)(0.0087) = 29.88 a.m.u ≅ 29.9 a.m.u.

So, the right choice is: A. 29.9

This is known as photochemistry

Answer:A. Both animals and plants have changed over time.

Explanation:

Because plants and animals go through adaptations.

Answer: A. Both animals and plants have changed over time.

Explanation: study island

Answer:

Final pH of the solution: 2.79.

Explanation:

What's in the solution after mixing?

[tex]\displaystyle c = \frac{n}{V}[/tex],

where

[tex]V(\text{Final}) = 0.050 \;\textbf{L} + 0.050\;\textbf{L} = 0.100\;\textbf{L}[/tex].

Acetic (ethanoic) acid:

[tex]\displaystyle \begin{aligned}n &= c(\text{Before})\cdot V(\text{Before}) \\&= 0.050\;\text{L} \times 0.200\;\text{mol}\cdot\text{L}^{-1}\\ &= 0.0100\;\text{mol}\end{aligned}[/tex].

[tex]\displaystyle \begin{aligned}c(\text{After}) &= \frac{n}{V(\text{After})}\\ &= \frac{0.0100\;\text{mol}}{0.100\;\text{L}}\\ &= 0.100\;\text{mol}\cdot\textbf{L}^{-1}\\ &= 0.100\;\text{M}\end{aligned}[/tex].

Hydrochloric acid HCl:

[tex]\begin{aligned}n &= c(\text{Before})\cdot V(\text{Before})\\ &= 0.050\;\text{L} \times 1.00\times 10^{-3}\;\text{mol}\cdot\text{L}^{-1}\\ &= 5.00\times 10^{-5}\;\text{mol}\end{aligned}[/tex].

[tex]\displaystyle \begin{aligned}c(\text{After}) &= \frac{n}{V(\text{After})}\\ &= \frac{5.00\times 10^{-5}\;\text{mol}}{0.100\;\text{L}}\\ &= 5.00\times 10^{-4}\;\text{mol}\cdot\textbf{L}^{-1}\\ &= 5.00\times 10^{-4}\;\text{M}\end{aligned}[/tex].

HCl is a strong acid. It will completely dissociate in water to produce H⁺. The H⁺ concentration in the solution before acetic acid dissociates shall also be [tex]5.00\times 10^{-4}\;\text{M}[/tex].

The Ka value of acetic acid is considerably small. Acetic acid is a weak acid and will dissociate only partially when dissolved. Construct a RICE table to predict the portion of acetic acid that will dissociate. Let the change in acetic acid concentration be [tex]-x\;\text{M}[/tex]. [tex]x > 0[/tex].

[tex]\begin{array}{c|ccccc}\textbf{R}&\text{CH}_3\text{COOH}\;(aq) &\rightleftharpoons &\text{CH}_3\text{COO}^{-}\;(aq) &+& \text{H}^{+}\;(aq)\\\textbf{I}&0.100\;\text{M} & & & & 5.00\times 10^{-4}\;\text{M}\\\textbf{C}&-x\;\text{M} & & +x\;\text{M} & & +x\;\text{M} \\ \textbf{E}&0.100\;\text{M}-x\;\text{M} & & x\;\text{M} & & 5.00\times 10^{-4}\;\text{M} + x\;\text{M}\end{array}[/tex].

[tex]\displaystyle K_a = \frac{[\text{CH}_3\text{COO}^{-}\;(aq)]\cdot[\text{H}^{+}\;(aq)]}{[\text{CH}_3\text{COOH}\;(aq)]} = \frac{x\cdot(x + 5.00\times 10^{-4})}{0.100 - x}[/tex].

Rewrite as a quadratic equation and solve for [tex]x[/tex]:

[tex]x\cdot(x + 5.00\times 10^{-4}) = (1.8\times 10^{-5} )\cdot (0.100 - x)[/tex]

[tex]x\approx 0.00111[/tex].

The pH of a solution depends on its H⁺ concentration.

At equilibrium

[tex][\text{H}^{+}\;(aq)] = 5.00\times 10^{-4}\;\text{M} + x\;\text{M} = 0.00161\;\text{M}[/tex].

[tex]\text{pH} = -\log{[\text{H}^{+}]} = 2.79[/tex].

To calculate the pH of the given solution, we first use the ICE approach and Henderson-Hasselbalch equation to determine the initial pH. After adding HCL, HCL ionizes to increase the hydronium ion concentration. The pH of solutions with excess titrant is determined mostly by the amount of excess strong base.

To calculate the pH of the solution containing 50.0 ml of 0.200 m acetic acid and 50.0 ml of 1.00 x 10-3m hcl, we can use the ICE (Initial - Change - Equilibrium) approach and the Henderson-Hasselbalch equation. Initially, we determine the hydronium ion concentration [H3O+] using the expression: [H3O+] = √(Ka × [CH3CO₂H]). Substituting known values, [H3O+] = √(1.8 × 10-5 × 0.100).

Following that, we can find the initial pH, which is -log([H3O+]). After HCL is added, since HCL is a strong acid, it will further ionize, increasing the [H3O+].

Furthermore, in cases where excess titrant is used, the solution pH is determined mainly by the amount of excess strong base. For instance, if the titrant volume is 37.50 mL, which represents a stoichiometric excess of titrant, and the reaction solution contains both the titration product, acetate ion, and the excess strong titrant, we calculate [OH-] and use that to find pOH and then pH.

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Answer:

This definitely is important:

Explanation:

Because if the police, FBI, etc., find something else about the case where the man has already been tried for the entire case, otherwise known as the same crime, and not convicted, there is literally nothing that any of them can do because the government would be looked at as not working fast enough. BUT it is also important simply because of the fact that if you are someone who has been tried for the crime, and you weren't actually the one who did it or even simply witnessed it, they can't try you for that same crime even if they find a small smidge as to how you are involved, or if you even witnessed or HEARD it happening. Police sometimes try to convict the person who heard the crime happening simply because they don't know what else to do, or even to try to get the case closed to work on something else, because if you heard the crime happening, then it's counted as involvement in the investigation and the police could also think that it means that you're also involved in the crime itself, but don't have any other evidence as to why or how you could be the criminal in the investigation. It does happen, even if certain or lots of simply random people admit or not.

The double jeopardy clause in the Fifth Amendment is important for several reasons.

The double jeopardy clause in the Fifth Amendment is significant for a few reasons.

First, it stops the government from bothering and punishing people. If the government could try someone again for a crime they were already found not guilty of, it could use its power to overpower the defendant and make it hard for them to have a fair trial.

The double jeopardy clause keeps people from having to go through the emotional and psychological pain of being tried for the same crime more than once. Going through a trial can be very stressful, and being put on trial more than once for the same crime can be really tough.

The double jeopardy clause helps make sure that once someone has been tried and convicted for a crime, they can't be tried and convicted again for the same crime. When someone is found not guilty of a crime, they should be allowed to continue with their life without worrying about facing another trial.

In simple words, the double jeopardy clause helps protect people's rights and keeps the criminal justice system fair. It makes sure that people are not bothered or harmed by the government, and that they don't have to go through the emotional and mental stress of facing many trials for the same crime.

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Answer:

Explanation:

The basic expression for the ideal gas law is:

Where:

You can perform different algebraic operations to obtain equivalent equations:

Choice b) Divide equation 1 by T and you get:

Choice c) Divide equation 1 by n × V and you get:

Choice d) Divide equation 1  n × T and you get:

The choice a. p = nRTV states that p and V are in direct relation, when the ideal gas law states that p and V are inversely related, so that equation is wrong.

Conclusion: the choice a, p = nRTV, is not a statement of the ideal gas law.

The option that does not represent the ideal gas law is a. P = nRTV. The correct form of the ideal gas law is PV = nRT, and options b, c, and d can be rearranged to match this form.

The correct form of the ideal gas law is PV = nRT. Let's break down each option:

Thus, the statement that does not represent the ideal gas law is a. P = nRTV.

Answer: Im pretty sure n=1 as thats the first one indicated.

Explanation:

Answer:

n=1

Explanation:

Miscible-liquids that dissolve freely in one another in any proportion

Miscible liquids, such as ethanol and water, can be mixed together in any proportion to form solutions. Miscibility is a unique property that facilitates the infinite mutual solubility of these liquids. This concept is different from solubility, which pertains to a solid's ability to dissolve in a liquid, and Henry's law, that relates to gaseous solutes.

The question pertains to liquids that can be mixed together in any proportions to form solutions. These liquids are referred to as miscible. Examples of such liquids include ethanol, sulfuric acid, and ethylene glycol, which are all miscible with water. Miscible liquids have infinite mutual solubility, meaning they can dissolve into each other in any ratio.

Miscibility is different from solubility, which refers to a solid's ability to dissolve in a liquid. In contrast, miscibility refers to the ability of two liquids to mix without separating into two stages. For instance, water and oil are considered immiscible because they cannot mix together and will instead separate into two layers.

Another important concept related to the behavior of solutions is Henry's law, which states that the concentration of a gaseous solute in a solution is proportional to the partial pressure of the gas to which the solution is exposed. This law, however, is more relevant when discussing solubilities for gaseous solutes.

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Answer:

c.)long chain of carbon molecules

Explanation:

Answer:

In an endothermic reaction, the products are at a higher energy level than are the reactants.

Explanation:

ΔH = E products - E reactants.

So, for endothermic reactions, the products are at a higher energy level than are the reactants.

Kindly see the attached image.

Answer:

well its D Mg + 2HCl ----- MgCl2 + H2

Explanation:

Because Magnesium Replaces Hydrogen

Answer:

[tex]\boxed{\text{190 g}}[/tex]

Explanation:

We know we will need a balanced equation with masses, moles, and molar masses, so let’s gather all the information in one place.

M_r:                                          44.01  

                 2C₆H₁₀ + 17O₂ ⟶  12CO₂ + 10H₂O

n/mol:                         6

1. Use the molar ratio of CO₂:O₂ to calculate the moles of CO₂.

[tex]\text{Moles of CO$_{2}$ = 6 mol O$_{2}$}  \times \dfrac{\text{12 mol CO$_{2}$}}{\text{17 mol O$_{2}$}} =\text{4.24 mol CO$_{2}$}[/tex]

2. Use the molar mass of CO₂ to calculate the mass of CO₂.

[tex]\text{Mass of CO$_{2}$ = 4.24 mol CO$_{2}$} \times \dfrac{\text{44.01 g CO$_{2}$}}{\text{1 mol CO$_{2}$}} = \text{190 g CO$_{2}$}\\\\\text{The reaction will produce }\boxed{\textbf{190 g}}\text{of CO}_{2}[/tex]

Explanation:

Lewis dot structure is the representation of the valence electrons around the atom of an element. it also shows the number of unpaired electrons present in a molecule.

Nitrogen has atomic number of 7 and electronic configuration is given as:

[tex][N]=1s^22s^22p^3[/tex]

Fluorine has atomic number of 9 and electronic configuration is given as:

[tex][F]=1s^22s^22p^9[/tex]

Since fluorine is highly electronegative atom.will attract electrons of nitrogen towards itself.So in Lewis dot structure the fluorine atom will present around single nitrogen atom.

The Lewis structure is given in an image attached.

Using Lewis dot symbols, nitrogen forms three covalent bonds with fluorine atoms to create a molecule where each achieves an octet. Nitrogen shares its three unpaired electrons with each fluorine's unpaired electron, resulting in nitrogen trifluoride (NF3) with all atoms following the octet rule.

Using Lewis dot symbols, we can visualize the sharing of electrons between a nitrogen atom and fluorine atoms to form a molecule where each atom achieves an octet of electrons. Nitrogen, being a Group 15 element, has five valence electrons: one lone pair and three unpaired electrons. The Lewis dot symbol for nitrogen is represented as 'N' with three dots surrounding it, each representing one unpaired valence electron and a pair of dots for the lone pair.

Fluorine is a Group 17 element and has seven valence electrons: three lone pairs and one unpaired electron. Its Lewis dot symbol is 'F' with three pairs of dots and one single dot.

To form a stable compound, nitrogen shares its three unpaired electrons with three fluorine atoms, each of which contributes an unpaired electron of its own. Consequently, nitrogen forms three single covalent bonds with three fluorine atoms. Each fluorine atom in the molecule will have three lone pairs of electrons in addition to the shared electron pair, satisfying the octet rule.

The resulting compound, nitrogen trifluoride (NF3), has a Lewis structure symbolized as:

:F:
  |
N
  |
:F:

With the nitrogen atom in the center sharing a pair of electrons with each of the three fluorine atoms and each fluorine atom having three lone pairs, all atoms satisfy the octet rule, with nitrogen having its octet by sharing three pairs of electrons and each fluorine by having three lone pairs and one shared pair.

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in absence of oxygen.

i have resd about in my biology textbook.

sorry i kniw this much

The velocity for the forward reaction equal that of the reverse reaction.

Answer: - the velocity for the forward reaction equal that of the reverse reaction

Explanation:-

Equilibrium constant is defined as the ratio of concentration of product to the concentration of reactants each raised to the power their stoichiometric ratios. It is represented by the symbol 'K'. For the general equilibrium equation:

[tex]aA+bB\rightleftharpoons cC+dD[/tex]

The expression for equilibrium constant is given as:

[tex]K=\frac{[C]^c[D]^d}{[A]^a[B]^b}[/tex]

Characteristics of equilibrium reaction:

Chemical equilibrium are attained is closed system.

The macroscopic remains constant like: volume, pressure, energy etc.

Rate of forward reaction is equal to the rate of backward reaction. The concentration of the reactants and products remain constant.They are not always equal.

Answer:

4 outer atoms, 2 lone pairs

Explanation:

A square planar molecular structure has four outer atoms bonded to the central atom, and two lone pairs of electrons on opposite sides of the central atom, contributing to the square planar shape.

A molecule with a square planar shape essentially has an octahedral electron-pair geometry, but with two lone electron pairs on opposite sides of the central atom. By occupying these positions, the lone pairs minimize repulsions with other atoms and lone pairs around the central atom. As a result, the molecule appears square planar.

In this case, there are four outer atoms bounded to the central atom, without any additional lone pairs on them. The molecule, therefore, also has two lone pairs on opposite sides (180° apart) of the central atom, hence appearing square planar. These two lone pairs are considered when describing the electron-pair geometry, but not when we describe the molecular structure, which focuses on the position of atoms rather than electron pairs.

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Answer:

B. they are unsaturated

Explanation:

Alkanes are long chain hydrocarbons with only single bonds, alkenes are hydrocarbons with at least one double bond and alkynes are hydrocarbons with at least one triple bond.

Alkanes, alkenes and alkynes are all hydrocarbons. Therefore statement D. is incorrect

Hydrocarbons are compounds containing carbon and hydrogen only

Neither of the three are aromatic compounds therefore statement A is incorrect

Saturated hydrocarbons are where all the bonds between atoms are single bonds. Unsaturated hydrocarbonds are when at least there's one double or triple bond.

Alkanes are saturated and Alkynes and alkenes are unsaturated.

therefore statement B is correct where alkenes and alkynes are unsaturated but alkanes are not

Final answer:

Alkenes and alkynes are unsaturated hydrocarbons due to the presence of carbon-carbon double and triple bonds, respectively, differentiating them from saturated alkanes.

Explanation:

The correct answer to the question is B: Alkenes and alkynes are unsaturated hydrocarbons. This is because they contain double or triple carbon-carbon bonds respectively, which means they have fewer hydrogen atoms attached to the carbon backbone compared to alkanes, which contain only single bonds and are therefore saturated. The term saturated indicates that a molecule contains the maximum possible number of hydrogen atoms whereas unsaturated indicates the presence of double or triple bonds, which replace some hydrogen atoms.

Aromatic compounds, like benzene, are indeed hydrocarbons but they are classified by their distinct ring structure with delocalized electrons, which is not a characteristic of alkenes or alkynes. Alkenes and alkynes are not aromatic simply because they have unsaturated bonds. Alkanes are also hydrocarbons; however, they are saturated, which is a term not applicable to alkenes or alkynes.

Answer:

activity involving mental or physical effort done in order to achieve a purpose or result.

Explanation:

The scientific definition of work is: using a force to move an object a distance .

Niel bohr - Bohrium 107