Which of the following is the strongest base?
a. ammonia b. dimethylamine c. aniline d. 4-nitroaniline

The pH of the buffer is approximately 12.0,when Concentration of Na2HPO4 = 0.16 M Concentration of Na3PO4 = 0.38 M

To calculate the pH for this buffer, we need to first determine the pKa values for the phosphoric acid (H3PO4) species. The given Ka1 value for H3PO4 is missing in the question, so we cannot calculate the pH directly. However, we can assume that the Ka2 and Ka3 values are small compared to Ka1 and therefore negligible.
To prepare a buffer, we need to have an equal concentration of both the acid and its conjugate base. Here, Na2HPO4 is the conjugate base (A-) and Na3PO4 is the acid (HA). Therefore, we need to find the concentration of the conjugate base.
Concentration of Na2HPO4 = 0.16 M
Concentration of Na3PO4 = 0.38 M
Let x be the concentration of HPO4^2-, then the concentration of H2PO4^- will be (0.38 - x) M.
Ka1 for H3PO4 is 7.5 x 10^-3.
Using the Henderson-Hasselbalch equation, we can calculate the pH of the buffer as:
pH = pKa1 + log([A-]/[HA])
pH = -log(7.5 x 10^-3) + log(0.16/x)
pH = 2.12 + log(0.16/x)
Simplifying the equation further:
x = 0.01 M
[H2PO4^-] = 0.38 - x = 0.37 M
[OH-] = Kw/[H+] = 1 x 10^-14/ x = 1 x 10^-12
pH = 12.0
Therefore, the pH of the buffer is approximately 12.0.

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Answer:

We don't know what solvent X and solvent Y are, but from the chart, we can see that in solvent X, hydrochloric acid can conduct electricity (bulb lights up), and react with calcium carbonate.

So, we can say the electrical conductivity when HCl is dissolved in solvent X is high, and when HCl is dissolved in solvent Y, the electrical conductivity is low (because light bulb doesn't light up).

Additionally, in solvent X, HCl ionizes, this shows the property of acids: reacts with carbonates to give CO2 (because CO2 reacts with lime water to make it cloudy).

In solvent Y, HCl does not ionize, so there is no reaction between acid and calcium carbonate.

The repulsion of the electron pair surrounding the core atom has a significant impact on the geometry or shape of the electron.

The tendency of the electron pairs in an atom to repel one another when they are present is known as electron pair repulsion.

The more repulsion there is between the electron pairs, the more the electrons want to organize themselves to lessen it.

Here, the issue of how electron pair repulsion affects molecule geometry is raised.

The fundamental explanation is that the molecule will change its structure to keep the repelling electron pair apart.

The electron pair repulsion also plays a significant role in determining molecular geometry, since molecules prefer to modify their form and geometry in response to the electron pair.

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ANSWER Since 1.0 × 10 -7 has two significant figures, the pH can be reported as 7.00. A logarithmic scale condenses the range of acidity to numbers that are easy to use. Consider a solution with [H + ] = 1.0 × 10 -4 M. That is a hydrogen-ion concentration that is 1000 times higher than the concentration in pure water.

The periodic trend of electronegativity is a key part of figuring out how atoms will react with each other when they mix chemically. Atoms with higher electronegativity will form polar bonds with atoms of lower electronegativity, while atoms of similar electronegativity will form nonpolar bonds.

Electronegativity is a measure of an atom's ability to attract electrons, and it is essential to understanding how atoms combine chemically. Electronegativity increases from left to right across a period and decreases from top to bottom within a group on the periodic table. The greater the difference in electronegativity, the more polar the bond. For instance, oxygen (O) has a stronger electronegativity than hydrogen (H), thus when they combine, they create a polar bond. Atoms with similar electronegativity, on the other hand, will form nonpolar bonds. Carbon (C) and hydrogen (H) have similar electronegativity, therefore when they unite, they create a nonpolar bond. Knowing the electronegativity of various elements allows us to predict how they will mix to form various sorts of bonds.

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Explanation:

1.False

2.False

3.True

4.True

5.False

The volume of 0.26 M HBr required to neutralize 40 mL of 0.8 M NaOH is 123.08 mL

We'll begin by writing the balanced equation for the reaction. This is given below:

HBr + NaOH —> NaBr + H₂O

From the balanced equation above,

The mole ratio of the acid, HBr (nA) = 1

The mole ratio of the base, NaOH (nB) = 1

From the question given above, the following data were:

Volume of base, NaOH (Vb) = 40 mL

Molarity of base, NaOH (Mb) = 0.8 M

Molarity of acid, HBr (Ma) = 0.26 M

The volume of the acid, HBr needed for the reaction can be obtained as follow:

MaVa / MbVb = nA / nB

0.26 × Va / (0.8 × 40) = 1

0.26 × Va / 32 = 1

Cross multiply

0.26 × Va = 32

Divide both side by 0.26

Va = 32 / 0.26

Therefore, the volume the acid, HBr needed to neutralize the base, NaOH is 123.08 mL

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Fatty acid groups are referred to as B) acyl groups.

Fatty acids are organic compounds that consist of a long hydrocarbon chain with a carboxyl group (-COOH) at one end. The hydrocarbon chain is composed of carbon and hydrogen atoms, and its length can vary. Fatty acids play essential roles in various biological processes and are major components of lipids, including triglycerides and phospholipids.

When a fatty acid is involved in chemical reactions or is attached to other molecules, it typically undergoes a process called activation, where it is converted into an acyl group. An acyl group is formed by replacing the -OH (hydroxyl) group of the carboxyl group with an -OR (alkoxy) group. The -OR group can be derived from various molecules, such as coenzyme A (CoA) or other acyl carrier proteins.

For example, when a fatty acid is activated for incorporation into a triglyceride molecule, it forms a triglyceride acyl group. Similarly, when a fatty acid is incorporated into a phospholipid molecule, it forms a phospholipid acyl group. The acyl group represents the hydrocarbon chain of the fatty acid, which may vary in length and saturation.

Therefore, the correct answer to the question is B) Acyl.

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Answer:Landslide

Explanation:

Just did this question.

Answer:

tn

Explanation:

If an observer in the northern hemisphere was to face south at noon on January 1, they would be presented with a unique sight.

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The rate of reaction refers to how quickly or solwly a reaction occurs;

a) Both A and B are second order

b) The rate law of the reaction is R = k[A]^2 [B]^2

c)The rate constant is  5.21 * 10^5 mol-3L^3s-1.

The term rate of reaction refers to how quickly or slowly a reaction occurs.

a) To obtain the order with respect to A, we divide reaction (3) by (2) as follows;

5.01 * 10^-1/1.25 * 10^-1 = k[0.0070]^m [0.14]^n/k[0.0035]^m [0.14]^n

4 = 2^m

2^2 = 2^m

m =2

To obtain the order with respect to B, we divide reaction (2) by (1);

1.25 * 10^-1/3.13 * 10^-2 = k[0.0035]^m [0.014]^n/k[0.0035]^m [0.0070]^n

4 = 2^n

2^2 = 2^n

n = 2

b)The reaction is second order in both A and B hence the rate law is R = k[A]^2 [B]^2

c) We can obtain K using any of the reactions;

0.0313 molL-1s-1 = k[0.0035molL-1]^2 [0.0700molL-1]^2

k = 0.0313 molL-1s-1/[0.0035molL-1]^2 [0.0700molL-1]^2

k = 5.21 * 10^5 mol-3L^3s-1

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Answer: Here u go

Explanation:

Atomic radii varies in a predictable way across the periodic table. The atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.

Cr-V of the following systems  would you expect to exhibit complete solid solubility.

Option A is correct.

A solid solution is produced when two metals have similar dimensions and properties like electronegativity. Cr and V are adjoining components in the occasional table ( they will have comparable sizes and different properties).

Atomic radiuses are comparable and each has a BCC crystal lattice.They are anticipated to produce a soluble solution as a result. Another duo is Ag-Au. These elements have the same crystal structure, FCC, and their sizes are similar (though not very different). Additionally, this produces soluble solid solutions.

Solute and solvent crystal structures must be comparable. Complete dissolvability happens when the dissolvable and solute have a similar valency. A metal with a lower valency is more likely to dissolve another metal with a higher valency. The electronegativity of the solute and the solvent ought to be comparable.

Incomplete question:

Which of the following systems (i.e., pair of metals) would you expect to exhibit complete solid solubility?

A. Cr-V

B. Mg-Zn

C. Al-Zr

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To solve this problem, you can use the following formula:

M = m/V

where M is the molarity of the solution, m is the mass of the solute, and V is the volume of the solution. In this case, you are given the molarity and the mass of the solute, and you need to find the volume of the solution.

Substituting the given values into the formula and solving for V, you get:

V = m/M = (18.0 g) / (0.405 M) = 44.3 mL

So, you need 44.3 mL of the solution to obtain 18.0 g of oxalic acid.

Answer:

84%

Explanation:

Fossil Fuels Supply 84 Percent Of Worlds Electricity

A radioactive element has a half life of 10 days then there are  7 days would it take for 1000 grams of it to decay to 125 grams .

Calculation ,

radioactive element has a half life = 10 days ( given )

Kt = 0.069

K = 0.069 / t

K = 0.069 /  10 days = 0.0069

Kt = ㏑a/a-x

where ,

a = concentration of radioactive element at time 0  = 1000 grams

a-x = concentration of radioactive element at time t = 125 grams

Putting the value of a , a- x and K in equation ( i ) we get ,

0.0069 × t = ㏑1000 grams/125 grams = ㏑8 = 2.07

t= 2.07 / 0.0069 = 7 .05 days or 7 days

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Answer:

thermal shock

Explanation:

the temperatures inside the glass jar should have continued to increase over time. Internal stresses due to uneven heating. This is also known as “thermal shock”.

In general, the thicker the glass, the more prone it will be to breaking due to the immediate differences in temperature across the thickness of glass.

Borosilicate glass is more tolerant of this, as it has a higher elasticity than standard silicon glass.

You may also note that laboratory test tubes and flasks are made with thinner walls, and of borosilicate glass, when designated for heating.

The empirical formula of the compound obtained from the question given is NaBrO₃

The empirical formula of the compound can be obtained as illustrated below:

Divide by their molar mass

Na = 15.24 / 22.99 = 0.663

Br = 52.95 / 79.90 = 0.663

O = 31.81 / 16 = 1.988

Divide by the smallest

Na = 0.663 / 0.663 = 1

Br = 0.663 / 0.663 = 1

O = 1.988 / 0.663 = 3

Thus, the empirical formula of the compound is NaBrO₃

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Universe, Stars, Planets, Asteroids

Answer:

Universe, Stars, Planets, Asteroids

Explanation:

Answer:

Nonmetal reactivity decreases down a group because the nucleus' ability to gain more valence electrons weakens due to more nuclear shielding. For Metals: the most reactive metals are those that can lose their valence electrons the most easily. ... Francium is the most reactive metal

Explanation:

Answer:

While moving from top to bottom in a group of the periodic table, the reactivity of non- metals decreases. ... Thus, the tendency of gaining electron/s in the valence shell decreases as well as the chemical reactivity also decreases on moving from top to bottom in a group of non- metals.

a. The number of grams of sodium oxide produced by 100 g Na would be 134.85 grams while the amount produced by 60 g oxygen would be 232.5 grams.

b. The mass of excess reactant left over at the conclusion of the reaction would be 24.624 grams of oxygen.

The unbalanced equation goes thus: \(Na + O_2 -- > Na_2O\)

First, we need to balance the equation of the reaction. This balanced equation is written as:

\(4 Na + O_2 -- > 2Na_2O\)

From the equation:

With 100 g Na:

Mole = 100/23

        = 4.35 moles

Equivalent mole of \(Na_2O\) = 4.35/2

                                          = 2.175 moles

Mass of 2.175 moles of \(Na_2O\) = 2.175 x 62

                                                 = 134.85 grams

Thus, 134.85 grams of \(Na_2O\) will be produced with 100g of Na.

With 60 g of oxygen:

Mole = 60/32

        = 1.875 moles

Equivalent moles of \(Na_2O\) = 1.875 x 2

                                           = 3.75 moles

Mass of 3.75 moles \(Na_2O\) = 3.75 x 62

                                           = 232.5 grams.

Thus, 232.5 grams of \(Na_2O\) will be produced with 60 g of oxygen.

To get the excess reactant:

Mole of 100 g Na = 4.35 moles

Mole of 60 g oxygen = 1.875 moles

Mole ratio of Na to oxygen = 4:1

Thus the excess reactant is oxygen.

Actual amount of oxygen = 4.35/4

                                           = 1.0875 moles

Excess mole of oxygen = 1.857 - 1.0875

                                       = 0.7695 moles

Mass of excess oxygen = 0.7695 x 32

                                       = 24.624 grams

Thus, the mass of the excess reactant left over after the conclusion of the reaction is 24.624 grams of oxygen.

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Whole wheat loaves accounted for approximately 23.08% of the total bread sold.

To determine the percentage of whole wheat loaves out of the total bread sold, we need to calculate the proportion of whole wheat loaves and express it as a percentage. In July, the bakery sold 2070 loaves of whole wheat bread, and in total, they sold 9000 loaves of bread.

To find the percentage, we divide the number of whole wheat loaves by the total number of loaves and multiply by 100:

Percentage of whole wheat loaves = (2070 / 9000) * 100 = 23.08%

Therefore, approximately 23.08% of the bread sold were whole wheat loaves.

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The substances in order of decreasing boiling point are: CH₃OH > CO₂ > Ne > KF.

This means that CH₃OH has the highest boiling point and KF has the lowest boiling point. The reason for this order is based on the intermolecular forces between the molecules. CH₃OH has hydrogen bonding between its molecules, which is a strong intermolecular force, causing it to have a high boiling point.

CO₂ and Ne have weaker intermolecular forces, resulting in lower boiling points. KF has an ionic bond, which is the weakest intermolecular force, causing it to have the lowest boiling point.

In summary, the ranking of substances in decreasing order of boiling point is determined by the strength of the intermolecular forces present between the molecules.

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Answer:

B. Fission

Explanation:

On edge

The correct answer is B. Adding 0.050 moles of NaOH will destroy the buffer effectiveness in buffer solution.

A buffer solution is a solution that can resist changes in pH when small amounts of acid or base are added to it. In this case, the buffer solution consists of acetic acid (HC2H3O2) and its conjugate base (C2H3O2- or NAC2H3O2).

To determine if an action will destroy the buffer effectiveness, we need to consider what happens to the buffer components and how they affect the pH of the solution.

A. Adding 0.050 moles of NaC2H3O2: This will not destroy the buffer effectiveness because we are adding more of the conjugate base, which can react with any added acid to maintain the pH.

B. Adding 0.050 moles of NaOH: This will destroy the buffer effectiveness because the added base will react with the weak acid (HC2H3O2) to form water and the acetate ion (C2H3O2-), which is a strong conjugate base. This will shift the equilibrium towards the products and decrease the concentration of the weak acid, making it less effective at resisting changes in pH.

C. Adding 0.050 moles of HCl: This will not destroy the buffer effectiveness because we are adding acid, which can be neutralized by the buffer components.

D. Adding 0.050 moles of HC2H3O2: This will not destroy the buffer effectiveness because we are adding more of the weak acid, which can react with any added base to maintain the pH.

E. None of the above: This is not the correct answer because option B (adding 0.050 moles of NaOH) will destroy the buffer effectiveness.

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Balanced chemical equation:

\(3 Ba(NO3)2 (aq) + 2 K3PO4 (aq) ----- > 6 KNO3 (aq) + Ba3(PO4)2(s)\)

What is double-displacement reaction?

In an aqueous solution, a double-displacement reaction takes place when the positive and negative ions of two ionic compounds exchange positions to form two completely different compounds.

Chemical formula for :

Barium nitrate---> Ba(NO3)2  (aq)

Pottasium Phosphate = K3PO4 (aq)

Reaction between these two is a type of double displacement type reaction in which ions are exchanged , forming

Pottasium Nitrate -----> KNO3 (aq)

Barium Phosphate -----> Ba3(PO4)2 (s)

(aq) means the phase is aqueous and (s) means phase is solid or the compound precipitated out .

Now, writing the molecular formula using the above data , we get:

\(Ba(NO3)2 (aq) + K3PO4 (aq) ------ > KNO3 (aq) + Ba3(PO4)2 (s)\)

A equation is called balanced when number of chemical species are same on both sides of the equation .

Here, in product side there are 3 Ba and 2 (PO4) and only 1 Ba and 1 PO4 in reactant side to balance this let's multiply

2 with K3PO4 on reactant side and ,

3 with Ba(NO3)2 on reactant side

The equation thus becomes:

\(3 Ba(NO3)2 (aq) + 2 K3PO4 (aq) ------ > KNO3 (aq) + Ba3(PO4)2 (s)\)

Now,

There are 6 K atoms on reactant side to balance this let's multiply 6 with KNO3 in product side by doing so we also balanced NO3.

Consequently, the balanced chemical equation is

3 Ba(NO3)2 (aq) + 2 K3PO4 (aq) ----- > 6 KNO3 (aq)  + Ba3(PO4)2(s)

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Answer:

B. electric energy then chemical energy

Explanation:

Answer:

Melting point is a intensive property and Intensive properties can be used to help identify a sample because these characteristics do not depend on the amount of sample, nor do they change according to conditions.

Explanation:

Answer:

I would say B. melting point but then again all of them are very important exept for state, because even though state is important it only determines if it's a gas liquid or solid! so Mass and volume are Important, but volume also just determines 1 thing, how big it is, so mass or melting point, which mass just tells you how much space it takes up, so I'd say B. Melting point

The energy of the photon from the calculation performed is 3.5 * 10^-16 J.

A photon is a packet of light. It was derived from the theory of Albert Einstein. The energy of a photon is obtained from; E = hc/λ

Now we have that;

E = 6.6 * 10^-34 * 3 * 10^8/562 * 10^-9

E = 3.5 * 10^-16 J

Missing parts:

Calculate the energy, in joules, of a photon of green light having a wavelength of 562nm?

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