An analytical chemist is titrating 111.0 mL of a 0.3700 M solution of aniline (C6H5NH2) with a 0.3500 M solution of HNO3. The pK_b of aniline is 9.37. Calculate the pH of the base solution after the chemist has added 79.1 mL of the HNO_3 solution to it.

Ans：2.3

Explanation:

pH = -log[H+(aq)]

= -log[0.00476]

=2.3

As HCl solution is monobasic. Each molecule ionizes in water to form ONE hydrogen ion. So the H+(aq) is equal to its molarity.

2.3 is he pH of a 0.00476 M HCI solution and this value tells that solution is acidic in nature.

pH of any solution can be define as the negative log of the concentration of the H⁺ ions.

In the question given that:

Concentration of HCl solution = 0.00476 M

Concentration of H⁺ ions is equal to concentration of HCl solution as it completely ionize into their ions. So, pH can be calculated as:

pH = -log[H⁺] = -log[0.00476] = 2.3

Hence, pH of the solution is 2.3.

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Answer:

C₃H₈O

Explanation:

From the question given above, the following data were obtained:

Mass of Carbon (C) = 0.599 g

Mass of Hydrogen (H) = 0.134 g

Mass of Oxygen (O) = 0.266 g

Empirical formula =?

The empirical formula of the compound can be obtained as follow:

C = 0.599 g

H = 0.134 g

O = 0.266 g

Divide by their molar mass

C = 0.599 / 12 = 0.050

H = 0.134 / 1 = 0.134

O = 0.266 / 16 = 0.017

Divide by the smallest

C = 0.050 / 0.017 = 3

H = 0.134 / 0.017 = 8

O = 0.017 / 0.017 = 1

Empirical formula => C₃H₈O

Answer:

Dude its A.Feeding

Explanation:

Its common scene that when u eat you are getting nutrient directly from the food. Come on Sponge Bob Me Boy

Answer: 4.87 g

Explanation:

We know that for every 3 moles of zinc that are consumed, 3 moles of hydrogen are produced (we can reduce this to the number of moles of zinc consumed = moles of hydrogen produced)

We know that the formula mass of hydrogen is 2(1.00794)=2.01588 g/mol, so in 0.15 g, there is about 0.15/2.01588 = 0.074409191023275 moles.

This means that about 0.074409191023275 moles of zinc are needed, and since the atomic mass of zinc is 65.409 g/mol, the answer is (0.074409191023275)(65.409)=4.87 g

Answer:

When an element exists in more than one crystalline form, those forms are called allotropes; the two most common allotropes of carbon are diamond and graphite. Every carbon atom is covalently bonded at the four corners of the tetrahedron to four other carbon atoms.

Answer:

74.08%

Explanation:

We'll begin by calculating the mass of

Oxygen in 4 g of N₂O₅. This can be obtained as follow:

Molar mass of N₂O₅ = (14×2) + (16×5)

= 28 + 80

= 108 g/mol

Mass of oxygen in N₂O₅ = 5 × 16 = 80 g

Mass of oxygen in 4 g of N₂O₅

= 80 / 108 × 4

= 2.963 g

Finally, we shall determine the percentage of oxygen in 4 g of N₂O₅. This can be obtained as follow:

Mass of oxygen = 2.963 g

Mass of N₂O₅ = 4 g

Percentage of oxygen =?

Percentage of oxygen = mass of oxygen / mass of N₂O₅ × 100

Percentage of oxygen = 2.963 / 4 × 100

Percentage of oxygen = 74.08%

Answer:

[tex]\Delta H_{comb}=2043.85kJ/mol[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction, it possible for us to set up the expression for the calculation of the enthalpy change as shown below:

[tex]\Delta H_r=-\Delta H_{comb}=3\Delta _fH_{CO_2}+4\Delta _fH_{H_2O}-\Delta _fH_{C_3H_8}-3\Delta _fH_{O_2}[/tex]

Thus, given the values of the enthalpies of formation on the attached file, we obtain:[tex]-\Delta H_{comb}=3(-393.5kJ/mol)+4(-241.8kJ/mol)-(-103.85kJ/mol)-3(0kJ/mol)\\\\-\Delta H_{comb}=-2043.85kJ/mol\\\\\Delta H_{comb}=2043.85kJ/mol[/tex]

Best regards!

Answer:

9.43 L Br₂ (g)

Explanation:

First, write a balanced reaction equation. Then use dimensional analysis to convert from grams of aluminum chloride to moles of aluminum chloride (with molar mass from the periodic table), from moles of aluminum chloride to moles of bromine gas (using the balanced equation), and from moles of bromine gas to liters of bromine gas (remember at STP, 1 mol = 22.4 L). See the attached image for the work out. Finally, account for sig figs to get 9.43 L of bromine gas

Answer:

o diferença chave entre a radioatividade e a transmutação é que a radioatividade se refere à transmutação natural, enquanto a transmutação se refere à mudança de um elemento químico em outro por meios naturais ou artciais.Tanto a radioatividade quanto a transmutação são processos químicos que envolvem a mudança de núcleos atômicos para formar um novo elemento químico a partir de um elemento químico existente. A radioatividade é um tipo de processo de transmutação

Explanation:

mais informação em; ahttps://pt.strephonsays.com/radioactivity-and-transmutation-9500

Answer:

Hello There!!

Explanation:

I think the answer is possibly C. It identified the charge on a single electron.

hope this helps,have a great day!!

~Pinky~

[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]

C. It identified the charge on a single electron.

Answer:

0.31g KCl

Explanation:

Before we can start, we have to wonder, how many moles of KCl is formed from KClO3? To figure that out we have to make a balanced equation.

KClO3 -> KCl + O2

How do I know it makes O2? Looking back at the problem they're asking for KCl, which has less ions than KClO3 so it must have been broken down. So we can say it's a decomposition type of reaction. We can't just slap on O3, we know oxygen is one of our diatomic elements that usually exists as O2 so we'll put it down as O2 and balance our equation.

2KClO3 -> 2KCl + 3O2

Now that we know every 2 moles of KClO3 makes 2 moles of KCl, this is our mole to mole ratio. Knowing the ratio between the 2 compounds in our problem is the stepping stone from converting from grams KClO3 -> moles KClO3 -> moles KCl -> grams KCl.

1. Let's first convert grams KClO3 -> moles KClO3

[tex]0.500g KClO3 x \frac{1 mol}{123g KClO3} = 0.0041 mol KClO3[/tex]

2. Convert moles KClO3 -> moles of KCl using our mole to mole ratio

[tex]0.0041 mol KClO3 x \frac{2 mol KCl}{2 mol KClO3} = 0.0041 mols KCl[/tex]

3. Convert moles KCl -> grams KCl

[tex]0.0041 mol KCl x\frac{75g KCl}{1 mol} = 0.31g KCl[/tex]

Answer:

When you build up a soapy lather, the molecules help lift the dirt, oil and germs from your skin

Explanation:

Soap molecules have one end that bonds with water and the other end that bonds with oils and fats .

Hope this helped!!

Answer:

See explanation.

Explanation:

Hello there!

In this case, for the chemical reaction:

[tex]H_2O(g) CO(g)\rightleftharpoons CO_2(g) H_2(g)[/tex]

It is widely known that the the only factor altering the equilibrium constant is the temperature because of its thermodynamic definition:

[tex]K=exp(-\frac{\Delta G(T)}{RT} )[/tex]

Which is temperature dependent on the denominator and on the Gibbs free energy of reaction. In such a way, the answers can be just f and g, as the other factors modify Q (reaction quotient) rather than K. Thus, we can discuss about f and g:

f. This would increase K if the Gibbs free energy of reaction is positive (nonspontaneous).

g. This would increase K if the Gibbs free energy of reaction is negative (spontaneous).

It is important to discuss those two because the Gibbs free energy is not given.

Regards!

Answer:

Only anions

Explanation:

Polyatomic positive ions often have common name ending with the suffix anions

Answer:

[tex]k =0.101 \ min^{-1}[/tex]

Explanation:

From the given information:

The initial concentration of a chemical [tex]C_{AO} = 15 \ mg/L[/tex]

The final concentration is [tex]C_A = 5 \ g/m^3[/tex] = 5 mg/L

Volume flow rate [tex]V_o = 0.42 \ m^3/sec[/tex]

Volume of the tank V = 500 000 L = 500 m³

The time t is determined by using the formula:

[tex]t= \dfrac{V}{V_o}[/tex]

[tex]t= \dfrac{500 \ m^3}{0.42 \ m^3/sec}[/tex]

t = 1190.47 sec

t ≅ 19.8 min

∴

The rate of the decay constant is:

[tex]kt= \dfrac{C_{AO}-C_{A}}{C_A} \\ \\ k = \dfrac{1}{19.8}( \dfrac{15-5}{5})[/tex]

[tex]k =0.101 \ min^{-1}[/tex]

Answer:

[tex]=1.76gCa[/tex]

Explanation:

Hello there!

In this case, according to the given atoms of calcium, it is possible to calculate the mass of this element by considering that the definition of mole is in terms of atoms and also the atomic mass of calcium:

[tex]1molCa=6.022x10^{23}atoms Ca=40.08gCa[/tex]

In such a way, by considering the following setup, we can obtain:

[tex]=2.65x10^{22}atomsCa*\frac{1molCa}{6.022x10^{23}atoms} *\frac{40.08gCa}{1molCa}\\\\=1.76gCa[/tex]

Best regards!

Answer:

Convection

Explanation:

Convection definition:

the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat.

The method of heat transfer that occurs when particles move through a fluid is called convection.

Convection relies on the principle of fluid flow, where hotter particles become less dense and rise while cooler particles sink due to their increased density.

This movement creates a continuous circulation of the fluid, enabling the transfer of thermal energy. As the hot particles rise, they carry their thermal energy with them, and as the cooler particles sink, they absorb heat from their surroundings.

Convection is also observed in natural phenomena such as ocean currents, air currents, and even the movement of magma in the Earth's mantle.

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Answer:

answer po Yan hope it help

Answer:

46.41%

Explanation:

Find the total r.m.m of AL(CLO3)3 put it equals to 100%.....The take 106.5,the total r.m.m of Cl and find the missing which is the percentage by cross multiplication

Answer:

[tex]M_{base}=0.173M[/tex]

Explanation:

Hello there!

In this case, since the titration of acids like KHP with bases like NaOH are performed in a 1:1 mole ratio, it is possible for us to know that their moles are the same at the equivalence point, and the concentration, volume and moles are related as follows:

[tex]n_{acid}=M_{base}V_{base}[/tex]

Thus, by solving for the volume of the base as NaOH, we obtain:

[tex]M_{base}=\frac{n_{acid}}{V_{base}} \\\\M_{base}=\frac{0.8675g*\frac{1mol}{204.22g} }{0.02456L} \\\\M_{base}=0.173M[/tex]

Best regards!

Explanation:

(I only know this thing vaguely lol)

1.) It's the study of the chemistry that is happening here on earth that is not bounded by a laboratory.

2.) The early gas clouds compressed and formed a star we now call the sun and the massive gravitational pull of this star grabbed nearby debris and the debris formed and compressed into the planets and moons that we know today.

Answer:

1.2*10^24 molecules of CF4

Explanation:

the molar mass of cf4 is 88.0043 g/mol

176/88.0043 = 2 moles of CF4

Then multiply by avogadro's number (6.022*10^23) to get the number of molecules

2*6.022*10^23 = 1.2*10^24 molecules of CF4

There are 1.204 × 10²⁴ molecules of carbon tetrafluoride in 176 grams of CF4.

HOW TO CALCULATE NUMBER OF MOLECULES:

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Answer:

The type of reaction is a single-replacement reaction.

Explanation:

Mg switches places with H, leaving H by itself.