A 0.085 M solution of a weak acid has a pH of 2.68. Determine the Ka value for this acid.

Answer:

B. Protons and Neutrons

Answer:

Option"B" is correct.

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Answer:

The limiting reagent is CuCl

Explanation:

The initial number of moles of aluminum, Al = 4.5 moles

The number of moles of copper, Cu = 6.5 moles

The given chemical reaction is presented as follows;

2Al + 3CuCl → 2AlCl₃ + 3Cu

Therefore, we have, 2 moles of aluminum combine with 3 moles of CuCl produces 2 moles of AlCl₃ and 3 moles of Cu

1 mole of Al will combine with (3/2) moles of CuCl,

Therefore, 4.5 moles of Al will combine with (4.5 × (3/2) = 6.75) 6.75 moles of CuCl

Given that the number of moles of CuCl present is only 6.5 moles which is less than the 6.75 moles required to combine with the 4.5 moles, the 6.5 moles of CuCl limits the amount of AlCl₃ and Cu produced, and therefore the CuCl is the limiting reagent.

Isotopes are atoms of the same element that have different masses. The relative atomic mass (am) is a weighted average that takes into account the abundance of each isotope. We can calculate the relative atomic mass using the following expression.

[tex]am = \frac{\Sigma m_i \times ab_i}{100}[/tex]

where,

For Gallium,

[tex]70.59 amu = \frac{69 amu\ x + 71 amu\ y}{100}[/tex]     [1]

where "x" and "y" are the unknown abundances.

We also know that the sum of both abundances must be 100%.

x + y = 100

y = 100 - x   [2]

If we replace [2] in [1], we get

[tex]70.59 amu = \frac{69 amu\ x + 71 amu\ (100-x)}{100} \\7059 amu = -2 amu\ x + 7100amu \\x = 20.5[/tex]

Then, in [2]

y = 100 - x = 100 - 20.5 = 79.5

In conclusion, Ga-69 has an abundance of 20.5% and Ga-71 has an abundance of 79.5%.

You can learn more about isotopes in: https://brainly.com/question/21536220?referrer=searchResults

Answer:

sry i don't know answer of This question

Explanation:

Answer is that : no heat will flow

Answer:

Heat will flow from the ice cube to the dry ice

Explanation:

Answer:

2H2S (g) + 3O2 (g) = 2H2O (l) + 2SO2 (g)

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[tex]\boxed{\pmb{\green{\sf{2H_{2}S(g) + 3O_{2}(g)\dashrightarrow 2H _{2}O(l)+2SO_{2}(g)}}}}[/tex]

▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓

Answer:

Following are the solution to the given question:

Explanation:

Its maximum oxidation zone is exceptionally stable and has the greatest ability to charge density, while fluoride and oxide ions are the largest particles with the largest durability of charge.

Or it might be assumed as oxygen and fluorine are the system particle atoms that have the highest electron number of metals.

Answer:

[tex]\boxed {\boxed {\sf 2.73 \ g \ He}}[/tex]

Explanation:

We are asked to find the mass of helium gas given a volume.

1 mole of any gas occupies a volume of 22.4 liters. So, 1 mole of helium gas contains 22.4 liters of helium. Create a ratio using this information.

[tex]\frac {1 \ mol \ He }{ 22.4 \ L \ He}[/tex]

We are converting 15.3 liters of gas to moles, so we multiply by that value.

[tex]15.3 \ L \ He *\frac {1 \ mol \ He }{ 22.4 \ L \ He}[/tex]

The units of liters of helium (L He) cancel.

[tex]15.3 *\frac {1 \ mol \ He }{ 22.4}[/tex]

[tex]\frac {15.3}{22.4} \ mol \ He[/tex]

[tex]0.6830357143 \ mol \ He[/tex]

The molar mass is the mass of 1 mole of a substance. These values are found on the Periodic Table as atomic masses, but the units are grams per moles. Look up the molar mass of helium.

Create another ratio using the molar mass.

[tex]\frac {4.0026 \ g \ He}{1 \ mol \ He}[/tex]

Multiply by the number of moles we calculated.

[tex]0.6830357143 \ mol \ He *\frac {4.0026 \ g \ He}{1 \ mol \ He}[/tex]

The units of moles of helium (mol He) cancel.

[tex]0.6830357143*\frac {4.0026 \ g \ He}{1 }[/tex]

[tex]2.73391875 \ g \ He[/tex]

The original measurement of volume has 3 significant figures, so our answer must have the same.

For the number we calculated, that is the hundredths place.

The 3 in the thousandths place to the right (2.73391875) tells us to leave the 3 in the hundredths place (2.73391875).

[tex]2.73 \ g \ He[/tex]

15.3 liters of helium gas is approximately 2.73 grams of helium.

Answer:

It is called bleaching oxidation process.

Answer:

s orbital

Explanation:

it has the lowest energy because

Paulis law state that orbitals with lower energy must be fill first before that of higher energy

and the s orbital is filled first

Answer:

B. Transfer energy to reaction center chlorophylls.

Explanation:

Accessory pigments absorbs sunlight, these compounds are found in photosynthetic organisms, which work in conjunction with chlorophyll. Acessory pigments absorbs and transfer light energy to reaction center chlorophylls.

Answer:

In this reaction, nitrogen acts as the oxidizing agent. Mg is a reducing agent.

Answer:

các oxit đồng khi nó tiếp xúc với không khí. nó phản ứng đặc biệt với oxy trong không khí (không phải hơi ẩm), và tạo ra nấm mốc

Answer:

Amino Acid

Explanation:  

It's part of the Amino group, which are substituted hydrocarbons.

When NH₂  and  COOH  replaces hydrogens on the same carbon atom in a molecule, an Amino acid is formed.

What group is a COOH?

COOH : a Carboxylic Acid group!

Answer:

Pertaining to the interrogate, the answer to such is acknowledged and henceforth disseminated as 43.0%

Explanation:

To evaluate such, the following must be comprehended:

Percent Yield Calculator:

% Yield = (What You Actually Got / What You Should Theoretically Get) * 100

The following variables may be denoted, as stated within the interrogate:

Yielded/Produced: 6 grams.

Theoretical Yield: 14 grams.

(6 g/14 g) * 100 = 42.8571428571

*Grams measurement cancels*

42.8 ==> 43.0%

Thus, if rounded to the nearest tenth, the percent yield is equivalent to 43.0%.

Answer:

C. ATP.

Explanation:

During the process of aerobic cellular respiration, energy is said to be released in three main stages: glycolysis, Krebs cycle and oxidative phosphorylation (electron transport chain). The electron transport chain produces the most energy and it involves the transfer of electrons through series of complex proteins.

As the electrons move through the individual complexes, energy is lost to form a proton gradient (H+). The proton gradient powers the synthesis of ATP from ADP as catalyzed by ATP synthase.

Answer:

Zn + O2 = ZnO

Mg + O2 = MgO

Cu + O2 = CuO

Al + O2 = Al2O3

Explanation:

Explanation:

This reaction is also known as double decomposition reaction.

HCl + CaCO3 + MgCO3 → H2O + H2 + CO2 + CaCl2 + MgCl2

Answer:

–2400 N

Explanation:

This is a physics question. However, the answer to the question is given below.

We'll begin by converting 36 Km/hr to m/s. This can be obtained as follow:

3.6 Km/hr = 1 m/s

Therefore,

36 Km/hr = 36 Km/hr × 1 m/s / 3.6 km/hr

36 Km/hr = 10 m/s

Thus, 36 Km/hr is equivalent 10 m/s.

Next, we shall determine the acceleration of the car. This can be obtained as follow:

Initial velocity (u) = 10 m/s

Final velocity (v) = 0 m/s

Time (t) = 5 s

Acceleration (a) =?

a = (v – u) / t

a = (0 – 10) / 5

a = – 10 / 5

a = –2 m/s²

Finally, we shall determine the force required to stop the car. This can be obtained as follow:

Mass (m) = 1200 Kg

Acceleration (a) = –2 m/s²

Force (F) =?

F = ma

F = 1200 × –2

F = –2400 N

NOTE: The negative sign indicate that the force is in opposite direction to the motion of the car.

Answer:

5.ethanol and carbon dioxide

6.it contains ethyl alcohol which can be effective at killing viruses and bacteria

Answer:

A ball is thrown straight up from a rooftop 320 feet high. The formula below describes the ball's height above the ground, h, in feet, t seconds after it was thrown. The ball misses the rooftop on its way down and eventually strikes the ground. How long will it take for the ball to hit the ground? Use this information to provide tick marks with appropriate numbers along the horizontal axis in the figure shown.

h=-16t^2+16t+320

Answer:

[tex]\boxed {\boxed {\sf 8.0 \ M \ NaCl}}[/tex]

Explanation:

Molarity is a measure of concentration in moles per liter, therefore the formula is:

[tex]molarity= \frac{moles \ of \ solute}{lites \ of \ solution}[/tex]

There are 2.0 moles of solute or sodium chloride dissolved in 0.25 liters of water or solution.

Substitute these values into the formula.

[tex]molarity= \frac{ 2.0 \ mol \ NaCl}{0.25 \ L}[/tex]

Divide.

[tex]molarity=8 \ mol \ NaCl / L[/tex]

Molarity is measured in molars or M. 1 molar is equal to 1 mole per liter, so our answer is equal to 8 molars.

[tex]molarity= 8 \ M \ NaCl[/tex]

The original measurements of moles and liters have 2 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. There are no numbers to round, so we add a 0 in the tenths place.

[tex]molarity= 8.0 \ M \ NaCl[/tex]

The molarity of the solution is 8.0 M NaCl.

Answer:

B

Explanation:

Pure water always has equal concentrations of hydrogen and hydroxide ions.

Answer:

There are main six noble gases in the periodic table. The filling of 4f-orbitals occurs after 6s orbitals. The noble gas that belongs to the sixth period is Radon. Its electronic configuration is [ X e ] 6 s 2 4 f 14 5 d 10 6 p 6  .

Therefore, the name of noble gas is Radon.

Answer:

c

Explanation:

Cạnh của hình lập phương là

³\(125 = 5cm

Diện tích đáy của hình lập phương là

5²=25cm²

Đáp án C