the half-life of iodine-123 is 13.3 hours. how much of a 25.0 mg sample will remain after 39.9 hours?

[HA] is equal to the 58 X \(10^{3}\) ц mole In the 0.1M solution, micromoles.

According to the question we get

HA ⇄ \(A^{-}\) \(H^{+}\)

HA= 0.1M

\(A^{-}\) = 0

\(H^{+}\) = 0

HA ⇄ \(A^{-}\) \(H^{+}\)

0.1 M  ⇄ 0 0

0.1 - x  ⇄ 0 0   {at equilibrium}

Now given ration of x and 0.1-x = 0.73

Therefore (\(\frac{x}{0.1-x}\)) = 0.73

Now solving for the value of x we will get

x=0.73-0.73x

x=1.73x=0073

x=0.073M

‘The value for the HA is 0.1-0.042 = 0.058 M.

Assuming the solution to be of 1litre.

Moles of x (A") in 1 litre of solution is calculated as follows:

x=0042Mx1L

x= \(\frac{0.042moles}{1L}\) x 1L

x= 42 X \(10^{3}\)

Similarly, for the acid as follows

HA =0058Mx1L

\(\frac{0.058moles}{1L}\) x 1L

[HA] is equal to the 58 X \(10^{3}\) ц mole.

To know more about moles

https://brainly.com/question/26416088

#SPJ4

The technique to calculate how many grams of element are produced using limiting reactant is shown.

The term "limiting reactant" refers to the reactant that is entirely consumed in a chemical reaction and restricts the quantity of product that can be produced.

1. Determine the limiting reactant by comparing the amount of each reactant to the stoichiometric ratio given in the balanced equation.

2. Use the stoichiometric ratio to calculate the number of moles of the element produced from the limiting reactant.

3. Convert the moles of the element to grams using its molar mass.

The formula is:

Grams of element produced = Moles of element produced x Molar mass of element

where Moles of element produced is calculated using the stoichiometric ratio from the balanced equation, and Molar mass of element is the atomic mass of the element in grams per mole.

To know more about limiting reactant, click here

https://brainly.com/question/2948214

#SPJ1

Place the cursor at the start of the text, then press CTRL+SHIFT+DOWN ARROW. Press CTRL+SHIFT+UP ARROW after advancing the cursor to the end of the paragraph. The Correct option is B.

To Learn more About end of the paragraph refer to:

https://brainly.com/question/25717629

#SPJ1

It is important to add the same amount of alkyl halide to each test tube in the nucleophilic substitution experiment for two main reasons.

Firstly, the amount of reactants used in a chemical reaction can greatly affect the outcome of the reaction. If different amounts of the alkyl halide are added to each test tube, the reaction rates will differ and the products obtained will be inconsistent, making it difficult to draw accurate conclusions from the experiment.

Secondly, by adding the same amount of alkyl halide to each test tube, the experiment can be considered fair and controlled. This means that any differences observed in the reactions can be attributed solely to the changes in the nucleophile used in each reaction. It allows for accurate comparison of the reactions and the identification of trends or patterns in the reactivity of different nucleophiles.

Overall, adding the same amount of alkyl halide to each test tube in the nucleophilic substitution experiment ensures that the results obtained are reliable and can be used to draw meaningful conclusions.

To know more about nucleophilic substitution click here:

https://brainly.com/question/31158017

#SPJ11

Answer:

The answer is thermodynamic because in this branch branch we study heat and Temperature and their relationship

Explanation:

I hope this will help you:)

The relationship between the change in Gibbs free energy and the emf of an electrochemical cell is given by the equation ΔG = -nFE. The equation shows that the magnitude of ΔG is inversely proportional to the emf of the cell and is dependent on the number of electrons transferred during the reaction and the Faraday constant.

The Gibbs free energy change (ΔG) of a chemical reaction is a measure of the potential energy released or absorbed during the reaction. In an electrochemical cell, the chemical reaction that occurs involves the transfer of electrons from one species to another.

This transfer of electrons is associated with a change in the electrical potential energy of the system, which is measured by the electromotive force (emf) of the cell.
The relationship between ΔG and the emf of an electrochemical cell is given by the following equation:
ΔG = -nFE
Where n is the number of electrons transferred during the reaction, F is the Faraday constant (96,485 C/mol), and E is the emf of the cell. The negative sign in the equation indicates that the change in Gibbs free energy is inversely proportional to the emf of the cell.

This means that as the emf of the cell increases, the magnitude of ΔG decreases.
The equation also shows that the relationship between ΔG and the emf of an electrochemical cell is dependent on the number of electrons transferred during the reaction.

This means that the magnitude of ΔG is proportional to the number of electrons transferred. Additionally, the equation shows that the relationship is dependent on the Faraday constant, which is a constant that relates the number of coulombs of charge to the number of moles of electrons transferred.
In summary, the relationship between the change in Gibbs free energy and the emf of an electrochemical cell is given by the equation ΔG = -nFE.

The equation shows that the magnitude of ΔG is inversely proportional to the emf of the cell and is dependent on the number of electrons transferred during the reaction and the Faraday constant.

For more such questions on electrochemical cell

https://brainly.com/question/28498981

#SPJ11

The answer to the first question is E) an element. The answer to the second question is C) 0.50 L. The answer to the third question is A) Silver fluoride.

A substance is a material that has a fixed composition and set of properties, and can not be separated into simpler components by physical means. It can be a pure chemical element such as iron or a compound made up of two or more elements combined in a fixed ratio, such as water (H2O). Substances can exist as solids, liquids, or gases and can be characterized by their chemical and physical properties, such as density, melting point, and boiling point. A substance is a material that has a fixed composition and set of properties, and can not be separated into simpler components by physical means. It can be a pure chemical element such as iron or a compound made up of two or more elements combined in a fixed ratio, such as water (H2O).

Learn more about Substances:

brainly.com/question/24372098

#SPJ4

The mass of iron should be produced if 11. 0g of aluminum reacts with 30. 0g of iron (III) oxide is 10.50 g.

To determine the mass of iron produced, we need to use stoichiometry and the balanced chemical equation for the reaction between aluminum and iron(III) oxide.

The balanced chemical equation is:

2 Al + \(Fe_{2} O_{3}\) →  + 2 Fe

From the equation, we can see that 2 moles of aluminum react with 1 mole of iron(III) oxide to produce 1 mole of iron.

First, we need to determine the limiting reactant by comparing the number of moles of aluminum and iron(III) oxide.

Moles of aluminum = mass of aluminum / molar mass of aluminum

= 11.0 g / 26.98 g/mol (molar mass of aluminum)

= 0.407 mol

Moles of iron(III) oxide = mass of iron(III) oxide / molar mass of iron(III) oxide

= 30.0 g / 159.69 g/mol (molar mass of iron(III) oxide)

= 0.188 mol

Since the stoichiometric ratio of aluminum to iron(III) oxide is 2:1, we can see that 0.188 mol of iron(III) oxide requires 0.376 mol of aluminum. However, we have only 0.407 mol of aluminum, which is in excess.

Therefore, the limiting reactant is iron(III) oxide. The amount of iron produced is determined by the moles of iron(III) oxide used. Moles of iron = 0.188 mol (same as moles of iron(III) oxide)

Now we can calculate the mass of iron produced using its molar mass (55.85 g/mol):

Mass of iron = Moles of iron × Molar mass of iron

= 0.188 mol × 55.85 g/mol

= 10.50 g

Therefore, the mass of iron produced is approximately 10.50 grams.

Know more about the Balanced chemical equation here:

https://brainly.com/question/13451900

#SPJ8

Answer:

The Answer is ground or air

To find the final temperature at thermal equilibrium, we can use the principle of conservation of energy. The heat lost by gold is equal to the heat gained by water. The heat lost by gold can be calculated using the formula: q = m * c * ∆T, where q is the heat lost, m is the mass of gold, c is the specific heat capacity of gold, and ∆T is the change in temperature.

The heat gained by water can be calculated using the same formula, but with the mass and specific heat capacity of water.Setting these two equations equal to each other, we can solve for the final temperature.

Using the given values:
m(gold) = 31.5 g
m(water) = 63.3 g
c(gold) = 0.128 J/(g⋅∘C)
c(water) = 4.18 J/(g⋅∘C)
∆T(gold) = T(final) - 69.9 ∘C
∆T(water) = 26.9 ∘C - T(final)
Solving the equation gives the final temperature of both substances at thermal equilibrium.

To know more about equilibrium visit:-

https://brainly.com/question/30694482

#SPJ11

Answer:

has two double C-C bonds

Explanation:

A saturated compound is a compound having the full complement of hydrogen atoms for every carbon atom while an unsaturated compound does not contain the full complement of hydrogen atoms for every atom of carbon.

If we look at C3H4, the only possible structure of the compound is H2C=C=CH2. We can see from this arrangement that the compound contains a cumulative double bond. This is the specific structure that fits into one of the descriptions in the options, the compound contains two double bonds.

1) Which element is oxidized

Oxidation numbers

I2: 0

ClO3-: for Cl +5 and for O is -2

IO3-: for I is +5 and for O -2

Cl-: -1.

According to the oxidation number

a. Iodine (I) has been oxidized. It changed from 0 to +5.

b. Chlorine has been reduced. It changed from +5 to -1

2) reducing agent and oxidizing agent

c. A reducing agent donates electrons. In the reaction, Iodine is the reducing agent.

d. An oxidizing agent accepts electrons. In the reaction, Chlñorine is the oxidizing agent.

3) Balancing the chemical equation

Step 1: break the reaction into two half-reactions.

Oxidation half-reaction

Reduction half-reaction

Step 2: balance all elements EXCEPT for hydrogen and oxygen

Oxidation half-reaction

Reduction half-reaction

Step 3: Balance OXYGEN. We do so by adding water molecules to the half-reactions as needed.

Oxidation half-reaction

Reduction half-reaction

Step 4: Balance HYDROGEN. We do so by adding protons (H+) to the half-reactions as needed.

Oxidation half-reaction

Reduction half-reaction

Step 5: Balance CHARGES. We do so by adding electrons

Oxidation half-reaction

Reduction half-reaction

Step 6: Multiply each half-reaction in such a way we can cancel the electrons.

Oxidation half-reaction

New oxidation half-reaction

Reduction half-reaction

New reduction half-reaction

Step 7: combine the half-reactions. We have 30e in the reactants and 30e in the products. We can cancel them and combine the remaining species.

New oxidation half-reaction

New reduction half-reaction

Overall reaction

Step 8: Balance the reaction by reducing the number of water molecules and protons.

Overall reaction

e. Balance the reaction

.

Answer:

H₂CO₃

Explanation:

Water + Carbon di oxide

H20+ CO2

= H2CO3

Answer:

the agriculture sector is an industrial facility that releases nitrous oxide

Explanation:

Answer: Hello!

Agriculture sector. The agriculture sector dominates emissions of N2O: emissions from agricultural soils in 2019 account for 55% of total UK emissions, and other agricultural sources add another 12%.

Explanation:

Feel Free to ask me anything if questions. Mark me brainest please. Hope I helped! Hope you make an 100%

-Anna♥

The number of amount of moles contained in 7.90 grams of carbon is 0.66 moles.

Mole is the base unit of amount of substance i.e. the amount of substance of a system which contains exactly 6.02214076 × 10²³ elementary entities.

The number of moles in a substance can be calculated by dividing the mass of the substance by its molar mass as follows:

no of moles = mass ÷ molar mass

According to this question, 7.90g of carbon is given.

molar mass of carbon is 12g/mol

moles = 7.90g ÷ 12g/mol

moles = 0.66 moles

Learn more about moles at; https://brainly.com/question/26416088

#SPJ1

To calculate the amount of silver that will precipitate, we need to use Faraday's laws of electrolysis, which relate the substance produced or consumed in a cell to the amount of electric charge passed through it.

The first law of electrolysis states that the amount of substance produced or consumed in an electrolytic cell is proportional to the amount of electric charge passed through the cell. The proportionality constant is known as the Faraday constant, which is equal to 96,485 coulombs per mole of electrons.

The second law of electrolysis states that the amount of different substances produced or consumed in an electrolytic cell is proportional to their respective chemical equivalents.

In this problem, the substance being produced is silver, which has a chemical equivalent of 1 (i.e., one mole of electrons produces one mole of silver). The electric charge passed through the cell can be calculated as follows:

electric charge = current x time

electric charge = 5 A x 2.5 hours x 3600 s/hour

electric charge = 45,000 C

The amount of silver that will precipitate can be calculated using the first law of electrolysis and the Faraday constant:

moles of silver = electric charge / Faraday constant

moles of silver = 45,000 C / 96,485 C/mol

moles of silver = 0.467 mol

To convert moles of silver to mass, we need to know the molar mass of silver. The molar mass of silver is 107.87 g/mol. One teaspoon is approximately 5 mL.

mass of silver = moles of silver x molar mass

mass of silver = 0.467 mol x 107.87 g/mol

mass of silver = 50.4 g

number of teaspoons = mass of silver / (density of silver x volume of teaspoon)

Assuming the density of silver is 10.5 g/mL, we get:

number of teaspoons = 50.4 g / (10.5 g/mL x 5 mL)

number of teaspoons = 0.96 teaspoon

Therefore, approximately 0.96 teaspoons of silver will precipitate.

To learn about precipitation further, visit:

https://brainly.com/question/29762381

#SPJ1

Based on effective collision, in order for a reaction to occur, molecules must collide at a high enough energy to break bonds.

Effective collision are collision between reactant particles which result in the formation of product from reactant molecules.

For effective collisions to occur, the reactant molecules must possess a minimum amount of energy known as activation energy which is required  to break the bonds present in the reactant molecules.

Therefore, in order for a reaction to occur, molecules must collide at a high enough energy to break bonds.

Learn more about effective collisions at: https://brainly.com/question/14566831

Answer:

1.) Molecules must collide at a high enough energy to break bonds.

2.) the minimum amount of energy required to break bonds and start a chemical reaction

3.) Which change can encourage a reaction? adding heat

4.) More energy is released when forming the bonds of the products because a lot of heat is given off, which indicates energy was released.

5.) Two H–H bonds are broken, one O=O bond is broken, and four H–O bonds are

formed.Explanation:

^^ (be carefull with the last question, the answers look very similar)

A heterogeneous mixture is not uniform in composition. Hence, option C is correct.

A heterogeneous mixture is a mixture in which the composition is not uniform throughout the mixture.

This substance is not an element or compound, because different components could be observed in the substance.  

A pure substance is made up of only one type of atom (element) or only one type of molecule (compound), mixtures and solutions are made from two or more types of pure substances.

For example, aluminium is an element and ammonia is a compound.

This substance is not a homogeneous mixture, because different samples of the substance appeared to have different proportions of the components.

Hence, this substance is a heterogeneous mixture.

Learn more about the heterogeneous mixture here:

https://brainly.com/question/11315552

#SPJ1

Answer:

heterogeneous mixture

Explanation:

Answer:

use the pH equation :

pH: -log [H+]

pH: -log 1×10^-11

pH: 11.00

the pH of the solution is 11.00 and the solution is basic.

and make sure to remember :pH does not have a value .

a solution merely has pH(11.00)

Answer:

compound

Explanation:

There are 8.59 × 10^22 formula units in 24.65 g CaCl2.

The formula unit for CaCl2 is CaCl2, which indicates that there are one Ca and two Cl atoms bonded together. The number of formula units in 24.65 g of CaCl2 can be calculated using the mole-mass relationship. Since the molecular weight of CaCl2 is 111 g/mol, the number of moles of CaCl2 in 24.65 g is given by: 0.143 mol CaCl2

The number of formula units of CaCl2 can be calculated using Avogadro's number (6.022 × 10^23 formula units/mol).

6.022 × 10^23 formula units/mol = 1 molCaCl2 X formula units /mol × 0.143 mol CaCl2 = 0.859 × 10^23 formula units. Therefore, there are 8.59 × 10^22 formula units in 24.65 g CaCl2.

For more such questions on moles, click on:

https://brainly.com/question/29367909

#SPJ11

Answer:

Exposure to oxygen (especially when combined with sunlight) alters the molecular structure of lignin, causing a change in how the compound absorbs and reflects light, resulting in the substance containing oxidized lignin turning a yellow-brown color in the human visual spectrum.

The initial electric force acting on each charge due to the other charge is F = (1/4πε) * (q1q2 / r²)= (1/4π(8.85 × 10⁻¹² C² N⁻¹ m⁻²)) * (-6 × 10⁻⁶ C)² / (0.003 m)²= -5.94 × 10⁻² N = -0.0594 N .  The path of the charge is a hyperbola.

Given that two identical and isolated charges, X and Y, of −6μC each, initially at rest in a vacuum.

The initial separation of the two charges is 3.0 mm and they subsequently move apart in the directions shown. To find (a) the initial electric force acting on each charge due to the other charge, and (b) to discuss the motion of one of the two charges after it begins to move.

(a) The initial electric force acting on each charge due to the other charge is given by Coulomb's law, that is F = (1/4πε) * (q1q2 / r²),

where q1 and q2 are the charges,

r is the separation distance and

ε is the permittivity of free space.

Here q1 = q2 = -6μC, r = 3 mm = 0.003 m and ε = 8.85 × 10⁻¹² C² N⁻¹ m⁻²So, the initial electric force acting on each charge due to the other charge is

F = (1/4πε) * (q1q2 / r²)= (1/4π(8.85 × 10⁻¹² C² N⁻¹ m⁻²)) * (-6 × 10⁻⁶ C)² / (0.003 m)²= -5.94 × 10⁻² N = -0.0594 N (repulsive force

)(b) When one of the charges begins to move, its kinetic energy increases and it experiences a decrease in potential energy. Thus, its total energy remains constant. Hence, the charge moves away from the other charge with a constant speed. The direction of the velocity vector is along the straight line that joins the charges, and the acceleration vector is perpendicular to it. The path of the charge is a hyperbola.

To know more about electric force, visit:

https://brainly.com/question/20935307

#SPJ11

Answer: .04544 or 4.544 x 10^-2

Explanation: Simply divide 923.0 by 20312. Use 4 significant figures because it is the least amount of significant figures present in your calculation.

The answer for the given equation in significant figures is 0.045.

The number of digits in a value, often a standard measure, that make a contribution to the precision of the value is referred to as significant figures. The first non-zero digit is used to begin counting significant figures.

All zeros to the right and left of a decimal point are never significant. For example, the number 0.00798 had three significant digits.

In the given equation, let us assume the number is X.

X = 923.0/20312

X = 0.0454.

Thus, the answer is 0.045.

For more details regarding significant figures, visit:

https://brainly.com/question/14359464

#SPJ1

Explanation:

1.False

2.False

3.True

4.True

5.False