what is the ph of a solution in which [ha] = 2[a–] and the pka of ha is 5.5? (tip: use henderson-hasselbalch equation)

To calculate the remaining amount of a cobalt-60 sample after 20 years, we can use the formula for radioactive decay:N = N₀ * (1/2)^(t / t(1/2)). Hence remaining amount of the cobalt-60 sample after 20 years is approximately 0.1891 times the initial amount

Given that the half-life of cobalt-60 is 5.27 years, we can substitute the values into the formula:

N = N₀ * (1/2)^(20 / 5.27)

Simplifying the equation:

N = N₀ * (1/2)^(3.7941)

Calculating the value inside the parentheses:

(1/2)^(3.7941) ≈ 0.1891

Now, multiplying the initial amount N₀ by the calculated value:

N = N₀ * 0.1891

Therefore, the remaining amount of the cobalt-60 radioactive isotope sample after 20 years is approximately 0.1891 times the initial amount. Please provide the unit symbol for the initial amount, and you can multiply it by the calculated value to obtain the unit symbol for the remaining amount.

Learn more about radioactive isotope here: brainly.com/question/28039996

#SPJ11

Complete question:

cobalt-60 is radioactive and has a half-life of 5.27 years. how much of a sample would be left after 20 years? round your answer to significant digits. also, be sure your answer has a unit symbol.

Answer:

Amplification

Explanation:

No, diatomic elements cannot exist as single atoms.

Diatomic elements are those that naturally occur as a molecule of two atoms of the same element, such as oxygen (O2), nitrogen (N2), and hydrogen (H2). These elements are chemically stable in their diatomic form and have strong covalent bonds that keep the atoms together.

It is thermodynamically unfavorable for diatomic elements to exist as single atoms, as the energy required to break the covalent bond is very high. Therefore, diatomic elements will always exist as a molecule of two atoms. This can be observed in their physical and chemical properties, which are unique to the diatomic form of the element.

Overall, diatomic elements are a unique class of elements that exist naturally as molecules of two atoms. It is not possible for them to exist as a single atom due to their strong covalent bond.

For more such questions on diatomic elements

https://brainly.com/question/30188486

#SPJ11

The outer shell (the outermost shell) of Na there is 1 electron while in F there are 7 electrons

Given

Sodium and Fluorine

Required

The outer shell difference

Solution

Sodium (symbol Na) is an element in group 1 (alkaline) which has the atomic number 11

So the electron configuration is: [Ne] 3s¹

Meanwhile, Fluorine (symbol F) is a halogen element (group 17) which has atomic number 9

So the electron configuration is: [He] 2s² 2p⁵

If we look at the electron configurations of these two elements, it shows that the element Na to achieve its stability will release 1 electron in the outer shell so that it has an electron configuration like Ne

Meanwhile, Fluorine will need 1 more electron so it can be stable like Ne

So in the outer shell of Na there is 1 electron while in F there are 7 electrons

Answer: 110 g/mol

Explanation:

First we need to find the molar mass of CaCl2 using the periodic table:

Ca: 40

Cl: 35 (Since Cl has a 2 at the end, multiply 35 by 2)

70+40= 110

Then multiply by amount of moles

110g×1.000mol = 110 g/mol

Answer:

Magnetized objects move in the direction that reduces their magnetic potential energy. This is no different than the skate park.

Explanation:

To prepare 0.194 M potassium acetate, add 2.379895 g of potassium acetate to a 125 mL volumetric flask and fill with water to the mark.

Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution.

The following data were obtained from the question:

Molarity of potassium acetate = 0.194 M

Volume of solution = 125 mL

Mass of potassium acetate =?

Next, we shall convert 125 mL to L. This can be obtained as follow:

1000 mL = 1 L

Therefore,

125 mL = 0.125 L

Thus, 125 mL is equivalent to 0.125 L.

Next, we shall determine the number of moles of potassium acetate in the solution. This can be obtained as follow:

Molarity of potassium acetate = 0.194 M

Volume of solution = 0.125 L

Moles of potassium acetate =?

Molarity = \(\frac{mole}{Volume}\)

Cross multiply

Mole of potassium acetate = 0.194 M × 0.125

Mole of potassium acetate = 0.02425 mole

Finally, we shall determine the mass of potassium acetate

Molar mass of potassium acetate= 98.14 g/mol

Mass of potassium acetate =?

Mole = \(\frac{mass}{Molar mass}\)

Mass of potassium acetate =0.02425  × 98.14

Mass of potassium acetate = 2.379895 g

Thus, to prepare 0.194 M potassium acetate, add 2.379895 g of potassium acetate to a 125 mL volumetric flask and fill with water to the mark.

Learn more about molarity here:

https://brainly.com/question/20713567

#SPJ1

Its is true that light from an unshaded bulb radiates in all directions

A 67.0 ml portion of a 1.30 m solution is diluted to a total volume of 238 ml. a 119 ml portion of that solution is diluted by adding 189 ml of water.  The final concentration is  0.2304 M

Concentration is calculated by dividing a constituent's abundance by the combination as a whole. The qualities of mass awareness, molar awareness, amount attention, and volume focus can all be found in exceptional mathematical formulations.

M₁V₁=M₂V₂ where M is concentration and V is volume

M₁ =1.30 M

V₁ = 67 ml = 0.067 L

M₂ = ?

V₂ = 238 ml = 0.238 L

M₁V₁=M₂V₂

M₂ = M₁V₁ / V₂

   = 1.30 × 0.067 / 0.238

   = 0.3659 M

New volume V₁ = 119 ml = 0.119 L

                   V₂ = 0.189 L

M₁  = 0.3659 M

M₂ =  M₁V₁ / V₂

   = 0.3659 ×0.119 /0.189

    = 0.2304 M

Learn more about final concentration here: brainly.com/question/13184071

#SPJ4

Answer:

i think its both objects have to have mass

Matter are anything that is made up of atoms. The quantity of matter can be observed only on the basis of mass and volume calculation. Therefore, the correct option is option D.

Matter is a substance that has some mass and can occupy some volume. The matter is mainly used in science. Matter can be solid, liquid or gas.

Matter is anything that is made up of atoms. Anything around us that can be physically seen and touched are matter. Ice, water and water vapors are example of matter.

So as we saw that matter has some mass so mass can be measured in gram only. Mass can also be represented as number of molecules. We also saw that matter occupy some volume and that volume is measured only in liter. For a gravitational field to be generated between two objects, Both objects must have mass.

Therefore, the correct option is option D.

To learn more about matter, here:

https://brainly.com/question/4562319

#SPJ2

Biosphere, ecosystem, community, population, species is the correct order of organizational level within an ecosystem.

Biosphere is the arrangement of the biological organisms has relation with each other.

More complex system of relationships are seen when bottom to top movement occurs.

Individual organisms are in the first level. This system is concerned with the biological, morphological and the physiological development of the organism with respect to the response to the environment.

In the second level it has populations, means a group. Then is the ecosystem, here the non-living components are also present.

Biosphere is in this phase and everything in the earth is present in it, along with their interactions.

To learn more about biosphere,

brainly.com/question/13552922

#SPJ1

2 C4H10 + 13 O2 → 8 CO2 + 10 H2O.

Answer:

  72.8 liters (see comment below)

Explanation:

You want the volume of CO₂ at STP resulting from the decomposition of 3.25 moles of CaCO₃.

The balanced reaction is ...

  CaCO₃(s) + heat ⇒ CaO(s) + CO₂(g)

This tells you that 3.25 moles of CaCO₃ will evolve 3.25 moles of CO₂ gas.

At STP, each mole of gas has a volume of 22.4 liters. The volume of CO₂ produced is ...

  (3.25 mol) × (22.4 L/mol) ≈ 72.8 L

At STP, the volume of gas produced is 72.8 liters.

__

Additional comment

After 1982, the IUPAC defined STP as 0 °C, 100 kPa, so one mole of gas occupies 22.711 liters. If this is the value of STP you're to use, then the appropriate answer is ...

  (3.25 mol) × (22.711 L/mol) ≈ 73.8 L

Prior to 1982, IUPAC standard pressure was 1 atm, or 101.325 kPa. At that pressure the volume of one mole is 22.414 liters. Many authors continue to use this definition of STP, so that is the value we have used in the answer above.

We have rounded the volume to 3 significant figures, in accordance with the precision of the given amount of material.

If the natural abundance of chlorine-35 is 75.8% and that of chlorine-37 is 24.2%, then the average atomic mass of chlorine will be 35.44 amu.

Chlorine exists in two isomeric forms which are the chlorine-35 and chlorine-37. The atomic mass of the chlorine elements is basically the average atomic mass of its isotopes depending upon their abundance in nature.

The atomic mass of chlorine-35 is 34.97amu and a natural abundance equal to 75.8 %. The atomic mass of chlorine-37 is equal to 36.97 amu with an abundance of 24.2%.

To calculate the average atomic mass of chlorine,

The abundance of chlorine-35 = 75.8% = 0.758

The abundance of chlorine-37 = 24.2% = 0.242

⇒ Average atomic mass = 34.97 × 0.758 + 36.97 × 0.242

⇒ Average atomic mass = 26.50 + 8.94

⇒ Average atomic mass = 35.44 amu  

To know more about chlorine here

https://brainly.com/question/11008051

#SPJ4

Answer:

Rubidium

Explanation:

Add the exponents: 2+2+6+2+6+2+10+6+1=37

Look for the atomic number 37

The element having electronic configuration 1s₂, 2s₂, 2p₆, 3s₂, 3p₆, 4s₂, 3d₁₀, 4p₆, 5s₁ is rubidium .

A chemical element is a species of atoms, including the pure substance made entirely of that species, that have a specific number of protons in their nuclei. Chemical elements, in contrast to chemical compounds, cannot be reduced by any chemical process into simpler molecules.

They can be identified by their particular atomic number. The periodic table groups the elements according to their atomic number and draws attention to those with related qualities.

The most vital ingredient for life is carbon. Life as we know it would not exist without this element. You'll see that carbon is the main component of the chemicals required for life.

Thus, The element having electronic configuration 1s₂, 2s₂, 2p₆, 3s₂, 3p₆, 4s₂, 3d₁₀, 4p₆, 5s₁ is rubidium .

To learn more about an element, follow the link;

https://brainly.com/question/13025901

#SPJ2

Answer:

The heat released when the temperature of 60 g of water decreases from 75 degrees Celsius to 27 degrees Celsius is -12,049.92 J.

Explanation:

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

Sensible heat is the amount of heat that a body absorbs or releases without any changes in its physical state or phase change. Sensible heat is measured by the expression:

Q = c * m * ΔT

Where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.

In this case:

Replacing:

Q= 4.184 \(\frac{J}{g*C}\) *60 g* (-48 C)

Q= -12,049.92 J

The heat released when the temperature of 60 g of water decreases from 75 degrees Celsius to 27 degrees Celsius is -12,049.92 J.

The properties of solid NaOH that necessitate standardization of a NaOH solution are primarily its Hygroscopic nature, its tendency to react with atmospheric CO2, and its variable purity.

1. Hygroscopic nature: Solid NaOH (sodium hydroxide) has a strong affinity for water, meaning it readily absorbs moisture from the air. This can lead to changes in its mass and concentration, affecting the accuracy of a prepared NaOH solution.

2. Reaction with atmospheric CO2: Solid NaOH reacts with carbon dioxide (CO2) present in the air, forming sodium carbonate (Na2CO3). This reaction alters the composition of the NaOH, again affecting its concentration in a solution.

3. Variable purity: Commercially available NaOH often contains impurities due to the manufacturing process. These impurities can impact the effective concentration of NaOH in a solution.

To ensure accurate results in experiments, it's crucial to standardize the NaOH solution. Standardization is the process of determining the exact concentration of a solution using a primary standard, such as potassium hydrogen phthalate (KHP).

By titrating the NaOH solution with a known amount of primary standard, you can precisely calculate its concentration, accounting for any changes caused by its hygroscopic nature, reaction with atmospheric CO2, and impurities.

To Learn More About Hygroscopic

https://brainly.com/question/29493408

#SPJ11

The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition.

In scientific investigations, the effect of fertilizer on plant growth can be studied by examining various variables. Two key variables in this context are the presence or absence of fertilizer (independent variable) and the size or growth of the plant (dependent variable).

When investigating the effect of fertilizer on plant growth, the independent variable is the presence or absence of fertilizer. This variable is controlled by having two groups of plants: one group receiving fertilizer (experimental group) and another group without fertilizer (control group). By comparing the growth of these two groups, we can determine the impact of fertilizer on plant size.

The dependent variable, on the other hand, is the size or growth of the plant. This variable is measured or observed as the outcome of interest. In this case, it would be the height, weight, or overall size of the plants.

By systematically changing the independent variable (presence or absence of fertilizer), we can observe how it affects the dependent variable (plant growth). The experimental group receiving fertilizer is expected to show greater plant growth compared to the control group without fertilizer. This allows us to draw conclusions about the effect of fertilizer on plant growth.

However, it is important to note that the specific outcome may vary depending on other factors such as plant species, soil conditions, and environmental factors. Conducting a controlled experiment while considering these factors helps in obtaining more reliable results.

learn more about fertilizer here

https://brainly.com/question/14012927

#SPJ11

Option B" Removing the H₂O as it forms" would shift the equilibrium to produce the maximum possible amount of H₂O? 2H₂ + O₂2H₂O + energy

In the realm of chemistry, attaining a state of equilibrium denotes achieving balance between opposing forces - the forward and reverse reaction rates being equal. This balance guarantees that there are no changes in reactant or product concentrations as time elapses.

Despite being in a state of stasis, it's essential to remember that equilibrium remains dynamic because both reactions continue consistently.

Learn about equilibrium here https://brainly.com/question/517289

#SPJ1

Answer:

A conditioned stimulus is a stimulus that can eventually trigger a conditioned response. In the described experiment, the conditioned stimulus was the ringing of the bell, and the conditioned response was salivation. It is important to note that the neutral stimulus becomes the conditioned stimulus

Explanation:

˙˚ʚ(´◡`)ɞ˚˙

The correct answer is b. more info is needed.
For the reaction 2 NO(g) ⇌ \(N_2(g) + O_2(g),\); Heat change= ?: with a decrease in temperature the effect on the concentration of [\(O_2\)] can not be determined as it is not given whether the heat is released or absorbed.

To determine the effect on the concentration of \(O_2\), we'll apply Le Chatelier's principle. The principle states that if a system at equilibrium is subjected to a change in temperature, pressure, or concentration of a component, the system will adjust to counteract that change and re-establish equilibrium.

Since the reaction is exothermic (releases heat) or endothermic this can not be said unless we have the value of heat change we can not determine the effect of change in temperature on the concentration of oxygen gas.

Therefore, to determine the effect on the concentration of \(O_2\):

b. more information is needed.

Learn more about Le Chatelier's principle here: https://brainly.com/question/29009512

#SPJ11

Answer:

The pressure in atm is 6.04 x 10^-3

Explanation:

Pressure of the gas is defined as the force exerted by the particles on the walls of the container. It is expressed in various terms like 'mmHg', 'atm', 'kiloPascals' etc..

All these units of pressure are inter convertible.

Pressure of the gas = 4.59 mm Hg

760 mm Hg = 1 atm

4.59 mm Hg= 1/760 x 4.59 = 6.04 x 10^-3atm

The pressure in atm is 6.04 x 10^-3

salat tarawih itu boleh dilakukan di masjis

Answer and Explanation:

The freezing point of Titanium is 1668 C or 3034.4 F...

The freezing point of Titanium (Ti) is 1668°C.

Titanium is a chemical element. The symbol of titanium is Ti. Atomic number of Ti is 22. Electronic configuration of Titanium is [Ar] 3d² 4s².

The temperature of a liquid which changes its state and becomes a solid is called as Freezing point. The freezing point of Titanium is 1668°C.

Thus from the above conclusion we can say that The freezing point of Titanium (Ti) is 1668°C.

Learn more about the Freezing point here: https://brainly.com/question/17048792

#SPJ2

Answer:

becoz vvv is always with you

Answer:

Alkali metals have one valence electron on their outer shell. They are more stable when they have eight valence electrons so they tend to loose that one electron and obtain a full octet, therefore become stable

A typical IR spectrum displays peaks between 3600 and 500 cm-1, allowing us to link particular peaks to particular functional groups.

A specific range characteristic of each type of compound is assigned the value of the C=O. stretching wavenumber to execute the analysis. Therefore, it is believed that ketones exist between 1715 and 1740 cm-1, while simple esters are found between 1740 and 1760 cm-1, which is 20 to 30 cm-1 higher.

Aldehydes and ketones exhibit a strong, distinct band in the shape of a stake between 1710 and 1720 cm-1 (right in the middle of the spectrum).

To know more about spectrum visit:-

https://brainly.com/question/3997802

#SPJ4

Answer:

1.a member of carbon family  with 14 eletrons is silicon

2.halide which is liquid at room temperature is bromine

3.transition metal with 79 electrons/protons and neutron 80 for me Is Gold

The heat of reaction when 44.4 ml of 1.3M nitric acid reacts with 51.5 ml of 0.6M sodium hydroxide is equal to 1.66 KJ.

A neutralization reaction is a chemical reaction in which an acid and base react with each other to generate salt and water. The acidic strength of the reactant (strong acid) will give the pH of the neutralized solution.

HCl    +    NaOH →   NaCl   +   H₂O

Given, the nitric acid, V = 44.4 ml and concentration = 1.3 M

The sodium hydroxide, V = 51.5 ml and concentration = 0.6 M

The number of moles of nitric acid = 44.4 × 1.3 = 57.59 mmol

The number of moles of sodium hydroxide = 51.5 × 0.6 = 30.9 mmol

Here sodium hydroxide is the limiting reagent.

The heat of reaction for one mole = 53.7 KJ

Then for 30.9 mmol, the heat of reaction = (30.9/1000) ×53.7 = 1.66 KJ

Learn more about neutralization reaction, here:

brainly.com/question/20038776

#SPJ1