once you have extracted caffeine, how will you confirm that it is caffeine? how will you test the purity of your caffeine? select three techniques to characterize your substance and describe what information each technique can provide you.

The statement that must be true of a spontaneous process is C) entropy of the universe increases as heat is generated.

In thermodynamics, a spontaneous process is one that occurs on its own without any external intervention or help. The Second Law of Thermodynamics states that entropy, a measure of disorder and randomness, must increase for a spontaneous process to occur. This means that the entropy of the universe must increase, as entropy of the system and its surroundings could both increase, decrease, or stay the same.

In terms of enthalpy, which is the energy required to bring the system to its initial state, it could increase, decrease, or stay the same, depending on the process. The flow of heat is related to entropy, as a change in entropy is accompanied by a flow of heat. This means that in a spontaneous process, there must be a flow of heat, but it doesn’t necessarily have to be from the system to the surroundings.

To summarize, for a spontaneous process to occur, entropy of the universe must increase and the flow of heat must be present, but the enthalpy of the system can remain the same, increase, or decrease, depending on the process.

To learn more about spontaneous, click here:

https://brainly.com/question/5372689

#SPJ11

To create 100ml of a 4% w/v stock solution, how many grams of neutral red would your IA have to use? It is 4 gm.

Let's calculate this in detail:

To make 100 ml of 4% w/v stock solution of Neutral Red dye, the quantity of Neutral Red that must be used can be calculated as follows:

Weight of Neutral Red = (Volume x Concentration x 10^4) / 100

Weight of Neutral Red = (100 x 4 x 10^4) / 100

Weight of Neutral Red = 4000 mg = 4 gm

Therefore, to create 100 ml of a 4% w/v stock solution of Neutral Red dye, 4 gm of Neutral Red must be used. Hence, the correct answer is 4 gm.

Learn more about solutions: What is meant by concentration of a solution​? https://brainly.com/question/17206790

#SPJ11

If 0.0200 m fe3 is initially mixed with 1.00 m oxalate ion, then concentration of Fe3+ ion at equilibrium is 0 M.

The balanced chemical equation for the reaction of Fe3+ ion and oxalate ion is:

Fe3+ + 3C2O42- -> Fe(C2O4)33-

The reaction quotient, Qc, for the above reaction is given by the expression:

Qc = [Fe(C2O4)33-]/[Fe3+][C2O42-]

Here, the initial concentration of Fe3+ ion

= 0.0200 m

And, the initial concentration of oxalate ion is 1.00 m . According to the stoichiometry of the balanced equation, 1 mole of Fe3+ ion reacts with 3 moles of C2O42- ions to form 1 mole of Fe(C2O4)33- complex ion. Hence, the concentration of C2O42- ion that reacts with the given initial concentration of Fe3+ ion is given by the expression: [C2O42-] = 3[Fe3+] = 3 x 0.0200 m = 0.0600 m. After the reaction comes to equilibrium, let the concentration of Fe3+ ion be x M.Now, [Fe(C2O4)33-] = 0 M (as the entire Fe3+ ion is converted into Fe(C2O4)33- complex ion)Substituting the given and calculated values in the expression for Qc, we get:

Kc = [Fe(C2O4)33-]/[Fe3+][C2O42-]

=> 0/[x][0.0600]

=> 0x

=> 0 M

To learn more about Equilibrium :

https://brainly.com/question/19340344

#SPJ11

a) The electron pair geometry of the compound with a sulfur atom double bonded to an oxygen atom on the left and the right and has a lone pair is tetrahedral, whereas its molecular geometry is bent. Each oxygen atom has two lone pairs.b) The electron pair geometry of the compound with a sulfur atom bonded to a chlorine atom on the left and the

right and has two lone pairs is tetrahedral, whereas its molecular geometry is bent. Each chlorine atom has three lone pairs.c) The electron pair geometry of the compound with a beryllium atom bonded to two chlorine atoms 180 degrees

apart, each chlorine atom having three lone pairs, is linear. Its molecular geometry is also linear.d) The electron pair geometry of the compound with a phosphorous atom bonded to a fluorine atom on the left, the right, and the bottom,

and has one lone pair is tetrahedral. Its molecular geometry is trigonal pyramidal. Each fluorine atom has three lone pairs.e) The electron pair geometry of the compound with a boron atom bonded to a fluorine atom on the left, the right, and the bottom, and each fluorine atom having three lone pairs is trigonal planar. Its molecular geometry is also trigonal planar.f) The electron pair geometry of the compound with a carbon atom bonded to a hydrogen atom on the left, the right, the top, and the bottom is tetrahedral. Its molecular geometry is also tetrahedral. The bond angle between the carbon and hydrogen atoms is 109.5 degrees.

The electron pair geometry of each compound is determined by its molecular geometry, which depends on the number of bonds and lone pairs of electrons around the central atom. When there are two bonded atoms and no lone pairs, the molecular geometry is linear. When there are three bonded atoms and no lone pairs, the molecular geometry is trigonal planar. When there are two bonded atoms and one lone pair, the molecular geometry is bent or angular. When there are four bonded atoms and no lone pairs, the molecular geometry is tetrahedral. When there are three bonded atoms and one lone pair, the molecular geometry is trigonal pyramidal.

For more similar questions on topic Indicate the el

https://brainly.com/question/29470595

#SPJ11

The electron pair geometry of all six compounds is tetrahedral, while the molecular geometry of (b), (d), and (e) is trigonal planar, and the molecular geometry of (a), (c), and (f) is tetrahedral.

On the other hand, molecular geometry refers to the actual arrangement of atoms in space.

a) In the case of sulfur dioxide the electron pair geometry is trigonal planar because the sulfur atom has three electron pairs and one lone pair, resulting in a bent or V-shaped molecular geometry.

b) For sulfur trichloride, the electron pair geometry is tetrahedral because the sulfur atom has four electron pairs and one lone pair, resulting in a trigonal pyramidal molecular geometry.

c) In beryllium chloride the electron pair geometry is linear because the central atom has only two electron pairs and no lone pairs, resulting in a linear molecular geometry.

d) For phosphorus trifluoride, the electron pair geometry is tetrahedral because the central atom has four electron pairs and one lone pair, resulting in a trigonal pyramidal molecular geometry.

e) In boron trifluoride, the electron pair geometry is trigonal planar because the central atom has only three electron pairs and no lone pairs, resulting in a trigonal planar molecular geometry.

f) Finally, for methane, the electron pair geometry is tetrahedral because the central atom has four electron pairs and no lone pairs, resulting in a tetrahedral molecular geometry.

Learn more about  electron pair geometry

https://brainly.com/question/24232047

#SPJ4

The remaining radioactivity after one day will be 0.0063% of the original radioactivity. This is because the half-life of a radioactive material is the amount of time it takes for half of the original radioactivity to decay. So, after one day, the original radioactivity will have decayed to 0.0063%.

The process through which an unstable atomic nucleus loses energy through radiation is known as radioactive decay, also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration. A substance that has unstable nuclei is regarded as radioactive. Alpha decay, beta decay, and gamma decay are three of the most frequent kinds of decay, and they all entail the emission of one or more particles. Beta decay is a result of the weak force, while the nuclear force and electromagnetism are in charge of the other two mechanisms.  Electron capture, which occurs when an unstable nucleus seizes an inner electron from one of the electron shells, is the fourth prevalent kind of decay. A series of electrons drop as a result of that electron being lost from the shell.

At the level of individual atoms, radioactive decay is a stochastic (i.e. random) process. No matter how long an atom has existed, quantum theory says it is impossible to forecast when an atom will decay. Nonetheless, the overall decay rate can be stated as a half-life or as a decay constant for a sizable number of similar atoms. There is a wide variation in the half-lives of radioactive atoms, from almost instantaneous to much longer than the age of the universe.

The remaining radioactivity after one day will be 0.0063% of the original radioactivity. This is because the half-life of a radioactive material is the amount of time it takes for half of the original radioactivity to decay.

1/2^(24/20) = 0.0063%.

Therefore, after one day, the original radioactivity will have decayed to 0.0063%.

For more such questions on radioactivity , Visit:

https://brainly.com/question/23959901

#SPJ11

Einstein's famous equation say that all matter is option B. concentrated energy that has condensed into the atoms.

When combined with the speed of light, Einstein's famous equation E=mc2 demonstrates mathematically that energy and matter are one and the same. m stands for mass, c for the speed of light, and E stands for energy. This equation states that all matter is simply concentrated energy that has condensed into atoms.

Einstein's famous equation is E=mc², which expresses the relationship between mass (m) and energy (E), and the constant speed of light (c) in a vacuum. This equation shows that mass and energy are interchangeable, and that a small amount of mass can be converted into a large amount of energy, as demonstrated in nuclear reactions.

Learn more about Einstein at:

https://brainly.com/question/26366397

#SPJ1

The most likely identity of the unknown gas that effuses taking 37s is Oxygen(O₂).

Since the unknown gas effuses out faster, it must be lighter than Xe.

The most likely identity of the unknown gas can be determined using Graham's Law of Diffusion. According to this, the time taken for effusion/diffusion of two different gases under identical conditions is directly proportional to the square roots of their densities or molecular masses. It is given as:

t₂/t₁ = √(M₂/M₁)

where t₂,t₁ are the times taken and M₂, M₁ are the molecular masses.

This ratio is determined by the ratio of the molecular weights of the unknown gas and the sample of Xe. The heavier the molecular weight, the slower the rate of effusion.

Rearranging and plugging in the values as t₂= 75s, t₁= 37s,  M₁= 131g (for Xe), we get M₂ as follows:

M₂= (37/75)² x 131 = 31.8 ≈ 32g

32g corresponds to the molecular weight of O₂ and it is lighter than Xe.

Therefore, the unknown gas that effuses out of the container faster than the sample of Xe, resulting in the unknown gas taking 37 seconds, and the sample of Xe taking 75 seconds is oxygen(O₂).

To know more about effusion, refer here:

https://brainly.com/question/2655041#

#SPJ11

The compound in which the oxidation state of oxygen is -1 is H2SO4, also known as sulfuric acid.

It is an inorganic, strong acid that has two hydrogen atoms, one sulfur atom, and four oxygen atoms. The oxidation state of oxygen in this compound is -1 because it has been oxidized by the sulfur atom, which has an oxidation state of +6.

The other compounds listed (KCH3COO, O2, H2O2, and H2O) do not have an oxidation state of -1 for oxygen. KCH3COO is potassium acetate, which has two oxygen atoms with oxidation states of -2 and +4, respectively. O2 is oxygen gas, which has an oxidation state of 0. H2O2 is hydrogen peroxide, which has two oxygen atoms with oxidation states of -1 and -1, respectively. Lastly, H2O is water, which has two hydrogen atoms and one oxygen atom, with the oxygen atom having an oxidation state of -2.

To know more about sulphuric acid click on below link :

https://brainly.com/question/28513840#

#SPJ11

The number of moles of sodium hydroxide present in the sample, is 0.00839 moles.

To calculate the number of moles of sodium hydroxide present in a 26.80 ml sample of a 0.315 m solution, use the following equation:

Moles = concentration (M) x volume (L)

Moles = 0.315 M x 0.02680 L

Moles = 0.00839 moles of sodium hydroxide present in a 26.80 ml sample of a 0.315 m solution.

To explain this in further detail, moles are a unit of measurement for an amount of substance and are typically expressed as mol. A mole is equal to 6.02 x 10^23 atoms or molecules, and is represented by the letter 'n' or 'N'.

The concentration of a solution is a measure of the amount of solute dissolved in a given volume of solvent and is expressed in molarity (M). Volume is expressed in litres (L).

By multiplying the concentration of a solution (0.315 M) by the volume of the sample (0.02680 L).

Sodium hydroxide, also known as lye, is a highly reactive and caustic inorganic compound. It is commonly used in soap and detergent production, as well as in the paper and textile industries.

It is also used in the production of a variety of other chemicals, including pharmaceuticals and food additives.

To know more about  Sodium hydroxide refer here:

https://brainly.com/question/29327783#

#SPJ11

When reactant molecules bind to the active site, the conformational or shape change that enzymes undergo is called induced fit.

Induced fit is the change in the shape of the active site of an enzyme, caused by the binding of a substrate. Induced fit helps in the proper alignment of the substrate with the catalytic site of the enzyme. It enhances the ability of the enzyme to carry out the chemical reaction.

Induced fit is a term used in biochemistry and enzyme kinetics. It describes the process of conformational changes in an enzyme when it binds to a substrate. This change helps in the proper orientation of the enzyme and substrate for the chemical reaction to occur.

Therefore we can say that the conformational or shape change that enzymes undergo when reactant molecules bind to the active site is called "induced fit."

To learn more about enzymes refer: https://brainly.com/question/13694504

#SPJ11

The orientation of the glycosidic bond affects the properties of the polysaccharides it creates by determining the geometry of the sugar units in the polymer chain. When the glycosidic bond is in the alpha configuration, the sugar ring has a twisted conformation, which results in the sugar units being oriented in a more linear fashion.

In contrast, when the glycosidic bond is in the beta configuration, the sugar ring has a more planar conformation, which results in the sugar units being oriented in a more zig-zag fashion.

This difference in orientation affects the overall structure of the polysaccharide. Polysaccharides with alpha glycosidic bonds tend to form helical structures, while polysaccharides with beta glycosidic bonds tend to form sheet-like structures. This is because the twisted conformation of the alpha sugar units allows for the formation of hydrogen bonds between adjacent sugar units, which leads to the formation of a helix.

In contrast, the more planar conformation of the beta sugar units does not allow for the formation of hydrogen bonds between adjacent sugar units, which leads to the formation of a sheet.

Additionally, the orientation of the glycosidic bond affects the solubility and digestibility of the polysaccharide. Polysaccharides with alpha glycosidic bonds tend to be more soluble and more easily digested than polysaccharides with beta glycosidic bonds.

This is because the helical structure of alpha-polysaccharides allows for more surface area to be exposed to water and digestive enzymes, while the sheet-like structure of beta-polysaccharides does not.

Learn more about polysaccharides here:
https://brainly.com/question/30529578#



#SPJ11

The mass number of an atom is determined by the total number of protons and neutrons in its nucleus.

The mass number is always a whole number because it is the sum of the number of protons and neutrons in the nucleus, and both of these particles have a mass of approximately 1 atomic mass unit (amu). Since the mass of an electron is much smaller compared to protons and neutrons, it is not included in the calculation of the mass number.

The isotope of carbon that has the same mass number and atomic mass is carbon-12. Its atomic mass is exactly 12 amu.

The approximate mass of one proton is 1 amu.

The approximate mass of one neutron is also 1 amu.

Answer: The theoretical yield of carbon dioxide formed is therefore 2.05 mol, or approximately 183.45 g.

The theoretical yield of carbon dioxide formed from the reaction of 2.6 g hexane and oxygen gas can be determined using the balanced equation for the reaction:

2 C6H14 + 19 O2 → 12 CO2 + 14 H2O

The amount of oxygen required for the reaction is given by:

(2.6 g hexane) × (1 mol hexane/86.18 g hexane) × (19 mol O2/1 mol hexane) = 3.29 mol O2

The theoretical yield of carbon dioxide formed can then be determined by multiplying the number of moles of oxygen by the molar ratio of carbon dioxide to oxygen:

(3.29 mol O2) × (12 mol CO2/19 mol O2) = 2.05 mol CO2

The theoretical yield of carbon dioxide formed is therefore 2.05 mol, or approximately 183.45 g.


Learn more about theoretical yield here:

https://brainly.com/question/14966377#

#SPJ11

The correct formula for copper(II) phosphate is Cu3(PO4).

Copper (II) phosphate is a compound made up of copper ions and phosphate ions. Its chemical formula is Cu3(PO4)2. Copper(II) phosphate is a deep blue colour and has a high boiling point because of the strong bonds between the copper and phosphate ions.The chemical formula for copper(II) phosphate is Cu3(PO4)2.

A chemical formula is a collection of chemical symbols used to express the elements, atoms, and molecules in a chemical compound. They are a shorthand method of representing chemical compounds, and the chemical composition of molecules, elements, and atoms can be deduced from them. Chemical formulas are essential in chemistry because they provide the necessary details for reactions, such as how many atoms are present in a molecule or the number of each type of atom that is required to balance the equation.

Learn more about Copper (II) phosphate at:

https://brainly.com/question/25867932

#SPJ11

The volume of oxygen gas will it occupy when the pressure is changed to 912 torr and temperature remains constant is 2.41 L.

PV = nRT is the equation for an ideal gas. In this equation, P stands for the ideal gas's pressure, V for the ideal gas' volume, n for the total amount of the ideal gas expressed in moles, R for the universal gas constant, and T for temperature.

a formula that converts the volume and pressure of a mole of gas into its combined thermodynamic temperature and gas constant. At low pressures, the equation is a decent approximation for actual gases and is precise for an ideal gas. Also known as the ideal gas law and ideal gas equation.

According to ideal gas equation

PV = nRT

Here P is pressure, V is Volume, n is mole, R is gas constant, T is temperature

Now if T is constant the nRT term will become constant

So PV = constant

And P1V1 = P2V2

now P1 = 1156 torr        V1 = 1.9L

        P2 = 912 torr          V2 = ??

Put all values

1156 × 1.9 = 912 × V2

V2 = 2.41 L.

Learn more about Volume of gas:

https://brainly.com/question/24453878

#SPJ4

81 g of Al reacts with plenty of chlorine to form 3 moles of aluminum chloride (AlCl3).

To find the number of moles of aluminum chloride (AlCl3), we need to first calculate the number of moles of aluminum (Al) reacting with chlorine (Cl2) based on the given mass of Al.

Given: Mass of Al = 81 g; Molar mass of Al = 27 g/mol

Number of moles of Al = Mass of Al / Molar mass of Al

= 81 g / 27 g/mol

= 3 moles of Al

From the balanced chemical equation, we know that 2 moles of Al react with 3 moles of Cl2 to form 2 moles of AlCl3.

Thus, for 3 moles of Al, we need 3/2 * 3 moles of Cl2 = 4.5 moles of Cl2.

And, for 2 moles of AlCl3, we need 4.5/3 * 2 moles of AlCl3 = 3 moles of AlCl3.

Therefore, 81 g of Al reacts with plenty of chlorine to form 3 moles of aluminum chloride (AlCl3).

learn more about moles here

https://brainly.com/question/14357742

#SPJ1

The correct answers are: A strong acid dissociates completely in solution to produce its conjugate. The conjugate of a strong acid is an anion. The conjugate of a strong acid is neutral in pH when in solution. The conjugate of a strong acid is basic in solution.

A strong acid is a compound that dissociates completely in a solution to produce H+ ions. An example of a strong acid is Hydrochloric acid (HCl) which dissociates completely in a solution to produce H+ ions and Cl- ions.

The conjugate base is an anion and it is formed when the acid donates a proton. It is neutral in pH when it is in a solution. For instance, HCl donates its proton to water to form H3O+ and Cl-. H2O is the base (conjugate) of H3O+ and Cl- is the base (conjugate) of HCl.

When the conjugate base of a strong acid is dissolved in water, it accepts a proton from water and increases the concentration of OH- ions in solution. Therefore, the conjugate base of a strong acid is basic in solution.

To know more about strong acid, refer here:

https://brainly.com/question/28858976#

#SPJ11

In summary, a bond having "more ionic" or "more covalent" character refers to the degree to which the bond is either purely ionic or purely covalent, with most bonds falling somewhere in between.

When a bond has more ionic character, it means that the electrons are transferred more completely from one atom to another, resulting in larger differences in electronegativity and a greater degree of charge separation between the atoms. This typically occurs when there is a large difference in electronegativity between the atoms involved in the bond.

On the other hand, when a bond has more covalent character, it means that the electrons are shared more equally between the atoms, resulting in a smaller difference in electronegativity and less charge separation. This typically occurs when the atoms involved in the bond have similar electronegativities.

To know more about chemical bonds, visit:

https://brainly.com/question/12907148

#SPJ1

The empirical formula of the compound that produces 330 g of carbon, 69.5 g of hydrogen, and 440.4 g of oxygen upon decomposition is CHO2.

The empirical formula of a compound is the simplest whole-number ratio of atoms present in it. Follow the below steps to calculate the empirical formula of the given compound: Calculate the mass of each element present in the compound.

Calculate the mole of each element present in the compound by dividing its mass by its atomic mass. Determine the mole ratio by dividing each mole value by the smallest mole value obtained. Rearrange the ratio obtained in step 3 in the form of whole numbers. Moles of hydrogen/moles of oxygen = 69.5/27.5 = 2.53 ≈ 2.5Moles of oxygen/moles of oxygen = 27.5/27.5 = 1Therefore, the mole ratio of carbon: hydrogen: oxygen = 1: 2.5: 1Rearranging the above ratio to whole numbers, we get the mole ratio of carbon: hydrogen: oxygen as 2: 5: 2. The empirical formula of the compound is therefore CHO2.

Read more about Moles :

https://brainly.com/question/15356425

#SPJ11

In order to ensure that 900 mL of 1/3 strength solution is delivered over 8 hours via a nasogastric tube, you must add 300 mL of water to the 1/3 strength solution.

This will give a total volume of 1.2 L, which when divided by 8 hours, equals 150 mL per hour.

Use the formula for calculating dilution, which is: Final Volume / Concentration = Amount of Solvent to be Added.

We are given the Final Volume, which is 900 mL, and the Concentration, which is 1/3 strength. We can calculate the Amount of Solvent (in this case, water) to be Added :

900 mL / (1/3) = 2700 mL

The amount of water needed to be added to the 1/3 strength solution to achieve 900 mL of 1/3 strength is 2700 mL.

However, since the total volume of the solution must not exceed 1.2 L, only 300 mL of water must be added to the 1/3 strength solution,

giving us a total volume of 1.2 L when the 900 mL of 1/3 strength is taken into consideration.

to know more about solution refer here:

https://brainly.com/question/30665317#

#SPJ11

The temperature of the sample of CO² gas is 87.41 Kelvin.

Combined gas law put together both Boyle's Law, Charles's Law, and Gay-Lussac's Law. It states that "the ratio of the product of volume and pressure and the absolute temperature of a gas is equal to a constant.

It is expressed as;

P₁V₁/T₁ = P₂V₂/T₂

At STP (standard temperature and pressure), the temperature is 273.15 K and the pressure is 1 atm.

Therefore, we can use the combined gas law to solve for the final temperature:

P₁V₁/T₁ = P₂V₂/T₂

Where P₁ = 1 atm, V₁ = 0.50 L, T₁ = 273.15 K, P₂ = 1.6 atm, V₂ = 0.10 L, and we are solving for T₂.

Substituting the values and solving for T2, we get:

T₂ = (P₂V₂T₁) / (P₁V₁)

T₂ = ( 1.6 atm × 0.10 L × 273.15 K) / (1 atm × 0.50 L)

T₂ = 87.41 K

Therefore, the temperature of the sample is 87.41 K.

Learn more about the combined gas law here: brainly.com/question/25944795

#SPJ1

Natural cements that hold clasts together precipitate in the empty pore spaces after compaction due to the combined effects of;

Pressure, temperature, chemical composition, and length of exposure to groundwater. The most common cements are calcite, quartz, clay, and iron oxide.

The natural cements that hold clasts together precipitate in the empty pore spaces after compaction come from the groundwater that has traveled through the sediment.

The groundwater carries dissolved ions of calcium, silica, and other elements.

As the pore spaces are compressed, the pressure on the water within them increases, causing the dissolved ions to come out of solution as solid minerals or precipitates.

These cements act to bind the sediment particles together and are commonly composed of calcite, quartz, clay, and iron oxide.

Compaction of the sediment is one of the major factors controlling cementation. As the sediment is buried deeper and pressure increases, the pore spaces are squeezed shut, forcing the fluids out of them.

Once the water is squeezed out, the dissolved ions can come out of solution and cement the sediment together.

Temperature is another factor that influences the rate of cementation. The warmer the temperature, the faster the reactions occur, so cementation can be accelerated at higher temperatures.

In addition to temperature and pressure, the chemical composition of the groundwater also affects cementation.

The concentration of ions in the water determines what cements are formed, as the most soluble ions will be precipitated first.

For example, calcium ions in groundwater will be the first to precipitate, forming calcite cement.

Finally, the length of time during which the sediment is exposed to the groundwater can also influence cementation. The longer the sediment is exposed to the water, the more time it has to react and form cement.

to know more about cement refer here:

https://brainly.com/question/15286339#

#SPJ11

Answer: The pH of the solution is 9.22.

Explanation:

The given solution is a mixture of 200 mL of 0.20 M NaH2PO4 and 200 mL of 0.60 M Na2HPO4. NaH2PO4 is a weak acid and Na2HPO4 is a weak base. When they are mixed, they undergo a buffer solution.

The Henderson-Hasselbalch equation for a buffer is:

pH = pKa + log ([A-]/[HA])

Where,

pKa = -log Ka (dissociation constant of the acid)

[HA] = concentration of the acid (NaH2PO4)

[A-] = concentration of the conjugate base (HPO42-)

The pKa value for NaH2PO4 is 7.21 (at 25°C). The concentrations of the acid and the conjugate base can be calculated as follows:

For NaH2PO4:

moles of NaH2PO4 = 0.20 M x 0.2 L = 0.04 mol

concentration of NaH2PO4 = 0.04 mol / 0.4 L = 0.10 M

For Na2HPO4:

moles of Na2HPO4 = 0.60 M x 0.2 L = 0.12 mol

concentration of Na2HPO4 = 0.12 mol / 0.4 L = 0.30 M

Using the Henderson-Hasselbalch equation and substituting the values:

pH = 7.21 + log ([HPO42-]/[H2PO4-])

pH = 7.21 + log (0.30/0.10)

pH = 9.22

Therefore, the pH of the solution is 9.22.

Answer:

I needed points

Explanation:

i need them

Answer:

Explanation:

NH₄

N: 1 x 5 valence electrons = 5 valence electrons

H: 4 x 1 valence electrons = 4 valence electrons

Total valence electrons to account = 9

Subtract 1 electron from the total since NH₄⁺ has a plus one charge.

9 - 1 = 8 electrons

There are no nonbonding electrons in the structure.

      H

       |

H -- N -- H

       |

      H

Answer:

0.972

Explanation:

The balanced chemical equation for the reaction is:

3 NaOH + H3PO4 → Na3PO4 + 3 H2O

From the equation, we can see that for every 1 mole of H3PO4 reacted, 3 moles of water are produced. Therefore, we need to first calculate how many moles of H3PO4 are present in 4.30 g of NaOH:

molar mass of NaOH = 23.0 g/mol + 16.0 g/mol + 1.0 g/mol = 40.0 g/mol

moles of NaOH = 4.30 g / 40.0 g/mol = 0.108 mol

According to the balanced equation, 3 moles of water are produced for every 1 mole of H3PO4. Therefore, we can calculate how many moles of water are formed as follows:

moles of H3PO4 = 3/1 * 0.108 mol = 0.324 mol

moles of water = 3/1 * 0.324 mol = 0.972 mol

Therefore, 0.972 moles of water are formed when reacting 4.30 g of sodium hydroxide with phosphoric acid.

The IUPAC name for the compound 2-bromobutanal is 2-bromobutane-1-al.


The IUPAC name for the compound 3-bromobutanone is 3-bromobutane-1-one.  The IUPAC name for the compound 2-bromobutanone is 2-bromobutane-1-one. The IUPAC name for the compound 3-bromobutanal is 3-bromobutane-1-al.
The given compound is a ketone, identify the longest carbon chain that includes the carbonyl group, then change the -e ending of the corresponding alkane name to -one, which is the suffix for a ketone.

We can see that the carbonyl group is located at the second carbon atom of the parent chain, and the parent chain is the butane which has four carbon atoms. The name of this ketone is 2-bromobutanone because the bromine atom is bonded to the second carbon atom of the parent chain. Hence, the correct option is c. 2-bromobutanone.

Read more about carbonyl :

https://brainly.com/question/13564853

#SPJ11

Magnetism, texture, color and odor are all properties that can be observed in a substance.

Properties of a substance are characteristics that can be used to describe and identify the substance.

Physical properties are those that can be observed or measured without changing the composition of the substance, while chemical properties describe how a substance reacts with other substances.

Intensive properties are independent of the amount of substance, while extensive properties depend on the amount of substance. Examples of properties include color, texture, density, melting point, boiling point, reactivity, and flammability.

Learn about Physical properties of a substance here https://brainly.com/question/12330204

#SPJ1

NaCl crystallizes in a cubic unit cell, meaning each side of the cell is equal in length. In this structure, each corner of the cell has a Cl- ion and each face of the cell has a Na+ ion, totaling 8 Cl- ions and 6 Na+ ions per unit cell. So, there are 8 Cl- ions and 6 Na+ ions in each unit cell of NaCl.

NaCl is an ionic compound, meaning it is composed of a metal cation (Na+) and a nonmetal anion (Cl-). Ionic compounds form when electrons are transferred from the metal to the nonmetal, creating a strong electrostatic attraction between the two ions. The oppositely charged ions are then arranged into a lattice structure with a repeating pattern of alternating cations and anions.

The unit cell of a NaCl crystal is a cube, meaning all the sides of the unit cell are of equal length. A single unit cell of NaCl contains eight Cl- ions at the corners and six Na+ ions at the faces of the cube. Since the unit cell of NaCl is symmetrical, the same arrangement of ions is repeated in each adjacent unit cell of the crystal. The arrangement of ions in a NaCl unit cell is important in understanding its properties. Because the cations and anions are arranged in an alternating pattern, the ions form a strong ionic bond. This bond gives the crystal its hardness and stability, making NaCl one of the most common and widely used compounds.

In summary, each unit cell of NaCl contains 8 Cl- ions at the corners and 6 Na+ ions at the faces, forming a cube of equal sides. The alternating arrangement of cations and anions creates an ionic bond which gives NaCl its hardness and stability.

Know more about unit cell   here:

https://brainly.com/question/29537966

#SPJ11

Answer:

The major ion in seawater is chloride.

Explanation:

Seawater is composed of various ions such as sodium, magnesium, sulfate, and chloride. However, the most abundant ion in seawater is chloride (Cl-), which accounts for approximately 55% of the total ion concentration. This is due to the fact that chloride is a relatively stable ion and does not react with other ions in seawater. Therefore, it tends to accumulate in seawater over time, making it the most prevalent ion in seawater.

Answer: THE ANSWER IS OPTION D) chloride.

Explanation: I GOT A 100 ON THE QUIZ ( please mark brainliest )