in a test tube containing precipitatie of pbcro4 in water: what are the concentraions of lead(II) and chromate ions in equilibrium with the solid? show your calculations. use the Ksp from the prelab table above

The mass of oxygen gas in the unknown mixture is approximately 5.868 g. The mass of ethane gas in the unknown mixture is approximately 0.812 g. The mass percent of oxygen gas in the unknown mixture is approximately 71.83%.

To solve this problem, we need to determine the masses of oxygen gas and ethane gas in the unknown mixture, as well as the mass percent of oxygen gas.

Let's start by calculating the mass of water produced;

Mass of water = 1.48 g

Since water is composed of hydrogen and oxygen in a 2:1 ratio, the molar mass of water is:

Molar mass of water = 2(1.00784 g/mol) + 15.999 g/mol = 18.015 g/mol

Now we can calculate the number of moles of water produced;

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

= 1.48 g / 18.015 g/mol

≈ 0.082 mol

From balanced chemical equation for the combustion of ethane;

C₂H₆ + 7/2 O₂ → 2 CO₂ + 3 H₂O

We can see that 1 mole of ethane produces 3 moles of water. Therefore, the number of moles of ethane can be calculated as;

Number of moles of ethane = (Number of moles of water) / 3

≈ 0.082 mol / 3

≈ 0.027 mol

The molar mass of ethane (C₂H₆) is;

Molar mass of ethane = 2(12.011 g/mol) + 6(1.00784 g/mol)

= 30.0708 g/mol

Finally, we can calculate the mass of ethane;

Mass of ethane = Number of moles of ethane × Molar mass of ethane

≈ 0.027 mol × 30.0708 g/mol

≈ 0.812 g

Now, to determine the mass of oxygen gas, we subtract the mass of ethane and water from the total mass of the unknown mixture:

Mass of oxygen gas = Total mass of unknown mixture - Mass of ethane - Mass of water

= 8.16 g - 0.812 g - 1.48 g

≈ 5.868 g

Finally, we can calculate the mass percent of oxygen gas in the unknown mixture;

Mass percent of oxygen gas = (Mass of oxygen gas / Total mass of unknown mixture) × 100%

= (5.868 g / 8.16 g) × 100%

≈ 71.83%

Therefore;

The mass of oxygen gas in the unknown mixture is approximately 5.868 g.

The mass of ethane gas in the unknown mixture is approximately 0.812 g.

The mass percent of oxygen gas in the unknown mixture is approximately 71.83%.

To know more about mass percent here

https://brainly.com/question/5840377

#SPJ4

Answer:

Input Mask

Explanation:

In this scenario, the best tool for Raul to use would be an Input Mask. When dealing with Microsoft Access or any other database tool, Input Masks are a great way of validating data inputs so that they always match the desired format. In this case, Raul would need to use input mask and apply the desired format while comparing it to the order date, therefore, making sure that it is always a minimum of 2 days after before it is accepted as a valid entry in the database.

Answer:

c

Explanation:

The chemical formula of the gas is Option c, Helium.

We need to take into account the molar masses and the root mean square (RMS) speeds of various gases in order to ascertain the chemical formula of the gas that escapes through the pinhole 2.65 times quicker than N₂ gas.

The following equation describes how a gas's molar mass and RMS speed are related:

RMS velocity = 1/√(molar mass)

The following ratio may be established since the provided gas leaves 2.65 times more quickly than N₂ gas:

RMS speed of the given gas / RMS speed of N₂ gas = 2.65

Now, let's compare the molar masses of the options provided:

a. Ne (Neon) has a molar mass of approximately 20 g/mol.

b. O₂ (Oxygen) has a molar mass of approximately 32 g/mol.

c. He (Helium) has a molar mass of approximately 4 g/mol.

d. Ar (Argon) has a molar mass of approximately 40 g/mol.

Since the ratio of RMS speeds is greater than 1, the molar mass of the given gas must be less than that of N₂ gas. Among the options, the only gas with a molar mass significantly lower than N₂ gas is Helium (He) with a molar mass of approximately 4 g/mol.

Therefore, the chemical formula of the gas is Option C, Helium.

To learn more about gas, refer to:

https://brainly.com/question/6140407

#SPJ4

The correct order of increasing magnitude of lattice energy is:

MgO < Sr O < KI.

Lattice energy is a measure of the energy released when ions in the gas phase come together to form a solid ionic compound. It represents the strength of the electrostatic attraction between oppositely charged ions in a crystal lattice. Lattice energy is an important property in understanding the stability, solubility, and other physical and chemical properties of ionic compounds.

Lattice energy is influenced by several factors, including the charges and sizes of the ions involved. Generally, compounds with higher charges or smaller ions tend to have higher lattice energies because the electrostatic attraction between the ions is stronger. Therefore, the correct order of increasing magnitude of lattice energy is:

MgO < Sr O < KI.

Learn more about Lattice energy from the link given below.

https://brainly.com/question/29735933

#SPJ4

Answer:

120 liters

Explanation:

From the question,

Applying boyles law

PV = P'V'................ Equation 1

Where P = initial pressure, V = Initial Volume, P' = Final pressure, V' = Final Volume.

make V' The subject of the equation

V' = PV/P'............. Equation 2

Given: P = 2 kpa, V = 60 liters, P' = 1 kpa

Substitute these values into equation 2

V' = (2×60)/1

V' = 120 liters

Hence the right option is A. 120 liters

Answer:

terminal velcity

Explanation:

The correct answer is 5 Ni 138 56.

Explanation :

The nucleotide which has the largest nuclear binding energy per nucleon is nickel-56 (56Ni). It is important to note that nuclear binding energy per nucleon refers to the energy released when a nucleus is formed by assembling its nucleons.

The nuclear binding energy is the amount of energy required to separate an atomic nucleus into its individual nucleons. It is the sum of the energy of the individual nucleons in the nucleus. It's important to remember that when atomic nuclei are formed, they release a certain amount of energy in the process.

The nuclear binding energy per nucleon depends on the total number of nucleons present. In general, the larger the number of nucleons in an atomic nucleus, the greater the amount of nuclear binding energy per nucleon.

Therefore, among the given nucleotides, nickel-56 (56Ni) has the largest nuclear binding energy per nucleon. The amount of energy released when nickel-56 (56Ni) is formed is greater than that released by any other nuclide. The high energy released by nickel-56 (56Ni) makes it important for the process of nuclear fusion in stars.

Thus, the answer to this question is nickel-56 (56Ni).

Learn more about nuclear binding Energy Here https://brainly.in/question/54749380

#SPJ11

Answer:

a

Explanation:

The equilibrium constant expression for the reaction CO(g) + 2H₂(g) ⇌ CH₃OH(g) is K = [CH₃OH] / [CO][H₂]^{2}.

The equilibrium constant is a measure of the relative concentrations of the reactants and products at equilibrium. A large value of K indicates that the reaction is product-favored, while a small value of K indicates that the reaction is reactant-favored.

The equilibrium constant is calculated by taking the product of the equilibrium concentrations of the products and dividing it by the product of the equilibrium concentrations of the reactants.

The equilibrium concentrations are the concentrations of the reactants and products at equilibrium, which is the point at which the forward and reverse reactions are occurring at the same rate.

The equilibrium constant is a useful tool for predicting the direction of a chemical reaction. A large value of K indicates that the reaction is product-favored, meaning that the products will be more abundant at equilibrium than the reactants.

A small value of K indicates that the reaction is reactant-favored, meaning that the reactants will be more abundant at equilibrium than the products.

The equilibrium constant is also a useful tool for predicting the effect of changes in temperature and pressure on a chemical reaction. An increase in temperature will generally shift the equilibrium to the side of the reaction that produces more moles of gas.

A decrease in pressure will generally shift the equilibrium to the side of the reaction that has fewer moles of gas. The equilibrium constant is a valuable tool for understanding and predicting the behavior of chemical reactions.

By understanding the equilibrium constant, chemists can predict the direction of a reaction, the effect of changes in temperature and pressure, and the relative concentrations of the reactants and products at equilibrium.

To know more about equilibrium constant expression, refer here:

https://brainly.com/question/29748652#

#SPJ11

Answer:

Depending on the different angles the sun reaches the earth at, the amount of the suns ray may differ per angle. Smaller, more concentrated areas of the suns rays would result in warmer temperatures while areas where sunlight is spread out may have colder temperatures.

Answer:

Physics is a natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. More broadly, it is the study of nature in an attempt to understand how the universe behaves.

Explanation:

a) To determine the number of possible emission lines, we need to consider the transitions between the energy levels. The formula to calculate the number of possible transitions is given by:

Number of transitions = n*(n-1)/2

where n is the number of energy levels. In this case, considering the four energy levels (n = 1, 2, 3, 4), we have:

Number of transitions = 4*(4-1)/2 = 6

Therefore, there are six possible emission lines considering only the four quantum levels.

b) The lowest energy transition occurs from the level with n=4 to the level with n=1. This transition represents the largest energy drop and therefore emits photons of the lowest energy.

c) The emission line with the shortest wavelength corresponds to the transition with the highest energy. In this case, it occurs from the level with n=4 to the level with n=1. The transition from a higher energy level to a lower energy level results in the emission of a photon with a shorter wavelength.

Learn more about emission lines here:

https://brainly.com/question/32493509

#SPJ11

Answer: a) 0.579 atm

b) 0.585 bar

c) 58662 Pa

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.

We are given:

Pressure of the gas = 440 mmHg

a) Converting this unit of pressure into 'atm' by using conversion factor:

[tex]760mmHg=1atm[/tex]

[tex]440mmHg=\frac{1}{760}\times 440=0.579atm[/tex]

b) Converting this unit of pressure into 'bars' by using conversion factor:

[tex]760mmHg=1.01bar[/tex]

[tex]440mmHg=\frac{1.01}{760}\times 440=0.585bar[/tex]

c) Converting this unit of pressure into 'Pascal' by using conversion factor:

[tex]760mmHg=101325Pa[/tex]

[tex]440mmHg=\frac{101325}{760}\times 440=58662Pa[/tex]

The correct option is (C) [B] > [C].

A + 2B ⇌ 2CThe equilibrium constant, Keq = 100Mole of A, nA = 0.1 molMole of B, nB = 0.1 molInitial concentration of A, [A] = 0.1/1.0 = 0.1 MInitial concentration of B, [B] = 0.1/1.0 = 0.1 MAt equilibrium, the reaction quotient (Qc) is given as,Qc = [C]²/([A][B]²)As Keq > Qc, the forward reaction is favored and the concentration of reactants decreases while the concentration of products increases. Now, let us determine the concentration of products C when the reaction reaches equilibrium.As the mole ratio of A:B:C is 1:2:2, the number of moles of C formed = 2nB = 2(0.1) = 0.2molConcentration of C at equilibrium, [C] = 0.2/1.0 = 0.2 MNow, let us compare the concentration of each reactant and product at equilibrium:[A] > [B][A] = [B][A] < [B][B] > [C][B] = [C]Hence, the correct option is (C) [B] > [C].

Learn more about  equilibrium constant here:

https://brainly.com/question/28559466

#SPJ11

Taking into account the reaction stoichiometry, the volume of O₂ is 7.28406 L when 28.5 g of hydrogen peroxide decomposes to form water and oxygen at 150 degrees c and 2.0 atm.

The balanced reaction is:

2 H₂O₂  → 2 H₂O + O₂

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

The following rule of three can be applied: if by reaction stoichiometry 68 grams of H₂O₂ form 1 mole of O₂, 28.5 grams of H₂O₂ form how many moles of O₂?

moles of O₂= (28.5 grams of H₂O₂×1 mole of O₂)÷68 grams of H₂O₂

moles of O₂= 0.42 grams

Then, 0.42 moles of O₂ are formed.

Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.

The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:

P×V = n×R×T

Where:

In this case, you know:

Replacing in the definition of the ideal gas law:

2 atm×V = 0.42 moles×0.082 (atmL)÷(molK)× 423 K

Solving:

V = (0.42 moles×0.082 (atmL)÷(molK)× 423 K)÷ 2 atm

V= 7.28406 L

Finally, the volume of O₂ is 7.28406 L.

Learn more about the reaction stoichiometry:

brainly.com/question/24741074

#SPJ4

The pH at the equivalence point when 35.0 mL of a 0.200 M solution of acetic acid (CH3COOH) is titrated with 0.100 M NaOH to its end point is 4.76.

The pH at the equivalence point when 35.0 mL of a 0.200 M solution of acetic acid (CH3COOH) is titrated with 0.100 M NaOH to its end point can be calculated using the formula derived from the Henderson-Hasselbalch equation.

The balanced chemical equation for this reaction is as follows: CH3COOH + NaOH → CH3COONa + H2OSince the reaction between the acetic acid and sodium hydroxide is a 1:1 ratio, the number of moles of NaOH required to reach the equivalence point will be equal to the number of moles of CH3COOH present in the 35.0 mL solution of 0.200 M acetic acid.

This can be calculated using the following formula: moles of CH3COOH = M x V moles of CH3COOH = 0.200 M x 0.0350 L = 0.00700 mol of CH3COOHTo calculate the volume of NaOH required to reach the equivalence point, we can use the formula: moles of NaOH = moles of CH3COOHmoles of NaOH = 0.00700 mol of CH3COOHNow that we know the number of moles of NaOH, we can calculate the volume of NaOH required to reach the equivalence point using the following formula: V = n / CV = 0.00700 mol / 0.100 M = 0.0700 L = 70.0 mL.

Since we have added 70.0 mL of 0.100 M NaOH to the 35.0 mL of 0.200 M acetic acid solution, the total volume of the solution at the equivalence point is: Vtotal = 35.0 mL + 70.0 mL = 105.0 mL. Now that we have determined the volume and concentration of the NaOH solution required to reach the equivalence point, we can use the Henderson-Hasselbalch equation to calculate the pH at the equivalence point: pH = pKa + log([A-]/[HA])At the equivalence point, the concentration of CH3COOH and CH3COO- are equal.

Therefore, the concentration of [HA] and [A-] are equal, and we can simplify the equation to:pH = pKa + log(1)Since the pKa of acetic acid is 4.76, we can substitute this value into the equation and solve for pH:pH = 4.76 + log(1)pH = 4.76.

To know more about titrated refer here: https://brainly.com/question/31483031#

#SPJ11

Answer:

From top to bottom coyote, crow, squirrel, then acorn

Explanation:

The coyote has the least amount of energy and its the biggest predator so it belongs at the top. The crows eat squirrels and the squirrels eat acorns.

Answer:

9.63 L of NO

Explanation:

We'll begin by calculating the number of mole in 50.0 g of NH₄ClO₄. This can be obtained as follow:

Mass of NH₄ClO₄ = 50 g

Molar mass of NH₄ClO₄ = 14 + (4×1) + 35.5 + (16×4)

= 14 + 4 + 35.5 + 64

= 117.5 g/mol

Mole of NH₄ClO₄ =?

Mole = mass /molar mass

Mole of NH₄ClO₄ = 50/117.5

Mole of NH₄ClO₄ = 0.43 mole

Next, we shall determine the number of mole of NO produced by the reaction of 50 g (i.e 0.43 mole) of NH₄ClO₄. This can be obtained as follow:

3Al + 3NH₄ClO₄ –> Al₂O₃ + AlCl₃ + 3NO + 6H₂O

From the balanced equation above,

3 moles of NH₄ClO₄ reacted to produce 3 moles of NO.

Therefore, 0.43 mole of NH₄ClO₄ will also react to produce 0.43 mole of NO.

Finally, we shall determine the volume occupied by 0.43 mole of NO. This can be obtained as follow:

1 mole of NO = 22.4 L

Therefore,

0.43 mole of NO = 0.43 × 22.4

0.43 mole of NO = 9.63 L

Thus, 9.63 L of NO were obtained from the reaction.

Answer:

A- Before the mechanic left, the molecules were moving away from each other. When she returned, they were moving around each other.

Explanation:

Brainliest?

Zinc hydroxide, which is represented by the chemical formula Zn(OH)₂, is a basic hydroxide salt of zinc.

In a saturated solution of Zn(OH)₂, the concentration of the zinc ions and the hydroxide ions will be equal to the solubility product of Zn(OH)₂. As a result, we can calculate the pH of a saturated solution of Zn(OH)₂ by using the equation for the solubility product constant (Ksp).

The solubility product constant for Zn(OH)₂ is given as Ksp=1.8x10⁻¹⁴. This means that the product of the zinc ion concentration [Zn²⁺] and the hydroxide ion concentration [OH⁻] in a saturated solution of Zn(OH)₂ will be equal to 1.8x10⁻¹⁴.

Using this equation, we can calculate the concentration of hydroxide ions in a saturated solution of Zn(OH)₂. Since the concentration of zinc ions is equal to the concentration of hydroxide ions in a saturated solution of Zn(OH)₂, we can calculate the concentration of zinc ions as well.

[Zn²⁺][OH⁻] = 1.8x10⁻¹⁴∴ [Zn²⁺] = [OH⁻] = √(1.8x10⁻¹⁴) = 1.34x10⁻⁷ M. The pH of the solution can be determined by using the formula: pOH = -log[OH⁻] = -log(1.34x10⁻⁷) = 6.87pH = 14 - pOH = 7.13. Therefore, the pH of a saturated solution of Zn(OH)₂ is approximately 7.13.

To know more about basic hydroxide salt refer here: https://brainly.com/question/15898567#

#SPJ11

A. [tex]HC_{2} O^{-} _{4[/tex] (oxalate ion) acts as a base by accepting a proton from [tex]HS^{-}[/tex] (hydrosulfide ion) to form [tex]H_{2}C_{2} O_{4}[/tex] (oxalic acid).

B. [tex]HC_{2} O^{-} _{4[/tex] (oxalate ion) acts as an acid by donating a proton to [tex]HS^{-}[/tex](hydrosulfide ion) to form [tex]C_{2} O^{-} _{4[/tex] (oxalate ion).

A. At the point when [tex]HC_{2} O^{-} _{4[/tex] goes about as a base, it acknowledges a proton ([tex]H^{+}[/tex]) from [tex]HS^{-}[/tex], which goes about as a corrosive. The condition can be addressed as:

[tex]HC_{2} O^{-} _{4[/tex]+ [tex]HS^{-}[/tex] → [tex]H_{2}C_{2} O_{4}[/tex] +[tex]S^{-} _{2}[/tex]

In this response,[tex]HC_{2} O^{-} _{4[/tex] goes about as a base by tolerating a proton from the corrosive [tex]HS^{-}[/tex], shaping the impartial particle [tex]H_{2}C_{2} O_{4}[/tex] (oxalic corrosive) and the form base [tex]S^{-} _{2}[/tex].

B. At the point when [tex]HC_{2} O^{-} _{4[/tex] goes about as a corrosive, it gives a proton ([tex]H^{+}[/tex]) to [tex]HS^{-}[/tex], which goes about as a base. The condition can be addressed as:

[tex]HC_{2} O^{-} _{4[/tex] +[tex]HS^{-}[/tex] → [tex]HC_{2} O^{-} _{4[/tex]+ [tex]H_{2} S[/tex]

In this response, [tex]HC_{2} O^{-} _{4[/tex]goes about as a corrosive by giving a proton to the base [tex]HS^{-}[/tex], bringing about the development of the form base [tex]HC_{2} O^{-} _{4[/tex](oxalate particle) and the unbiased atom [tex]H_{2} S[/tex] (hydrogen sulfide).

In the two cases, [tex]HC_{2} O^{-} _{4[/tex] displays its amphoteric nature by having the option to go about as both a corrosive and a base, contingent upon the idea of the responding species.

[tex]HS^{-}[/tex], thus, exhibits its capacity to go about as a corrosive while responding with [tex]HC_{2} O^{-} _{4[/tex] as a base and as a base while responding with [tex]HC_{2} O^{-} _{4[/tex] as a corrosive.

To learn more about acid and base, refer:

https://brainly.com/question/31324718

#SPJ4

The complete chemical equation for cellular respiration is:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy

In this equation, glucose (C₆H₁₂O₆) is combined with oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O). The process of cellular respiration occurs in the mitochondria of cells and involves the breakdown of glucose to release energy in the form of ATP (adenosine triphosphate).

During cellular respiration, glucose is oxidized to form carbon dioxide, and oxygen is reduced to form water. This process releases energy that is stored in ATP molecules and is used by cells to carry out various metabolic activities.

Overall, cellular respiration is a vital process in organisms to generate energy for cellular functions and is essential for the survival and functioning of living organisms.

To know more about the cellular respiration refer here :

https://brainly.com/question/13721588#

#SPJ11

The required correct answer is option D) Te.

An atom of Tellurium (Te) has 52 electrons and its electron configuration is 1s22s22p63s23p64s23d104p65s24d105p4. It has six electrons in its outermost shell and it requires two more electrons to complete its octet. Upon gaining two electrons, the electron configuration of Te will become 1s22s22p63s23p64s23d104p65s24d105p6.Te (Tellurium) is a chemical element with an atomic number of 52. It is a rare, silvery-white metalloid that is widely used in various industries. The majority of tellurium is used in alloys and as an additive to copper, steel, and lead to increase their strength and durability. It's also used in the production of solar panels and other electronic devices.

Learn more about electron here,

https://brainly.com/question/860094

#SPJ11

The theoretical values for ΔS and ΔG for the dissolution reaction of calcium chloride in water are approximately:

ΔS = 401.0 J/(mol·K)

ΔG = -343.6 kJ/mol

The standard molar entropy values (ΔS°) at 298 K (25°C) are as follows:

ΔS°(CaCl₂(s)) = 115.3 J/(mol·K)

ΔS°(Ca²⁺(aq)) = 72.1 J/(mol·K)

ΔS°(2Cl⁻(aq)) = 222.1 J/(mol·K)

The standard Gibbs free energy change (ΔG°) at 298 K (25°C) is given by the equation:

ΔG° = ΣnΔG°(products) - ΣnΔG°(reactants)

The standard Gibbs free energy change values (ΔG°) at 298 K (25°C) are as follows:

ΔG°(CaCl₂(s)) = -795.4 kJ/mol

ΔG°(Ca²⁺(aq)) = -544.6 kJ/mol

ΔG°(2Cl⁻(aq)) = -167.2 kJ/mol

For the dissolution reaction of CaCl₂ in water:

CaCl₂(s) → Ca²⁺(aq) + 2Cl⁻(aq)

To calculate the theoretical values of ΔS and ΔG, we use the stoichiometric coefficients of the balanced equation. The stoichiometric coefficients for the products and reactants are as follows:

n(Ca²⁺) = 1

n(Cl⁻) = 2

Calculating the values:

ΔS°(reaction) = ΣnΔS°(products) - ΣnΔS°(reactants)

= (1 * ΔS°(Ca²⁺(aq))) + (2 × ΔS°(Cl⁻(aq))) - ΔS°(CaCl₂(s))

Substituting the values:

ΔS°(reaction) = (1 × 72.1 J/(mol·K)) + (2 × 222.1 J/(mol·K)) - 115.3 J/(mol·K)

= 401.0 J/(mol·K)

ΔG°(reaction) = ΣnΔG°(products) - ΣnΔG°(reactants)

= (1 × ΔG°(Ca²⁺(aq))) + (2 × ΔG°(Cl⁻(aq))) - ΔG°(CaCl₂(s))

Substituting the values:

ΔG°(reaction) = (1 × -544.6 kJ/mol) + (2 × -167.2 kJ/mol) - (-795.4 kJ/mol)

= -343.6 kJ/mol

Therefore, the theoretical values for ΔS and ΔG for the dissolution reaction of calcium chloride in water are approximately:

ΔS = 401.0 J/(mol·K)

ΔG = -343.6 kJ/mol

Learn more about dissolution reaction from the link given below.

https://brainly.com/question/30516012

#SPJ4

A dilute solution of NaOH needs to be standardized in order to accurately determine its concentration. Standardization involves comparing the concentration of the NaOH solution to a known concentration of a primary standard substance.

There are several reasons why standardization is necessary. Firstly, NaOH is highly hygroscopic, meaning it readily absorbs moisture from the air. This moisture absorption can alter the concentration of the solution over time, leading to inaccurate results. By standardizing the NaOH solution, we can ensure that its concentration is accurately determined at a specific point in time. Secondly, during the manufacturing and storage process, impurities may be introduced into the NaOH solution, affecting its concentration. Standardization allows us to account for these impurities and determine the true concentration of the solution. Lastly, dilution of the NaOH solution introduces a potential for errors in the preparation process, such as inaccuracies in volumetric measurements. Standardization helps correct for these errors and provides a reliable concentration value for subsequent use in various analytical procedures.

Learn more about dilute solution here : brainly.com/question/31521767

#SPJ11

Answer:

4.9 atm

Explanation:

Given:

Total pressure = 7.0 atm

(Total number of moles)=[ (1.5 mol arg) + (3.5 mol co2) ]

= 5 moles

Let Partial pressure of CO2 gas = P(CO2)

✓✓partial pressure of CO2 can be calculated using below expresion.

P(CO2) / Total pressure = (moles of CO2 gas) / Total number of moles

✓✓ Let us substitute the values into the above expresion.

[P(CO2) / 7.0 atm ] = [3.5 mol / 5 moles]

P(CO2)= [7 atm × 3.5 moles] / [5 moles]

= 4.9 atm

Hence, the partial pressure of CO2 is 4.9 atm

Answer:

Partial pressure of CO₂ = 4.9 atm

Explanation:

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

Mole of Ar = 1.5 moles

Mole of CO₂ = 3.5 moles

Total pressure (Pₜ) = 7.0 atm

Partial pressure of CO₂ =?

Next, we shall determine the mole fraction of CO2. This can be obtained as follow:

Mole of Ar = 1.5 moles

Mole of CO₂ = 3.5 moles

Total mole = 1.5 + 3.5

Total mole = 5 mole

Mole fraction of CO₂ = mole of CO₂ / total mole

Mole fraction of CO₂ = 3.5 / 5

Mole fraction of CO₂ = 0.7

Finally, we shall determine the partial pressure of CO₂. This can be obtained as follow:

Total pressure (Pₜ) = 7.0 atm

Mole fraction of CO₂ = 0.7

Partial pressure of CO₂ =?

Partial pressure of CO₂ = mole fraction of CO₂ × total pressure

Partial pressure of CO₂ = 0.7 × 7

Partial pressure of CO₂ = 4.9 atm

The ∆H° for the reaction  [tex]1/2 Mg_3N_2(s) + 3H_2O(l)[/tex]→[tex]1/2 Mg(OH)_2 (s) + NH_3(g)[/tex] is approximately -1372.54 kJ/mol

To calculate the ∆H° for the reaction[tex]1/2 Mg_3N_2(s) + 3H_2O(l)[/tex] → [tex]1/2 Mg(OH)_2 (s) + NH_3(g)[/tex], we need to use the given information that 3.4 kJ of energy are released when excess water is added to 0.50 g of Mg3N2(s).

First, let's calculate the moles of [tex]Mg_3N_2[/tex](s):

Molar mass of [tex]Mg_3N_2[/tex] = 3 * molar mass of Mg + 2 * molar mass of N

Molar mass of [tex]Mg_3N_2[/tex] = 3 * 24.31 g/mol + 2 * 14.01 g/mol = 100.95 g/mol

Moles of [tex]Mg_3N_2[/tex](s) = Mass / Molar mass

Moles of [tex]Mg_3N_2[/tex](s) = 0.50 g / 100.95 g/mol = 0.004955 mol

Next, we can determine the ∆H° per mole of [tex]Mg_3N_2[/tex](s):

∆H° per mole = Energy released / Moles of [tex]Mg_3N_2[/tex](s)

∆H° per mole = -3.4 kJ / 0.004955 mol = -686.27 kJ/mol

Since the balanced equation shows that only half a mole of [tex]Mg_3N_2[/tex](s) is involved, we multiply the ∆H° per mole by 2:

∆H° = 2 * ∆H° per mole

∆H° = 2 * (-686.27 kJ/mol) = -1372.54 kJ/mol

Therefore, the ∆H° for the reaction  [tex]1/2 Mg_3N_2(s) + 3H_2O(l)[/tex]→[tex]1/2 Mg(OH)_2 (s) + NH_3(g)[/tex] is approximately -1372.54 kJ/mol.

Learn more about  Molar mass here:

https://brainly.com/question/31545539

#SPJ11

Answer:

Lithium has 5 elements, sulphur has 2 elements and oxygen has 4 elements