When magnesium reacts with nitrogen, the reaction container becomes very hot. the δh for this reaction will have a positive sign.

a. true
b. false

13.1 g of KBr is required to produce 429.5 mL of a 0.256 M solution of KBr.

To calculate the mass of solute required to produce 429.5 mL of a 0.256 M solution of KBr, we can use the formula below;

Mass of solute = Molarity × Volume (liters) × Molecular weight of solute

We can also convert the volume of the solution from milliliters to liters by dividing by 1000.

Thus,429.5 mL = 429.5/1000 = 0.4295 Liters

Therefore,

Mass of KBr required = Molarity × Volume × Molecular weight of KBr= 0.256 mol/L × 0.4295 L × 119 g/mol= 13.1 g KBr

Thus, 13.1 g of KBr is required to produce 429.5 mL of a 0.256 M solution of KBr.

Learn more about Molarity here:

https://brainly.com/question/31545539

#SPJ11

Answer:

D

Explanation:

pressure is inversely proportional to gas volume

In comparison to the other ionic compounds, CaCO₃ is more soluble in acid solution.

Calcium carbonate (CaCO₃) is sparingly soluble in water. It undergoes a limited degree of dissociation and forms a weakly soluble salt.

However, when CaCO₃ is exposed to an acid solution, such as hydrochloric acid (HCl), it reacts to form a soluble salt, calcium chloride (CaCl₂), carbon dioxide (CO₂), and water (H2O). The following illustrates the reaction:

[tex]CaCO_3 + 2HCl \rightarrow CaCl_2+ CO_2 + H_2O[/tex]

Increased solubility of the CaCO₃ is the result of this reaction, which makes it easier for it to dissolve in an acidic solution as opposed to water.

Contrarily, the solubility of CuI (copper(I) iodide), PbCl₂ (lead(II) chloride), and Fe(OH)₃ (iron(III) hydroxide) in water and acid is limited and they are not greatly influenced by acid solutions.

Learn more about ionic compounds here:

https://brainly.com/question/13058663

#SPJ4

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 40.51 g is the mass of 2.31x10²³ formula units of SrF[tex]_2[/tex].

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample.

Given number of atoms= 2.31x10²³atoms

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole =given number of atoms ÷ 6.022×10²³(Avogadro number)

Substituting the values

mole= 2.31x10²³÷ 6.022×10²³

mole = 0.38 moles of SrF[tex]_2[/tex]

mass of SrF[tex]_2[/tex]= moles of SrF[tex]_2[/tex] × Molar mass of SrF[tex]_2[/tex]

mass of SrF[tex]_2[/tex]= 0.38  × 106.6184

mass of SrF[tex]_2[/tex] = 40.51 g

Therefore, 40.51 g is the mass of 2.31x10²³ formula units of SrF[tex]_2[/tex].

To know more about mole, here:

https://brainly.com/question/15209553

#SPJ1

The value of Qc for the given solution is approximately 3.67425e⁻⁶.

To find the value of Qc (the reaction quotient) for the given solution, we need to determine the concentrations of the respective ions and use them to calculate Qc.

The balanced equation for the dissolution of lead(II) chloride (PbCl₂) in water is:

PbCl₂(s) ⇌ Pb²⁺(aq) + 2Cl⁻(aq)

From this equation, we can see that one mole of PbCl₂ dissociates to yield one mole of Pb²⁺ ions and two moles of Cl⁻ ions.

Given that the concentration of lead(II) nitrate (Pb(NO₃)₂) is 1.82e⁻⁴ M and the concentration of sodium chloride (NaCl) is 2.25e⁻² M, we can use the stoichiometry of the balanced equation to determine the concentrations of Pb²⁺ and Cl⁻ ions.

Since lead(II) nitrate dissociates completely, the concentration of Pb²⁺ ions is equal to the concentration of lead(II) nitrate:

[Pb²⁺] = 1.82e⁻⁴ M

Sodium chloride dissociates into one mole of Na⁺ ions and one mole of Cl⁻ ions. Since we're interested in the concentration of Cl⁻ ions, we'll use the given concentration of NaCl to calculate it:

[Cl⁻] = 2 * 2.25e⁻² M

      = 4.5e⁻² M

Now, we can write the expression for Qc using the concentrations of the respective ions:

Qc = [Pb²⁺][Cl⁻]²

Putting in the values we obtained:

Qc = (1.82e⁻⁴ M)(4.5e⁻² M)²

   = 1.82e⁻⁴ (20.25e⁻⁴)

   = 36.7425e⁻⁸  

Simplifying the expression:

Qc = 3.67425e⁻⁶

Therefore, the value of Qc for the given solution is approximately 3.67425e⁻⁶.

Learn more about balanced chemical equation visit:

brainly.com/question/28294176

#SPJ4

The percent by mass of the solution made from 17 g sodium chloride, NaCl (the solute) and 59 g water is 22.4%

First, we shall obtain the mass of the solution. Details below:

Mass of solution = Mass of NaCl + mass of water

Mass of solution = 17 + 59

Mass of solution = 76 grams

Finally, we shall determine the percent by mass of the solution. Details below:

Percent by mass = (mass of NaCl / mass of solution) × 100

= (17 / 76) × 100

= 22.4%

Thus, the percent by mass of the solution is 22.4%

more about mass percent of solution:

https://brainly.com/question/32122082

#SPJ4

Given :

A compound is found to be made up of 3.21 g Carbon and 1.02 g Oxygen.

To Find :

The percent composition from this data.

Solution :

We know, percentage composition is given by :

[tex]\%mass = \dfrac{mass}{mass of compound}\times 100[/tex]

So, percentage composition of Carbon is :

[tex]\%Carbon = \dfrac{3.21}{3.21+1.02}\times 100\\\\\%Carbon = \dfrac{3.21}{4.23}\times 100\\\\\%Carbon = 75.89 \%[/tex]

Since, compound is made up of Carbon and Oxygen.

So, %Oxygen is ( 100 - 75.89 )% = 24.11%

Hence, this is the required solution.

Answer:

The variable Q

Explanation:

i just took the test and got it right.... i hope this helps :)

The variable Q represents thermal energy in the equation Q = mcΔT. Hence, option B is correct.

The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases by 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).

Q =  mcΔT

Q = heat energy

m = mass

c = specific heat capacity

ΔT = change in temperature

Hence, option B is correct.

Learn more about specific heat capacity here:

brainly.com/question/2530523

#SPJ2

Answer:

Homework hint: P1V1 = nRT1 and V1, n, and R are constant. Remember to use Kelvin.

Answer:

algae

Explanation:

fish and herons arent herbivores

Herbivores are typically tagged as animals that feeds directly on the plants in a food chain.

In the given food chain, Fish is the herbivore

Learn more about food chains: https://brainly.com/question/16504883

The new pressure of the gas is [tex]45.906 torr.[/tex]

To calculate the new pressure:

[tex]P2 = P1 * (T2 / T1)[/tex]

where:

P1 is the initial pressure[tex](32.6 torr)[/tex]

T1 is the initial temperature [tex](735 K)[/tex]

P2 is the final pressure (unknown)

T2 is the final temperature [tex](1035 K)[/tex]

Substituting the values into the formula, we get:

[tex]P2 = 32.6 torr * (1035 K / 735 K)[/tex]

[tex]P2 = 45.906 torr[/tex]

Therefore, the new pressure of the gas is [tex]45.906 torr.[/tex]

To know more about pressure:

https://brainly.com/question/14696697

#SPJ12

Answer:

In a titration, you determine an unknown concentration of a sample by adding a second reactant of known concentration. In many titrations, you use a chemical called an indicator, which lets you know when the titration finishes.

Explanation:

Answer:

2.69g

Explanation:

The molar masses of

Cu = 63.5

Cl = 35.5

So the molar mass of [tex]CuCl_{2}[/tex] is 63.5 + (35.5 x 2) = 134.5

134.5 x 0.02 = 2.69g

The answer is 0.015295197308045

We assume you are converting between moles Zinc and gram. You can view more details on each measurement unit: molecular weight of Zinc or grams The molecular formula for Zinc is Zn

Answer: I honestly think it might be C

Explanation: Collisions between objects are governed by laws of momentum and energy. When a collision occurs in an isolated system, the total momentum of the system of objects is conserved. ... In the collision between the two cars, total system momentum is conserved.

Answer: C. The total momentum after the collision is equal to the total momentum before the collision.

Hope this helps

Explanation: Collisions between objects are governed by laws of momentum and energy. When a collision occurs in an isolated system, the total momentum of the system of objects is conserved. ... In the collision between the two cars, total system momentum is conserved.

Answer:

both are done due to the enviroment??

The number of hydrogen atoms required to convert all of the oxygen atoms into nitric acid is 6000.

One molecule of nitric acid has a formula of HNO3, containing one nitrogen atom, one hydrogen atom, and three oxygen atoms. Therefore, if there are 6000 nitrogen atoms and 6000 oxygen atoms present, this means that there are 6000/3 = 2000 nitric acid molecules. Each nitric acid molecule has one hydrogen atom. Therefore, to convert all 6000 oxygen atoms into nitric acid, we need 3 times as many hydrogen atoms, which is 3 x 2000 = 6000 hydrogen atoms. This is because each molecule of nitric acid requires three oxygen atoms and one hydrogen atom.So, the number of hydrogen atoms required to convert all of the oxygen atoms into nitric acid is 6000.

To know more about hydrogen visit:

https://brainly.com/question/30623765

#SPJ11

Answer: it is an importtant resource because it is what keeps most things alive in earth.

Explanation:

The standard free-energy change ΔG° at 25°C for the reaction H2(g) + Br2(l) → 2HBr(g) is -95.6 kJ/mol. The thermodynamic equilibrium constant K is 1.1 × 10^8.

To calculate ΔG°, we need to know the value of R and the temperature in Kelvin. The gas constant R is approximately 8.314 J/(mol·K), and to convert 25°C to Kelvin, we add 273.15 to the temperature, giving us 298.15 K. Plugging these values into the equation, we can solve for ΔG°.

Once we have the value of ΔG°, we can rearrange the equation ΔG° = -RT ln(K) to solve for K. Rearranging the equation gives us K = e^(-ΔG°/(RT)), where e is the base of the natural logarithm.

Therefore, in order to provide the specific value of ΔG° and calculate K, we need the standard free-energy change ΔG° at 25°C for the reaction H2(g) + Br2(l) → 2HBr(g).

To learn more about standard free-energy here brainly.com/question/28237924

#SPJ11

The formula of the coordination compound lithium pentacyanocobaltate(II) is [LiCo(CN)₅]²⁻.

What is lithium pentacyanocobaltate(II) ?

Pentacyanocobaltate attracted attention as an early example of a metal complex that reacts with hydrogen. It contains low-spin cobalt(II) with a doublet ground state.

Let's break down the formula to understand its components:

The central metal ion is cobalt (Co) in the +2 oxidation state, denoted as Co(II).

The ligands are pentacyanocobaltate, which means there are five cyanide ligands (CN⁻) bonded to the cobalt ion.

The coordination complex is negatively charged, with a charge of 2-, so it requires two lithium ions (Li⁺) as counter ions to balance the charge.

Therefore, the complete formula is [LiCo(CN)₅]²⁻, where the square brackets indicate the coordination complex and the superscript 2- indicates the charge.

The formula of the coordination compound pentaamminechlorocobalt(III) nitrate is [Co(NH₃)₅Cl]NO₃.

Breaking down the formula:

The central metal ion is cobalt (Co) in the +3 oxidation state, denoted as Co(III).

The ligands are pentaamminechlorocobalt, indicating there are five ammonia ligands (NH₃) and one chloride ligand (Cl⁻) bonded to the cobalt ion.

There is no need for any counter ions to balance the charge in this compound.

Thus, the complete formula is [Co(NH₃)₅Cl]NO₃, where the square brackets denote the coordination complex, and NO₃ indicates the presence of nitrate ions as the counter ions.

To learn more about lithium pentacyanocobaltate(II) from the given link

https://brainly.com/question/30766130

#SPJ4

Given, the balanced chemical equation is:

2 NH₃(g) → N₂(g) + 3 H₂(g)

The absolute magnitude of the rate of change for [NH₃] is 4.35 m/s.

Therefore, option A is the correct answer.

Given, the balanced chemical equation is:

2 NH₃(g) → N₂(g) + 3 H₂(g)

The rate of change for H2 is 8.70 m/s.

To find the absolute magnitude of the rate of change for [NH₃], we have to use the stoichiometric coefficient in the balanced chemical equation. From the balanced chemical equation, 2 mol NH₃ reacts with 3 mol H₂

We can write,

Rate of change of NH₃ (in m/s) = -1/2 * rate of change of H₂ (in m/s)

So,Rate of change of NH₃ = -1/2 * 8.70 m/s= -4.35 m/s

The absolute magnitude of the rate of change for [NH₃] is 4.35 m/s.

Therefore, option A is the correct answer.

To know more about balanced chemical equation visit:

https://brainly.com/question/14072552

#SPJ11

The one which is a non-electrolyte in aqueous solution among the options is the compound (d) CH4 is the non-electrolyte in aqueous solution.

A non-electrolyte is a substance that does not dissociate into ions when dissolved in water, meaning it does not conduct electricity. In the case of the options provided:

a) NH4F: This compound dissociates into ammonium ions (NH4+) and fluoride ions (F-) in water, making it an electrolyte.

b) NH4Cl: This compound dissociates into ammonium ions (NH4+) and chloride ions (Cl-) in water, making it an electrolyte.

c) NaHS: This compound dissociates into sodium ions (Na+) and hydrogen sulfide ions (HS-) in water, making it an electrolyte.

d) CH4: Methane does not dissociate into ions in water and does not conduct electricity, making it a non-electrolyte.

e) Na2S: This compound dissociates into sodium ions (Na+) and sulfide ions (S2-) in water, making it an electrolyte.

Learn more about non-electrolyte here, https://brainly.com/question/15194255

#SPJ11

The standard enthalpy change for the given reaction is approximately -156.87 kJ.

To calculate the standard enthalpy change (ΔH°) for the given reaction using standard heats of formation, the balanced equation for the reaction is:

Fe(s) + 2HCl(aq) → [tex]FeCl_2[/tex](s) + [tex]H_2[/tex](g)

The standard heats of formation (ΔH°f) for the compounds involved are as follows:

Fe(s): 0 kJ/mol

HCl(aq): -92.31 kJ/mol (source: NIST Chemistry WebBook)

[tex]FeCl_2[/tex](s): -341.49 kJ/mol (source: NIST Chemistry WebBook)

[tex]H_2[/tex](g): 0 kJ/mol

Now, let's calculate the standard enthalpy change (ΔH°):

ΔH° = Σ(ΔH°f products) - Σ(ΔH°f reactants)

ΔH° = [ΔH°f([tex]FeCl_2[/tex]) + ΔH°f([tex]H_2[/tex])] - [ΔH°f(Fe) + 2ΔH°f(HCl)]

ΔH° = [-341.49 kJ/mol + 0 kJ/mol] - [0 kJ/mol + 2(-92.31 kJ/mol)]

ΔH° = -341.49 kJ/mol + 2(92.31 kJ/mol)

ΔH° = -341.49 kJ/mol + 184.62 kJ/mol

ΔH° = -156.87 kJ/mol

To learn more about enthalpy follow the link:

https://brainly.com/question/29145818

#SPJ4

Among the given functions, (a) e^ikx, (c) k, and (d) kx are eigenfunctions of the operator d/dx. The corresponding eigenvalues are (a) ik, (c) 0, and (d) k, respectively.

To determine whether a function is an eigenfunction of the operator d/dx, we need to check if applying d/dx to the function yields a scalar multiple of the original function.

(a) For the function e^ikx, we have d/dx(e^ikx) = ike^ikx. This shows that e^ikx is an eigenfunction of d/dx with an eigenvalue of ik.

(b) Taking the derivative of cos(kx) with respect to x gives us -ksin(kx), which is not proportional to the original function. Therefore, cos(kx) is not an eigenfunction of d/dx.

(c) For the constant function k, d/dx(k) = 0. This implies that k is an eigenfunction of d/dx with an eigenvalue of 0.

(d) The function kx has a derivative of d/dx(kx) = k. Hence, kx is an eigenfunction of d/dx with an eigenvalue of k.

(e) The derivative of e^(-ax^2) with respect to x is -2axe^(-ax^2). Since -2ax is not proportional to e^(-ax^2), e^(-ax^2) is not an eigenfunction of d/dx.

(a) e^ikx, (c) k, and (d) kx are eigenfunctions of d/dx, with corresponding eigenvalues of (a) ik, (c) 0, and (d) k, respectively. On the other hand, (b) cos(kx) and (e) e^(-ax^2) are not eigenfunctions of d/dx.

To learn more about eigenfunctions here brainly.com/question/2289152

#SPJ11

The best statement that describes the reflection of a wave is: When a wave reflects off a surface, it retains its characteristics and changes direction.

A wave is defined as a disturbance that moves through space and matter with the transfer of energy from one place to another. When the wave moves from one medium to another, it reflects off the surface. Reflection of a wave is described as the change in the direction of the wave when it bounces back from the surface on which it strikes.

When a wave reflects off a surface, the angle of incidence is equal to the angle of reflection, which is known as the law of reflection. The normal line, which is perpendicular to the surface, splits the incident and reflected waves at the point of incidence. The angle between the normal line and the incident wave is the angle of incidence, and the angle between the normal line and the reflected wave is the angle of reflection.

You can learn more about Wave at: brainly.com/question/3639648

#SPJ11

The Kb expression for the reaction of propylamine, C3H7NH2, with water is [C3H7NH2][C3H7NH+3][OH−] . Hence, option (c) is correct.

The Kb expression for the reaction of propylamine (C3H7NH2) with water can be determined by considering the equilibrium between the amine (C3H7NH2) and its conjugate acid (C3H7NH+3) with hydroxide ions (OH−) in water. The reaction can be represented as follows:

C3H7NH2 + H2O ⇌ C3H7NH+3 + OH−

The equilibrium constant expression for this reaction, Kb, is given by the product of the concentrations of the products (C3H7NH+3 and OH−) divided by the concentration of the reactant (C3H7NH2):

Kb = [C3H7NH+3][OH−] / [C3H7NH2]

Therefore, the correct Kb expression for the reaction is [C3H7NH2][C3H7NH+3][OH−] (option c).

The Kb expression for the reaction of propylamine, C3H7NH2, with water is [C3H7NH2][C3H7NH+3][OH−] (option c).

To know more about propylamine, visit:

https://brainly.com/question/3131130

#SPJ11

The reaction between CdSO₄ and K₂S is a precipitation reaction where cadmium sulfide precipitates as a solid, while potassium sulfate remains in the aqueous form.

a) The "(s)" in the chemical equation CdS(s) represents that cadmium sulfide is a solid precipitate. It indicates that the product formed in the reaction is solid.

b) The chemical equation for the dissolution of cadmium sulfate (CdSO₄) in water is:

CdSO₄(s) → Cd²⁺(aq) + SO₄²⁻(aq)

The chemical equation for the dissolution of potassium sulfide (K₂S) in water is:

K₂S(s) → 2K⁺(aq) + S²⁻(aq)

c) The difference between potassium sulfate being aqueous (K₂SO₄(aq)) and cadmium sulfide being a solid (CdS(s)) lies in their solubility in water. Potassium sulfate is soluble in water, meaning it dissolves and dissociates into its respective ions (K⁺ and SO₄²⁻) in the solution. On the other hand, cadmium sulfide is insoluble in water and forms a solid precipitate, indicating that it does not dissolve but instead forms solid particles.

In the lab, the difference can be observed by visual inspection. When the reaction between CdSO₄ and K₂S takes place, a yellow precipitate of cadmium sulfide will form, indicating the presence of the solid. The potassium sulfate, being in an aqueous form, will remain dissolved and not form any visible solid.

d) The name for this type of reaction is a precipitation reaction or double displacement reaction. In this reaction, the ions from two compounds exchange to form an insoluble solid (precipitate) and a soluble compound.

In the given reaction between CdSO₄ and K₂S, cadmium sulfide (CdS) is the insoluble solid (precipitate), and potassium sulfate (K₂SO₄) is the soluble compound formed in solution.

Learn more about precipitation reaction here:

https://brainly.com/question/29762381

#SPJ4

Answer:

Where is the chemical equations?

A balanced equation obeys the law of conservation of mass. The coefficient represent the number of molecules in a chemical equation.

An equation in which the number of reactants and products on the both sides of the reaction are equal can be defined as the balanced chemical equation. The coefficient are the numbers in front of the formula.

The coefficients are the numbers that must be added in front of the species involved in the reaction in order to balance it. It tells how many number of atoms or molecules are present in a reaction.

In the reaction N₂ + 3H₂ → 2NH₃ which is called Haber's process.

The coefficients are:

1 for Nitrogen molecule, 3 for Hydrogen molecule and 2 for the compound Ammonia.

Thus coefficients are numbers in front of each formula.

To know more about balanced chemical equation, visit;

https://brainly.com/question/15052184

#SPJ6