A student notices that a flask containing several reagents forms ice crystals on its outer surface as they react. He places the flask in a warm bath to prevent further crystal formation. How would this bath affect the new concentration of product at equilibrium?

Answer:

Molar concentration of [tex]CuSO_4[/tex] solution = 0.0056 moles / liter

Explanation:

Looking at the chemical reaction we realize that the precipitate, formed by adding the iron powder, is cooper.

Then for finding the number of moles of precipitated copper:

[tex] number.of.moles= \frac{mass (g)}{molecular.mass (g/mole)}[/tex]

[tex]number.of.moles.of.solid.copper = \frac{0.089}{63.5} =1.4*10^{3}[/tex]

From the chemical reaction we deduce that [tex]1.4*10^{3}[/tex] moles of Cu equals to [tex]1.4*10^{3}[/tex] moles of [tex]CuSO_4[/tex] in the initial solution.

So molar concentration is defined as:

[tex]molar.concentration = \frac{number.of.moles}{solution.volume (liters)}[/tex]

[tex]molar.concentration.of.CuSO_4.solution= \frac{1.4*10^{3}}{0.250}= 5.6*10^{3} moles/liter = 0.0056 moles/liter[/tex]

Answer:

[tex]M=5.6x10^{-3}M[/tex]

Explanation:

Hello,

In this case, we first must consider the given already-balanced chemical reaction to realize that 89 mg of copper were recovered, moreover we can relate such mass with the employed moles of copper (II) sulfate via this reaction's stoichiometry as follows:

[tex]n_{CuSO_4}=89mg Cu*\frac{1gCu}{1000mgCu} *\frac{1molCu}{63.546gCu} *\frac{1molCuSO_4}{1molCu} \\n_{CuSO_4}=1.4x10^{-3}molCuSO_4[/tex]

Now, if we state the molarity (mol/L) as the required concentration, we apply its mathematical definition as shown below:

[tex]M=\frac{n_{CuSO_4}}{V_{sln}} =\frac{1.4x10^{-3}molCuSO_4}{0.250L} \\M=5.6x10^{-3}M[/tex]

Best regards.

Answer:

For iron

Final temperature = 54,22°C

For copper

Final Temperature = 63.67 °C

Explanation

Hello,

You are using a torch to warm up a block of iron that has an initial temperature of 32°C.

The first you have to know is that the "heat capacity" could simply define as the heat required to go from an initial temperature to a final temperature.

So you need to use the heat capacity equation as follow in the paper.

The equation has to have all terms in the same units, so:

q = 12000 J

s = 0.450 J / g °C

m = 1200 g

Ti = 32 °C

Answer : The fugacity in the solution is, 16 bar.

Explanation : Given,

Fugacity of a pure component = 40 bar

Mole fraction of component  = 0.4

Lewis-Randall rule : It states that in an ideal solution, the fugacity of a component is directly proportional to the mole fraction of the component in the solution.

Now we have to calculate the fugacity in the solution.

Formula used :

[tex]f_i=X_i\times f_i^o[/tex]

where,

[tex]f_i[/tex] = fugacity in the solution

[tex]f_i^o[/tex] = fugacity of a pure component

[tex]X_1[/tex] = mole fraction of component

Now put all the give values in the above formula, we get:

[tex]f_i=0.4\times 40\text{ bar}[/tex]

[tex]f_i=16\text{ bar}[/tex]

Therefore, the fugacity in the solution is, 16 bar.

Answer:

To control reactivity.

Explanation:

One of the natural isotopes of boron (¹⁰B) with an abundance of 20%, has a high neutron cross section, wich means that it can absorb a high number of protons, thus helping in the leakage of protons to the outiside. Boron is usually added to the reactor water in form of boric acid (H₃BO₃).

Answer:

Explanation:

Butane is an alkane and has no multiple bond in it.

The isomers of butane are

a) n-butane

b) t-butane

The structures are shown in the figure.

The most stable radical will be tertiary butyl radical.

The structures are shown in figure.

Answer:

On the attached document.

Explanation:

Hello,

At first, if we're looking for the tertiary arrangement we must consider butane's branched structure which is shown on the attached document whose name is tert-butane. Afterwards, one must remove one hydrogen to let the tert-butyl radical, which is stood for a dot above the tertiary carbon, to be formed.

Best regards.

Answer:

[tex]E_{red}^{0}[/tex] for X is -1.20 V

Explanation:

Oxidation: [tex]2\times[/tex][[tex]X^{2-}(aq.)-2e^{-}\rightarrow X(s)[/tex]]

reduction: [tex]2SO_{3}^{2-}(aq.)+3H_{2}O(l)+4e^{-}\rightarrow S_{2}O_{3}^{2-}(aq.)+6OH^{-}(aq.)[/tex]

---------------------------------------------------------------------------------------------------

overall:[tex]2X^{2-}(aq.)+2SO_{3}^{2-}(aq.)+3H_{2}O(l)\rightarrow 2X(s)+S_{2}O_{3}^{2-}(aq.)+6OH^{-}(aq.)[/tex]

So, [tex]E_{cell}^{0}=E_{red}^{0}(SO_{3}^{2-}\mid S_{2}O_{3}^{2-})-E_{red}^{0}(X\mid X^{2-})[/tex]

or, [tex]0.63=-0.57-E_{red}^{0}(X\mid X^{2-})[/tex]

or, [tex]E_{red}^{0}(X\mid X^{2-})= -1.20[/tex]

So, [tex]E_{red}^{0}[/tex] for X is -1.20 V

Answer: The standard reduction potential of X is -1.20 V

Explanation:

For the given chemical equation:

[tex]2X^{2-}(aq.)+2SO_3^{2-}+3H_2O(l)\rightarrow 2X(s)+S_2O_3^{2-}(aq.)+6OH^-[/tex]

The half reaction follows:

Oxidation half reaction:  [tex]X^{2-}(aq.)\rightarrow X(s)+2e^-[/tex]     ( × 2 )

Reduction half reaction:  [tex]2SO_{3}^{2-}(aq.)+3H_{2}O(l)+4e^{-}\rightarrow S_{2}O_{3}^{2-}(aq.)+6OH^{-}(aq.)E^o=-0.57V[/tex]

Substance getting oxidized always act as anode and the one getting reduced always act as cathode.

To calculate the [tex]E^o_{cell}[/tex] of the reaction, we use the equation:

[tex]E^o_{cell}=E^o_{cathode}-E^o_{anode}[/tex]

We are given:

[tex]E^o_{cell}=0.63V[/tex]

Putting values in above equation, we get:

[tex]0.63=-0.57-E^o_{anode}\\\\E^o_{anode}=-0.57-0.63=-1.20V[/tex]

Hence, the standard reduction potential of X is -1.20 V

Answer:

ACIDIC

Explanation:

Usually beverages contain carbonated water. Carbonated water is the water containing dissolved carbon dioxide gas.

The carbon dioxide gas (CO₂) when dissolved in water produces carbonic acid (H₂CO₃), which makes the drinks acidic in nature.

H₂O(l) + CO₂(g) → H₂CO₃(aq)

This makes the pH of the drinks around 3 - 4.

Therefore, the beverages are usually acidic and not basic.

Final answer:

Beverages can either be acidic or basic based on their pH value. Orange juice is an example of a mildly acidic beverage, while baking soda is an example of a basic beverage.

Explanation:

Beverages can be either acidic or basic. The acidity or basicity of a beverage is determined by its pH value. On the pH scale, which ranges from 0 to 14, anything below 7.0 is considered acidic, and anything above 7.0 is considered basic. The pH of common beverages can vary - for example, orange juice has a pH of approximately 3.5, making it mildly acidic, while baking soda has a pH of 9.0, making it basic.

The toboggan, having initial kinetic energy, gains potential energy as it goes up the hill until it stops. The kinetic energy's conversion into potential energy is described by the equation 0.5 * m * v^2 = m * g * h. TThe toboggan will stop approximately 2.82 m high above the base.

This is a question about kinematics, more specifically potential and kinetic energy conversion in the presence of gravity. In this scenario, the kinetic energy of the toboggan is being converted into potential energy as it climbs up the hill.

The main formula we will use is the energy conservation law: Kinetic Energy = Potential Energy, or 0.5*m*v^2 = m*g*h where:

Even though we do not know the mass of the toboggan, it cancels out in the equation. So the actual height could be evaluated as h = v^2 / (2*g), substituting the given v and g into this formula, h = (11.5)^2 / (2*9.8) ≈ 6.75 m.

The actual vertical height above the base is h' = h * sinθ, where θ is the angle of the hill. Substituting into the formula, h' = 6.75 * sin(25) ≈ 2.82 m. So, the toboggan will go approximately 2.82m high vertically above the base before stopping.

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The toboggan will ascend the hill to a height of approximately 6.75 meters before stopping. This solution was derived using the principles of conservation of energy and kinematics.

This question can be solved using the principles of conservation of energy and kinematics in physics. The toboggan, at the bottom of the hill, possesses kinetic energy (KE) which can be calculated using the formula KE = 1/2 m×v², where 'm' is the mass of the toboggan and 'v' is its speed.

As the toboggan moves up the icy, frictionless hill, this kinetic energy is gradually converted to gravitational potential energy (PE = m×g×h, where 'm' is the mass, 'g' is the acceleration due to gravity, and 'h' is the height). At the point when the toboggan stops, all the kinetic energy has been converted into potential energy.

It's important to note that we don't actually need the mass of the toboggan for this calculation because it cancels out in the equation KE = PE. Rearranging the equation to solve for 'h' gives us h = v² / (2*g)

Substituting the given values (v = 11.5 m/s and g = 9.81 m/s²), we get a height of approximately 6.75 meters. Therefore the toboggan will go up the hill to a height of approximately 6.75 meters above the base before stopping.

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Answer: The limiting reagent in the given equation is lithium metal.

Explanation:

Limiting reagent is defined as the reagent which is present in less amount and also it limits the formation of products.

Excess reagent is defined as the reagent which is present in large amount.

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]   ....(1)

Given mass of lithium metal = 1.50 g

Molar mass of lithium metal = 6.94 g/mol

Putting values in equation 1, we get:  

[tex]\text{Moles of lithium metal}=\frac{1.50g}{6.94g/mol}=0.216mol[/tex]

Given mass of nitrogen gas = 1.50 g

Molar mass of nitrogen gas = 28.01 g/mol

Putting values in equation 1, we get:  

[tex]\text{Moles of nitrogen gas}=\frac{1.50g}{28.01g/mol}=0.053mol[/tex]

[tex]6Li+N_2\rightarrow 2Li_3N[/tex]

By stoichiometry of the reaction:

6 moles of lithium reacts with 1 mole of nitrogen gas

So, 0.216 moles of lithium will react with = [tex]\frac{1}{6}\times 0.216=0.036moles[/tex] of nitrogen gas.

As, the given amount of nitrogen gas is more than the required amount. Thus, it is considered as an excess reagent.

So, lithium metal is considered as a limiting reagent because it limits the formation of products.

In the reaction between lithium and nitrogen to form lithium nitride, lithium is the limiting reactant because we need more lithium than nitrogen for the reaction, but we have less available.

To identify the limiting reactant in a chemical reaction, we need to compare the stoichiometric ratios of the reactants with the given amounts. The balanced equation for the reaction between lithium (Li) and nitrogen (N2) to form lithium nitride (Li3N) is:
6Li + N2 ⟶ 2Li3N

From this balanced equation, we see that six moles of lithium react with one mole of nitrogen. If we first convert the given masses to moles, we find that we have more moles of lithium (0.216 moles) than nitrogen (0.0535 moles). However, considering the stoichiometric ratio from the balanced equation, we need more moles of lithium than nitrogen for the reaction to occur. Therefore, lithium is the limiting reactant here as it will be completely used up before nitrogen is.

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Answer:

a. Are miscible because each can hydrogen bond with the other.

Explanation:

Both ethanol and water are miscible. The reason why they can both mix freely is due to the hydrogen bonds that will form between their molecular structure.

Hydrogen bonds are special dipole-dipole attraction between polar molecules in which hydrogen atoms are directly joined to an electronegative atom.

Ethanol has an hydroxyl group which will bond to form an intermolecular bond with the oxygen and hydrogen on the water molecule. This attraction makes them miscible.

Final answer:

Ethanol and water are miscible because they can form hydrogen bonds with each other, resulting in a homogeneous solution. The polar nature of both substances facilitates this mixing.

Explanation:

When ethanol (C₂H₅OH) is poured into water (H₂O), the two liquids are miscible because each can form hydrogen bonds with the other. This mixing leads to the formation of a single homogeneous solution. This miscibility is due to the polar nature of both ethanol and water, which allows ethanol molecules to hydrogen bond with water molecules, resulting in a stable mixture. In contrast, substances that cannot form such interactions are immiscible, like oil and water, which do not mix to form a homogeneous solution.

Answer:

Mole fraction of alcohols in liquid phase [tex]x_1=0.2727\& x_2=0.7273[/tex].

Mole fraction of alcohols in vapor phase [tex]y_1=0.1468\& y_2=0.8516[/tex].

Explanation:

The total vapor pressure of the solution = p =38.6 Torr

Partial vapor pressure of the  n-propyl alcohol =[tex]p^{o}_1=21.0 Torr[/tex]

Partial vapor pressure of the isopropyl alcohol =[tex]p^{o}_2=45.2 Torr[/tex]

[tex]p=x_1\times p^{o}_1+x_2\times p^{o}_2[/tex]  (Raoult's Law)

[tex]p=x_1\times p^{o}_1+(1-x_1)\times p^{o}_2[/tex]

[tex]38.6 Torr=x_1\times 21.0 Torr+(1-x_1)\times 45.2 Torr[/tex]

[tex]x_1=0.2727[/tex]

[tex]x_2=1-0.2727=0.7273[/tex]

[tex]x_1\& x_2[/tex] is mole fraction in liquid phase.

Mole fraction of components in vapor phase [tex]y_1\& y_2[/tex]

[tex]p_1=y_1\times p[/tex] (Dalton's law of partial pressure)

[tex]y_1=\frac{p_1}{38.6 Torr}=\frac{p^{o}_1\times x_1}{38.6 Torr}[/tex]

[tex]y_1=\frac{21.0 Torr\times 0.2727}{38.6 Torr}=0.1468[/tex]

[tex]y_1=\frac{p_2}{38.6 Torr}=\frac{p^{o}_2\times x_2}{38.6 Torr}[/tex]

[tex]y_2=\frac{45.2 Torr\times 0.7273}{38.6 Torr}=0.8516[/tex]

Mole fraction of alcohols in vapor phase [tex]y_1=0.1468\& y_2=0.8516[/tex]

Answer:

The minimum molarity of acetic acid in vinegar according to given standards is 0.6660 mol/L.

Explanation:

4% acetic acid by mass means that 4 gram of acetic acid in 100 g solution.

Given that density of the vinegar is same is that of water =  1 g/mL

Mass of the vinegar solution = 100 g

Volume of the vinegar solution = V

[tex]Density=\frac{Mass}{Volume}[/tex]

[tex]1 g/mL=\frac{100 g}{V}[/tex]

V = 100 mL = 0.1 L

Moles of acetic acid =[tex]\frac{4 g}{60.052 g/mol}=0.0666 mol[/tex]

[tex]Molarity=\frac{\text{Moles of solute}}{\text{Volume of solution(L)}}[/tex]

[tex]M=\frac{0.0666 mol}{0.1 L}=0.6660 mol/L[/tex]

The minimum molarity of acetic acid in vinegar according to given standards is 0.6660 mol/L.

Explanation:

According to the ideal gas equation, PV = nRT.

So,           V = [tex]\frac{nRT}{P}[/tex]       ......... (1)

Since, it is given that volume of the gas is increases. So, change in volume will be as follows.

               [tex]\Delta V = V_{f} - V_{i}[/tex]

Hence, equation (1) will become as follows.

       [tex]\Delta V[/tex] = [tex]\frac{nRT_{f}}{P} - \frac{nRT_{i}}{P}[/tex]

             [tex]P \Delta V[/tex] = nR[tex](T_{f} - T_{i})[/tex]

Therefore, work done on the gas will be given as follows.

                       W = - P [tex]\Delta V[/tex]

                           = [tex]-n \times R(T_{f} - T_{i})[/tex]    

                           = [tex]- 0.0180 mol \times 8.31 atm L/mol K (340^{o}C - 18.5^{o}C)[/tex]                    

                           = 48.09 J

Thus, we can conclude that work done on the gas is 48.09 J.

Answer :

(a) The value of [tex]K_p[/tex] is, [tex]5.0\times 10^{-4}[/tex]

(b) The value of [tex]K_c[/tex] is, [tex]3.83\times 10^{-2}[/tex]

Explanation:

(a) We have to determine the value of [tex]K_p[/tex].

The given balanced reaction is,

[tex]2A(g)+2B(g)\rightleftharpoons C(g)[/tex]

The relation between [tex]K_p[/tex] and [tex]K_c[/tex] are :

[tex]K_p=K_c\times (RT)^{\Delta n}[/tex]

where,

[tex]K_p[/tex] = equilibrium constant at constant pressure = ?

[tex]K_c[/tex] = equilibrium concentration constant = 55.6

R = gas constant = 0.08206 L⋅atm/(K⋅mol)

T = temperature = [tex]313^oC=273+313=586K[/tex]

[tex]\Delta n[/tex] = change in the number of moles of gas = [1 - (2 + 2)] = -3

Now put all the given values in the above relation, we get:

[tex]K_p=55.6\times (0.08206L.atm/K.mol\times 586K)^{-3}[/tex]

[tex]K_p=0.00050=5.0\times 10^{-4}[/tex]

The value of [tex]K_p[/tex] is, [tex]5.0\times 10^{-4}[/tex]

(b) We have to determine the value of [tex]K_c[/tex].

The given balanced reaction is,

[tex]X(g)+2Y(g)\rightleftharpoons 3Z(g)[/tex]

The relation between [tex]K_p[/tex] and [tex]K_c[/tex] are :

[tex]K_p=K_c\times (RT)^{\Delta n}[/tex]

where,

[tex]K_p[/tex] = equilibrium constant at constant pressure = [tex]3.83\times 10^{-2}[/tex]

[tex]K_c[/tex] = equilibrium concentration constant = ?

R = gas constant = 0.08206 L⋅atm/(K⋅mol)

T = temperature = [tex]119^oC=273+119=392K[/tex]

[tex]\Delta n[/tex] = change in the number of moles of gas = [3 - (2 + 1)] = 0

Now put all the given values in the above relation, we get:

[tex]3.83\times 10^{-2}=K_c\times (0.08206L.atm/K.mol\times 392K)^{0}[/tex]

[tex]K_c=3.83\times 10^{-2}[/tex]

The value of [tex]K_c[/tex] is, [tex]3.83\times 10^{-2}[/tex]

To calculate Kp for the reaction 2A(g) + 2B(g) ⇌ C(g) with Kc = 55.6 at 313 °C, convert the temperature to Kelvin, use Δn = -3, and apply the formula Kp = Kc(RT)Δn. Calculating Kp gives its value. To find Kc for the reaction X(g) + 2Y(g) ⇌ 3Z(g) where Kp is given at 119 °C, convert temperature to Kelvin, use Δn = 0, and Kp = Kc, giving Kc = 3.83×10⁻².

To calculate the equilibrium constant Kp for the reaction 2A(g) + 2B(g) ⇌ C(g), where Kc = 55.6 at a temperature of 313 °C. First, we convert the temperature to Kelvin by adding 273.15 to the Celsius temperature. The temperature in Kelvin is T = 313 + 273.15 = 586.15 K. We use the equation Kp = Kc(RT)Δn, where Δn is the change in moles of gas, R is the ideal gas constant 0.08206 L·atm/(K·mol), and T is the absolute temperature in Kelvin.

For the reaction, Δn = 1 - (2 + 2) = -3. Plugging values into the equation: Kp = 55.6 x (0.08206 L·atm/(K·mol) x 586.15 K)^-3. Calculating Kp gives the value of Kp for this reaction.

To find Kc from Kp for the reaction X(g) + 2Y(g) ⇌ 3Z(g), where Kp = 3.83×10⁻² at a temperature of 119 °C, we again convert to Kelvin (119 + 273.15 = 392.15 K), and this time Δn = 3 - (1 + 2) = 0. With Δn = 0, Kp = Kc, so Kc = 3.83×10⁻² for this reaction.

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Answer:

D: More than one Answer is correct.

Explanation:

The enzyme at the heart of the question is peroxidase.The reaction of enzyme catalase with hydrogen peroxide produces oxygen gas.   This catalase enzyme is present in all the above mentioned vegetables, i.e. radish, cabbage as well as carrot.

So more than one answer is correct in this case.

More than one of the listed items could cause the evolution of gas when added to hydrogen peroxide, as each can contain enzymes that act as catalysts for the decomposition of hydrogen peroxide. Hence option d More than one answer is correct.

The question is related to the decomposition of hydrogen peroxide (H₂O₂) and the role of catalysts in this chemical process. The decomposition reaction is known as the breakdown reaction happens when a single reactant splits into two or more products.  Hydrogen peroxide has the ability to decompose into water and oxygen gas, but in the absence of a catalyst, this reaction is slow. When a catalyst like manganese (IV) oxide is added to a solution of hydrogen peroxide, it speeds up the reaction, leading to the rapid evolution of oxygen gas without being consumed in the process. As for the answer to the question, raw carrot, cabbage, or radish contain various enzymes that could act as potential catalysts. Therefore, more than one answer is correct as each of these foods could potentially contain enzymes that catalyze the decomposition of hydrogen peroxide, leading to the evolution of gas.

Answer:

The correct answer is: Dynamic equilibrium in a chemical reaction is the condition in which the rate of the forward reaction equals the rate of the reverse reaction.

Explanation:

Dynamic equilibrium is a chemical equilibrium between froward reaction and backward or reverse reaction where rate of reaction going forwards is equal to the rate of reaction going backward (reverse).  

Some other properties of dynamic equilibrium are:

Answer:

B: At dynamic equilibrium, the rate of the forward reaction is higher than the rate of the reverse reaction.

Answer : The pressure of the liquid at depth of 48 ft below the surface of fluid is, 21 psi.

Explanation : Given,

The pressure of the liquid at depth 8 ft = 3.5 psi

Now we have to calculate the pressure of the liquid at depth 28 ft.

According to the question,

As, the depth of 8 ft below the surface of a stagnant fluid has pressure = 3.5 psi

So, the depth of 48 ft below the surface of a stagnant fluid has pressure = [tex]\frac{3.5\text{ psi}}{8\text{ ft}}\times 48\text{ ft}=21\text{ psi}[/tex]

Therefore, the pressure of the liquid at depth of 48 ft below the surface of fluid is, 21 psi.

Answer:

[tex]\boxed{3}[/tex]

Explanation:

The Rydberg equation gives the wavelength λ for the transitions:

[tex]\dfrac{1}{\lambda} = R \left ( \dfrac{1}{n_{i}^{2}} - \dfrac{1}{n_{f}^{2}} \right )[/tex]

where

R= the Rydberg constant (1.0974 ×10⁷ m⁻¹) and

[tex]\text{$n_{i}$ and $n_{f}$ are the numbers of the energy levels}[/tex]

Data:

[tex]n_{f} = 2[/tex]

λ = 657 nm

Calculation:  

[tex]\begin{array}{rcl}\dfrac{1}{657 \times 10^{-9}} & = & 1.0974 \times 10^{7}\left ( \dfrac{1}{2^{2}} - \dfrac{1}{n_{f}^{2}} \right )\\\\1.522 \times 10^{6} &= &1.0974\times10^{7}\left(\dfrac{1}{4} - \dfrac{1}{n_{f}^{2}} \right )\\\\0.1387 & = &\dfrac{1}{4} - \dfrac{1}{n_{f}^{2}} \\\\-0.1113 & = & -\dfrac{1}{n_{f}^{2}} \\\\n_{f}^{2} & = & \dfrac{1}{0.1113}\\\\n_{f}^{2} & = & 8.98\\n_{f} & = & 2.997 \approx \mathbf{3}\\\end{array}\\\text{The value of $n_{i}$ is }\boxed{\mathbf{3}}[/tex]

Using Bohr's model and the energy-wavelength relationship for photons, we can explore the transition of an electron in a hydrogen atom from a higher energy level to a lower one. Given the emitted photon's wavelength is 657 nm, we can calculate the energy difference that represents this transition. Substituting these values into the formula, we get an approximation for the initial principal quantum number ni.

The question pertains to the transition of an electron in a hydrogen atom from a higher principle quantum state (ni) to a lower principle quantum state (n=2). The wavelength of the emitted photon during this transition is 657 nm. The energy levels of atoms are quantized, and this is especially evident in the hydrogen atom. According to Bohr's model, the energy of each level is given by the equation E=-13.6/n² eV, where n is the principal quantum number. The difference in energy ∆E between two levels ni and nf (final), given that energy has to be conserved during the transition, is given to the photon.

 Given this information, and the relationship between energy and wavelength of a photon (E=hc/λ where h is Planck's constant, c is the speed of light, and λ is the wavelength), we can determine the starting principal quantum number, ni. Emission of photons means energy is released from the atom, and hence ∆E = Ef - Ei, will be negative; i.e., the energy of the final state is lesser than the initial state. Substituting the values, we get ni as the integral part of the solution.

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Answer:

70.77 g/mol is the molar mass of the unknown gas.

Explanation:

Effusion is defined as rate of change of volume with respect to time.

Rate of Effusion=[tex]\frac{Volume}{Time}[/tex]

Effusion rate of oxygen gas after time t = [tex]E=\frac{4.64 mL}{t}[/tex]

Molar mass of oxygen gas = M = 32 g/mol

Effusion rate of unknown gas after time t = [tex]E'=\frac{3.12 mL}{t}[/tex]

Molar mass of unknown gas = M'

The rate of diffusion of gas, we use Graham's Law.

This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows:

[tex]\text{Rate of effusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}[/tex]

[tex]\frac{E}{E'}=\sqrt{\frac{M'}{M}}[/tex]

[tex]\frac{\frac{4.64 mL}{t}}{\frac{3.12 mL}{t}}=\sqrt{\frac{M'}{32 g/mol}}[/tex]

M' = 70.77 g/mol

70.77 g/mol is the molar mass of the unknown gas.

Under identical conditions 4.64 mL of O₂ and 3.12 mL of an unknown gas effuse for the same time. The molar mass of the unknown gas is 70.1 g/mol.

Graham's law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

r ∝ 1/√M

where,

Under identical conditions and after the same amount of time (t), 4.64 mL of O₂ and 3.12 mL of an unknown gas X effuse. The ratio of their rates of effusion is:

[tex]\frac{rO_2}{rX} = \frac{\frac{vO_2}{t} }{\frac{vX}{t} } = \frac{vO_2}{vX} = \frac{4.64 mL}{3.12 mL} = 1.48[/tex]

We can calculate the molar mass of the unknown gas by applying Graham's law.

[tex]\frac{rO_2}{rX} = 1.48 = \sqrt{\frac{M(X)}{M(O_2)} } = \sqrt{\frac{M(X)}{32.00 g/mol} }\\\\M(X) = 70.1 g/mol[/tex]

Under identical conditions 4.64 mL of O₂ and 3.12 mL of an unknown gas effuse for the same time. The molar mass of the unknown gas is 70.1 g/mol.

Learn more about Graham's law here: https://brainly.com/question/22359712

Explanation:

Suppose in 100 g of alloy contains 90% titanium 6% aluminum and 4% vanadium.

Mass of titanium = 90 g

Moles of titanium = [tex]\frac{90 g}{47.87 g/mol}=1.8800 mol[/tex]

Total number of atoms of titanium ,[tex]a_t=1.8800 mol\times N_A[/tex]

Mass of aluminum = 6 g

Moles of aluminium = [tex]\frac{6 g}{26.98 g/mol}=0.2223 mol[/tex]

Total number of atoms of aluminium,[tex]a_a=0.2223 mol\times N_A[/tex]

Mass of vanadium  = 4 g

Moles of vanadium= [tex]\frac{4 g}{50.94 g/mol}=0.0785 mol[/tex]

Total number of atoms of vanadium[tex]a_v=0.0785 mol\times N_A[/tex]

Total number of atoms in an alloy = [tex]a_t+a_a+a_v[/tex]

Atomic percentage:

[tex]Atomic\%=\frac{\text{total atoms of element}}{\text{Total atoms in alloy}}\times 100[/tex]

Atomic percentage of titanium:

:[tex]\frac{a_t}{a_t+a_a+a_v}\times 100=\frac{1.8800 mol\times N_A}{1.8800 mol\times N_A+0.2223 mol\times N_A+0.0785 mol\times N_A}\times 100=86.20\%[/tex]

Atomic percentage of Aluminium:

:[tex]\frac{a_a}{a_t+a_a+a_v}\times 100=\frac{0.2223 mol\times N_A}{1.8800 mol\times N_A+0.2223 mol\times N_A+0.0785 mol\times N_A}\times 100=10.19\%[/tex]

Atomic percentage of vanadium

:[tex]\frac{a_v}{a_t+a_a+a_v}\times 100=\frac{0.0785 mol\times N_A}{1.8800 mol\times N_A+0.2223 mol\times N_A+0.0785 mol\times N_A}\times 100=3.59\%[/tex]

Answer: Both the salts are basic salts.

Explanation:

Salts are formed when an acid reacts with a base during a neutralization reaction.

When a strong acid and a weak base reacts, it leads to the formation of acidic salt.

When a strong base and weak acid reacts, it leads to the formation of basic salt.

When a strong acid and strong base or weak acid and weak base reacts, it leads to the formation of neutral salts.

[tex]Ba_3(PO_4)_2[/tex] is a salt which is formed by the combination of [tex]H_3PO_4\text{ and }Ba(OH)_2[/tex]. Phosphoric acid is a weak acid and barium hydroxide is a strong base. So, the given salt is a basic salt.

[tex]NaCN[/tex] is a salt which is formed by the combination of [tex]HCN\text{ and }NaOH[/tex]. Hydrogen cyanide is a weak acid and sodium hydroxide is a strong base. So, the given salt is a basic salt.

Hence, both the salts are basic salts.

Ba3(PO4)2 forms a basic solution due to the phosphate ions derived from a weak acid, while NaCN also yields a basic solution because the cyanide ion acts as a weak base.

To determine whether an aqueous solution of a salt is acidic, basic, or neutral, one can consider the hydrolysis of the ions formed when the salt dissolves in water. The acid or base strength of the parent acid and base from which the salt is derived plays a key role in this behavior.

Regarding Ba3(PO4)2, barium ions (Ba2+) are from a strong base (barium hydroxide, Ba(OH)2), and phosphate ions (PO43-) are from a weak acid (phosphoric acid, H3PO4). The Ba2+ ion does not hydrolyze significantly because it is from a strong base, whereas the PO43- ions will hydrolyze to produce hydroxide ions (OH-), making the solution basic.

For NaCN, the sodium ion (Na+) does not affect the pH since it is from a strong base (sodium hydroxide, NaOH). However, the cyanide ion (CN-) is a weak base since it comes from a weak acid (hydrocyanic acid, HCN). Therefore, the CN- ion will accept protons from water to produce hydroxide ions (OH-), resulting in a basic solution.

Answer:

(a) backward direction

(b) forward direction

(c) no change

Explanation:

(a)

On increasing the concentration of NO , the reaction will go in backward direction , as, according to le chatelier's principle ,

In a chemical equilibrium , when the concentration , pressure or temperature is changed , the equilibrium of the reaction is disturbed , hence, in order to gain attain the equilibrium the reaction moves in order to counteract the changes.

So, in this case, the reaction goes back , to reduce the increased concentration of NO.

(b)

On increasing the concentration of NO2 , the reaction goes in forward direction ,

according to le chatelier's principle ,

the reaction moves in forward direction , to reduce the increased concentration of NO2.

(c)

No change ,

As, changing the volume , does not effect change in the concentration,

Hence,

No change , as the system is allowed to expand to 5 times its initial value.

hey there!:

A) Knowing theatre the protease is showing the highest activity at pH 4-6, implies that the amino acid that amino acid that it is acting in is an amino acid with a basic side chain. Therefore, the residues can be any one of the three basic amino acids being histidine, arginine or lysine , having basic side chains at neutral pH.

b) The mechanism of reaction of cysteine proteases is as follows:

 First step in the reaction is the deprotonation of a thiol in the cysteine proteases's active site by an adjacent amino acid with a basic side chain, which might be a histidine residue. This is followed by a nucleophilic attack by the anionic sulfur of the deprotonated cysteine on the substrate carbonyl carbon.

Here, a part of the substrate is released with an amine terminus, restoring the His into a deprotonated form, thus forming a thioester intermediate, forming a link between the carboxy-terminal of the substrate and cysteine, resulting in thiol formation. Thus the name thiol proteases. The thioester bond is then hydrolyzed into a carboxylic acid moiety while again forming the free enzyme.

C) cysteine proteases have a pka of 8-9 but when they are deprotonated by a His residue, their pka would come down to 6-8, which would be their optimal pH for functioning. This is because there is a deprotonation of the thiol group , later restoring the HIS deprotonated form and then formation of a thioester bond. This thioester bond when hydrolysed will a carboxylate moeity , which is responsible for bringing the pH down towards a more acidic side.  

d) at the optimal pH , the fraction of deprotonated cysteine and protonated B will be equal which will change with the change in pH.

Hope this helps!

Answer: Option (1) is the correct answer.

Explanation:

Melting point is defined as the point at which a solid state of a substance starts to melt and it converts into liquid state.

Also, it is known that more is the number of linear carbon atoms attached to each other, more is the melting point of a substance. Whereas more is the branching present in a compound least will be its melting point.

For example, [tex]CH_{3}CH_{2}CH_{2}CH_{2}CH_{2}COOH[/tex] has only 5 carbon atoms attached to carboxylic acid group. Whereas [tex]CH_{3}CH_{2}CH_{2}CH_{2}CH_{2}CH_{2}CH_{2}CH_{2}CH_{2}COOH[/tex] has 9 carbon atoms attached to carboxylic acid group.

Therefore, compound [tex]CH_{3}CH_{2}CH_{2}CH_{2}CH_{2}COOH[/tex] will have low melting point.

Thus, we can conclude that out of the given options, fatty acid [tex]CH_{3}CH_{2}CH_{2}CH_{2}CH_{2}COOH[/tex] has the lowest melting point.

Answer:Kindly find the structure of A and B in attachment.

Explanation:

Lindlars catalyst is basically a palladium metal based catalyst which reduces specifically the alkynes to just alkenes and only reduce them in cis manner.

The palladium catalyst is poisoned by lead or quinoline so that the reduction reaction can be stopped at a point when alkynes are just reduced to alkenes because palladium in presence of hydrogen reduces the alkyne completely to alkane.

So lindlars catalys is very specific in its action and even in terms of stereochemistry as it only reduces alkynes to alkenes and the stereochemistry of reduced alkyne is cis.

The general formula of lindlars catalyst is : 5%Pd-CaCO3,Pb(OCOCH3)2 and quinoline.

A chiral alkyne would have all 4 different substituents present at the carbon next to triple bond.

since the reduction of chiral alkyne A would be done using Lindlars catalyst hence the reduced product formed would have Cis -stereochemistry.

The structures of A&B are drawn in attachments. Kindly find in attachment.

The chiral alkyne is 2-hexyne and when it's reduced using H2 and Lindlar catalyst, it forms cis-2-hexene which has the R configuration at its stereogenic center.

The molecule A is a chiral alkyne with the molecular formula C6H10. This indicates that this alkyne molecule contains a chiral center. The most likely structure is 2-hexyne (CH3CH2C≡CCH2CH3), which features a triple bond between the 2nd and 3rd carbons.

When reduced with H2 and Lindlar catalyst, the molecule A is converted into molecule B. The Lindlar catalyst is used specifically to reduce alkynes to cis-alkenes. Thus, molecule B would be cis-2-hexene (CH3CH2CH=CHCH2CH3) as this is the alkene version with a chiral center.

It is specified that molecule B has the R configuration at its stereogenic center. The R or S configuration can be determined by the Cahn-Ingold-Prelog (CIP) priority rules. In the case of cis-2-hexene, assuming the hydrogen atom is bonded to the chiral carbon, a clockwise (R) configuration can be achieved.

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Answer:

37 mmol of acetate need to add to this solution.

Explanation:

Acetic acid is an weak acid. According to Henderson-Hasselbalch equation for a buffer consist of weak acid (acetic acid) and its conjugate base (acetate)-

[tex]pH=pK_{a}(acetic acid)+log[\frac{mmol of CH_{3}COO^{-}}{mmol of CH_{3}COOH }][/tex]

Here pH is 5.31, [tex]pK_{a}[/tex] (acetic acid) is 4.74 and number of mmol of acetic acid is 10 mmol.

Plug in all the values in the above equation:

[tex]5.31=4.74+log[\frac{mmol of CH_{3}COO^{-}}{10}][/tex]

or, mmol of [tex]CH_{3}COO^{-}[/tex] = 37

So 37 mmol of acetate need to add to this solution.

hey there!:

2HgO (s) =>  2Hg (l) + O2 (g)

2 moles of HgO decompose to form 2 moles of Hg and 1 mole of O2 according to the reaction mentioned in the question.

So 4.00 moles of HgO must give 4 moles of Hg and 2 moles of O2 theoretically.

603 g of Hg = 603 / 200.6 = 3 moles

Percent yield = ( actual yield / theoretical yield) * 100

= ( 3/4) * 100

= 75 %

Hope this helps!

Answer: The percent yield of the reaction is 75 %

Explanation:

We are given:

Moles of HgO decomposed = 4.00 moles

The given chemical reaction follows:

[tex]2HgO(s)\rightarrow 2Hg(l)+O_2(g)[/tex]

By Stoichiometry of the reaction:

2 moles of HgO produces 1 moles of oxygen gas

So, 4.00 moles of HgO will produce = [tex]\frac{1}{2}\times 4.00=2mol[/tex] of oxygen gas

To calculate the percentage yield of the reaction, we use the equation:

[tex]\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100[/tex]

Experimental yield of oxygen gas = 1.50 moles

Theoretical yield of oxygen gas = 2.00 moles

Putting values in above equation, we get:

[tex]\%\text{ yield of oxygen gas}=\frac{1.50}{2.00}\times 100\\\\\% \text{yield of oxygen gas}=75\%[/tex]

Hence, the percent yield of the reaction is 75 %

Cyclopentadiene is unusually acidic for a hydrocarbon because its conjugate base, the cyclopentadienyl anion, is aromatic and thus highly stable, unlike an unstable diradical.

Cyclopentadiene is unusually acidic for a hydrocarbon due to its ability to form a stable cyclopentadienyl anion, which is aromatic after deprotonation. When a hydrogen atom is removed from cyclopentadiene, the remaining electrons are delocalized around the ring structure, satisfying Huckel's rule (4n+2 π electrons, where n is a non-negative integer), and thus making the anion particularly stable. The conjugate base of cyclopentadiene is not an unstable diradical; instead, it is stabilized by the delocalization of electrons which is a characteristic feature of aromatic compounds like benzene. For comparison, in cyclohexane and other cycloalkanes, carbon atoms are sp³ hybridized and the rings feature different conformations that alleviate strain, such as the chair conformation in cyclohexane, which has minimal ring strain and no aromatic stabilization.

Answer:

2C₈H₁₈(g) + 25O₂(g)→16CO₂(g) + 18H₂O

Explanation:

To balance an equation, the moles of one element on one side of the equation should be the same as those on the other side of the equation. This is because (as a law of thermodynamics), in a chemical reaction, the matter is not destroyed nor created - atoms are only rearranged.

Answer: The coefficients are 2, 17, 8 and 18

Explanation:

A balanced chemical equation always follow law of conservation of mass.

This law states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form. This also means that total number of individual atoms on reactant side must be equal to the total number of individual atoms on the product side.  

For the given chemical reaction, the balanced equation follows:

[tex]2C_8H_{18}(g)+25O_2(g)\rightarrow 16CO_2(g)+18H_2O(g)[/tex]

By Stoichiometry of the reaction:

2 moles of octane reacts with 25 moles of oxygen gas to produce 16 moles of carbon dioxide gas and 18 moles of water vapor.

Hence, the coefficients are 2, 25, 16 and 18