The standard Gibbs free energy of formation of ________ is zero. (
a. Rb(s) (
b. H2(
g. (
c. Pb(s)

The mass of aluminum, the heat energy equation Q = mcΔT is used with the given values, resulting in a calculated mass of 12 grams.

The mass of aluminum using the given energy, temperature change, and specific heat capacity, we employ the formula for heat transfer: Q = mcΔT, where Q is the heat energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature.

Given that Q = 216 J, c = 0.90 J/°C·g, and ΔT = (35 - 15)°C = 20°C, we can rearrange the equation to solve for m:

m = Q / (cΔT) = 216 J / (0.90 J/°C·g · 20°C) = 216 J / (18 J/g) = 12 g

Therefore, the mass of aluminum is 12 grams.

he is right he is correct

Methanol is the most plausible candidate among these potential contaminants because its oxygen content is closest to the reported mass percent of oxygen in the sample (49.7%).

The proportional amount of a certain component (typically a substance or element) in a combination, compound, or solution is expressed as mass percent (also known as weight percent or weightage). It is a percentage that represents the component's mass in relation to the overall mass of the combination, compound, or solution multiplied by 100.

molecular formula mass of [tex]\rm C_6H_{12}O_6[/tex] = 180.18 g/mol

mass percent of oxygen is

(96.00 g/mol / 180.18 g/mol) × 100%

≈ 53.3%

In water, the mass percent of oxygen is:

(16.00 g/mol / 18.02 g/mol) × 100%

≈ 88.9%

In formaldehyde, the mass percent of oxygen is:

(16.00 g/mol / 30.03 g/mol) × 100%

≈ 53.3%

In methanol, the mass percent of oxygen is:

(16.00 g/mol / 32.04 g/mol) × 100%

≈ 50.0%

To know more about mass percent, here:

https://brainly.com/question/14990953

#SPJ12

The molar mass of the solute is calculated by first finding the molality of the solution using the freezing point depression, then using this to find the number of moles of solute, and finally dividing the mass of the solute by the number of moles. The computed molar mass of the solute is 62.15 g/mol.

To calculate the molar mass of the solute, we first need to calculate the molality of the solution using the freezing point depression formula, ΔTf = iKfm, where i is the van't Hoff factor (which is 1 for a non-electrolyte), Kf is the freezing point depression constant for water (1.86°C/m), and m is molality. We know that ΔTf = -1.23°C. So, molality can be determined as follows: m = ΔTf / (i x Kf) = -1.23°C / (1 x 1.86°C/m) = -0.66mol/kg.

Molality is defined as moles of solute per kilogram of solvent. Therefore, if we multiply the molality by the mass of the solvent (105g or 0.105kg), we get the moles of solute. Moles of solute = m x mass of solvent = -0.66mol/kg x 0.105kg = -0.0693mol.

Finally, to determine the molar mass of the solute, we divide the mass of the solute by the number of moles. Molar mass = mass of solute / moles of solute = 4.305g / -0.0693mol = -62.15g/mol. The negative sign indicates a freezing point depression, but the molar mass of a substance cannot be negative. Therefore, the molar mass of the solute is 62.15g/mol.

https://brainly.com/question/25879634

#SPJ11

The correct formula for sodium hydroxide in the given word equation is NaOH.

The word equation provided is:

[tex]\[ \text{sodium oxide} + \text{water} \rightarrow \text{sodium hydroxide} \][/tex]

To represent this equation with chemical formulas, we need to know the formulas for each compound:

- Sodium oxide (Na2O) is an ionic compound composed of sodium ions (Na+) and oxide ions (O2-).

- Water (H2O) is a molecular compound composed of two hydrogen atoms and one oxygen atom.

- Sodium hydroxide (NaOH) is an ionic compound composed of sodium ions (Na+) and hydroxide ions (OH-).

The balanced chemical equation for the reaction is:

[tex]\[ \text{Na}_2\text{O} + \text{H}_2\text{O} \rightarrow 2\text{NaOH} \][/tex]

This equation shows that sodium oxide reacts with water to form sodium hydroxide. The formula for sodium hydroxide is NaOH, which consists of one sodium ion (Na+) and one hydroxide ion (OH-). The coefficient 2 in front of NaOH indicates that two moles of sodium hydroxide are produced for every mole of sodium oxide and water that react.

Answer : Any natural sources of CFC's are not known only the major sources like aerosols, propellants, refrigerants,etc are known. So, if any natural sources are given then it cannot be called as a major source for emitting CFC into environment.

Answer:

• televisions

Approximately 21.4 kJ of energy is needed to convert 64.0 grams of ice at 0.00°C to liquid water at the same temperature. This is calculated using the concept of 'enthalpy of fusion', which is the energy required to convert a substance from solid to liquid without changing its temperature.

To find out how much energy is needed to convert 64.0 grams of ice at 0.00°C to water at the same temperature, we should first understand that the melting of ice is an endothermic process, meaning it requires energy. The energy required to convert a substance from solid to liquid state without changing its temperature is termed the enthalpy of fusion.

For water, the enthalpy of fusion is 334 kJ/kg. However, our given mass is in grams, so we need to convert it to kilograms, thus we have 0.064 kg of ice. Using the formula Q=mLf (where Q is energy, m is mass, and Lf is the enthalpy of fusion), we can calculate the necessary energy: Q = (0.064 kg)(334 kJ/kg) = 21.376 kJ.

So, approximatley 21.4 kJ of energy is required to convert 64.0 grams of ice at 0.00°C into water at the same temperature.

https://brainly.com/question/32361849

#SPJ3

Solubility product constant (Ksp) is applied to the saturated ionic solutions which are in equilibrium with its solid form. The solid is partially dissociated into its ions.

For the BaF, the dissociation as follows;
BaF₂(s) ⇄ Ba²⁺(aq) + 2F⁻(aq)

Hence,
        Ksp = [Ba²⁺(aq)] [F⁻(aq)]²

When 0.440 mol of aluminum react with excess chlorine gas, 0.440 mol of aluminum chloride are produced according to the 1:1 stoichiometric ratio in the balanced chemical equation.

When 0.440 mol of aluminum are allowed to react with an excess of chlorine gas (Cl2), to determine how many moles of aluminum chloride (AlCl3) are produced, we look at the stoichiometry of the balanced equation:

2 Al (s) + 3 Cl2 (g) → 2 AlCl3 (s)

This reaction shows that 2 moles of aluminum react with 3 moles of chlorine gas to produce 2 moles of aluminum chloride. Given the stoichiometry is a 1:1 ratio between aluminum and aluminum chloride, if you start with 0.440 mol of aluminum, you would end up producing 0.440 mol of aluminum chloride as well, provided chlorine is in excess.

Answer:

Sodium chloride, regular table salt, is also known as the mineral halite. The diagram to the right shows how sodium and chlorine atoms pack tightly together to form cube-like units of the compound NaCl

Explanation:

Answer : The process in which sediment is dropped and comes to rest is called, Deposition.

Explanation:

Deposition : It is a type of process in which the molecules are settle down at the bottom of the container. In this process, there is no intermolecular space present between the atoms of molecule.

This process results in the formation of the sedimentary rocks which are made out of ice, wind and water flows which carry particles in the suspension.

Hence, the process in which sediment is dropped and comes to rest is called, Deposition.

The electrochemical cell in the diagram is an electrolytic cell used for gold plating. Electroplating is an electrolytic process used to coat metal objects with a more expensive and less reactive metal. The metal to be plated is used as the anode and the electrolyte solution contains the ions of the metal to be plated.

In the diagram, the gold strip on the left is connected to the positive terminal of the battery and is anode. The aluminum glasses on the right is connected to negative terminal of the battery and is cathode. Anode is positive electrode and cathode is negative.

When the power is switched on, the electrolyte solution splits into ions. Positively charged Au³⁺ ions are attracted to the negatively charged cathode, aluminum glasses and slowly deposit on it. The negatively charged ions are attracted to positively charged anode, the gold strip and release electrons. The electrons move through battery towards the cathode.

Au goes into the solution at the anode and get reduced at the cathode, and is thus plated. A constant concentration of Au³⁺ is maintained in the electrolyte solution surrounding the electrodes.

Anode: Au(s) → Au³⁺(aq) + 3e-​ ............(oxidation)

Cathode: Au³⁺(aq) + 3e​- → Au(s) .........(reduction)

The all substances that participate in the reaction are in gaseous phase and the given data are the concentrations when the reaction at equilibrium. Hence, we can use that given concentrations directly to find out the equilibrium constant, Kc.

The balanced equation for the equilibrium is,

                 2SO₂(g) + O₂(g) ⇄ 2SO₃(g)

Kc = [SO₃(g)]² / [SO₂(g)]² [O₂(g)]
Kc = (4 mol/L)² / (2 mol/L)² (1 mol/L)
Kc = 4 mol⁻¹ L

Hence, the equilibrium constant is 4 mol⁻¹ L

Answer:

0.952 °C

Explanation:

The change in melting point is computed as:

ΔT = k*m*i

where ΔT is the difference between the melting point of water and of solution, k is a constant (1.86 °C*kg/mol for water), i is the van't Hoff factor (equal to 2 for sodium chloride because 2 ions are obtained after its dissolution), and m is the molality of the solution.

Molar mass of sodium chloride: 58.44 g/mol

Moles of of sodium chloride: mass / molar mass 3.5/58.44 = 0.059 mol

Density of water 1 kg/L

230 mL of water are equivalent to 0.23 L

mass of water: density * volume = 1*0.23 = 0.23 kg

Molality of the solution: m = moles of solute/ kg of solvent = 0.059/0.23 = 0.256

Finally:

ΔT = 1.86*0.256*2 = 0.952 °C

Water melting point: 0 °C

So, the solution melting point is: 0 - 0.952 = 0.952 °C