It took 2.30 minutes using a current of 3.00 A to plate out all the copper from 0.300 L of a solution containing Cu2 . What was the original concentration of Cu2

To find the oxidation number we can check the periodic table of the elements. There are some elements that have only one oxidation state, others can have more than one.

We must take into account that the total oxidation state of the molecule must be 0, so the sum of the oxidation states of the elements must equal 0.

To start, let's identify the possible oxidation states of elements in molecules.

Pb: +4, +2

Cr: +6, +3, +2

Or: -2

Oxygen has only one oxidation state equal to -2 so we'll start by placing that. Regarding chromium, in this case, the only possibility is that it has an oxidation state of +6 since if the oxidation state is lower, the molecule could not be neutralized with a single Pb atom.

With an oxidation state of oxygen of -2, of Cr equal to +6, the lead must have an oxidation state of +4. To understand it we can see the following table:

Therefore, the answer will be:

p) Oxidation number of Pb in Pb(Cr2O7)2: +4

q) Oxidation number of Cr in Pb(Cr2O7)2: +6

r) Oxidation number of O in Pb(Cr2O7)2: -2

Answer:

The moon will be positioned so that the earth is between the moon and the sun

The heat released is 439.5 J during the reaction.

The heat released can be calculated using the formula:

where q is the heat released, m is the mass of the solution, C is the specific heat of water, and ΔT is the change in temperature.

First, we need to calculate the total mass of the solution:

The density of water is 1 g/mL, so the mass of the solution is 35 g.

Next, we can calculate the change in temperature:

Finally, we can substitute these values into the formula:

Therefore, 439.5 J of heat was released during the reaction.

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Answer:

[H₃O⁺] = 2.5 × 10⁻¹⁰ M

pH = 9.6

Explanation:

Step 1: Given data

Concentration of OH⁻ in the solution ([OH⁻]): 4.0 × 10⁻⁵ M

Step 2: Calculate the concentration of H₃O⁺ in the solution

Let's consider the self-ionization of water.

2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻(aq)

The ion-product of water (Kw) is:

Kw = 1.0 × 10⁻¹⁴ = [H₃O⁺] × [OH⁻]

[H₃O⁺] = 1.0 × 10⁻¹⁴/[OH⁻]

[H₃O⁺] = 1.0 × 10⁻¹⁴/4.0 × 10⁻⁵

[H₃O⁺] = 2.5 × 10⁻¹⁰ M

Step 3: Calculate the pH of the solution

We will use the following expression.

pH = -log [H₃O⁺]

pH = -log 2.5 × 10⁻¹⁰

pH = 9.6

Taking into account the definition of pH and pOH, the pH and [H₃O⁺] of the solution is 9.602 and 2.5×10⁻¹⁰ M respectively.

First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.

The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:

pH= - log [H⁺]= - log [H₃O⁺]

Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:

pOH= - log [OH⁻]

The following relationship can be established between pH and pOH:

pH + pOH= 14

In this case, you know that [OH⁻]= 4×10⁻⁵ M. For this concentration, the pOH is calculated as:

pOH= - log (4×10⁻⁵ M)

pOH= 4.398

Then, pH can be calculated as:

pH + 4.398= 14

pH= 14 - 4.398

pH= 9.602

So, the [H₃O⁺] is calculated as:

9.602= - log [H₃O⁺]

[H₃O⁺]= 10⁻⁹ ⁶⁰²

[H₃O⁺]= 2.5×10⁻¹⁰ M

Finally, the pH and [H₃O⁺] of the solution is 9.602 and 2.5×10⁻¹⁰ M respectively.

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Answer:

One team pulls with more force than the other

The mass of the asteroid is C. 1.2 x \(10^{12}\) Kg

To find the mass of the other asteroid, we can rearrange the equation for the gravitational force between two objects:

F = (G * m1 * m2) / \(r^{2}\)

where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the two asteroids, and r is the distance between them.

Given that the distance between the asteroids is 75000 m, the force of gravity between them is 1.14 N, and one asteroid has a mass of 8 x \(10^{7}\) kg, we can substitute these values into the equation and solve for the mass of the other asteroid (m2):

1.14 N = (6.67430 × \(10^{-11}\) N \(m^{2}\)/\(Kg^{2}\) * 8 x \(10^{7}\) kg * \(m2\)) / \((75000 m)^{2}\)

Simplifying and solving the equation, we find that the mass of the other asteroid (m2) is approximately 1.2 x \(10^{12}\) kg. Therefore, Option C is correct.

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Two asteroids are 75000 m apart one has a mass of 8 x \(10^{7}\) kg if the force of gravity between them is 1.14 what is the mass of the asteroid

A. 3.4 x \(10^{11}\) kg

B. 8.3 x \(10^{12}\) kg

C. 1.2 x \(10^{12}\) kg

D. 1.2 x \(10^{10}\) kg

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The one on the top left corner is condensation. The one below that is evaporation. The one below that in the water is accumulation. The one next to accumulation is ground flow. The one on the trees is transpiration. The one above transpiration is surface flow. The one above surface flow is precipitation and above precipitation it’s condensation. Lmk if you were able to get that.

The heat released in the combustion of lactic acid is absorbed by the

calorimeter and in the decomposition of the lactic acid.

ΔH°f of lactic acid is approximately -716.2 kJ

Reasons:

Known parameters are;

Mass of the lactic acid = 3.93 grams

Heat  capacity of the bomb calorimeter = 10.80 kJ·K⁻¹

Change in temperature of the calorimeter, ΔT = 5.34 K

ΔHrxn = ΔErxn

ΔH°f of H₂O(l) = -285.8 kJ·mol⁻¹

ΔH°f of CO₂(g) = -393.5 kJ·mol⁻¹

The chemical equation for the reaction is presented as follows;

The heat of the reaction = 10.80 kJ·K⁻¹ × 5.34 K = 57.672 kJ

Molar mass of C₃H₆O₃ = 90.07 g/mol

Number of moles of C₃H₆O₃ = \(\dfrac{3.93 \, g}{90.07 \, g/mol}\) = 0.043633 moles

Number of moles of CO₂ produced = 3 × 0.043633 moles = 0.130899 moles

Heat produced = 0.130899 mole × -285.8 kJ·mol⁻¹ = -37.4109342 kJ

Moles of H₂O produced = 0.130899 moles

Heat produced = 0.130899 mole × -393.5 ≈ -51.51 kJ

Therefore, we have;

Heat absorbed by the lactic acid = ΔH°f of H₂O + ΔH°f of CO₂ + Heat absorbed by the calorimeter

Which gives;

Heat absorbed by lactic acid  = -37.4109342 kJ - 51.51 kJ + 57.672 kJ ≈ -31.249 kJ

The heat absorbed by the lactic acid ≈ -31.249 kJ

ΔH°f of C₃H₆O₃ ≈ -716.2 kJ

Heat of formation of lactic acid ≈ -716.2 kJ.

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According to the picture, Global average surface temperature, is in extreme levels and shows that human actions contributed to this increase in global temperature.

Answer:

uranium U

radium. RA

thorium TH

polonium PO

radium. RN

carbon. C

Answer:

3 atoms of Ba

2 x 1 = 2 atoms of Cl

2 x 3 = 6 atoms of O

So, the total number of atoms for each element in 3Ba(ClO3)2 are:

Barium (Ba): 3 atoms

Chlorine (Cl): 2 atoms

Oxygen (O): 6 atoms

Explanation:

Answer:

Volume = 3.4 L

Explanation:

In order to calculate the volume of CO₂ produced when 15.2 g of CaCO₃ is heated, we need to first write out the balanced equation of the thermal decomposition of CaCO₃:

CaCO₃ (s) + [Heat] ⇒ CaO (s) + CO₂ (g)

Now, let's calculate the number of moles in 15.2 g CaCO₃:

mole no. = \(\mathrm{\frac{mass}{molar \ mass}}\)

                 = \(\frac{15.2}{40.1 + 12 + (16 \times 3)}\)

                 = 0.1518 moles

From the balanced equation above, we can see that the stoichiometric molar ratios of CaCO₃ and CO₂ are equal. Therefore, the number of moles of CO₂ produced is also 0.1518 moles.

Hence, from the formula for the number of moles of a gas, we can calculate the volume of  CO₂:

mole no. = \(\mathrm{\frac{Volume \ in \ L}{22.4}}\)

⇒ \(0.1518 = \mathrm{\frac{Volume}{22.4}}\)

⇒ Volume = 0.1518 × 22.4

                 = 3.4 L

Therefore, if 15.2 g of CaCO₃ is heated, 3.4 L of CO₂ is produced at STP.

Answer: 184 g of nitrogen dioxide that are produced from 4 moles of nitric oxide

Explanation:

The balanced chemical reaction is:

\(2NO(g)+O_2(g)\rightarrow 2NO_2(g)\)  

According to stoichiometry :

2 moles of \(NO\) produce = 2 moles of \(NO_2\)

Thus 4 moles of \(NO\) will require=\(\frac{2}{2}\times 4=4moles\)  of \(NO_2\)

Mass of \(NO_2=moles\times {\text {Molar mass}}=4moles\times 46g/mol=184g\)

Thus 184 g of nitrogen dioxide that are produced from 4 moles of nitric oxide

1. The % concentration is 20.7% and the molar concentration, Cm, is 1.5 M.

2. 7.8 grams of potassium sulfate will be formed.

3. 10.7 grams of ammonium chloride will be formed.

4. The volume of hydrogen gas that will be produced is 3.86 liters.

5. 21.43 grams of the 70% acetic acid is needed to prepare 500 grams of 3% acetic acid solution.

1. Mass of potassium sulfate = 1.5 moles * (174.26 g/mol) = 261.39 g

Mass of water (H₂O) = 1000 g

% = (mass of solute/mass of solution) x 100

% = (261.39 g / (261.39 g + 1000 g)) x 100

% ≈ 20.7%

Cm = moles of solute / volume of solution

Moles of potassium sulfate (K2SO4) = 1.5 moles

Volume of water (H2O) = 1000 g / (density of water) = 1000 g / 1 g/mL = 1000 mL = 1 L

Cm = 1.5 moles / 1 L

Cm = 1.5 M

2. The balanced equation for the reaction is:

H₂SO₄ + 2 KOH → K₂SO₄ + 2 H₂O

Molar mass of sulfuric acid (H₂SO₄) = 98.09 g/mol

Moles of sulfuric acid = 10 g / 98.09 g/mol

Moles of sulfuric acid = 0.102 mol

Based on the mole ratio of the reaction, 0.102 moles of sulfuric acid will react to form 0.102 moles of potassium sulfate.

Molar mass of potassium sulfate = 174.26 g/mol

Mass of potassium sulfate = 0.102 mol x 174.26 g/mol

Mass of potassium sulfate ≈ 17.8 g

3. The balanced equation for the reaction is:

Molar mass of hydrochloric acid (HCl) = 36.46 g/mol

Moles of hydrochloric acid (HCl) = 7.3 g / 36.46 g/mol

Moles of hydrochloric acid ≈ 0.2 mol

Based on the mole ratio of the reaction, 0.2 moles of hydrochloric acid will react to form 0.2 moles of ammonium chloride.

Molar mass of ammonium chloride (NH₄Cl) = 53.49 g/mol

Mass of ammonium chloride = 0.2 mol x 53.49 g/mol

Mass of ammonium chloride ≈ 10.7 g

4. The balanced equation for the reaction is:

Molar mass of zinc (Zn) = 65.38 g/mol

Moles of zinc = 13 g / 65.38 g/mol

Moles of zinc ≈ 0.199 mol

Based on the mole ratio of the reaction, 0.199 moles of zinc will react to produce 0.199 moles of hydrogen gas.

Volume of sulfuric acid = 30 g / (density of H₂SO₄ )

The density of H₂SO₄ is 1.84 g/mL

Volume of sulfuric acid  = 30 g / 1.84 g/mL

Volume of sulfuric acid ≈ 16.3 mL or 0.0163 L

Using the ideal gas law, the volume of hydrogen gas produced will be:

V = nRT / P

V = (0.199 mol)(0.0821 L·atm/(mol·K))(273 K) / (1 atm)

V ≈ 3.86 L

5. Assuming that the concentrated original solution of acetic acid is 100% acetic acid (CH₃COOH).

Mass of acetic acid = 500 g x (3/100) = 15 g

The concentrated original solution, however, is 70% acetic acid.

70% acetic acid (mass) = 100% acetic acid (unknown mass)

0.7 * (unknown mass) = 15 g

Solving for the unknown mass:

unknown mass = 15 g / 0.7

unknown mass ≈ 21.43 g

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Answer:

Annual precipitation

Explanation:

Annual precipitation seems like the correct one

Answer:

It is an unstable form of a chemical element that releases radiation as it breaks down and becomes more stable.

ANSWER

STEP-BY-STEP EXPLANATION:

Given information

The number of moles of chlorine = 3.4 moles

Step 1: write a balanced equation of aluminum and chlorine

Step 2: Find the number of moles of aluminum using a stoichiometry ratio

From the above reaction, you will see that 2 moles of aluminum react with 3 moles of chlorine to give 3 moles of aluminum chloride.

Let x represents the number of aluminum

The volume of the balloon once they have cooled to the outside temperature of -34.0 c is 1.53 L.

Charles' law predicts the relationship between the volumes and the temperatures of a sample of an ideal gas at different conditions. For this equation to hold true, the number of molecules and the pressure must remain constant despite changes in the environment.

Determine the volume of the balloon outside, V2. We do this by applying Charles' law, such that we relate the volume, V, and the temperature, T, of a sample of gas as

V₁ /T₁ = V₂/ T₂

at two conditions. We are given the following values for the variables:

• V₁ = 1.90 L

T₁ = 22.0+ 273.15 = 295.15 K

T₂= 34.0+273.15= 239.15 K

We proceed with the solution.

V₁/T₁ = V₂/T₂

V₁ /T₁ × T₂ = V₂

1.90 L/295.15 K x 239.15 K = V₂

1.53 L =V₂

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The complete question is

Balloons for a New Year's Eve party in Fargo, ND, are filled to a volume of 1.90 L at a temperature of 22.0 degrees Celsius and then hung outside where the temperature is -34.0 degrees Celsius. What is the volume of the balloons after they have cooled to the outside temperature? Assume that atmospheric pressure inside and outside the house is the same.

If an equation includes 7(CrO₄)₂, the numbers of Cr's and O's atoms that are there are 14 and 56 respectively.

The number of atoms present in a chemical compound can be calculated by multiplying the subscript of the particular element by any coefficient.

According to this question, 7 moles of chromate with the chemical formula; (CrO₄)₂ is given. The number of oxygen and chromium atoms in this compound can be calculated as follows:

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Part A is labeled as geosphere, B is biospere and C is hydrosphere.

The Earth can be divided into four interconnected spheres: the geosphere, atmosphere, hydrosphere, and biosphere.

The geosphere refers to the solid, rocky part of the Earth, including the crust, mantle, and core. The mud and dirt surrounding the water puddle would be considered part of the geosphere.

The biosphere includes all living things on Earth and the environments in which they live. The frog sitting at the edge of the water puddle is part of the biosphere.

The hydrosphere refers to all the water on Earth, including oceans, lakes, rivers, and groundwater. The water in the puddle would be part of the hydrosphere.

These spheres are interconnected and influence each other. For example, the biosphere relies on the geosphere for nutrients and minerals, while the geosphere is shaped by the movement of water in the hydrosphere.

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Answer:

3.10 × 10⁻⁴ mg

Explanation:

In the Minnesota Department of Health set a health risk limit for benzene in groundwater of 10.0 μg/L. Suppose an analytical chemist receives a sample of groundwater with a measured volume of 31.0 mL. Calculate the maximum mass in milligrams of benzene which the chemist could measure in this sample and still certify that the groundwater from which it came met Minnesota Department of Health standards. Be sure your answer has the correct number of significant digits.

Step 1: Given data

Step 2: Convert "V" to L

We will use the conversion factor 1 L = 1000 mL.

31.0 mL × 1 L/1000 mL = 0.0310 L

Step 3: Calculate the maximum mass of benzene (m)

We will use the following expression.

m = C × V = 10.0 μg/L × 0.0310 L = 0.310 μg.

Step 4: Convert "m" to mg

We will use the conversion factor 1 mg = 1000 μg.

0.310 μg × 1 mg/1000 μg = 3.10 × 10⁻⁴ mg

Answer:

The three main kinds of intermolecular interactions are dipole-dipole interactions, London dispersion forces, and hydrogen bonds

Explanation:

The vapor pressure lowering of water in this solution is 1165 torr.

What is vapor pressure?
The pressure that a vapour exerts on its condensed phases in a closed system at a specific temperature is known as the vapour pressure or equilibrium vapour pressure. An indicator of a liquid's evaporation rate is the equilibrium vapour pressure. It has to do with how easily liquid-borne particles tend to elude detection (or solid). Volatile is a term used to describe a chemical that, at room temperature, has a high vapour pressure. Vapor pressure is the force that a vapour cloud exerts over a liquid surface. The kinetic energy of a liquid's molecules increases along with the temperature. The number of molecules vaporising also rises as a function of the molecules' rising kinetic energy, which raises the vapour pressure.

the vapor pressure of water and the mixture is 355 torr and 760 torrs. Therefore, the value of vapor pressure of oxygen would be,

Ptotal=PO2+PH2O

760=PO2+355

760−355=PO2

405=PO2

So, at the temperature, the vapor pressure of  Ethylene is 405 torr.

When volume reduces to 50ml, the pressure of the oxygen would be,

P1V1=P2V2

where P1 and P2 are the pressure and V1 and V2 are the volumes.

P1V1=P2V2

P1V1/V2=P2

405×100 / 50=P2

810=P2

So, when the volume is 50ml the vapor pressure of the oxygen is 810 torr.

Now the total pressure of water-saturated oxygen at 50 ml volume is,

Ptotal=PO2+PH2O

Ptotal=810+355

Ptotal=1165

So, the total vapor pressure is 1165 torr.
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Answer: Nuclear fusion- The simple answer is that deep inside the core of the Sun, enough protons can collide into each other with enough speed that they stick together to form a helium nucleus and generate a tremendous amount of energy at the same time.

Answer:

From the chemical isotopes in leftover shells of foraminifera, scientists can estimate the ocean's temperature and are able to determine the air's carbon dioxide content.

What are isotopes?

Isotopes are the elements which have same atomic number but different mass number. For example - Carbon has three isotopes- C-12, C-13, C-14

In the three isotopes of carbon, all three isotopes have six protons, but carbon-12 has six neutrons, carbon-13 has seven neutrons, and carbon-14 has eight neutrons. Hence, Mass number differs in case of isotopes.

Scientists can learn about the climate at the time the foraminifera lived by analyzing the chemical isotopes in their leftover shells. Estimation of the ocean's temperature based on the ratio of oxygen isotopes in the shells can also be done. The amount of carbon dioxide in the air at the time based on the ratio of carbon isotopes in the shells can also be calculated.

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Your question is incomplete, but most probably your full question was,

What can scientists learn from the chemical isotopes in leftover shells of foraminifera about the climate at the time the foraminifera lived?

a. They can calculate the amount of carbon dioxide in the air.

b. They can estimate the ocean's temperature.

c. They can calculate the amount of rainfall.

d. They can estimate the air temperature.

Answer:

How does adding a lone pair affect the position of existing atoms and lone pairs? It decreases the angles between the atoms - the atoms are moving closer because they are being repelled further away from the lone pairs then they are from the other atoms

Explanation:

hope it helps!

Answer:

b

Explanation:

Answer:

1.96 × 10²⁴ molecules

Explanation:

Step 1: Given data

Mass of ethanol (m): 150. g

Step 2: Calculate the number of moles (n) corresponding to 150. g of ethanol

The molar mass of ethanol is 46.07 g/mol.

150. g × 1 mol/46.07 g = 3.26 mol

Step 3: Calculate the number of molecules in 3.26 moles of ethanol

To convert moles into molecules, we need Avogadro's number: there are 6.02 × 10²³ molecules in 1  mole of molecules.

3.26 mol × 6.02 × 10²³ molecules/1  mol = 1.96 × 10²⁴ molecules