Is 0.257G sample of chromium reacts with oxygen to form 0.3763 of chromium oxide what is the mass percent of chromium

According to unit conversion, there are  0.00085 miligrams in 850 nanograms .

Unit conversion is defined as a multi-step process which involves multiplication or a division operation by a numerical factor.The process of unit conversion requires selection of appropriate number of significant figures and the rounding off procedure.

It involves a conversion factor which is an expression for expressing the relationship between the two units.A conversion ratio always has value which equals to one which indicates that numerator and denominator have values which are expressed in different units.

As 1 nanogram = 1×10[tex]^-6[/tex] mg , thus, 850 nanograms = 850×10[tex]^-6[/tex]= 0.00085 mg.

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Based on the volume and the density of the iceberg, the mass of the iceberg is 197475.603 kg.

The volume of the iceberg in cm³ is determined as follows:

1 ft = 30.48 cm

1 ft³= 30.48 cm * 30.48 cm * 30.48 cm

1 ft³=  28316.847 cm³

The volume of the iceberg in cm³ = 7605 * 28316.847 cm³

The volume of the iceberg in cm³ = 215349621.4 cm³

The mass of the iceberg is then determined as follows:

Mass = density * volume

The mass of the iceberg = 215349621.4 cm³ * 0.917 g/m³

The mass of the iceberg = 197475602.9 g 197475.603 kg

The mass of the iceberg = 197475.603 kg

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Compounds are more stable than elements, so they have less energy in them. Alkali metals are very reactive and can release a lot of energy when they react with water. So K is the correct answer.

Alkali metals react violently with water to produce alkaline solutions and hydrogen gas. This reaction is exothermic (releasing a certain amount of energy) so that it can produce an explosion and even an explosion (if the amount of potassium metal is greater).

Alkali metals react with water to form bases and hydrogen gas. Reacted rather slowly; Na reacts violently with sparks; K, Rb, and Cs explode when placed in water.

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Answer:

The molar mass of CoCl2 2H2O is 165.87 g/mol.

This can be calculated by adding the molar masses of each component:

Co: 58.93 g/mol2

Cl: 2 x 35.45 g/mol = 70.90 g/mol

2H2O: 2 x 18.02 g/mol = 36.04 g/mol

To find the mass of the anhydrous compound, we need to subtract the mass of the water that was driven off during heating. The difference in weight between the original sample and the final, heated sample is equal to the weight of the water that was lost.

Le Chatelier's principle states that when a system at equilibrium is disturbed, the system will react in such a way as to minimize the effect of the disturbance. For example, if the pressure or temperature of the system is changed, the system may shift to a new equilibrium in order to restore balance. Likewise, if a reactant or product is added/removed, the system may shift again in order to counteract the change.

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Reaction B (2,3-dimethylheptane) will have the largest heat of combustion. This is because the larger alkyl group of the 2,3-dimethylheptane (3 methyl groups vs 2 methyl groups in the other two isomers) will require more energy to break, resulting in a higher heat of combustion.

It is also important to note that the larger alkyl group of the 2,3-dimethylheptane means that there will be more carbon-carbon (C-C) and carbon-hydrogen (C-H) bonds to break in order to oxidize the molecule. This means that more energy is required to break these bonds and therefore the heat of combustion will be higher.

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In an ecosystem, all the given options are the processes that can be performed by bacteria.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .

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If a filament electron enters the tungsten atom with 80 keV of energy and leaves the atom with 75 keV of energy, it has lost 5 keV of energy.

This energy loss is usually due to the electron releasing a bremsstrahlung photon, which carries away the energy. The photon is emitted in the direction of the incoming electron, and has an energy equal to the energy lost by the electron.

Filament electrons are electrons emitted by a heated filament, such as a tungsten filament in a light bulb. When the filament is heated, the electrons become energized and can escape the filament and travel through the air or through a vacuum. This process is known as thermionic emission. The electrons are attracted to a positive voltage, such as a plate, and can be used to create an electric current. Filament electrons can also be used in electron microscopes to create images of microscopic objects.

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The element symbol, mass number, and charge of this ion would be:

Element symbol: Sr

Mass number: 87

Charge: +2

Given :

Protons = 38

Neutrons = 49

Electrons = 36

Mass number = protons + neutrons

Mass number = 48+49 = 87

In this case, the number of protons is 38 and the number of electrons is 36, so the charge of the ion would be 38 - 36 = +2, meaning that it is a positively charged ion (cation).

Is the mass number the number of protons and neutrons?

The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

What is the charge of an ion?

An ion is an atom or group of atoms that has an electric charge. Ions with a positive charge are called cations. Ions with a negative charge are called anions. Many normal substances exist in the body as ions.

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First, find the molecular weight of Mg(NO3)2.

The molecular weight of Mg is 24.3 g/mol and the molecular weight of NO3 (nitrate ion) is 62 g/mol.

So, the molecular weight of Mg(NO3)2 is 24.3 + (2 x 62) = 150 g/mol.

Next, we can find the number of moles in 120 g of Mg(NO3)2:

120 g / 150 g/mol = 0.8 mol

So, there are 0.8 moles of Mg(NO3)2 in 120 g.

The mass of a mole of a material is its molecular weight. Typically, grams per mole are used as the unit of measurement. In this video, we demonstrate how to determine a substance's molecular weight using the periodic table's listed atomic weights. On a different page, we perform a conversion between the macroscopic scale (represented by grams of a substance) and the microscopic scale using the molecular weight (number of molecules of that substance). The molecular weight of a material is the weight, in atomic mass units, of each atom in a specific formula. One atomic mass unit is equal to one-twelfth of the weight of carbon-12. The most accurate sign is u, while the previous one was amu (a lowercase letter u).

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The number of moles of solute in 122.4 L of 0.990 M sodium cyanide is 119.082 moles. After rounding to four significant figures, the answer is 119.1 moles.

The number of moles of solute in 122.4 L of 0.990 M sodium cyanide is 119.082 moles. This can be determined by using the equation:

Where Molarity is 0.99 M and Volume is 122.4 L.

The molar mass of sodium cyanide (NaCN) is 49.01 g/mol [3], which means that 1 mole of NaCN contains 49.01 grams of the compound. This is important to know when calculating the mass of a given number of moles, as the two are directly related.

Rounding to four significant figures, the answer is 119.1 moles of sodium cyanide in 122.4 L of 0.990 M solution.

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In part B of this experiment, different solubilities were observed for NaCl in water and NaCl in pentanol because of the differences in the solute-solute, solvent-solvent, and solute-solvent interactions in each solution.

In water, NaCl is highly soluble due to the strong attractive forces between the positive and negative ions of NaCl and the polar water molecules. These interactions are referred to as solute-solvent interactions, and they facilitate the dissolution of NaCl in water. The high solubilities of NaCl in water is also due to the high polarity of water, which allows it to dissolve many polar solutes.

In pentanol, a nonpolar solvent, the solubility of NaCl was found to be much lower. The lack of attractive forces between the nonpolar pentanol molecules and the ions of NaCl means that there are limited solute-solvent interactions in this solution, resulting in lower solubility. Additionally, the intermolecular forces between the nonpolar pentanol molecules, such as London dispersion forces, are much weaker than the hydrogen bonds present in water. This means that pentanol molecules do not readily dissociate to allow for the dissolution of NaCl.

Therefore, the solubility of NaCl in water and pentanol can be explained by the differences in solute-solute, solvent-solvent, and solute-solvent interactions in each solution. The strong solute-solvent interactions in water result in high solubility, while the limited solute-solvent interactions in pentanol result in lower solubility.

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The metal bismuth has a pinkish tint and is white, crystalline, and brittle. The thermal conductivity of bismuth is lower than that of any other metal besides mercury, and it is the most diamagnetic of all metals.

The largest Hall effect of any metal and a high electrical resistance are also properties of bismuth (i.e. the greatest increase in electrical resistance when placed in a magnetic field).

Despite dissolving in strong nitric air, bismuth is stable to oxygen and water. When mixed with water, all bismuth salts produce insoluble compounds.

Although not a known carcinogen, bismuth is a recognized hazardous element, although some of its derivatives should be handled carefully due to their corrosiveness (e.g. bismuth chloride).

Therefore, The metal bismuth has a pinkish tint and is white, crystalline, and brittle. The thermal conductivity of bismuth is lower than that of any other metal besides mercury, and it is the most diamagnetic of all metals.

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The area of the surface with sides 500mm and 14.35mm is 7175mm^2

We know that the expression for area of flat rectangular surface is given as

Area = Length* Width

Substituting our given data into the expression we have

Area = 500*14.35

Area = 7175mm^2

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1a. The density of the gas, given that 3.05 g of it is stored in the flask is 2.10 g/L

1b. The molar mass of the gas is 46.7 g/mol

2. The temperature at 298.5 mL is 210 K

The density of the gas can be obtained as follow:

Density = mass / volume

Density of gas = 3.05 / 1.45

Density of gas = 2.10 g/L

Thus, the density is 2.10 g/L

The molar mass of the gas can be obtained as illustrated below:

M = DRT / P

M = (2.10 × 0.0821 × 298) / 1.10

M = 46.7 g/mol

Thus, the molar mas is 46.7 g/mol

The temperature of the gas at 298.5 mL can be obtained as follow:

V₁ / T₁ = V₂ / T₂

298.5 / T₁ = 547.8 / 385

Cross multiply

T₁ × 547.8 = 298.5 × 385

Divide both side by 547.8

T₁ = (298. × 385) / 547.8

T₁ = 210 K

Thus, the temperature is 210 K

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2)The first structure is a carbonate ion. The formal charge on the oxygen is -1, and on the carbon it is +1.

Carbonate ion (CO3) is an anion composed of a carbon atom doubly bonded to three oxygen atoms. It is formed when carbonic acid, a weak acid, is split into a hydrogen cation and a carbonate anion in an aqueous solution. Carbonate ions are found in minerals such as limestone and as part of the shells of marine creatures. Carbonate ions are also used in a variety of industrial applications.

There are two hydrogen atoms on each carbon, and two lone pairs of electrons on the oxygen. The better resonance form is shown below with the arrows to convert the two. O=C-O  ↔  O-C=O The second structure is a nitrate ion. The formal charge on the oxygen is -1 and on the nitrogen it is +1.

N-O-O  ↔  O=N-O

3) For the pair of molecules, the hydrogen atom on the carbon that is double bonded to oxygen (HyCo) is more acidic. This is because the conjugate base of the HyCo molecule is more stable (lower in energy) than that of the Vs molecule.

4) The hybridization for the CH3 molecule is sp3 and for the NH3 molecule it is also sp3. This is because both molecules have 4 electron groups around the central atom (3 hydrogens and 1 lone pair for CH3, and 3 hydrogens and 1 lone pair for NH3).

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The absorbance of a solution containing C can be calculated using the Beer-Lambert Law, which states that absorbance (A) is equal to the product of the molar absorptivity coefficient (ε), the pathlength (l) of the light through the cuvette, and the concentration (c) of the solution.

Thus, given that the wavelength and pathlength are known, the concentration of the solution can be calculated using the equation A = εlC.

The Beer-Lambert Law is an important equation used in spectroscopy to measure the concentration of a solution based on its absorbance at a certain wavelength. The equation is based on the fact that the amount of light absorbed by a solution is proportional to the concentration of the solution and the pathlength of the light through the sample.

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Short run heating oil consumption will decrease by 4%, and long-term demand will decrease by 14%. Because people can react to changes in the price of heating oil more readily, the change is greater over time.

The demand elasticity for heating oil at the going rate = 0.2 in the foreseeable future

Price change over the long term is 0.7%; price change over the short term is 2.20 - 1.80 / 2 x 100 = 20%.

Both the short-term and long run demand for heating oil will decline by 4% each.

The shift in the price of heating oil is bigger over time because customers can respond to changes more quickly. The ratio of variations in quantity demanded and price over the short term is known as price elasticity of demand.

To get the percentage change in quantity required, divide 20 by 0.2; the result is 4%.

The ratio of long-term variations in quantity required and price is known as price elasticity of demand.

Change in demand as a percentage: 20 * 0.7 = 14% Change in demand as a percentage: 0.7 Demand change as a percentage: 20

Your question is incomplete but most probably your full question was

Suppose the price elasticity of demand for heating oil is 0.2 in the short run and 0.7 in the long run. if the price of heating oil rises from $1.80 to $2.20 per gallon, what happens to the quantity of heating oil demanded in the short run? in the long run? (use the mid point method in your calculations.)

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The electric potential at the position of the electron is -8.23 ​​10⁻¹⁷ N / C.

The amount of labor required to convey a unit of electric charge from a reference point to a given place in an electric field is known as the electric potential (also known as the electric field potential, potential drop, or the electrostatic potential).

The energy gained by an object when it is moved against an electric field is known as the electric potential energy. Divide the potential energy by the amount of charge to get the charge's electric potential.

The electric potential for the ground state corresponding to the Bohr orbit in the Bohr model is

 E = k q₁ q₂ / r²

where,

q₁ is the charge of the proton and q₂ the charge of the electron

        E = - k e² / a₀²

       E = - 9 10⁹ (1.6 10⁻¹⁹)² / (0.529 10⁻¹⁰)²

        E = -8.23 ​​10⁻¹⁷ N / C

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The proposed mechanism indicates that the overall reaction is a two-step process. In the first step, H2 reacts with ICl to form HCl and I2. In the second step, HCl and HI react to form H2 and ICl.

Therefore, the rate law for the overall reaction should be expressed as:

Rate= k[H2][HI][ICl]2  where k is the rate constant of the reaction and [H2], [HI], and [ICl] represent the concentrations of the reactants. The rate law indicates that the rate of the overall reaction is directly proportional to the concentration of the three reactants and is proportional to the square of the concentration of ICl. This is because, in the second step, two molecules of ICl are consumed to form H2 and HI.

Therefore, the rate law for the overall reaction is Rate= k[H2][HI][ICl]2, which is consistent with the proposed mechanism.

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The arrow pushing mechanism for the reaction of ethanol and propionic acid using H+ in place of Dowex is as follows:

The H+ ion acts as a nucleophile and attacks the carbonyl carbon of propionic acid, forming a tetrahedral intermediate. This intermediate then collapses, resulting in the formation of an ethanol molecule and the release of a proton. The proton is then replaced by the H+ ion, resulting in the formation of an ethyl propionate molecule. The overall reaction is represented by the following equation:

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when we heating a solution to boiling on a hot plate, start by starting and stabilizing the stir function then, turn the heat to a medium heat to start. If necessary, turn up the heat setting after waiting about a ten minutes without seeing the boiling.

A chemical reaction can be defined as a chemical process which typically involves the transformation or the rearrangement of the atomic, ionic or molecular structure of an element through the breakdown and the formation of chemical bonds to produce a new compound or substance.

Some of the laboratory apparatus (equipment) which are used for conducting a chemical reaction are conical flask,  beaker, Bunsen burner, crucible, round bottom flask etc.

When heating a solution to boiling on a hot plate, start by starting and to stabilizing the stir function. Then, turn up the heat to a medium heat to start it.

The safety precautions which be taken when heating a solution to boiling on a hot plate: A proper inspection of the round bottom flask for cracks, irregularities or any kind of imperfection.

Be ensure you avoid heating the flask while it is closed.

When we suspending the flask on a hot plate, you should ensure that you use a clamp for the stability.

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The local field is in the opposite direction to the external field, causing the nucleus to experience a reduced external field. The electrons are said to shield the nucleus from the external field.

This polarization causes the nucleus to experience a reduced magnetic field, which is referred to as the shielding effect. The electrons absorb the energy from the external field, thus shielding the nucleus from it. This shielding effect is represented by the shielding parameter, which is the ratio of the external field to the local field experienced by the nucleus.

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The work function of metal was  6.08 * 10⁻¹⁹  J

The maximum number of electrons ejected are 1.21 * 10¹²electrons

The work function of a metal is the minimum amount of energy required to remove an electron from an atom of the element.

The work function of metal can be written as: φ = h f - E

where:

φ represents the work function of a metal,

hf represents the photon energy,

E is the kinetic energy.

For the given metal:

Work function =  6.63 * 10⁻³⁴ * 1.40 * 10¹⁵ -   3.20 × 10⁻¹⁹

Work function = 6.08 * 10⁻¹⁹  J

The maximum number of electrons ejected: total energy/work function

The maximum number of electrons ejected = 7.36 * 10⁻⁷/6.08 * 10⁻¹⁹

The maximum number of electrons ejected = 1.21 * 10¹²electrons

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The minimum energy of the photon is 3.60 * 10⁻¹⁹

The maximum kinetic energy electron ejected is 4.52 * 10⁻¹⁹ J

The minimum energy of the photon is calculated as follows:

E = hν

where:

h is the Planck's constant =  6.626x10-34 Js

ν is the frequency = 5.43 * 10¹⁴ s⁻¹

E = 6.63 * 10⁻³⁴ Js * 5.43 * 10¹⁴ s⁻¹

E = 3.60 * 10⁻¹⁹

The maximum energy is calculated as follows:

E = hc / λ

where

c is the speed of light = 3 * 10⁸ m/s

λ is the wavelength in m = 2.45 * 10⁻⁷m

E = 6.63 * 10⁻³⁴ * 3 * 10⁸ / 2.45 * 10⁻⁷

E = 8.12 * 10⁻¹⁹ J

The maximum kinetic energy electron ejected = 8.12 * 10⁻¹⁹ J - 3.60 * 10⁻¹⁹J

The maximum kinetic energy electron ejected = 4.52 * 10⁻¹⁹ J

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Moles can be converted to liters by the use of the stoichiometry of the reaction and the gas laws.

To convert moles to liters, you need to use the Ideal Gas Law. The Ideal Gas Law states that the number of moles of a gas is proportional to its volume at a given temperature and pressure. The equation is:

PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.

By rearranging the equation, you can find the volume of a gas in liters when the number of moles is known:

V = nRT / P

Since the volume is in liters, the number of moles can be converted to liters by multiplying it by the volume.

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A. temperature will increase because reaction is exothermic.

B. Average kinetic energy will increase.

C. Average speed will increase.

D. The dissolution reaction is exothermic.

Dissolution reaction is defined as the reaction where a single reactant breaks down into it's ions making an aqueous solution. If 15.0 grams of calcium chloride, CaCl2, is dissolved into 100.0 mL of water at 22.5°C, the final temperature of the solution was 32.2°C then the dissolution of CaCl2 in water is an example of exothermic reaction because heat is evolved during the process hence there is an increase in temperature is observed.  An exothermic reaction is defined as a chemical reaction in which less energy is needed to break bonds in the reactants than is released when new bonds form in the products.

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0.048moles are in 2.91 x 10²² atoms of He. Helium (He) is a chemical element and inert gas in Periodic Group 18 (noble gases).

Helium is a chemical element and inert gas in Periodic Group 18 (noble gases). Helium, the second smallest atom is a colorless, odorless, but tasteless gas that solidifies at 268.9 °C (452 °F).

Helium has lower boiling as well as freezing points than any other known material. Helium is the sole element that is not solidified by adequate cooling at normal pressure; it must be consolidated at a pressure of 25 earth's atmosphere at such a temperature of about one K

mole = given number of atoms/  6.022×10²³

        = 2.91   ×10²² /  6.022×10²³

       = 0.048moles

Therefore, 0.048moles are in 2.91 x 10²² atoms of He.

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In most living species, glucose is the monosaccharide which is the most important source of energy.

A simple sugar or monosaccharide is a carbohydrate which can be digested into smaller carbs. A monosaccharide, like other carbohydrates, is composed of three chemical components: carbon, hydrogen, as well as oxygen.

It is the most basic kind of molecule of glucose and therefore is frequently used to build more complicated compounds. Aldoses, ketoses, as well as their derivatives are examples of monosaccharides. A monosaccharide has the typical chemical formula CnH2nOn or (CH2O)n. In most living species, glucose is the monosaccharide which is the most important source of energy.

Therefore, in most living species, glucose is the monosaccharide which is the most important source of energy.

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In nuclear magnetic resonance (NMR) spectroscopy, the chemical shift is the resonant frequency of an atomic nucleus relative to a trendy in a magnetic field.

Often the placement and range of chemical shifts are diagnostic of the shape of a molecule. The chemical shift in absolute phrases is described via way of means of the frequency of the resonance expressed close to a trendy compound that is described to be at zero ppm. The scale is made greater workable via way of means of expressing it in elements in keeping with million (ppm) and is indepedent of the spectrometer frequency.

1)  electronegativity of atoms increases chemical shift value also increases.

2)  number of electronegative atoms increases chemical shift value is also more

3) CH4 has no Cl atoms . so it has least chemical shift

4) CHCl3 has 3  higher electronegative atoms . so it has higher chemical shift.

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