valence number of a metallic element X is 3. What is the formula of its oxide?​

Answer:

16.51%

Explanation:

The reaction that takes place is

Meaning that the white precipitate that formed is AgCl. Now we convert 0.535 g of AgCl into moles, using its molar mass:

Then we convert 0.00373 moles of AgCl into moles of CaCl₂, using the stoichiometric coefficients:

We convert moles of CaCl₂ into grams, using its molar mass:

Finally we calculate the percent of CaCl₂ by mass in the original mixture:

The percent calcium chloride by mass in the original mixture is 16.4%

The equation of the reaction between calcium nitrate and silver chloride is:

[tex]\mathbf{CaCl_2 + 2AgNO_3 \to 2 AgCl+Ca(NO_3)_2}[/tex]

Given that;

the number of moles of the precipitated AgCl is:

= 0.535 g / 143.32 g/mol

= 0.0037 moles

From the above reaction, If 2 moles of AgCl are formed  by 1 mole of CaCl2

Then, 0.0037 moles of AgCl will form (0.0037 × 1)/2 moles of CaCl2.

0.0037 moles of AgCl will form 0.00185 moles of CaCl2.

Now, we can say that the number of moles of CaCl2 present in the mixture is =  0.00185 moles

Mass amount of CaCl2 present = 0.00185 moles × 110.98 g/mol

Mass amount of CaCl2 present = 0.205 grams

Finally, the mass percentage   [tex]\mathbf{=\dfrac{0.205}{1.25}\times 100\%}[/tex]

= 16.4%

Therefore, we can conclude that the percent calcium chloride by mass in the original mixture is 16.4%

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Answer:

5.5

Explanation:

i think so?????????

The diluted solution of volume 120 ml has the molarity of 0.60 M. Then, the volume of the original solution with a molarity of2.25 M is 32 ml.

The molarity of a solution is the ratio of the number of moles of its solute particles to the volume of solution in liters.

To solve the given problem, we can use the formula for dilution:

C1V1 = C2V2

where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.

We are given that the diluted solution has a concentration of 0.60 M and a total volume of 120 mL. We are also given that the original concentration was 2.25 M, and we want to find the original volume.

Using the formula for dilution, we can write:

2.25 M x V1 = 0.60 M x 120 mL

Simplifying, we get:

V1 = (0.60 M x 120 mL) / 2.25 M

V1 = 32 mL

Therefore, the original volume of the KOH stock solution was 32 mL.

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Answer:

C. The solubility decreases.

Explanation:

Took the plato test!

Answer:

178.36 a.m.u

Explanation:

5 have a mass of 176,

5/100 * 176 = 8.8

19 have a mass of 177

19 / 100 * 176 = 33.44

27 have a mass of 178

27 / 100 * 178 = 48.06

14 have a mass of 179

14 / 100 * 179 = 25.06

35 have a mass of 180.0

35 / 100  * 180 = 63

Atomic Mass = 8.8 + 33.44 + 48.06 + 25.06 + 63

Atomic Mass = 178.36 a.m.u

Answer:

This is thought to aid in the extraction, as this dissolved phenol helps denature proteins while they are still in the aqueous solution. ... Phenol/Chloroform – This is a mixture of buffer-saturated phenol and chloroform, usually close to 1:1 for DNA purification with other ratios sometimes used for RNA purification

Explanation:

Hope it helps!

If you dont mind can you please mark me as brainlest?

Answer:

This is thought to aid in the extraction, as this dissolved phenol helps denature proteins while they are still in the aqueous solution. ... Phenol/Chloroform – This is a mixture of buffer-saturated phenol and chloroform, usually close to 1:1 for DNA purification with other ratios sometimes used for RNA purification

Explanation:

kcal = 1000 cal

2.024 Kcal to cal

= 2.024 × 1000

= 2024 cal

Answer:

We assume you are converting between moles CaCl2 and gram. You can view more details on each measurement unit: molecular weight of CaCl2 or grams This compound is also known as Calcium Chloride. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles CaCl2, or 110.984 grams.

The mass of calcium chloride is 53.27 grams.

Given:

Moles of CaCl₂ = 0.48 moles

Molar mass of CaCl₂ = 110.98 g/mol

To find:

Mass of CaCl₂ = ?

It is defined as given mass over molar mass.

Number of moles  =  Mass / Molar mass

Mass = Number of moles * Molar mass

Mass = 0.48 moles  * 110.98 g/mol

Mass = 53.27 grams

Thus, the mass of calcium chloride is 53.27 grams.

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Answer:

it is A tide (A,C)

Explanation:

i just took the test and tried c and it was a plzzzzz put a btw it was my test lol

Answer:

D. Na+

Explanation:

Na+ is the only ion here that is not related to pH. Adding OH- increases pH, and adding H3O+ or H+ (the two are interchangeable) decreases pH.

Hey love! <3

Answer:

C. Resource use by humans has gone up and down over the years is a false statement

Explanation:

In the graph you can make an observation on how the increase of human population is directly positive.

The resource use either has a positive or negative correlation, making it impossible for the usage to fluctuate over the years.

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Answer:

Approximately [tex]279\; \rm mg[/tex] of fluorine would be produced.

Explanation:

Look up the relative atomic mass of these calcium and fluorine on a modern periodic table:

In other words, the mass of each mole of calcium atoms is (approximately) [tex]40.078\; \rm g[/tex]. Similarly, the mass of each mole of fluorine atoms is (approximately) [tex]18.998\; \rm g[/tex].

Calculate the number of moles of calcium atom that were produced:

[tex]\begin{aligned} &n({\rm Ca}) \\ &= \frac{m({\rm Ca})}{M({\rm Ca})} \\ &= \frac{294\; \rm mg}{40.078\; \rm g \cdot mol^{-1}} \\ &= \frac{0.294\; \rm mg}{40.08 \; \rm g \cdot mol^{-1}}\\ & \approx 7.3357 \times 10^{-3}\; \rm mol\end{aligned}[/tex].

Every formula unit of calcium fluoride, [tex]\rm CaF_2[/tex], contains twice as many fluorine atoms as calcium atoms.

Hence, if the sample contained approximately [tex]7.33570 \times 10^{-3}\; \rm mol[/tex] calcium atoms, it would contain twice as many fluorine atoms:

[tex]\begin{aligned}n({\rm F}) &= 2\, n({\rm Ca}) \\ &\approx 2 \times 7.33570\times 10^{-3}\; \rm mol \\ &\approx 1.4671 \times 10^{-2}\; \rm mol\end{aligned}[/tex].

Calculate the mass of that many fluorine atoms:

[tex]\begin{aligned}& m({\rm F}) \\ &= n({\rm F}) \cdot M({\rm F}) \\ &\approx 1.4671 \times 10^{-2}\; \rm mol \times 18.998\; \rm g \cdot mol^{-1} \\ &\approx 278.72 \times 10^{-3}\; \rm g \\&\approx 279\; \rm mg\end{aligned}[/tex].

279 mg of Fluorine was formed in the decomposition reaction

The equation of the reaction is;

CaF2 -----> Ca + 2F

Mass of calcium formed = 294 mg

Number of moles of Ca in 294 mg = 294 × [tex]10^-3[/tex] g/40 g/mol = 0.00735 moles

From the equation, the products are in ration 1 : 2

Since 1 mole of Ca is to 2 moles of F

0.00735 moles of Ca is to 0.00735 moles × 2 moles/1 mole

= 0.0147 moles of F

Mass of F = 0.0147 moles × 19 g/mol

= 0.279g or 279 mg of F

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time travel is the best option

i think it is

(b) 4

:) hope its correct :)

Answer:

E. radium

E. radium

E. radium

Answer:

magnesium is the elwment which has the largest atomic number

Answer:

change in energy of the system = - 21 J

Explanation:

Δu = q + w

q = 364 J

w = - 385

Temperature of system drops from 25°c to 20°c

hence

Δu ( change in energy ) = q - w

                                       = 364 - 385

                                       = -21  J

Answer:

It takes 12,000 Joules of energy to melt 35 grams of ice at 0 °C

Explanation:

Good Luck!

Answer:

it should be 7.300 sorry if I am wrong

Answer:

The answer is 115

Explanation:

Teacher walked me through it.

Answer:

it's the amount of energy released by an earthquake

The volume 15.0 g of O₂ has at a certain temperature and pressure is 2.16 L.

Volume is the space occupied by a three-dimensional object.

By the law of dilution

M₁/V₁ = M₂/V₂

Mass 1 is 5.00

Volume 1 is 7.20 L

Mass 2 15.0 g

Volume 2 is to find

Putting the value in the equation

5.00/ 7.20 = 15.0 / V₂

V₂ = 7.20 × 15.00/ 5.00 = 21.6

Thus, the volume will be 21.6 L.

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Answer:

B) 1S and 40

hope it helps

Answer:

b is ur answer

Explanation:

1S and 4O

The number of moles of Gas B in the gas mixture is equal to 2.00 mol.

The ideal gas equation can be explained as an equation that describes the state of an ideal gas. This equation gives the product of the volume and pressure of ideal gas equal to the multiplication of the universal gas constant, absolute temperature, and moles of gas.

The mathematical form of the ideal gas equation mentioned below:

PV = nRT

Where P is the pressure, V is the volume, n is the moles, and R is the gas constant.

Given, the volume of the gas mixture, V = 500 ml = 0.5 L

The temperature of the gas mixture, T = 303 K

The pressure of the gas mixture = 5 atm

The value of gas constant, R =0.082 atmL/K mol

Substituting the values R, V, P, and T in the ideal gas law, we get:

The number of moles of the gas mixture, n = PV/RT

n = 5 ×20/(0.082 × 303)

n = 4.00 mol

The total number of moles of gas mixture = 4.00 mol

The moles of Gas A = 2.00 mol

The moles of Gas B = 4 - 2 = 2.00 mol

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Answer: radio wave frequencies have longer wavelengths and smaller

Energies per photon

On CK-12 all of these answers are correct

1.9

1.888

1.89

1.88

The molality of a 10.0 % by mass solution of sodium chloride (NaCl) is 1.7M.

Molarity of any solution will be calculated as number of moles of solutes present in per litre of the solution.

Moles of the substance will be calculated as:

n = W/M, where

W = given mass

M = molar mass

Given that percent mass of NaCl = 10% i.e. 10g of NaCl is present in 100 g of solution.

We know that 1 g = 0.001 L

100 g = 0.1 L

Moles of NaCl = 10g / 58.44g/mol = 0.17 mol

Molarity of NaCl = 0.17 / 0.1 = 1.7M

Hence required molarity is 1.7 M.

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Answer:

See explanation

Explanation:

The electrolysis of  nickel(II) iodide yields nickel solid and iodine gas.

In the oxidation half equation;

2I^-(aq)-------> I2(g) + 2e

In the reduction half equation;

Ni^2+(aq) + 2e  -----> Ni(s)

These are the half equations of the process;

The  overall equation is;

Ni^2+(aq) + 2I^-(aq)-------> NiI2

Answer:

4:5

Explanation:

No. of chickens before giving away 3 chickens = 30 x 3/5 = 18

No. of ducks before giving away 3 chickens = 30 - 18 = 12

After giving away 3 chickens,

No. of chickens = 15

No. of ducks = 12

New ratio = 12:15 = 4:5

Answer:

C）52g KCl in 100g water at 80°C

Explanation:

A saturated solution is one that contains as much solute as it can dissolve in the presence of excess solute at that particular temperature.

A solutibility curve is a graph that shows the variability with temperature of the solubility of a solute in a given solvent. A solutibility curve can provide information of whether a solution formed frommthe solute and solvent are saturated or not at a given temperature.

From the solubility curve in the attachment below:

A) A saturated solution of NH₄Cl will contain about 52 g solute per 100 g sat 50 °C. Thus, a solution of 40 g NH₄Cl in 100 g water at 50 °C is an unsaturated solution.

B) A saturated solution of SO₂ at 10°C will contain about 70 g of solute in 100 g of water. Thus a solution of 2g SO₂ in 100g water at 10°C is an unsaturated solution.

C) A saturated solution of KCl at 80 °C will contain about 52 g of solute in 100 g of water. Thus, a solution of 52g KCl in 100g water at 80°C is a saturated solution.

D) A saturated solution of Kl at 20 °C will contain about 145 g of solute in 100 g of water. Thus, a solution of 120g KI in 100g water at 20°C is an unsaturated solution.

Answer:

Explanation:

blach bal

Answer:

Explanation: A compound with the empirical formula SO has a molecular weight of 96.13

Answer:A

Explanation: I learned it from a gizmo