pls help !!!!!!!!!!!!!!!!

Answer:

0.85 M

Explanation:

Step 1: Given data

Step 2: Calculate the moles (n) corresponding to 660 g of calcium phosphate (solute)

We will use the following expression.

n = m/M

n = 660 g/(310.18 g/mol) = 2.13 mol

Step 3: Calculate the molar concentration (molarity) of the solution

Molarity is equal to the moles of solute divided by the liters of solution.

M = 2.13 mol/2.5 L = 0.85 M

Answer:

A heterogeneous mixture where the solids particles are large enough to be filtered out.

Explanation:

Answer:

No, the product is not chiral

Explanation:

The compound (S)-3-Methylhexane is chiral. However, the bromination of this compound via free radical mechanism yields an achiral intermediate as shown in the image attached to this answer.

This achiral intermediate is a flat and planar tertiary radical. Attack on either face of this radical specie is possible. This leads us to obtain a 50-50 mixture of (R) and (S) - 3-bromo-3-methylhexane.

This is a racemic mixture hence it is optically inactive.

Answer:

Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions: Ca^2 , Al^3 ,I^-,S^2-

Explanation:

1)Formula of calcium iodide:

The compound of Ca^2+ and I^-1:

[tex]CaI_2[/tex]

2) Formula of calcium sulfide:

[tex]CaS[/tex]

3) Formula of aluminum iodide:

[tex]AlI_3[/tex]

4) Formul aluminum sulfide:

[tex]Al_2S_3[/tex]

These are the four ionic compounds that are formed.

Answer:

37.09 g of B₅H₉ is required to form 148 g of  borate salt( Na₂B₄O₇  )

Explanation:

Given the data in the question;

B₅H₉ → H₃BO₃ → Na₂B₄O₇

find the mass (in grams) of B5H9 required to form 148 g of the borate salt by this reaction sequence.

S                                M.W

B₅H₉                          63

H₃BO₃                       62

Na₂B₄O₇                   201

So, moles of Na₂B₄O₇  = 148 / 201 = 0.736

Since Boron will be conserved,

Moles of Boron atoms in Na₂B₄O₇  will be;

⇒ 4 × 0.736 = 2.944

Now, Moles of Boron in Na₂B₄O₇ = Moles of Boron in H₃BO₃ = Moles of Boron in B₅H₉  

Hence,

Moles of Boron in B₅H₉ = 2.944

Moles of B₅H₉ = 2.944 / 5 = 0.5888

Mass of B₅H₉ = 0.5888 × 63 = 37.09 g

Therefore, 37.09 g of B₅H₉ is required to form 148 g of  borate salt( Na₂B₄O₇  )

Answer: The atomic radius of iron is 128 pm.

Explanation:

To calculate the radius of the metal having FCC crystal lattice, the relationship between edge length and radius follows:

[tex]4r=\sqrt{2}a[/tex]

Where,

a = edge length = 362 pm

r = atomic radius of iron = ?

Plugging values in above equation, we get:

[tex]r=\frac{\sqrt{2}\times 362}{4}\\\\a=128pm[/tex]

Hence, the atomic radius of iron is 128 pm.

Answer:

On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you go down a group. As a result, the most electronegative elements are found on the top right of the periodic table, while the least electronegative elements are found on the bottom left.

Explanation:

Answer:

The Electronegativity increases

Explanation:

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Answer: The correct option is E.) 2.749 M.

Explanation:

Density is defined as the ratio of mass and volume of a substance.

[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}} [/tex] ......(1)

Given values:

Volume of glycerol = 50.0 mL

Density of glycerol = 1.2656 g/mL

Putting values in equation 1, we get:

[tex]\text{Mass of glycerol }=(1.2656g/mL\times 50.0mL)=63.28g[/tex]

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(2)

Given values:

Given mass of glycerol = 63.28 g

Molar mass of glycerol = 92.094 g/mol

Volume of the solution = 250.00 mL

Putting values in equation 2, we get:

[tex]\text{Molarity of solution}=\frac{63.28\times 1000}{92.094\times 250.00}\\\\\text{Molarity of solution}=2.749M[/tex]

Hence, the correct option is E.) 2.749 M.

Answer:

12 mol CO₂

General Formulas and Concepts:

Atomic Structure

Stoichiometry

Explanation:

Step 1: Define

Identify

[rxn] 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

[Given] 2 mol C₆H₁₂O₆

[Solve] mol CO₂

Step 2: Identify Conversions

[rxn] 6CO₂ → C₆H₁₂O₆

Step 3: Convert

Answer:

1) increases

2) decrease

3) increase

4) decrease

Explanation:

When ionic compounds dissolve in water, the concentration of ions in solution increases since ionic substances dissociate into ions in solution. The greater the concentration of ions in a solution, the greater the ionic strength of that solution.

Hence, if HNO3 is added to KOH solution, the ionic strength of the solution is increased due to an increase in the number of ions in the solution.

Also, when benzoic acid is titrated against KOH, potassium benzoate (an ionic substance) is formed thereby increasing the ionic strength of the solution.

However, when KOH is added to CaCl2, a precipitate (Ca(OH)2) is formed. Also, when NaOH is added to FeCl2, a precipitate (Fe(OH)2) is formed. In both cases, the formation of the precipitate decreases the concentration of ions in the solution thereby decreasing the ionic strength of the solution.

Answer:

Explanation:

Answer:

Answer is in the explanation.

Explanation:

Before the equivalence point, the pH of the solution of HCl that is titrated with NaOH has a pH <<< 7. When you are adding more NaOH nearing, thus, to the equivalence point the change in pH occurs quickly, and, with 1 drop of excess of NaOH after equivalence, the pH of the solution change to a pH >>> 7

That means the volume added at pH 5 or pH 9 is, almost, the same doing the indicator work just as well as an indicator with change color at pH 7

Explanation:

A kind of chemical reaction in which a reaction between any combustible substance and an oxidizer takes place in order to form an oxidized product.

Eg: Fuel + O2 → CO2 + H2O.

The burning of charcoal is a combustion reaction.

A synthesis reaction occurs when two or more reactants combine to form a single product.

Eg: Na + Cl → NaCl

An example of a synthesis reaction is the combination of sodium (Na) and chlorine (Cl) to produce sodium chloride (NaCl).

A decomposition reaction occurs when one reactant breaks down into two or more products.

Eg: NaCl → Na + Cl

An example of a decomposition reaction is the breakdown of Sodium chloride to give sodium and chloride.

A single replacement reaction, sometimes called a single displacement reaction, is a reaction in which one element is substituted for another element in a compound.

Eg: Zn + 2 HCl → 2 ZnCl + H2

The reaction between zinc metal and hydrochloric acid to produce zinc chloride and hydrogen gas is an example of a single-displacement reaction.

A double replacement reaction is a type of chemical reaction that occurs when two reactants exchange cations or anions to yield two new products.

Eg: AgNO 3 + NaCl → AgCl + NaNO

The reaction between silver nitrate and sodium chloride to produce silver chloride and sodium nitrate is an example of a double-displacement reaction.

Answer:

6.9

Explanation:

Mass(m)=?

Density (D)=0.75

Volume (v)=9.2

M=D×V

M=0.75×9.2

M=6.9

Answer:

1.1 × 10² g

Explanation:

The combustion of gasoline releases energy that is used to move the car. The enthalpy of reaction (ΔH°rxn) of the combustion of gasoline is 47 kJ/g, that is, 47 kiloJoule are produced per gram of gasoline burned. The mass of gasoline to be burned to release 5,375 kJ is:

5,375 kJ × 1 g Gasoline/47 kJ = 1.1 × 10² g

Answer:

0.012288122055459

Explanation:

i might be wrong

Answer:

(a) boiling point

(d) density at a given temperature and pressure.

Explanation:

Isomers are compounds that have the same molecular formula but different structural formulas. They differ in chemical and physical properties depending on the type of isomerism displayed by the compounds.

The compounds stated here are structural or constitutional isomers hence they possess different boiling points and densities at a given temperature and pressure owing to structural differences in the molecules.

Since they have the same molecular formula, they must yield the same result during combustion analysis and they must have the same molecular weight.

Answer:

Argon

Explanation:

It has more electron than chlorine

Answer:

E) Two of the above statements are true.

Explanation:

The options are:

A) Before the solution is titrated with HCl it is pink and when the color changes from pink to colorless, the moles of H*(aq) equals the moles of OH"(aq) used in the hydrolysis of the neutralized aspirin. TRUE. Before the solution is titrated, there is an excess of NaOH (Basic solution, phenolphtalein is pink). Then, at equivalence point, after the addition of HCl, the pH is acidic and phenolphtalein is colorless.

B) Before the solution is titrated with HCl it is colorless and when the color changes from colorless to pink, the moles of H*(aq) equals the excess moles of OH(aq) added. FALSE. As was explained, before the titration, the solution is pink.

C) 25.0 mL of 0.100 M NaOH was added to the sample to hydrolyze the neutralized aspirin in the solution. The titration with HCl allows us to determine the moles of excess OH(aq) added. Once we determine the moles of excess OH(aq), we can determine moles of OH"(aq) used in the hydrolysis of the neutralized aspirin, which is equal to the moles of aspirin in the recrystallized aspirin. TRUE. Aspirin requires an excess of base (NaOH) for a complete dissolution (Hydrolysis). Then, we add H+ as HCl to know the excess moles of OH-. As we know the added moles of OH-, we can find the moles of OH that reacted = Moles of aspirin.  

D) We can determine the moles of aspirin in the recrystallized aspirin by titrating with the 0.100 M NaOH to the neutralization point. The purpose of the hydrolysis of the neutralized aspirin and the back-titration with the 0.100 M HCl is to confirm the moles of aspirin in the recrystallized aspirin. FALSE. NaOH can be added directly unyil neutralization point because, initially, aspirin can't be dissolved completely

E) Two of the above statements are true. TRUE

Right option is:

In this exercise it is necessary to identify the true alternatives and the false alternatives. Thus, classifying these alternatives we have:

A) True

B) False

C) True

D) False

E) True

So we can say that: Two of the above statements are true.

The options are:

A) Before the solution is titrated with [tex]HCl[/tex] it is pink and when the color changes from pink to colorless, the moles of [tex]H*(aq)[/tex] equals the moles of [tex]OH"(aq)[/tex] used in the hydrolysis of the neutralized aspirin. TRUE. Before the solution is titrated, there is an excess of [tex]NaOH[/tex] (Basic solution, phenolphtalein is pink). Then, at equivalence point, after the addition of [tex]HCl[/tex], the pH is acidic and phenolphtalein is colorless.

B) Before the solution is titrated with [tex]HCl[/tex] it is colorless and when the color changes from colorless to pink, the moles of [tex]H*(aq)[/tex] equals the excess moles of [tex]OH(aq)[/tex] added. FALSE. As was explained, before the titration, the solution is pink.

C) 25.0 mL of 0.100 M NaOH was added to the sample to hydrolyze the neutralized aspirin in the solution. The titration with [tex]HCl[/tex] allows us to determine the moles of excess [tex]OH(aq)[/tex] added. Once we determine the moles of excess [tex]OH(aq)[/tex], we can determine moles of [tex]OH"(aq)[/tex] used in the hydrolysis of the neutralized aspirin, which is equal to the moles of aspirin in the recrystallized aspirin. TRUE. Aspirin requires an excess of base [tex](NaOH)[/tex] for a complete dissolution (Hydrolysis). Then, we add [tex]H+[/tex] as [tex]HCl[/tex] to know the excess moles of [tex]OH-[/tex]. As we know the added moles of [tex]OH-[/tex], we can find the moles of [tex]OH[/tex] that reacted (Moles of aspirin).  

D) We can determine the moles of aspirin in the recrystallized aspirin by titrating with the [tex]0.100 M NaOH[/tex] to the neutralization point. The purpose of the hydrolysis of the neutralized aspirin and the back-titration with the [tex]0.100 M HCl[/tex] is to confirm the moles of aspirin in the recrystallized aspirin. FALSE. [tex]NaOH[/tex] can be added directly unyil neutralization point because, initially, aspirin can't be dissolved completely

E) Two of the above statements are true. TRUE

Learn more: brainly.com/question/15497011

Answer:

lithium 3

Explanation:

This is because lithium has three protons

The question is incomplete, the complete question is:

Identify the calculations possible using only 28.02 g/mol as a conversion factor. Select one or more:

(a): Calculate the grams of [tex]N_2[/tex] in 10.58 L of nitrogen gas

(b): Calculate the grams of [tex]N_2[/tex] in [tex]5.03\times 10^{20}[/tex] moles of nitrogen gas

(c): Calculate the moles of [tex]N_2[/tex] molecules in 3.94 grams of nitrogen gas

(d): Calculate the moles of [tex]N_2[/tex] molecules in 4.73 L of nitrogen gas

Answer: The correct options are (b) and (c).

Explanation:

We are given:

Molar mass of [tex]N_2[/tex] = 28.02 g/mol

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

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

At STP conditions:

1 mole of gas occupies 22.4 L of volume

For the given options:

(a): Volume is given and to calculate the mass of [tex]N_2[/tex], we need to use both the conversion factors above.

The equation formed will be:

Mass of [tex]N_2[/tex] = [tex]\frac{1mol}{22.4L}\times 10.58L\times 28.02 g/mol[/tex]

(b): Moles are given and to calculate the mass of [tex]N_2[/tex], we need only the first conversion factor.

The equation formed will be:

Mass of [tex]N_2[/tex] = [tex](5.03\times 10^{20}mol)\times 28.02g/mol[/tex]

(c): Mass is given and to calculate the moles of [tex]N_2[/tex] molecules, we need only the first conversion factor.

The equation formed will be:

Moles of [tex]N_2[/tex] molecules = [tex]\frac{3.94 g}{28.02g/mol}[/tex]

(d): Volume is given and to calculate the moles of [tex]N_2[/tex] molecules, we need only the second conversion factor.

The equation formed will be:

Moles of [tex]N_2[/tex] molecules = [tex]\frac{1mol}{22.4L}\times 4.73L[/tex]

Hence, the correct option is (b) and (c)

Using only 28.02 g/mol as a conversion factor, we can:

We want to identify the conversion factors required in a series of calculations.

A conversion factor is an arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.

28.02 g/mol, which is the molar mass of nitrogen, is a conversion factor to convert moles to mass and vice versa.

We want to convert 10.58 L (volume) to grams (mass). We need to conversion factors:

We want to convert 5.03 × 10²⁰ moles (moles) to grams (mass). We can do so by just using 28.02 g/mol as the conversion factor.

We want to convert 3.94 grams (mass) to moles. We can do so by just using 28.02 g/mol as the conversion factor.

We want to convert 4.73 L (volume) to moles. The required conversion factor is 22.4 L/mol.

Using only 28.02 g/mol as a conversion factor, we can:

The question is incomplete, the complete question is:

Identify the calculations possible using only 28.02 g/mol as a conversion factor. Select one or more:

(a): Calculate the grams of N₂ in 10.58 L of nitrogen gas.

(b): Calculate the grams of N₂ in 5.03 × 10²⁰ moles of nitrogen gas.

(c): Calculate the moles of N₂ molecules in 3.94 grams of nitrogen gas.

(d): Calculate the moles of N₂ molecules in 4.73 L of nitrogen gas.

Learn more about conversion factors here: https://brainly.com/question/97386

Answer:

If the density of the material is equal to the density of the material you have been working with it is possible that the samples are the samples

Explanation:

Density is an intensive property of the matter (Doesn't depends of its amount) that is widely used to identify a substance. Density is the ratio between the mass of the substance (In this case 25.62g) and the volume this amount occupies (21.9cm³). The density is:

25.62g / 21.9cm³ =

1.17g/cm³.

Answer:

Scandium, with atomic number of 21 = [Ar]3d¹4s²

Yttrium, with atomic number of 39 = [Kr]4d¹5s²

Lanthanum, with atomic number of 57 = [Xe]5d¹6s²

Actinium, with atomic number of 89 = [Rn]6d¹7s²

Explanation:

The electronic configuration of atoms of elements describes how electrons are arranged in the atomic orbitals of the atom. The electron configurations of atoms in standard notation is usually written sequentially with all electron-containing atomic subshells (s, p, d and f) and the number of electrons they contain in superscript. For example, the electron configuration of Neon is 1s²2s²2p⁶. However, an abbreviated notation can be used especially for elements having large atomic numbers. The symbol of the previous noble gas in square brackets indicating the core electrons is written before the outermost shell electrons of the atom. For example, the abbreviated electron configuration of sodium is [Ne]3s¹.

The electronic configuration of the given elements are shown below:

Scandium, with atomic number of 21 = [Ar]3d¹4s²

Yttrium, with atomic number of 39 = [Kr]4d¹5s²

Lanthanum, with atomic number of 57 = [Xe]5d¹6s²

Actinium, with atomic number of 89 = [Rn]6d¹7s²

Answer:

12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro's Number (6.0221421 x 1023).

Explanation:

carry on learning

Answer:

151200 minutes.

Explanation:

From the question given above, the following data were obtained:

Time (in week) = 15 weeks

Time (in min) =?

Next, we shall convert 15 weeks to days. This can be obtained as follow:

1 week = 7 days

Therefore,

15 weeks = 15 weeks × 7 days / 1 week

15 weeks = 105 days

Next, we shall convert 105 days to hours. This can be obtained as follow:

1 day = 24 h

Therefore,

105 days = 105 days × 24 h / 1 day

105 days = 2520 h

Finally, we shall convert 2520 h to mins. This can be obtained as follow:

1 h = 60 mins

Therefore,

2520 h = 2520 h × 60 mins / 1 h

2520 h = 151200 mins

Thus, 15 weeks is equivalent to 151200 minutes.