A reaction was performed, and the dichloromethane solvent was dried by adding magnesium sulfate drying agent. When the reaction flask was shaken, it was observed that the magnesium sulfate clumped together at the bottom of the flask. What does this observation indicate

Answer: The concentration of fluoride ions after the addition of 9.00 mL of 0.0100 M HCl to 25.0 mL of this solution is 0.0709 M.

Explanation:

Given: Concentration of hydrogen fluoride = 0.126 M

Concentration of fluoride ions = 0.1 M

Volume of HCl = 9.0 mL

Concentration of HCl = 0.01 M

Volume of HCl = 25.0 mL

Moles of [tex]F^{-}[/tex] ions are calculated as follows.

[tex]Moles of F^{-} = molarity \times volume\\= 0.1 M \times 0.025 L\\= 0.0025 mol[/tex]

Moles of HF are as follows.

[tex]Moles of HF = Molarity \times Volume\\= 0.126 M \times 0.025 L\\= 0.00315 mol[/tex]

Moles of HCl are as follows.

[tex]Moles of HCl = Molarity \times volume\\= 0.01 M \times 0.009 L\\= 0.00009 mol[/tex]

Now, reaction equation with initial and final moles will be as follows.

                        [tex]H^{+} + F^{-} \rightarrow HF[/tex]

Initial:      0.00009  0.0025    0.00315

Equilibrium:      (0.0025 - 0.00009)    (0.00315 + 0.00009)

                                = 0.00241                    = 0.00324

Total volume = (9.00 mL + 25.0 mL) = 34.0 mL = 0.034 L

Hence, concentration of fluoride ions is calculated as follows.

[tex]Concentration = \frac{moles}{volume}\\= \frac{0.00241 mol}{0.034 L}\\= 0.0709 M[/tex]

Thus, we can conclude that concentration of fluoride ions after the addition of 9.00 mL of 0.0100 M HCl to 25.0 mL of this solution is 0.0709 M.

Answer:

1). 1-pentanol - Primary

2). 3-ethyl-3-pentanol - Tertiary

3). 2-hexanol - Secondary

4). Alcohol with two other carbons attached to the carbon with the hydroxyl group - Secondary

5). Alcohol with one other carbon attached to the carbon with the hydroxyl group - Primary

6). Alcohol with three other carbons attached to the carbon with the hydroxyl group - Tertiary

Explanation:

The distinct types of alcohol have been matched with the categories above as per their descriptions provided. In chemistry, alcohols have been categorized into three different categories namely primary, secondary, and tertiary.

In the primary type, those alcohols are involved in which there is an association of hydroxyl group to a primary atom of carbon along with a minimum of two atoms of hydrogen. Example; ethanol.

In the secondary type, the alcohols have an association of carbon atoms to hydroxyl with a single atom of hydrogen and has a formula of '-CHROH.' Example: 2 - propanol.

In the tertiary alcohols, here the association is between the hydroxyl group with the carbon atom that is saturated and possessing 3 atoms of carbon associated with it. It has a formula of '-CR2OH.' Example:  3-ethyl-3-pentanol, -tert -butyl alcohol, etc.

Answer:

[tex]NCl_3[/tex]

Explanation:

An octet rule is a thumb rule in the chemical sciences in which there is a natural tendency for an atom to prefer eight electrons in the valence shell of the atom. When there are less than eight electrons in the atom, they react with other atoms and form more stable compounds.

In the context, nitrogen trichloride, [tex]NCl_3[/tex], is an example of molecular compound which obeys the octet rule having a zero formal charges on each atom of the compound.

Answer:

A and b are the both the answers

Answer:

0.000731 grams aluminium sulfate

46.0 mols ammonia

Explanation:

ALS = shorthand for aluminium sulfate which has a molar mass of 342.15 g/mol

[tex]ALS: \frac{0.250mols}{1} *\frac{1g}{342.15mols} = \frac{0.250g}{342.15}=0.0007307 g[/tex]

NH3 has a molar mass of 17.031 g/mol

[tex]NH3: \frac{2.70g}{1} *\frac{17.031mols}{1g} = \frac{0.250g}{342.15}=45.9837 mols[/tex]

Aluminium sulphate (AlS) whose molar mass is= [tex]\sf{ 342.15\dfrac{g}{mol} }[/tex]

we have to find the 0.250 moles of aluminum sulphate.

[tex]\implies AlS=\dfrac{1g}{342.15~mole}×0.250~mole \\\\\implies AlS=\dfrac{0.250}{342.15}\\\\\implies \dfrac{\frac{250}{1000}}{\frac{34215}{100}}\\\\\implies \dfrac{250}{1000}×\dfrac{100}{34215}\\\\=0.00073067\approx{0.0007307~g}[/tex]

[tex]\\\\\\[/tex]

Ammonia(NH3) whose molar mass is =[tex]\sf{17.031\dfrac{mol}{g} }[/tex]

We have to find 2.70 grams of ammonia

[tex]\implies NH_{3}=\dfrac{17.031~mol}{1g}×2.70g\\\\ 17.031×2.70\\\\\dfrac{17031}{1000}×\dfrac{270}{100}\\\\ \dfrac{4598370}{100000}\\\\=45.9837\approx{46~mole}[/tex]

Answer:

Partial Pressure = 0.630atm

Explanation:

The total pressure of a mixture of gases is equal to the partial pressure of those gases. The partial pressure of a gas is defined as:

Partial pressure = Mole Fraction * Total pressure

The mole fraction of a gas is the ratio between the moles of the gas and the total moles.

To solve this question we need to find the mole fraction of nitrogen to find its partial pressure:

Mole Fraction nitrogen:

7.00 moles Nitrogen / (7.00moles N2 + 2.50moles O2 + 0.500moles He) = 0.700 = Mole fraction.

Partial Pressure = 0.700* 0.900atm

Answer:

absorption, fluorescence = phosphorescence

Explanation:

Given a particular fluorophore, the wavelength of absorption of the fluorophore is always shorter. Both fluorescence and phosphorescence are kinds of photoluminescence.

Recall that both fluorescence and phosphorescence occur at a longer wavelength. The difference between the two is only in the time taken during the process. While fluorescence takes a shorter time to occur, phosphorescence takes a longer time to occur.

The major difference between fluorescence and phosphorescence is that change of spin occurs during phosphorescence but not fluorescence.

Answer:

carbohydrate, 6, a carbonyl, disaccharide

Explanation:

Fructose is an example of a ketohexose. The -hexose part of the name indicates that fructose is a carbohydrate that contains 6 carbons. There are more isomers that are ketohexoses.

The keto- part of the name indicates that fructose contains a carbonyl functional group. In ketones, the carbonyl is in an inner carbon.

Fructose can combine with glucose to form sucrose. Therefore, sucrose is a disaccharide. Disaccharides are formed by the bonding of 2 monosaccharides.

Answer:

A. 3-chloro-1-methylcyclobutane.

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to infer that the name of this compound is A. 3-chloro-1-methylcyclobutane because of the fact that the parent chain is a cyclobutane which starts by the methyl radical as it has the priority over the chlorine radical which is actually named first at the third carbon (clockwise).

Therefore the name is given in A, accordingly to the IUPAC rules of nomenclature.

Regards!

Answer:

[tex]\boxed {\boxed {\sf 63.0 \%}}[/tex]

Explanation:

The percent yield is the ratio of the actual yield to the theoretical yield.

[tex]percent \ yield = \frac{actual \ yield}{theoretical \ yield} * 100[/tex]

We can substitute the known values into the formula.

[tex]percent \ yield= \frac{ 14.8 \ g}{23.5 \ g}*100[/tex]

Divide.

[tex]percent \ yield = 0.629787234043*100[/tex]

Multiply.

[tex]percent \ yield = 62.9787234043[/tex]

The original measurements for the theoretical and actual yields have 3 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place.

The 7 to the right, in the hundredths place, tells us to round the 9 up to a 0. Since we rounded up to 0, we have to move to the next place to the left and round the 2 up to a 3.

[tex]percent \ yield \approx 63.0[/tex]

The percent yield is approximately 63.0 percent.

Explanation:

The given set of options are:

a) difluoroacetic acid: _______ fluoroacetic acid: _______ trifluoroacetic acid: _______

b) 2-chlorobutanoic acid: _______ 4-chlorobutanoic acid: _______ 3-chlorobutanoic acid: _______

c)cyclohexanol: _______ phenol: _______ benzoic acid:

A strong acid is one whose conjugate base is stabilized either by resonance or -I effect.

a) If -I groups are present on the carboxylic acid group then they stabilize the carboxylate anion (the conjugate base of the carboxylic acid) and give more strength to the carboxylic acid group. More the number of -I groups then more will be the strength of the carboxylic acid.

Among the given options,

Trifluoroacetic acid has three fluorine atoms in its structure thus it is a strong acid.

Fluoroacetic acid has only one fluorine atom in its structure. Hence it is the weak acid among the given options.

b) The -I groups should be nearer to the carboxylic acid group then it attains more stability.

If the distance of the -I group increases from the -COOH group then, the strength of the carboxylic acid group decreases.

So, the strongest acid is 2-chlorobutanoic acid.

The weak acid among them is 4-chlorobutanoic acid.

c) Among the given options benzoic acid is the strongest acid because due to resonance benzoate anion is stabilized more.

Here resonance exists in both phenyl group and [tex]-COO^-[/tex] group.

The weak acid is cyclohexanol.

Because cyclohexanolate anion is not stabilized by resonance.

Answer:

Because sucrose is a complex disaccharide, it is not classified as either an aldose or a ketone. Instead, it is a compound that contains both. glucose is aldose sugar and fructose is a ketose sugar.

Answer:

0.418 g of CO₂ will be produced

Explanation:

Equation of the reaction is given below:

CaCO₃ (s) + 2HCl (aq) ----> CaCl₂(aq) + CO₂ (g) + H₂O (l)

From the equation of reaction , 1 mole of CaCO₃ reacts with 2 molemolesmof HCl to produce 1 mole of CO₂

Number of moles of HCl in 25.7 ml of a 0.738 M solution of HCl is obtained using the formula below:

Number of moles = molarity × volume (Litres)

Number of moles of HCl = 0.738 M × 25.7 mL × 1 L/1000 mL = 0.0190 moles

Since the antacid, Tums will be excess, the limiting reactant is HCl

2 moles of HCl produces 1 mole of CO₂

0.0190 moles of HCl will produce 0.0190 moles ÷ 2 = 0.0095 molesof CO₂

Mass of 0.0095 moles of CO₂ = Numbe of moles × molar mass of CO₂

Molar mass of CO₂ = 44.0 g/mol

Mass of CO₂ produced = 0.00950 moles × 44.0 g/mol = 0.418 g of CO₂

Therefore, 0.418 g of CO₂ will be produced if Tums is added to 25.7 mL of a 0.738 M HCl solution

Answer:

please translate in english

Answer:

the constant temperature will be 12 .F bec in places it is cold

Answer:

The chlorine element belongs to group 17 because it has 7 valence electron . Its valency is 1 . It can gain one electron from any other atom to become stable. This means that it can never form a double or triple bond.

Answer:

2AgNO, K Cro-> 2KNO; 1Cro,

Answer:

B. Gravity

Explanation:

Gravity is a force, not a gas :)

Answer:

B: Gravity

Explanation:

gravity pulls on the gad

Explanation:

For a food with a relative humidity of 81, what is the water activity in the food?

Water activity in a food = relative humidity / 100

Substitute the given values in this formula to get water activity:

Water activity in a food = 81 / 100

Hence, water activity =0.81

Answer:

CrCl₂(s) ⇒ Cr²⁺(aq) + 2 Cl⁻(aq)

Explanation:

Chromium (II) chloride is a strong electrolyte, that is, when dissolved in water, it completely dissociates into the ions. The cation is chromium (II) and the anion is chloride. The balanced equation for the solution of chromium (II) chloride is:

CrCl₂(s) ⇒ Cr²⁺(aq) + 2 Cl⁻(aq)

Answer:

a) Linear polymerization

b) cyclic polymerization

Answer:

matter

1. Candle. not matter

1. light

2. Unburned Particles

2. heat

3. Ash

3. energy

Explanation:

1.The candle is experiencing a solid phase into a gas phase because the heat given off causes smoke.

2. Chemical Potential Energy to Heat EnergyThe candle has Chemical Potential Energy then when it gets lit by the flame heat energy is released.

Explanation:

here's the answer to your question

Answer:

1360kJ are evolved

Explanation:

When 1mole of H2 reacts with 1/2 moles O2 producing 1 mole of water and 241.8kJ.

To solve this question we need to find the limiting reactant knowing were added 90g of H2 and 90g of O2 as follows:

Moles H2 -Molar mass: 2g/mol-

90g H2 * (1mol / 2g) = 45 moles

Moles O2 -Molar mass: 32g/mol-

90g * (1mol / 32g) = 2.81moles

For a complete reaction of 2.81 moles of O2 are needed:

2.81 moles O2 * (1mol H2 / 1/2 mol O2) = 5.62 moles H2

As there are 45 moles, H2 is the excess reactant and O2 the limiting reactant.

As 1/2 moles O2 produce 241.8kJ, 2.81 moles will produce:

2.81 moles O2 * (241.8kJ / 1/2moles O2) =

The quantity of heat evolved when 180 g mixture containing equal parts of H₂ and O₂ burned is

The equation for the combustion of hydrogen is given as:

[tex]\mathbf{H_2 + \dfrac{1}{2}O_2 \to H_2O \ \ \ \ \Delta H_r^0 = -241.8\ kJ/mol}[/tex]

Recall that:

Since the mass of 180 g is equally shared by H₂ and O₂, then:

The number of moles of the reactant can be determined as follows:

For H₂:

[tex]\mathbf{no \ of \ moles = \dfrac{mass }{molar \ mass}}[/tex]

[tex]\mathbf{no \ of \ moles = \dfrac{90 \ g }{2.016 \ g/mol}}[/tex]

no of moles = 44.6 mol

For O₂:

[tex]\mathbf{no \ of \ moles = \dfrac{90 \ g }{32 \ g/mol}}[/tex]

no of moles = 2.8 mol

Here, since O₂ has a lesser amount of mole, then O₂ is regarded as the limiting reagent here:

If 1/2 moles of O₂ produces -241.8 kJ/mol of water;

Then, the quantity of heat that will evolve when 180 g mixture containing equal parts of H₂ and O₂ burned is:

[tex]\mathbf{= \Big (\dfrac{2.81 \ mol}{\dfrac{1}{2 } \ mol }\Big) \times (-241.8 \ kJ) }[/tex]

[tex]\mathbf{= \Big (5.62\Big) \times (-241.8 \ kJ) }[/tex]

= - 1358.91 kJ

≅ - 1360 kJ

Therefore, we can conclude that the quantity of heat evolved is - 1360 kJ

Learn more about the quantity of heat here:

https://brainly.com/question/3682138?referrer=searchResults

Answer:

60 mols hydrogen

Explanation:

1 mol of glucose contains 12 mols of Hydrogen

5 mols of glucose contains 12 * 5 = 60 moles of hydrogen.

Explanation:

example is copper iron...........

Answer:

97.0%m/m es la concentración de la solución

Explanation:

El porcentaje masa/masa (%m/m) se define como 100 veces el radio entre la masa de soluto (300g de HCl) y la masa de la solución. Para hallar la masa de la solución debemos hallar la masa del agua (Solvente) haciendo uso de la ecuación del volumen de un cono. Con el volumen del cono podemos hallar la masa del agua haciendo uso de la densidad, así:

Volumen:

Volumen Cono = π*r²*h / 3

Donde r es el radio = 0.300m

h la altura = 5m

Volumen = π*(5m)²*0.300m / 3

7.85m³

Masa Agua:

7.85m³ * (1.2g / m³) = 9.42g Agua

Masa solución:

300g HCl + 9.42g Agua = 309.42g Solución

%m/m:

300g HCl  / 309.42g * 100 =

Answer:

0.030 mole

Explanation:

Mass of crucible + lid = 23.422 g

Mass of crucible + lid + compound = 24.746 g

Mass of crucible + lid + compound - water = 24.213

Mass of water = Mass of crucible + lid + compound + heat

       = 24.746 - 24.213

                = 0.533 g

Mole of water in the hydrated compound = mass of water in the compound/molar mass of water

    = 0.533/18

         = 0.0296 mole = 0.030 mole

Answer:

See explanation

Explanation:

a) The balanced reaction equation is;

K2S + CO(NO3)2 ------> COS + 2 KNO3

b) When we include the states of matter, we have;

K2S(aq) + CO(NO3)2(aq) ----> COS(s) + 2 KNO3(aq)

c) The complete ionic equation is;

2K^+(aq) + S^2-(aq) + Co^2+(aq) + 2NO3^-(aq) ----> CoS(s) + 2K^+(aq) + 2NO3^-(aq)

Net ionic equation;

Co^2+(aq) + S^2-(aq) ----> CoS(s)

Answer:

Please find the complete solution in the attached file.

Explanation: