Nf3 Rotate the molecule until you have a feeling for its three-dimensional shape. How many atoms are bonded to the central atom?

Answer:

11.31g NaClO₂

Explanation:

Is given 250mL of a 1.60M chlorous acid HClO2 solution. Ka is 1.110x10⁻². What mass of NaClO₂ should the student dissolve in the HClO2 solution to turn it into a buffer with pH =1.45?

It is possible to answer this question using Henderson-Hasselbalch equation:

pH = pKa + log₁₀ [A⁻] / [HA]

Where pKa is -log Ka = 1.9547; [A⁻] is the concentration of the conjugate base (NaClO₂), [HA] the concentration of the weak acid

You can change the concentration of the substance if you write the moles of the substances:

[Moles HClO₂] = 250mL = 0.25L×(1.60mol /L) = 0.40 moles HClO₂

Replacing in H-H expression, as the pH you want is 1.45:

1.45 = 1.9547 + log₁₀ [Moles NaClO₂] / [0.40 moles HClO₂]

-0.5047 = log₁₀ [Moles NaClO₂] / [0.40 moles HClO₂]

0.3128 = [Moles NaClO₂] / [0.40 moles HClO₂]

0.1251 = Moles NaClO₂

As molar mass of NaClO₂ is 90.44g/mol, mass of 0.1251 moles of NaClO₂ is:

0.1251 moles NaClO₂ ₓ (90.44g / mol) =

Answer:

2 H⁺ + 2e = H₂    ( reduction )

Explanation:

Fe( s ) + 2 CH₃COOH = Fe ( OOCCH₃ ) ₂ + H₂

Fe( s ) = Fe⁺² + 2e     ( oxidation )

2 H⁺ + 2e = H₂    ( reduction )

Answer:

Explanation:

the molar mass for Na2CO3 is 2*23+12+3*16=106 g/mole

106*0.251=26.606 grames

Answer:

Balancing the equations means adding coefficients to the reactants or products so that there is an equal amount of atoms of an element on both sides of the equation.

1) 2Mg + O₂ ⇒ 2MgO

2) 2SO₂ + O₂ ⇒ 2SO₃

3) 2Na + Cl₂ ⇒ 2NaCl

4) 4K + O₂ ⇒ 2K₂O

Answer:

Following are the answer to this question:

Explanation:

In the given question an attachment file is missing, that is attached. please find the attached file, and the following are the description of the given points:

a. At 100 degrees in 100 mL 5 g is dissolved.  

For, it required:

[tex]\to 2g = 100 \times \frac{2}{5}[/tex]

         [tex]= 40 \ \ ml \ of \ water.[/tex]  

b. At 0 degrees 100 mL dissolve in 0.3 g.  

So, the dissolve:

[tex]\to 40 \ ml= 0.3\times \frac{40}{100}[/tex]

               [tex]= 0.12g.[/tex]

After refrigeration 0.12 g will still be dissolved.  

c. After dissolving and freezing, precipitation can occur which would still be impure if the cooling is instantaneous. The added solvent was also too hard to recrystallize. The solvent was placed below its place of reservation.  

d. Recovery percentage:

[tex]\to \frac{0.8}{2}\times100[/tex]

[tex]\to 40 \ \%[/tex]

The melting point of acetanilide:

[tex]\to 114.3^{\circ}.[/tex]

Found=109(medium)  

Melting point error percentages:

[tex]= \frac{114.3-109}{114.3}\\\\=4.63 \ \%[/tex]

Answer:

v/v % = 24.522 %

Explanation:

A percent v/v solution is calculated by the following formula using the milliliter as the base measure of volume (v):

v/v % = [(volume of solute) / (volume of solution)] x 100%

In this problem, the solute is ethylene gycol.

Mass = 136.1 g

Density = 1.11 g/mL

Density = Mass / Volume

Volume = Mass / Density = 136.1 / 1.11 = 122.61 mL

Volume of solution = 500 mL

v/v % = [(volume of solute) / (volume of solution)] x 100%

v/v % = (122.61 / 500 ) x 100

v/v % = 0.24522 x 100

v/v % = 24.522 %

Considering the definition of volume percentage and density, the %v/v of the solution is 24.522%.

Volume percentage is a measure of concentration that indicates the volume of solute per 100 volume units of the solution.

In other words, percent by volume is defined as the ratio of the volume of solute to the volume of the solution.

The volume percentage of a solution is determined by the following expression:

[tex]volume percentage=\frac{volume of solute}{total volume} x100[/tex]

In this case, you know that a solution made from 136.1 g of ethylene glycol (density is 1.11 g/mL) in water to form a total volume of 500.0 mL.

Knowing that the density is a quantity that allows us to measure the amount of mass in a certain volume of a substance, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:

[tex]density=\frac{mass}{volume}[/tex]

So, being 136.1 g of ethylene glycol (solute) with a density of 1.11 [tex]\frac{g}{mL}[/tex], the volume can be calculated as:

[tex]1.11 \frac{g}{mL} =\frac{136.1 g}{volume}[/tex]

Solving:

[tex]volumex1.11 \frac{g}{mL} =136.1 g[/tex]

[tex]volume=\frac{136.1 g}{1.11 \frac{g}{mL} }[/tex]

volume= 122.61 mL

So, you know that:

Replacing in the expresion for volume percentage:

[tex]volume percentage=\frac{122.61 mL}{500 mL} x100[/tex]

Solving:

volume percentage= 0.24522 ×100

volume percentage= 24.522 %

Finally, the %v/v of the solution is 24.522%.

Learn more about:

Answer:

Number of molecules = 1.8267×10^20

Explanation:

From the question, we can deuced that the gases behave ideally, the we can make use of the ideal gas equation, which is expressed below;

PV = nRT

where

P =pressure

V =volume

n = the number of moles

R is the gas constant equal to 0.0821 L·atm/mol·K

T is the absolute temperature

Given:

P = 6.75 atm;

T = 290.0 k,

; V = 1.07 cm³ = 0.001 L

( 6.75 atm)(0.00107 L) = n(0.0821 L·atm/mol·K)(290K)

n = 3.0335167*10^-4 moles

But there are 6.022×10²³ molecules in 1 mole,

Number of molecules = 1.8267×10^20

Answer:

There are  [tex]\mathbf{8.90172 \times 10^{-14}}[/tex] moles of bactoX present in a 3.0 μL sample volume that contains 7.512×106 bacterial cells

Explanation:

Given that:

The number of molecules present in one bacterial cell is [tex]7.140 \times 10^3[/tex] molecules

and the sample  contains [tex]7.512 \times 10^6[/tex] molecules.

Number of moles = number of molecules /Avogadro's number

where;

Avogadro's number = 6.023 × 10²³

Number of moles = [tex]\dfrac{7.140 \times 10^3}{6.023 \times 10^{23}}[/tex]

Number of moles = [tex]1.185 \times 10^{-20}[/tex] moles

So;  [tex]1.185 \times 10^{-20}[/tex] moles  is present in one bacteria cell

Similarly;  the sample  contains [tex]7.512 \times 10^6[/tex] molecules.

Therefore; the number of moles present in the bactoX is = [tex]1.185 \times 10^{-20} \times 7.512 \times 10^6[/tex]

= [tex]\mathbf{8.90172 \times 10^{-14}}[/tex] moles

Answer:

KK+reacts with water NaNa+reacts with water LiLi+reacts with water

Answer:

B

Explanation:

It should be 2s² which means the answer is the configuration is missing an electron in the 2s orbital.

Answer:

B.

Explanation:

It should be 2s² which means the answer

is the configuration is missing an electron

in the 2s orbital.

Answer:

160.53L

Explanation:

Since Pressure is kept constant we can use charles law

Answer:

first, to get rid of the division, multiply both sides by 2. you will get 7x=98. next, divide both sides by 7 to isolate x. x=14

Answer:

0.45 moles

Explanation:

The computation of the number of moles left in the cylinder is shown below:

As we know that

[tex]\frac{n1}{V1} = \frac{n2}{V2}[/tex]

we can say that

[tex]n2 = n1 \times \frac{V2}{V1}[/tex]

where,

n1 = 1.80 moles of gas

V2 = 12.0 L

And, the V1 = 48.0 L

Now placing these values to the above formula

So, the moles of gas in n2 left is

[tex]= 1.80 \times \frac{12.0\ L}{48.0\ L}[/tex]

= 0.45 moles

We simply applied the above formulas so that the n2 moles of gas could arrive

Answer:

346 hope this is helpfull

Answer:

2415.9g (corrected to 1 d.p.)

Explanation:

(Take the atomic mass of Ga=69.7 and S=32.1)

Assuming Ga is the limiting reagent (because the question did not mention the amount of sulphur burnt),

From the balanced equation, the mole ratio of Ga:Ga2S3 = 4: 2 = 2: 1, which means, every 2 moles of Ga burnt, 1 mole of Ga2S3 is produced.

Using this ratio, let y be the no. of moles of Ga2S3 produced,

[tex]\frac{2}{1} =\frac{20.5}{y}[/tex]

y = 20.5 / 2

= 10.25 mol

Since mass = no. of moles x molar mass,

the mass of Ga2S3 produced = 10.25 x (69.7x2 + 32.1x3)

= 2415.9g (corrected to 1 d.p.)

Answer:

You require 12.8mL of the 0.500M C₂H₃O₂Na and 7.2mL of the 0.500M C₂H₃O₂H

Explanation:

It is possible to obtain pH of a weak acid using H-H equation:

pH = pKa + log₁₀ [A⁻] / [HA]

For the buffer of acetic acid/acetate, the equation is:

pH = pKa + log₁₀ [C₂H₃O₂Na] / [C₂H₃O₂H]

Replacing:

5.00 = 4.75 + log₁₀ [C₂H₃O₂Na] / [C₂H₃O₂H]

1.7783 =  [C₂H₃O₂Na] / [C₂H₃O₂H] (1)

Buffer strength is the concentration of the buffer, that means:

0.1M = [C₂H₃O₂Na] + [C₂H₃O₂H] (2)

Replacing (2) in (1):

1.7783 =  0.1M - [C₂H₃O₂H] / [C₂H₃O₂H]

1.7783 [C₂H₃O₂H] = 0.1M -  [C₂H₃O₂H]

2.7783 [C₂H₃O₂H] = 0.1M

Also:

[C₂H₃O₂Na] = 0.1M - 0.036M

The moles of both compounds you require is:

[C₂H₃O₂Na] = 0.1L × (0.064mol / L) = 0.0064moles

[C₂H₃O₂H] = 0.1L × (0.036mol / L) = 0.0036moles

Your stock solutions are 0.500M, thus, volume of both solutions you require is:

[C₂H₃O₂Na] = 0.0064moles × (1L / 0.500M) = 0.0128L = 12.8mL

[C₂H₃O₂H] = 0.0036moles × (1L / 0.500M) = 0.0072mL = 7.2mL

Answer:

54

Explanation:

Mass number = protones + neutrons

Mass number = 24 + 30

Mass number = 54

Answer:

a. The pressure of a fixed amount of gas is inversely proportional to its volume.

Explanation:

At constant temperature, the relationship between pressure (P) and volume (V) illustrated in the plot for a gas gives a straight line from the origin.

This relationship was described by a law stated by Robert Boyle, an English Chemist, in 1662.

Boyle's law states that the pressure of a fixed mass of gas is inversely proportional to the volume, provided the temperature remains constant.

The relationship for Boyle’s Law can be expressed mathematically as follows:

P1V1 = P2V2; where P1 and V1 are the values of the initial pressure and volume, and P2 and V2 are the final values of the pressure and volume of the gas.

Answer:B

Explanation: I guessed and got it right. Also (1/V).

Answer:

The answer is option D.

Hope this helps you

Answer:

322

Explanation:

This is easy

Answer:

CaC₂  +  2H₂O  →  C₂H₂  + Ca(OH)₂

Explanation:

In order to find out the reaction, we must know the reactants.

For this situation, we make acetylene gas from carbide calcium CaC₂ and H₂O (water); therefore the reactants are:

- CaC₂  and  H₂O

Acetylene is one of the products made  →  C₂H₂

So the reaction can be formed as this:  CaC₂  +  H₂O  →  C₂H₂

We missed the calcium, and this reaction also makes, Calcium Hydroxide, so the complete equation must be:

CaC₂  +  H₂O  →  C₂H₂  + Ca(OH)₂

This is unbalanced, because we have 1 O in left side and 2 in right side so we add 2 in water so now, we get the complete reaction:

1 mol of calcium carbide reacts to 2 mol of water in order to produce 1 mol of acetylene and 1 mol of calcium hydroxide.

Answer:

The answer is option A.

Na4C

Hope this helps you

Answer:

8 electrons

Explanation:

The second principal energy level has two sublevels: 2s and 2p

2s : 2 electrons

2p : 6 electrons (3 sublevels × 2 electrons each = 6 electrons)

It can hold a maximum of 8 electrons.

Hope this helps. :)

Answer:

Maximum mass of compound produced = 64 Kg

Explanation:

Carbon monoxide react with hydrogen to produce methanol. Equation for the reaction is given as follows:

CO(g) + 2H₂(g) -----> CH₃OH(l)

From the equation of reaction, 1 mole of CO reacts with 2 moles of Hydrogen gas to produce 1 mole of methanol.

Molar mass of CO = 28 g

Molar mass of H₂ = 2 g

Molar mass of methanol = 32 g

Therefore, 28 g of CO reacts with  4 g of H₂ to produce 32 g of methanol

8.0 Kg of hydrogen will react with 8 * (28/4) Kg of CO = 56 Kg of CO.

therefore, hydrogen is the limiting reactant in the reaction under consideration.

8.0 Kg of Hydrogen will react with 56 Kg of CO to produce 8 * (32/4) Kg of methanol =  64 Kg of methanol

Therefore, maximum mass of compound produced = 64 Kg

Answer: It's is called Reaarrangement

Explanation:

Rearrangement is a chemic reaction in which an atom or group of atoms bond migrate from one carbon atom to another. The movement involves two adjacent atoms and move over a large distance. It is important in functional group transformation.

Reaarrangement can be classified based on the atom or group of atoms it migrate.

Nucleophilic rearrangement which involves the migration of atoms with electron pairs.

Electrophilic migration involved the migration of atom or groups without electron pair.

Free radical involves the atom or group of atoms moving with a lone pair of electron.

Answer: The mass percent by volume is 101.6%

Explanation:

The solution concentration expressed in percent by volume means that the amount of solute present in 100 parts volume of solution.

It is represented in formula as :

mass percent by volume =[tex]\frac{\text {mass of solute}\times 100}{\text {Volume of solution in ml}}\%[/tex]

Given : mass of glucose = 330.1 g

volume of solution = 325 ml

Thus mass percent by volume =[tex]\frac{330.1g\times 100}{325ml}=101.6\%[/tex]

Thus the mass percent by volume is 101.6%

Answer:

45.5

Explanation:

your question is not clear at all

your question has no unit for volume

Answer:

filter the hot mixture.

Explanation:

Solid is stayed undissolved since the arrangement is gotten super saturated. On the off chance that solid molecule is available recrysallization won't happen in this way we need expel the solid molecule by filtarion in hot condition itself . Subsequently, arrangement become totally homogenous and recrysallization item will shaped by moderate cooling

THIS IS THE COMPLETE QUESTION

Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq), as described by the chemical equation.

How much MnO2(s) should be added to excess HCl(aq) to obtain 185 mL of Cl2(g) at 25 °C and 715 Torr?

Answer:

0.62901mol of MnO2(s) should be added

Explanation:

Given:

P = 715/760 = 0.94078atm

v=195ml=0.195l

n = ? moles have to find

R = 0.0821 L atm/K/mole

T = 25 + 273 = 298 K

Then we will make use of below formula

PV = nRT

Insert the values

0.94078*0.195=n 0.0821*298

24.466n=0.1740443

n=0.174/24.466

n=0.007235 nb of moles of cl2

as 1 mole of Cl2 were obtained from 1 mole of MnO2

so 0.007235 of chlorine must have come from

0.007235 moles of MnO2

1 mole of MnO2 = 86.94 g/mole

so 0.007235 moles of MnO2== 86.94* 0.007235

=0.62901

Answer:

2 PbS(s) + 1.5 O₂(g) + PbO(s) ⇒ 2 SO₂(g) + 3 Pb(s)

Explanation:

Lead can be prepared from galena [lead(II) sulfide] by first heating with oxygen to form lead(II) oxide and sulfur dioxide. The corresponding chemical equation is:

PbS(s) + 1.5 O₂(g) ⇒ PbO(s) + SO₂(g)

Heating the metal oxide with more galena forms the metal and more sulfur dioxide. The corresponding chemical equation is:

2 PbO(s) + PbS(s) ⇒ 3 Pb(s) + SO₂(g)

We can get the overall reaction by adding both steps and canceling what is repeated on both sides.

2 PbS(s) + 1.5 O₂(g) + 2 PbO(s) ⇒ PbO(s) + 2 SO₂(g) + 3 Pb(s)

2 PbS(s) + 1.5 O₂(g) + PbO(s) ⇒ 2 SO₂(g) + 3 Pb(s)