Can someone please please help

Answer:

B

Explanation:

It's the same substance but in different states.

HETEROGENEOUS mixtures contain substances that are

not uniform in composition. The parts in the mixture can be separated by physical means.

Answer:

"1.4 mL" is the appropriate solution.

Explanation:

According to the question,

Now,

Increase in volume will be:

⇒ [tex]\Delta V = \alpha\times v_0\times \Delta \epsilon[/tex]

By putting the given values, we get

           [tex]=1.12\times 10^{-4}\times 500\times 25[/tex]

           [tex]=1.12\times 10^{-4}\times 12500[/tex]

           [tex]=1.4 \ mL[/tex]

The question is incomplete, the complete question is;

It takes 338. kJ/mol to break an carbon-chlorine single bond. Cal broken by absorbing a single photon Iculate the maximum wavelength of light for which an carbon-chiorine single bond could be Round your answer to 3 significant digits

Answer:

3.55 × 10^-7 m or 355 nm

Explanation:

Now, the energy of the photon = 338 × 10^3/6.02 × 10^23 = 5.61 × 10^-19 J

Recall that;

E= hc/λ

h= planks constant

c= speed of light

λ = wavelength

λ =hc/E

λ = 6.63 ×10^-34 × 3 × 10^8/5.61 × 10^-19

λ =3.55 × 10^-7 m or 355 nm

Answer: The boiling point of cyclohexane is 81oC and the boiling point of toluene is 111oC. Therefore the liquid collected first should be

CYCLOHEXANE

Explanation:

In chemistry, there are various separation techniques that can be used to separate the components of a mixture and even isolate each of these components. A typical example of such separation techniques is DISTILLATION. This is a method of separation that makes use of different boiling points of liquids in a mixture. A mixture of any number of liquids could be separated as long as they boil at different temperatures. Example include:

--> mixture of cyclohexane (boiling point is 81°C) and toluene (boiling point is 111°C)

--> mixture of alcohol (boiling point is 78°C) and water (boiling point 100°C).

The process involves heating the mixture of liquids until the more volatile liquid ( that is the one with the lower boiling point) changes to vapour. The vapour is cooled by passing it through a condenser and collected in a liquid form known as distillate.

Therefore in the mixture of cyclohexane and toluene, the liquid collected FIRST should be CYCLOHEXANE.

Explanation:

here are the answers. Note that because the pressure is constant, you can use Gay Lussac's formula

Answer:

2.75M

Explanation:

Density = mass/volume

Density of glycerol (C3H8O3) at 15°C is given as 1.2656 g/mL.

Volume of glycerol at this same temperature before dissolving in water = 50mL

Hence, using Density = mass/volume

1.2656 = mass/50

mass = 1.2656g/mL × 50mL

mass = 63.28g

Molarity of solution = number of moles (n) ÷ volume (V)

Volume of glycerol dissolved in water = 250mL = 0.250L

number of moles = mass/molar mass

Molar mass of C3H8O3 = 12(3) + 1(8) + 16(3)

= 36 + 8 + 48

= 44 + 48

= 92g/mol

n = 63.28g ÷ 92g/mol

n = 0.688mol

* Molarity = n/V

Molarity = 0.688/0.250

Molarity = 2.75M

Answer:

63.05% of MgCO3.3H2O by mass

Explanation:

of MgCO3.3H2O in the mixture?

The difference in masses after heating the mixture = Mass of water. With the mass of water we can find its moles and the moles and mass of MgCO3.3H2O to find the mass percent as follows:

Mass water:

3.883g - 2.927g = 0.956g water

Moles water -18.01g/mol-

0.956g water * (1mol/18.01g) = 0.05308 moles H2O.

Moles MgCO3.3H2O:

0.05308 moles H2O * (1mol MgCO3.3H2O / 3mol H2O) =

0.01769 moles MgCO3.3H2O

Mass MgCO3.3H2O -Molar mass: 138.3597g/mol-

0.01769 moles MgCO3.3H2O * (138.3597g/mol) = 2.448g MgCO3.3H2O

Mass percent:

2.448g MgCO3.3H2O / 3.883g Mixture * 100 =

Answer:

a) Attached below

b)  The presence of racemic mixture found as product in both  cases shows that   products are identical ( i.e. they have same configuration

Explanation:

Diagrams of the products obtained from hydroboration-oxidation of cis-2-butene , hydroboration-oxidation of trans-2-butene.

attached below

The presence of racemic mixture found as product in both  cases shows that   products are identical ( i.e. they have same configuration )

Answer:

[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]

Explanation:

For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:

[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]

where:

emitted radiation of the wavenumber  [tex]\bar v[/tex] = ???

atomic no of helium Z = 2

Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]

the initial energy of  the principal quantum [tex]n_1[/tex] = 2

the initial energy of  the principal quantum [tex]n_1[/tex] = 2

Now, the emitted radiation of the wavenumber can be computed as:

[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]

[tex]\bar v = 3.291 \times 10^ 7/m[/tex]

Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber  [tex]\bar v[/tex], which is:

[tex]\bar v = \dfrac{1}{\lambda}[/tex]

[tex]\lambda = \dfrac{1}{\bar v}[/tex]

[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]

[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]

[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]

P=18000000/6 zeros. not sure how to do rest

Explanation:

a) [tex]n = \dfrac{PV}{RT} = \dfrac{(1.8×10^7\:\text{Pa})(3\:\text{L})}{(8310\:\text{L•Pa/mol•K})(300\:\text{K})}[/tex]

[tex]\:\:\:\:\:\:\:= 21.7\:\text{mol}[/tex]

b) [tex]P = \dfrac{nRT}{V}[/tex]

[tex]\:\:\:\:\:\:\:\:\:= \dfrac{(50\:\text{mol})(8310\:\text{L•Pa/mol•K})(300\:K)}{(3\:L)}[/tex]

[tex]\:\:\:\:\:\:\:\:\:=4.2×10^7\:\text{Pa}[/tex]

Answer:

The air inside the Tyre causes pressure because the particles bump into each other and cause pressure the more they bump into each other or their container the higher the pressure is.

hope it is helpful for you

Answer:

90grams

Explanation:

The reaction given in this question is as follows:

2H2 + O2 → 2H20

Based on this equation, 1 mole of oxygen gas (O2) produces 2 moles of water (H2O)

Hence, 2.50moles of oxygen gas will react with excess hydrogen gas to produce (2.5 × 2) = 5.0moles of water.

Using mole = mass/molar mass

Molar mass of water (H2O) = 1(2) + 16

= 18g/mol

5 = mass/18

mass = 18 × 5

mass of H2O = 90grams

Answer:

Close to the calculated endpoint of a titration - Partially open

At the beginning of a titration - Completely open

Filling the buret with titrant - Completely closed

Conditioning the buret with the titrant - Completely closed

Explanation:

'Titration' is depicted as the process under which the concentration of some substances in a solution is determined by adding measured amounts of some other substance until a rection is displayed to be complete.

As per the question, the stopcock would remain completely open when the process of titration starts. After the buret is successfully placed, the titrant is carefully put through the buret in the stopcock which is entirely closed. Thereafter, when the titrant and the buret are conditioned, the stopcock must remain closed for correct results. Then, when the process is near the estimated end-point and the solution begins to turn its color, the stopcock would be slightly open before the reading of the endpoint for adding the drops of titrant for final observation.

Answer:

a

Explanation:

documentary is best researcher!.

Answer:

0.554 kg

Explanation:

We want to find the amount of kilograms of fluorine that will be released into the air over 6 months.

Let's convert to weeks to get;

6 × 4 = 24 weeks

Let's find Mass leak rate of fluorine from the formula;

Mass leak rate = (fluorine mass in freon/molar mass of freon) × leak rate

Molar mass of freon = ((12 × 2) + (1 × 2) + (19 × 3) + (35.5)) = 118.5 g/mol

Thus;

Mass leak rate = ((19 × 3)/(118.5)) × 47.97 = 23.074 g/week

Total fluorine leaked in 6 months = 24 × 23.074 = 553.776 g = 0.554 kg

Answer:

the discovery will always need to be tested more where if you're investigating you should already be in a more controlled environment

The difference between accidental discoveries and scientific investigations are as follows.

To learn more about accidental discoveries,

https://brainly.com/question/13167222

#SPJ2

Answer:

Methane is present in solid, liquid and gaseous form.

Explanation:

Methane hydrate is present in solid state when the hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in the deep oceans while on the other hand, methane which is present inside the earth surface in gaseous form due to non-availability of water that can combine with methane. Methane is also found in liquid form when it is cool with high pressure and low temperature.

Answer:

Explanation:

The mechanism of the reaction is shown in the diagram below. From the reaction, when (2S,3S)-2-Bromo-3-phenylbutane undergoes a reaction with sodium ethoxide (ETONa), the E2 elimination reaction is put into place. Here, the H and the leaving group are antiperiplanar to one another and the reaction mechanism proceeds to form an isomeric (E)-2-phenyl-2butane as the major product.

Answer:

HCN, weak acid

H⁺, Br⁻, strong acid

Explanation:

Hydrocyanic acid is a weak acid, according to the following equation.

HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)

Thus, it should be written in the undissociated form (HCN).

Hydrobromic acid is a strong acid, according to the following equation.

HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)

Thus, it should be written in the ionic form (H⁺, Br⁻).

Answer:

highest boiling point.

Explanation:

Hello there!

In this case, according to the given information, it turns out necessary for us to recall the definition of colligative properties, more specifically that of boiling point elevation, defined in terms of the temperature change, van't Hoff's factor, molality of the solution and boiling point elevation constant:

[tex]\Delta T_b=i*m*K_b[/tex]

In such a way, since all the given solutions have the same molality and solvent (water), they all have the same m and Kb, for which we focus on the van't Hoff's factor which is 1 for CH2O (nonionizing), 2 for NaCl (Na and Cl ions are released), 2 for HF (H and F ions are released) and 3 for AlCl₃ (one Al and three Cl ions are released).

Therefore, since D. 0.50 mol AICI, in 1.0 kg water  has the greatest van't Hoff's factor, we infer it has the highest boiling point.

Regards!

Answer:

qualatatiev is fs-hj_jakakak

Answer:

NH3 Ammonia

Explanation:

Ammonia has 4 regions of electron density around the central nitrogen atom (3 bonds and one lone pair). These are arranged in a tetrahedral shape. The resulting molecular shape is trigonal pyramidal with H-N-H angles of 106.7°.

Answer:

The material properties of nanostructures are different from the bulk due to the high surface area over volume ratio and possible appearance of quantum effects at the nanoscale. ... Yu; they found that the structural distortions on the quantum dots depend both on the kind of dopant and on the size of the dots.

Explanation:

hope it helps

Answer:

The correct answer is "-268.667°C".

Explanation:

Given:

Temperature,

= 4.483 K (below)

Now,

The formula of temperature conversion will be:

⇒ [tex]T(^{\circ} C)=T(K)-273.15[/tex]

By putting the values, we get

⇒            [tex]=4.483-273.15[/tex]

⇒            [tex]=-268.667^{\circ} C[/tex]

Thus the above is the correct answer.

Answer:

These batteries are constructed of several single cells connected in series each cell produces approximately 2.1 volts. ... A battery cell consists of two lead plates a positive plate covered with a paste of lead dioxide and a negative made of sponge lead, with an insulating material (separator) in between.

Answer:

H2CO

Explanation:

Becuase it has 2 sigma bonds plus one pi bond and one sigma bond that consitute the double bond between C and O.

Answer:

B. H2CO

Explanation:

Answer:

Endothermic

Explanation:

Endothermic reaction is one in which the enthalpy increases. What this implies is that, it is a closed system which absorbs heat from its surroundings and thus after reaction become cooler than prior to the reaction.

In this case, the mixture of the two liquids feel colder to touch. Thus, it is an endothermic reaction from the definition earlier given.