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Answer:

Because Sulphuric acid(H2SO4) is one of the substance which have a very high vigourous reaction if mix with chemicals thats why we take the same sulphuric acid but having lighter effects known to be as Dil.Sulphuric And so it is generally use for precaution while during experimentations Thats why we use it.

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Explanation:

4.5×6.022×10²³

27.099×10²³

According to Avogadro's number, there are 27.10×10²³ atoms in  4.5 moles of Al.

Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.

It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .

According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.

Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number.As 1 mole =6.023×10²³ atoms , thus,4.5 moles =4.5×6.023×10²³ = 27.10×10²³  atoms.

Thus, there are 27.10×10²³ atoms in  4.5 moles of Al.

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Answer:

Alkynes are saturated hydrocarbons

Explanation:

Alkynes are groups of hydrocarbons that have the general formula of {Cn H2n - 2}. They have a triple carbon to carbon bond (C≡C) in their structure. Ethyne (HC≡CH) is the first member of the alkyne series.

Alkynes like alkenes are unsaturated hydrocarbons because of their triple and double carbon bonds respectively. Unsaturated hydrocarbons do not have a complete hydrogen atom in their structural composition. Hence, the statement that "Alkynes are saturated hydrocarbons" is FALSE.

Answer:

they are all planets

Explanation:

Answer:

[tex]p_2=2.655kPa[/tex]

Explanation:

Hello there!

In this case, according to the Dalton's law, which states that the total pressure is equal the sum of the pressures of the gases in the mixture, we write the following for this system:

[tex]P_T=p_1+p_2[/tex]

Thus, we solve for the partial pressure of the gas #2 as shown below:

[tex]p_2=P_T-p_1\\\\p_2=5kPa-2.345kPa\\\\p_2=2.655kPa[/tex]

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Answer:

338.38 K

Explanation:

Applying,

PV = nRT............... Equation 1

Where P = pressure, V = Volume, R = Temperature, n = number of moles, T = temperature.

Make T the subject of the equation,

T = PV/nR............. Equation 2

From the question,

Given: P = 1.95 atm, V = 12.3 L, n = 0.854 moles

Constant: R = 0.083 L.atm/K.mol

Substitute these values into equation 2

T = (1.95×12.3)/(0.854×0.083)

T = 338.38 K

Answer: What is the mass of disulfur pentoxide (S2O5)?

Explanation:144.14g/mol

Answer:

it's A.

Explanation:

have uh good day ma :)))))))

it is held every 4-5 years

Answer:

I would say the purple one!

Explanation:

Answer:

When the ambulance is coming towardss you the waves are smushed together and sound higher pitched but then it passes you and when tracveling away the waves are scretched out so the whee whoo sounds lower and that is because of the doppler effect

Answer:

los metales alcalinotérreos: berilio (Be), magnesio (Mg), calcio (Ca), estroncio (Sr), bario (Ba) y radio (Ra).

o simplemente llamado grupo 2A

Explanation:

Answer:

(ii) 1 dye

(iii) Food coloring F is insoluble in the solvent

(iv) 'E' and 'H'

(b) Food colouring G

Explanation:

Paper chromatography principle is based on the rates of migration of chemicals across a sheet of paper which are different and it consists of a stationary phase such as the water in the paper and a mobile phase such as the solvent resulting in the partitioning of the components of the mixture across the paper

The solution components are positioned to start in one place from where they migrate and separate out on the chromatography paper

(ii) The number of components into which the food colouring 'H' separates into = 1

Therefore, the number of dyes in food colouring 'H' = 1 dye

(iii) Food coloring 'F' does not move because it is insoluble in the solvent, which is the mobile phase

(iv) The food colouring that contains the dye that is likely to be most soluble in the solvent are does for which the dyes travel furthest, which are;

Food coloring 'E' and 'H'

(b) Using a similar question solution found on 'tutor my self' website, we have;

The [tex]R_f[/tex] values are given as follows;

[tex]R_f = \dfrac{Distance \ moved \ by \ dye}{Distance \ moved \ by \ solvent}[/tex]

The distance moved by the solvent = 5 units

The distance moved by dyes in food colouring 'E' and 'H' = 4 units

The distance moved by dye in food colouring 'G' = 3.3 units

The distance moved by the second dye in food colouring 'E' = 2.7 units

By inspection, we get;

[tex]R_f[/tex] dye in food colouring 'G' = 3.3/5 = 0.66,

Therefore, the dye with [tex]R_f[/tex] value closest to 0.67 is the dye in food colouring 'G'.

Answer:

Synthesis Reaction

Explanation:

A synthesis reaction occurs when two or more reactants combine to form a single product. In a decomposition reaction, one reactant breaks down into two or more products. This is the reverse of a synthesis reaction. Replacement reactions occur when elements switch places in compounds.

Answer:

600 mL

Explanation:

molarity 1 * volume 1 = molarity 2 * volume 2. So this means 12 * 250 = 3000 and divide that by 5 to get 600 mL.

Answer:

0.113 liters

Explanation:

5.41 M / 47.71 moles = 0.113 liters

Answer:

If a substance can be dissolved it is called soluble.

if a substance cannot be dissolved it is called insoluble

Answer:

The period number on the Periodic table tells you the total number of orbits that the atom will have. In other words, the period number indicates the number of energy levels (or energy orbit) of an atom. For example, 1st period indicates that these elements possess 1 energy shell (or energy orbit).

Explanation:

Answer: (A) a cobalt atom contains 27 protons, and most cobalt atoms contain 32 neutrons.

Explanation: just answered the question and that was the correct answer

Answer:     The answer is :     A cobalt atom contains 27 protons and MOST  neutral cobalt atoms contain 32 electrons

Explanation:   I took the test

Answer: Mg and O

Explanation: just took the test. Trust

Answer:

Deci trebuie sa te aplici cu 2 din3 pe suprafata pamanyului chinez

Explanation:

Deci 1287+2086+2762+7:5

Answer: The statement, chemicals that you begin with found on the left side of the equation, describes reactant and where they are in a chemical equation.

Explanation:

An equation that includes symbolic formulas and represents chemical reaction between the substances initially present forming new substances is called a chemical equation.

For example, [tex]N_{2} + 3H_{2} \rightarrow 2NH_{3}[/tex]

Here, substances [tex]N_{2}[/tex] and [tex]H_{2}[/tex] are the reactants. Reactants in a chemical equation are always present on the left side as these are the chemicals we begin with.

Also here, [tex]NH_{3}[/tex] is the product. Product(s) in a chemical equation are always present on the right side as these are the chemicals we end with.

Thus, we can conclude that the statement, chemicals that you begin with found on the left side of the equation, describes reactant and where they are in a chemical equation.

Answer:

Explanation:

The pH of a solution can be found by using the formula

[tex]pH = - log [ {H}^{+} ][/tex]

From the question we have

[tex]ph = - log(9.3 \times {10}^{ - 11} ) \\ = 10.0315...[/tex]

We have the final answer as

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A blue light is shined on objects X and Y. Object X appears to be blue, and object Y appears to be black when Object X reflects blue light, and object Y absorbs blue light. Hence option B is correct.

Visible light spectrum is nothing but the range of wavelength of radiation from 4000 angstrom to 7000 angstrom(Violet to Red). light is a energy packet. Every Photon having different wavelength travels with same velocity c (velocity of light). When we focus numbers of colors from visible spectrum to a point, that point appears as a white light. hence white light is composed of numbers of Colors in it.

When we pass white light through a prism, as white light enters in the prism all the colors having different wavelength travels with different velocity in the prism due to that there is separation of colors from the white light. Therefore we get different colors of white light in the prism this phenomenon is know as dispersion of light.

Light can be reflected, absorbed, transmitted diffracted and scattered etc.

α + β + ν = 1 where α, β, ν are coefficient of absorption, reflection and transmission.

When any object appears to be black it means that radiation has been absorbed by that body, it has high absorption coefficient. and when a body appears to be colored, it means that object has reflected the particular color, it having high reflection coefficient.

Hence option B is correct.

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