Please I need help!!!!

Answer:

E =  0.14 ×10⁻¹⁷ J

Explanation:

Given data:

Wavelength of light = 142 nm (142 ×10⁻⁹ m)

Energy of light = ?

Solution:

Formula:

E = hc/λ

h = plancks constant = 6.63×10⁻³⁴ Js

c = speed of light = 3×10⁸ m/s

by putting values

E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 142 ×10⁻⁹ m

E = 19.89×10⁻²⁶ J.m/ 142 ×10⁻⁹ m

E =  0.14 ×10⁻¹⁷ J

Answer:

Being a weak acid and a strong base, where it is diluted in a neutral medium such as water, the basic medium predominates, almost alkaline pH.

Explanation:

The acidity of the solution, being weak, means that its pH is not so low, therefore it will be easier to reach the values of 7 or 7 where alkalinity or basity is indicated.

Answer:

If an equal number of moles of the weak acid HF and the strong base KO are added to water,

HF           +          KOH        ---->     KF       +      [tex]H_2O[/tex]

weak                  strong                salt

acid                     base

The salt formed is KF which is a basic salt since it is formed by reaction of weak acid and strong base

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Explanation:

An ionic bond is formed by the complete transfer of some electrons from one atom to another. The atom losing one or more electrons becomes a cation—a positively charged ion. The atom gaining one or more electron becomes an anion—a negatively charged ion.

Answer:

What’s the answer ‍♀️

Explanation:

Answer:

But-1-ene is another unsymmetrical alkene. As with all alkenes, unsymmetrical alkenes like propene react with hydrogen bromide in the cold. The double bond breaks and a hydrogen atom ends up attached to one of the carbons and a bromine atom to the other. In the case of propene, 2-bromopropane is formed.

Explanation:

Answer:

In Chemistry the coefficient is the number in front of the formula. The coefficient tells us how many molecules of a given formula are present.

Explanation:

Answer:

rrgffffffffffrrrddhgf

Explanation:

trrdfgfxfff

Answer:

maybe try 3825?

Explanation:

if not comment on this and ill try something else

or you can also just use those numbers in different order

Answer:

Explanation:

I think it is A=3 B=8 C=4 D=5

Answer:

A

Explanation:

complete question with the graphs are attached to this answer.

Let us consider the question closely. When the student was walking home, his/her speed was uniform. However, after 5 minutes, the student increased his/her pace due to the light rain. This is seen as a slight increase in speed after 5 minutes on the graph A. two minutes after (at the 7th minute) the rain comes hard and the student had to increase his/her speed by a much higher magnitude by running and maintaining this uniform speed all the way untill the end of the journey at the 10th minute.

Answer:

Qsp > Ksp, BaCO3 will precipitate

Explanation:

The equation of the reaction is;

Na2CO3 + BaBr2 -------> 2NaBr + BaCO3

Since BaCO3 may form a precipitate we can determine the Qsp of the system.

Number of moles of Na2CO3 = 0.96g/106 g/mol = 9.1 * 10^-3 moles

concentration of NaCO3 = number of moles/volume of solution = 9.1 * 10^-3 moles/10 L = 9.1 * 10^-4 M

Number of moles of BaBr2 = 0.20g/297 g/mol = 6.7 * 10^-4 moles

concentration of BaBr2 = 6.7 * 10^-4 moles/10 L = 6.7 * 10^-5 M

Hence;

[Ba^2+] = 6.7 * 10^-5 M

[CO3^2-] = 9.1 * 10^-4 M

Qsp = [6.7 * 10^-5] [9.1 * 10^-4]

Qsp = 6.1 * 10^-8

But, Ksp for BaCO3 is 5.1*10^-9.

Since Qsp > Ksp, BaCO3 will precipitate

Precipitate of BaCO₃ will form when 0.96g of Na₂CO₃ is combined with 0.20g BaBr₂ in a 10 L solution.

Precipitate will form in the reaction if for the given reaction value of Qsp i.e. solubility product quotient is more than Ksp i.e. solubility product constant.

Given chemical reaction is:
Na₂CO₃ + BaBr₂ → 2NaBr + BaCO₃

We can calculate the concentration of reactants in terms of molarity, as no. of moles of solute present in per liter of solution.

And moles will be calculate as n = W/M, where

W = given mass

M = molar mass

Given mass of Na₂CO₃ = 0.96g

Moles of Na₂CO₃ = 0.96g / 106 g/mol = 9.1×10⁻³ moles

Volume of solution = 10L

Concentration of Na₂CO₃ = 9.1×10⁻³ moles/10L = 9.1×10⁻⁴ M

Given mass of BaBr₂ = 0.20g

Moles of BaBr₂ = 0.20g / 297g/mol = 6.7×10⁻⁴ moles

Concentration of BaBr₂ = 6.7×10⁻⁴ moles/10L = 6.7×10⁻⁵ M

Qsp will be calculated as the product of their concentration:

Qsp = (9.1×10⁻⁴)(6.7×10⁻⁵) = 6.1×10⁻⁸

And value of Ksp for BaCO₃ = 5.1×10⁻⁹

From this we conclude that BaCO₃ will form precipitate.

Hence, precipitation of BaCO₃ takes place.

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Answer:

1 : motion as observed from or referred to some material system constituting a frame of reference (as two adjacent walls and floor of a room) — see relativity sense 3. 2 : the motion of one body with respect to another regarded as fixed — compare relative velocity

Answer:

Explanation:

formula of osmotic pressure is as follows

p= n RT

n is mole of solute per unit volume

If m be the grams of solute needed

m gram = m / 227.1 moles

m / 227.1 moles dissolved in .279 litres

n = m / (227.1 x .279 )

= m / 63.36

substituting the values in the osmotic pressure formula

5.14 = (m / 63.36)  x .082 x 298

m / 63.36 = .21

m = 13.32 grams .

Answer:

B. Soap solution

Explanation:

Hardness of water refers to the degree of calcium and magnesium in the water. In other words, hard water contains excessive mineral contents. The degree of hardness of a water body can be measured using the SOAP TEST KIT.

Due to the formation of insoluble minerals, soap forms an exvessive substance in the presence of hardwater because the particles or minerals contained in the water is reacting to form something insoluble. Hence, a SOAP test kit can be used to test the hardness of water.

Answer:

Change in temperature = 74

Explanation:

The initial Temperature of the chicken is given as 0° C. Then the question states that the chicken is added to sous-vide cooker. And the final equilibrium temperature after cooking is given as 74°C. The equilibrium temperature means that the temperature of each component in the system, such as cooker and chicken is same, which is 74°C. So, we have:

Initial Temperature = 0

Final temperature = 74

Therefore, the change in temperature during cooking will be:

Change in Temperature = Final Temperature - Initial temperature

Change in Temperature = 74 - 0

Change in temperature = 74

Answer:

Remain the same

Explanation:

If water dose no effect why would the moist air make a change

Answer:

202 L

Explanation:

Step 1: Write the balanced equation

C₆H₁₂O₆ + 6 O₂(g) ⇒ 6 CO₂(g) + 6 H₂O(l)

Step 2: Calculate the moles corresponding to 270 g of C₆H₁₂O₆

The molar mass of C₆H₁₂O₆ is 180.16 g/mol.

270 g × 1 mol/180.16 g = 1.50 mol

Step 3: Calculate the moles of CO₂ generated from 1.50 moles of glucose

The molar ratio of C₆H₁₂O₆ to CO₂ is 1:6. The moles of CO₂ formed are 6/1 × 1.50 mol = 9.00 mol

Step 4: Calculate the volume of 9.00 moles of CO₂ at STP

The volume of 1 mole of an ideal gas at STP is 22.4 L.

9.00 mol × 22.4 L/mol = 202 L

Answer:

I would say false.

Explanation:

Hope it helps:)

Answer:

Feed rate F = 625 kg/h

Explanation:

Given that:

percentage mass of the solids = 7% = 0.07

rate of removal of water W = 500 kg/h

Concetration  C = 35% = 0.35

To fine the feed rate = ???

Using the Overall balance equation,

Suppose: F = W + C

F = 500 + C  ---- (1)

Then, the Solids balance can be computed as:

(0.07)F = (0)500 + (0.35)C

0.07F = 0.35C

C = 0.07F/0.35

C = 0.2F

Now

F = 500 + 0.2F

Collect like terms

F – 0.2F = 500

0.8F = 500

F = 500/0.8

F = 625 kg/h

Therefore, the feed rate F = 625 kg/h

Answer:

7 is the answer as per the question

Answer: The number that represents a neutral pH is (7)

Explanation:

I took the test on flvs and got it right.

100% Guaranteed Correct :)

, Hope this helps

Have a great day!!

Answer:

All of these properties are due to the chemical structure of the compound. The chemical structure includes the bonding angle, the type of bonds, the size of the molecule, and the interactions between molecules. Slight changes in the chemical structure can drastically affect the properties of the compound.Some atoms become more stable by gaining or losing an entire electron (or several electrons). When they do so, atoms form ions, or charged particles. Electron gain or loss can give an atom a filled outermost electron shell and make it energetically more stable.

Explanation:

The chemical structure of the compound is responsible for all of these properties. The chemical structure includes the bonding angle, bond type, molecule size, and intermolecular interactions. Slight changes in the chemical structure can have a significant impact on the compound's properties.

A chemical compound is a substance made up of many identical molecules that contain atoms from more than one chemical element and are held together by chemical bonds. A molecule made up of only one element's atoms is thus not a compound.

An atom's valence shell electrons determine how it interacts with neighboring atoms, and thus its chemical properties. Because sodium and lithium both have one valence electron, their chemical properties are similar.

The number of electrons in an atom's outermost shell determines its reactivity, or proclivity to form chemical bonds with other atoms. This outermost shell is referred to as the valence shell, and the electrons found within it are referred to as valence electrons.

Thus, The chemical structure of the compound is responsible for all of these properties.

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Answer:

Endothermic and exothermic reactions are chemical reactions that absorb and release heat, respectively. A good example of an endothermic reaction is photosynthesis. Combustion is an example of an exothermic reaction. The categorization of a reaction as endo- or exothermic depends on the net heat transfer.

Explanation:

Answer:

An endothermic reaction

Explanation:

The heat is being absorbed so it's and endothermic reaction

Answer:

It is like about a attraction between atoms, molecules, and more.

Answer:

A. True

B. False

C. False

D. True

E. False

Explanation:

A. The proximal histidine covalently binds iron.

This statement is true because the proximal histidine is covalently bonded to the fifth coordination position of iron in myoglobin

B. The distal histidine covalently binds oxygen.

This statement is false because the distal histidine interacts with the oxygen covalently bonded to the sixty coordination position of iron by means of a hydrogen bond not a covalent bond.

C. The distal histidine binds iron

This statement is false because the distal histidine is not bonded to iron but to oxygen but stabilizes the oxygen bonded to iron

D. Free heme binds CO with the Fe, C and O atoms in a linear array.

This statement is true because free heme has more affinity for CO than O2 as it has the least steric hindrance when the Fe, C, and O atoms lie in a straight line. On the other hand, when O2 binds to free heme, the axis of the oxygen molecule is positioned at an angle to the Fe-O bond thereby producing significant steric hindrance.

E. The iron in heme binds the oxygen atom of CO.

This statement is false because the iron in heme binds to the carbon atom, C, of CO rather than to oxygen atom.

Answer:

An azeotrope or a constant boiling point mixture is a mixture of two or more liquids whose...Such a system of solvents is known as a heteroazeotrope. ... that will affect the volatility of one of the azeotrope constituents more than another.

Explanation:

Azeotrope, in chemistry, a mixture of liquids that has a constant boiling point because the vapor has the same composition as the liquid mixture. The boiling point of an azeotropic mixture may be higher or lower than that of any of its components.

Answer:

4.963x 10²

7.8761x 10³

8.9 x 10⁻²

Explanation:

Scientific notation is the way to express the large value in short form.

The number in scientific notation have two parts.

. The digits (decimal point will place after first digit)

× 10 ( the power which put the decimal point where it should be)

for example the number 6324.4 in scientific notation will be written as = 6.3244 × 10³

a) 496.3 x 10²

4.963x 10²

b) 7876.1 x 10⁻⁷

7.8761x 10³

c) 0.089 x 10⁻⁹

8.9 x 10⁻²

Mass of Hydrogen atoms : 18 g

Given

73 gram of HCl

144gram of H₂O

Required

Mass (gram) atom of Hydrogen

Solution

H atoms are in 2 compounds, H₂O and HCl, so we calculate their mass in each compound

[tex]\tt \dfrac{1}{36.5}\times 73=2~g[/tex]

mass H in HCl :

[tex]\tt \dfrac{2}{18}\times 144=16~g[/tex]

total mass = 2 g+ 16 g = 18 g

Answer:

Earthquakes are measured using instruments called seismometers, that detect the vibrations caused by seismic waves as they travel through the crust. Also, laser beams can be used

Explanation:

Answer:

See image attached and explanation

Explanation:

I have attached a detailed mechanism of the reaction to this answer. This reaction occurs by SN1 mechanism. It implies that the transition state involves a carbocation.

However, the initial carbocation formed is a primary carbacation. Remember that the order of stability of carbocations is methyl< primary < secondary< tertiary. This means that tertiary carbocations are the most stable carbocations. Tertiary carbocations are those in which the carbon atom bearing the carbon atom is attached to three other carbon atoms.

In the mechanism below, the substrate converts from a primary to a tertiary cabocation (most stable) by a 1,2-alkyl shift as shown giving the 3-ethoxy-3-methylpentane product.

Answer:

See image attached and explanation

Explanation:

The reaction of phenol with SO3/H2SO4 is an electrophilic reaction. The electrophile attacks portions of high electron density in the substrate phenol.

The -OH group activates phenol towards electrophilic substitution at the ortho and para positions, hence the product(s) formed in this reaction(only one product is shown here as required by the question).

The sulphonation of phenol using concentrated sulfuric acid at lower temperature yields majorly the ortho product whereas at higher temperature the para product predominates.