A student wants to examine a substance without changing its identity. Which of the following properties should the student examine?

Answer:

mdjnibfziedosnninjd.zjcssksskskbsksbivfdlvdxkvfuwhiwhwonsk jsbudwuvsaeigdOhgrauvdslnzarm cxwmvakbxsabxwrifwzpgsdoh

ds

Explanation:

Entropy of a reaction ΔS∘rxn is the degree of disoderliness in a system. Gases generally have a higher degree of disorder compared to liquids. Hence for the reaction 2H2(g)+O2(g) ⟶ 2H2O(l), the entropy decreases sice the reactants are in the gaseous state and the products is in the liquid state of matter

Answer:

[tex]Q=2091J=2.091kJ[/tex]

Explanation:

Hello,

In this case, the formula we use to compute the heat Q by increasing the temperature, in terms of the mass and the heat capacity is:

[tex]Q=mCp(T_2-T_1)[/tex]

Titanium's heat capacity is 0.544284 J/g°C, thus, the for such temperature increase, the heat results positive as shown below:

[tex]Q=22.6g*0.544284\frac{J}{g^oC}*(1590^oC-1420^oC) \\\\Q=2091J=2.091kJ[/tex]

Best regards.

Answer:

the motion of gravity

Explanation:

Answer:

its c

Explanation

advhuosijoklxcmnjdabsuhggggabciaciudeifweingivg eygerigsygfe97rsghisdcvhbsduigwiugfu9uigdgiurfgyisdgfsdgfegiygewifgsdygfewusgfuyesigf7wgfiesgfiusgdfies

Answer:

Explanation:

Mg + 2HCl = Mg Cl₂ + H₂

.594 g = .594 / 24.3

= .02444 mole

Heat evolved = msΔ T , m is mass of water ( solvant ) , s is specific heat of water , Δ T is rise in temperature

= 100 x 4.2 x ( 41.83 - 25 )

= 7068.6 J

.02444 mole  of Mg evolves 7068.6 J of heat

1 mole of Mg evolves 7068.6 /.02444 J

= 289222.6 J

= 289 kJ .

Molar heat enthalpy = 289 kJ .

Explanation:

6.02×1023 culture atoms have a mass of 63.5g. 12.0g. c +23.0g O2__44.0g CO2.(12.0+16.0+16.0=44.0g).1 mol 1 mol. 1 mol number molecules weight

The number of molecules in one mole of carbon dioxide is 6.02 × 10²³. Therefore, the number of moles of carbon dioxide which contains 4.11 × 10²³ molecules is 0.68.

The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to  6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.

Similarly, one mole of a compound contains  6.02 × 10²³ number of molecules. Thus, one mole of carbon dioxide contains these much molecules.

Given the number of molecules of carbon dioxide = 4.11 × 10²³

Then, no.of moles = number of molecules/ Avogadro number.

no.of moles = 4.11 × 10²³ /6.022 × 10²³  = 0.68.

Therefore, the number of moles of CO₂ that contains 4.11 × 10²³  molecules is 0.68.

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Answer:

Endothermic. The energy is flowing into the molecules causing them to break apart and the ice pop change state.

Answer:

Yes, an autumn day isn’t cold enough to keep an ice pop at freezing temperatures.

Answer:

Acanthite. MFCD00003406

Explanation:

Answer:

[tex]M=1.1M[/tex]

Explanation:

Hello,

In this case, since we are mixing two NaOH solutions, the first step is to compute the total moles once the mixing is done, by using the volumes and concentrations of each solutions and subsequently adding them:

[tex]n_T=2.0L*0.60\frac{mol}{L}+495mL*\frac{1L}{1000mL}*3.0\frac{mol}{L}= 2.7molNaOH[/tex]

Next, we compute the total volume by adding the volume of each solution:

[tex]V_T=2.0L+495mL*\frac{1L}{1000mL}= 2.495L[/tex]

Finally, we compute the molarity of the resulting solution by the division between the total moles and the total volume:

[tex]M=\frac{2.7mol}{2.495L}\\ \\M=1.1M[/tex]

Best regards.

Answer:

A. The Swallowing reflex

Explanation:

Dysphagia Is a a condition that makes swallowing difficult.

hEy!!!

Chlorine(CL) is the symbol for the entity that has 17 protons,20 neutrons and 18 electrons.

Hope it will be helpful to you...

Answer:chlorine

Explanation:

Answer:

LiF and RbBr

Explanation:

Salt is an ionic compound that is made from the reaction of an acid and a base solution. Salts dissolve in water to give solutions that are acidic, basic, or neutral.

Salt formed from a strong acid and a weak base will make an acidic solution when added to water. The reason this occurs is because when the salt dissociates, the conjugate acid of the weak base will donate a proton, or one hydrogen ion, to water and form hydronium ion.

If a salt is formed from a weak acid and a strong base, it dissolves in water and the conjugate base of the weak acid will accept a proton from water and yield the hydroxide ion. Hence the solution of the salt will be basic.

If the salt is formed from a strong acid and a strong base, the salt is neutral when dissolved in water. Both LiF and RbBr are formed from strong acids and strong bases hence they will have a pH of 7.0 in solution.

LiF RbBr NaClO4 NH4Cl is = LiF and RbBr The correction is 'C'.

Salt is an ionic mixture that is made from the reaction of an acid and a base resolution. Salts liquefy in water to give solutions that are acidic, basic, or neutral.

Salt constructed from a strong acid and a breakable base will make an acidic solution when added to water. The reason this occurs is that when the salt dissociates, the conjugate acid of the weak base will donate a proton, or one hydrogen ion, to water and form a hydronium ion.

If a grain of salt is formed from a weak acid and a powerful ground, it liquefies in water and the conjugate bottom of the weak acid will accept a proton from water and yield the hydroxide ion. Therefore, the solution of the salt will be basic.

If the salt is formed from a strong acid and a strong bottom, the salt is neutral when liquefied in water. Both LiF and also RbBr are formed from strong acids and powerful bases hence they will have a pH of 7.0 in resolution.

Therefore, the Correct option is 'C'

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Answer:

Dissociated state is the predominant one

Explanation:

When a molecule with pKa of 4.52 is in an aqueous solution at pH = 4.0, follows the H-H equation, thus:

pH = pKa + log₁₀ [A⁻] / [HA]

Where [A⁻] is the dissociated state and [HA] represents the protonated state

Replacing:

4.0 = 5.2 + log₁₀ [A⁻] / [HA]

-1.2 = log₁₀ [A⁻] / [HA]

0.063 =  [A⁻] / [HA]

[HA]  = 16 [A⁻]

That means you have 16 times more [HA] than [A⁻] and the dissociated state is the predominant one

Answer:

98.3 gradius Celsius

Explanation:

This problem is solved using the Ideal Gas Equation

pV = nRT

...

Please see the step-by-step solution in the picture attached below.

Hope this answer can help you. Have a nice day!

Answer:

1.3×10⁻³ M

Explanation:

Hello,

In this case, given the dissociation reaction of acetic acid:

[tex]CH_3CO_2H(aq) + H_2O(l) \rightleftharpoons H_3O^+(aq) + CH_3CO_2^-(aq)[/tex]

We can write the law of mass action for it:

[tex]Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}[/tex]

Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change [tex]x[/tex] due to the dissociation extent, we are able to rewrite it as shown below:

[tex]1.8x10^{-5}=\frac{x*x}{0.100-x}[/tex]

Thus, via the quadratic equation or solve, we obtain the following solutions:

[tex]x_1=-0.00135M\\x_2=0.00133M[/tex]

Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.

Regards.

Answer:

1.3×10^-3 M

Explanation:

Step 1:

Data obtained from the question:

Equilibrium constant (Ka) = 1.8×10^-5

Concentration of acetic acid, [CH3COOH] = 0.100 M

Concentration of hydronium ion, [H3O+] =..?

Step 2:

The balanced equation for the reaction.

CH3CO2H(aq) + H2O(l) ⇌ H3O+(aq) + CH3CO2-(aq)

Step 3:

Determination of concentration of hydronium ion, [H3O+].

This can be obtained as follow:

Ka = [H3O+] [CH3CO2-] / [CH3CO2H]

Initial concentration:

[CH3COOH] = 0.100 M

[H3O+] = 0

[CH3CO2-] = 0

During reaction

[CH3COOH] = – y

[H3O+] = +y

[CH3CO2-] = +y

Equilibrium:

[CH3COOH] = 0.1 – y

[H3O+] = y

[CH3CO2-] = y

Ka = [H3O+] [CH3CO2-] / [CH3CO2H]

1.8×10^-5 = y × y / 0.1

Cross multiply

y^2 = 1.8×10^-5 x 0.1

Take the square root of both side

y = √(1.8×10^-5 x 0.1)

y = 1.3×10^-3 M

[H3O+] = y = 1.3×10^-3 M

Therefore, the concentration of the hydronium ion, [H3O+] is 1.3×10^-3 M

Answer:

.It is easily synthesized from the reaction of propylene with sulfuric acid, followed by hydrolysis. Isopropyl alcohol (2-propanol) is made by indirect hydration of propylene (CH2CHCH3).… In some cases the hydration of propylene is carried out in one step, using water and a catalyst at high pressure.

Hope it'll help!

stay safe:)

Answer:

Catenation refers to the ability of an atom to link to other atoms of the same kind to form a chain.

Explanation:

Catenation is the binding of an element to itself through covalent bonds to form chain or ring .Catenation can also be defined as the self-linking of atoms of an element to form chains and rings. This definition can be extended to include the formation of layers like two-dimensional catenation and space lattices like three-dimensional catenation. Thus, we can boldly say that, Catenation occurs when atoms of the same element covalently bond to one another to create a chain or ring.

Catenation occurs most readily in carbon, forming covalent bonds to and longer chains and structures with other carbon atoms. This is why the vast number of organic compounds are found in nature. Carbon is best known for its catenation properties, with the analysis of catenated carbon structures in organic chemistry.

Carbon is by no means the only element capable of forming such catenae, however, and several other main group elements are capable of forming a wide range of catenae, including silicon, sulfur, and boron. In group 14, the high bond energy of carbon makes it able to self-link almost indefinitely when compared with other members of the group which form only a few bonds to other atoms of the same element.

Answer:

C)

Explanation:

JUST DID IT

Answer:

A D E

Explanation:

just did it

Answer:

[tex]M_2=0.51M[/tex]

Explanation:

Hello,

In this case, for this dilution process, we understand that the moles of the solute (potassium nitrate) remain unchanged upon the addition of diluting water. However, the resulting or final volume includes the added water as shown below:

[tex]V_2=300mL+50mL=350mL[/tex]

In such a way, we are able to relate the solution before and after the dilution by:

[tex]V_1M_1=V_2M_2[/tex]

Hence, we solve for the final molarity as:

[tex]M_2=\frac{M_1V_1}{V_2}=\frac{0.6M*300mL}{350mL}[/tex]

Best regards.

[tex]M_2=0.51M[/tex]

Answer:

The absorption and strength of the H-beta lines change with the temperature of the stellar surface, and because of this, one can find the temperature of the star from their absorption lines and strength. To better comprehend, let us look into the concept of the atom's atomic structure.  

Atoms possess distinct energy levels and these levels of energy are constant, that is, the temperature has no influence on it. However, temperature possesses an influence on the electron numbers found within these levels of energy. Therefore, to generate an absorption line of hydrogen in the electromagnetic spectrum's visible band, the electrons are required to be present in the second energy level, that is when it captivates a photon.  

Therefore, after captivating the photons the electrons jump from level 2 to level 4, which shows that there is an increase in the stellar surface temperature and at the same time one can witness a decline in the strength of the H-beta lines. In case, if the temperature of the surface increases too much, then one will witness no attachment of electron with the hydrogen atom and thus no H lines, and if the temperature of the surface becomes too low, then the electrons will stay in the ground state and no formation of H lines will take place in that condition too.  

Hence, to generate a very robust H line, after captivating photons the majority of the electrons are required to stay in the second energy level.  

Answer:

$95

Explanation:

.75 x 120 = 90

90+5 = 95

Answer:

See explaination

Explanation:

1. The addition of group 3A elements to group 4A semiconductors decreases the conductivity of the group 4A semiconductors: Wrong

The addition of 3A group elements inreases the conductivity and make them extrinsic semiconductors( p-type)

2. The conductivity of semiconductors can be increased by the doping process.: Correct

3.As the temperature increases, the conductivity of semiconductors decreases.. wrong

As the temperature increases, the conductivity of semiconductors increases.

4. The addition of group 5A elements to group 4A semiconductors increases the conductivity of the group 4A semiconductors: Correct : They will create n-type semicoductor.

5.Holes are charge carriers in p-type semiconductors: Correct

6. Electrons are charge carriers in n-type semiconductors: Correct

Answer:

the European countries grew together.

Explanation:

Europe saw human inflows from east and southeast.

the Roman Empire came to dominate the entire Mediterranean basin.

European politics from 1947 to 1989 made the European countries grew together.

Answer:

the claim is that when people avoid storms they hide in any secret place in there house

Explanation:

when people do that they don't even have to worry about a single thing that will happen to them

Answer:

(decreasing particle size) C

Explanation: That is one of the answers, if there are more I am sorry.

Answer:

3 half-lives

Explanation:

The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.

Let's suppose we start with 64 g of the radioactive element.

Answer:

Power, P = 300 W

Explanation:

We have,

Force acting on the box to take it is 300 N

It is moved to a distance of 10 m in 10 seconds

It is required to find the power required to move the box. The rate at which work is done is called power required by an object. It can be given by the formula as follows :

[tex]P=\dfrac{W}{t}\\\\P=\dfrac{Fd}{t}\\\\P=\dfrac{300\times 10}{10}\\\\P=300\ W[/tex]

So, the power required is 300 W.

Answer:

3 pieces of lunch-meat and 2 slices of cheese

Explanation:

You have enough bread to make 3 sandwiches

You have enough lunch-meat to make 4 sandwiches

You have enough cheese to make 5 sandwiches

In all you have enough material to make 3 sandwiches

so if you subtract three from each number above you will have no bread, enough lunch-meat to make one sandwich and enough cheese to make two sandwiches

luch-meat for one sandwich is: 3 pieces

Cheese for two sandwiches is:  2 pieces