Is anyone good at chemistry if so can someone help me please ?

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Answer:

In paper chromatography, the wet moving edge of the solvent that progresses along the surface where the separation of the mixture is occurring.

Explanation:

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Answer:

Ingles porfavor

Explanation:

The calorimeter is used to measure the heat of the system. The enthalpy of the combustion of magnesium cannot be measured by the calorimeter as it could melt the cup.

A coffee cup calorimeter is a styrofoam cup that contains partially filled water and is dipped with a thermometer. The reaction occurs in the water of the cup and hence differs from the bomb calorimeter.

The enthalpy of combustion is rigorous which can dissolve the polystyrene cup and hence is not used. They are better insulators than a beaker. The coffee cup calorimeter is not used to measure the enthalpy of hydrogen and oxygen as they involve gases that can escape the cup.

Learn more about coffee cup calorimeter here:

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Answer:

I hope it's helpful for you....

Explanation:

Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, a hydrogen atom.

Answer:

Density is a physical property that is determined by dividing the mass of a given amount of a substance by its volume.

Explanation:

Answer:

Ali is incorrect.

Explanation:

Ali is wrong because the climate is a study of the weather pattern over a long period of time. You cannot look outside one day and determine the climate because the climate is long-term.

She could say the weather is rainy, because that is short term, but not the climate.

Answer:

D. Streak.

Explanation:

A mineral, in simple terms, can be defined as a solid inorganic substance that occurs in a pure form with a specific crystal structure. A mineral is identified based on its physical properties which include luster, color, streak, crystal shape, etc.

The color of the powdered form of a mineral is called a streak. A streak is a useful property in distinguishing sulfide and oxide minerals. To check the color of a mineral, it is rubbed against the surface of a ceramic streak plate or a piece of unglazed ceramic. In its finely powdered form, a mineral is easy to identify.

Therefore, option D is correct.

Answer:

Low-density polyethylene is manufactured by the process of the polymerization of ethylene at very high temperatures in a tubular reactor. In this tubular reactor, high-pressure polymerization allows further copolymerization of ethylene with polar co-monomers. The tubular process has an advantage over autoclave process.

Explanation:

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Answer:

So, weight per litre (1.25g/l) times 22.4 l/mole equals the mole weight (28 g/mole).

Answer:

a

Explanation:

Answer:

Equilibrium will shift leftwards towards NO2.

Explanation:

Hello there!

In this case, according to the Le Cha telier's principle, it is possible to realize that the increase of the volume turns out in the shift towards the most of the gaseous moles are in; in such a way, for the given chemical reaction, we can notice how NO2 (reactant side) has the most of the moles (2 moles in comparison to 1 mole of N2O4); and therefore, by increasing the volume, the equilibrium will shift to it, it means leftwards.

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Answer:

ftb

Explanation:

Answer:

Iodine is a non-metal, but it is lustrous (lustrous is the property of metal) in nature.

Answer:

2.34

Explanation:

Answer:

see explanations

Explanation:

The graphic is the heating curve for water. Note that it is divided into 5 distinct heat flow segments. The segments with changing slopes are single phase segments with changes in temperature values. From left to right segment A is solid ice being warmed to it's melting point. Segment B is the melting segment in which 2 phases are in contact (solid + liquid). Note that addition of heat does not change the temperature. Segment C is warming of the liquid (single phase) up to its boiling point. At the boiling point the liquid begins to pass into the gas phase and again 2 phases are in contact; i.e., liquid & gas. Note again when two phases are in contact no temperature change occurs. Finally, segment E is the heating of the pure, single phase gas.

In summary ...

Segment A => heating single phase (solid) ice up to melting pt.

Segment B => melting of ice => 2 phases in contact (s & l) ΔT = ∅.

Segment C => heating single phase (liquid) water up to boiling pt.

Segment D => boiling of liquid => 2 phases in contact (l & g). ΔT = ∅.

Segment E => heating single phase (steam) up to desired temperature.

For what it's worth, the equation for the segments that show increasing temperature values is q = mcΔT (m= mass, c = specific heat & ΔT temp change.

The segments with zero slopes (horizontal lines) are defined by equations  q = m·ΔHₓ where m = mass & ΔHₓ = heat of fusion (a constant = 335 j/g). The same is true for the line at 100°C where q = m·ΔH(v) where m = mass & ΔH(v) is the heat of vaporization (a constant = 2259 j/g.

Calculations involve calculating the amount heat transfer for each segment individually and then adding the heat values to obtain the total heat transfer.

If you need more instruction on this topic, kick back a note and I'll try to help clarify. Good Luck, Doc :-)

Answer:

Picture attached has answers

Explanation:

Answer:

0.525 M

Explanation:

As the problem deals with a dilution process, we can use the following formula:

Where subscript 1 stands for initial concentration and volume, while 2 stands for the final conditions. Meaning that in this case:

We input the data given by the problem:

And solve for C₂:

The answer is 2Hz

To calculate frequency, divide the number of times the event occurs by the length of time.

Answer:

Because a redox reaction holds for both oxidation and reduction.

One half equation is of oxidation and the other is of reduction.

When these two half equations are combined, we get an overall equation of the redox reaction.

Answer:

Wind

Explanation:

Wind turbines make energy by the movement of the natural force on earth called 'wind' and renewable resources are resources that can be made from natural and environment-safe objects or things (e.g. Water, Geothermal Heat, The Sun, and Wind)

Answer:

formation of shadow is right

Answer:

correct answer is D

Explanation:

When you see a shadow, it is directly behind the object.

Answer:

F = ma, or force is equal to mass times acceleration.

Answer: a. A solid melts: [tex]\Delta S=+ve[/tex]

b. a vapor is converted to solid: [tex]\Delta S=-ve[/tex]

c. a liquid freezes:  [tex]\Delta S=-ve[/tex]

d. A solid sublimes:  [tex]\Delta S=+ve[/tex]

e.  a vapor condenses to liquid :  [tex]\Delta S=-ve[/tex]

f. a liquid boils:   [tex]\Delta S=+ve[/tex]

g. dissolving a tablespoon of salt in water:  [tex]\Delta S=+ve[/tex]

h. combustion of gasoline:  [tex]\Delta S=+ve[/tex]

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an ordered arrangement to a disordered arrangement, the entropy change is negative and vice versa.

a. A solid melts: The solid is converting to liquid, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

b. a vapor is converted to solid: The gas  is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger Thus the entropy change [tex](\Delta S)[/tex] is negative.

c. a liquid freezes: The liquid is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.

d. A solid sublimes: The solid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

e.  a vapor condenses to liquid : The gas  is converting to liquid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.

f. a liquid boils: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

g. dissolving a tablespoon of salt in water: The solid is converting to ions , thus the randomness is increasing as the ions can move freely. Thus the entropy change [tex](\Delta S)[/tex] is positive.

h. combustion of gasoline: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

A condition in which bones become weak and brittle.

The body constantly absorbs and replaces bone tissue. With osteoporosis, new bone creation doesn't keep up with old bone removal.

thus 2) is correct.

a disease in which bone tissue becomes breakable and thin.

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Answer:  If the gazelle population starts to decrease this could lead to some vultures not having enough food to eat

Explanation: This explains the obvious outcome of what would happen.

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Answer:

15.4%

Explanation:

If Ka = 0.54 mM = 1.51x10⁻⁵

Then;

C₄H₈O₂               -------->            C₄H₇O₂⁻          +           H⁺

I                    0.54x10⁻³                             0                                0

E                   0.54x10⁻³(1-x)                      0.54x10⁻³x                0.54x10⁻³x

Recall that x is the percentage degree of dissociation

From the ICE table;

Ka = [C₄H₇O₂⁻] [ H⁺]/[C₄H₈O₂]

1.51x10⁻⁵=(0.54x10⁻³x) (0.54x10⁻³x)/ 0.54x10⁻³(1-x)  

1.51x10⁻⁵ = 0.54x10⁻³x^2/1-x

1.51x10⁻⁵(1-x) = 0.54x10⁻³x^2

1.51x10⁻⁵ - 1.51x10⁻⁵x = 0.54x10⁻³x^2

Hence;

0.54x10⁻³x^2 + 1.51x10⁻⁵x - 1.51x10⁻⁵=0

x^2 + 0.028x - 0.028 = 0

Solving the quadratic equation here;

x = 0.154 or −0.182

Ignoring the negative result, x = 0.154

Hence, fraction of butanoic acid that is in the dissociated form in this solution = 15.4%

Answer:

ok

Explanation:

1d

2c

3b

4a

Answer:

A

Explanation:

The number of protons and neutrons of an element is the same. the electrons are the only thing that can differ.  The atomic number equal the protons and neutrons.

Answer:

The periodic table has been there for such a long time and how it is helpful in all science it is the element itself. How the element is used in real life. For example, oxygen is used in the atmosphere. Plants use carbon in order to covert it into oxygen more like that