what is the solubility of substance?

Answer:

Acidic.

Explanation:

pH is a logarithmic function of [H+]:

pH = −log[H+]

pH is usually (but not always) between 0 and 14. Knowing the dependence of pH on [H+], we can summarize as follows:

If pH < 7, then the solution is acidic.

If pH = 7, then the solution is neutral.

If pH > 7, then the solution is basic.

Given pH is 6.75 so it is acidic.

Answer:

The first option

Explanation:

Answer:

First Question, A, An atom consists of protons, electrons, and neutrons.

Second Question, B, A nucleus consists of protons and neutrons.

Explanation:

Answer:

Both apply to a certain region

Choice C is correct

Explanation:

Weather refers to the atmospheric conditions of a given place over a short period of time, like a day.

On the other hand, Climate refers to the average climatic conditions of a particular region measured over a long period of time.

Both weather and climate apply to a certain region.

The unknown solid with melting point of 78 degrees Celsius has been the molecular solid Naphthalene with formula [tex]\rm C_1_0H_8[/tex]. Thus, option A is correct.

Melting point has been defined as the temperature that has been able to transfer the solid to the liquid state.

The melting point has been higher for the substances with strong intermolecular interactions, and lower for weak attractive compounds.

The unknown sample has a melting point of 78 degree Celsius.

The molecular compounds have high melting point with strong intermolecular interactions, and ionic and covalent compounds have low melting point with weak intermolecular interactions.

The melting point of water has been zero degree Celsius.

Thus, the unknown solid with melting point of 78 degrees Celsius has been the molecular solid Naphthalene with formula [tex]\rm C_1_0H_8[/tex].

Thus, option A is correct.

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The most likely identity of the unknown white solid with a melting point of 78 °C is naphthalene, a molecular solid with the formula C10H8, commonly used in mothballs.

If the unknown substance is a white solid at room temperature and has a melting point of 78 °C, the most likely candidate from the given options would be naphthalene, which is a molecular solid. This substance has the formula C10H8 and is well-known for its use in mothballs. It has a melting point close to the given temperature, whereas the other given substances have significantly higher melting points and different chemical and physical properties.

SiO2, or silica, is a covalent network solid and CaCl2, or calcium chloride, is an ionic compound. Both have melting points that are much higher than 78 °C. Meanwhile, H2O, water, is a molecular compound that is not a solid at room temperature, as it has a melting point of 0 °C. Therefore, option A, naphthalene, is the most likely identity of the unknown solid.

Final answer:

Potassium nitrate (KNO3) contains both ionic and covalent bonds within the compound, while potassium sulfate (K2SO4) is an example of a compound containing only ionic bonds.

Explanation:

An example of a potassium compound containing both ionic and covalent bonds is potassium nitrate (KNO3), and an example containing only ionic bonds is potassium sulfate (K2SO4).

Potassium nitrate is composed of potassium ions (K+) and nitrate ions (NO3−), with the nitrate being a polyatomic ion held together by covalent bonds between nitrogen and oxygen atoms. This compound demonstrates ionic bonding between potassium and nitrate ions, as well as covalent bonding within the nitrate ion itself.

On the other hand, potassium sulfate is made up of potassium ions (K+) and sulfate ions (SO42−). This compound is purely ionic, with the bonds forming from the electrostatic attraction between the positively charged potassium ions and the negatively charged sulfate ions.

Answer:

HCL being a strong electrolyte dissociates in water to give H+ and Cl- ions. KMnO4 being a strong oxidising agent oxidises Chloride ion(Cl-) to Cl2. ... Hence more amount of KMnO4 is usedup which results in error in reading. The situation is completely the opposite with K2Cr2O7.

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Answer:

A negative beta particle

Yes

Explanation:

The incomplete equation of the reaction:

                  ²⁰³₈₀Hg → ²⁰³₈₁Tl + ?

In order to balance nuclear equations, we must conserve the mass number and atomic number.

For the mass number; 203 = 203 + a

                                         a = 0

             Atomic number; 80 = 81 + b

                                           b = -1

The unknown has no mass number but an atomic number of -1

This a  negative beta particle and it is designated as ⁰₋₁e

Answer:

1) Electron

2) Yes

Answer:

1. scientist

2. society

3. We can communicate to people across the world in a fraction of a second, our grandparents would've had to pay an extra fee to call anyone outside of the country. We've also made progress in medicine, making diseases like cancer more treatable.

4. Passion, determination, and intelligence.

5. You could ask yourself what factors do the other trees have that the unhealthy tree not have and then create an experiment as to how the variable missing from the unhealthy tree affects plants.

6. Life science was affected by each of these branches.

7. Investigations take a long time because of observations, forming hypothesis, creating an experiment and analyzing the data and then revizing the experiment and the hypothesis. This can take years and cannot be limited to one year.

8. The contributions of these scientists are absolutely still valuable, without these contributions many of the things we know in the modern world wouldn't be known today. Such as the types of organelles and their functions, the periodic table, and the importance of oxygen for human beings.

Explanation:

Answer:

Because both the bonding electrons come from the oxygen atom.

Explanation:

A coordinate covalent bond is formed when both the bonding electrons are coming from the same atom.

Here in the given situation, when H+ forms a bond with the water molecule [tex] H _ 2 O [/tex] to form the hydronium ion [tex] H _ 3 O + [/tex], then it is referred to as a coordinate covalent bond since both the bonding electrons are coming from the oxygen atom.

Answer:

Both the shared electrons come from single atom

Explanation:

Coordinate covalent bond is a type of bond in which both the shared pair of electrons are come from single bond. Whereas in simple covalent bond, sharing electrons come from both the participant atoms.

Coordinate covalent bond is also called dative bond and the atom which share both the electrons are called donar atom.

For a coordinate covalent atom to from, one participant atom should have lone pair of electron and other atom should be deprived of electrons.

In [tex]H_2O[/tex] molecule, O atom has lone pair of electrons while H+ ions has deficiency of electrons, so O atom shares its lone pair of electrons with H+ ions which results in the formation of coordinate covalent bond and forms [tex]H_3O^+ molecules[/tex].

Answer: The hydroxide ion concentration is [tex]1.26\times 10^{-4}M[/tex]

Explanation:

pOH is defined as the negative logarithm of hydroxide ion concentration in the solution.

To calculate the pOH of the reaction, we use the equation:

[tex]pOH=-\log[OH^-][/tex]

where,

[tex]pOH=3.90[/tex]

Putting values in above equation, we get:

[tex]3.90=-\log[OH^-][/tex]

[tex][OH^-]=1.26\times 10^{-4}M[/tex]

Hence, the hydroxide ion concentration is [tex]1.26\times 10^{-4}M[/tex]

Answer: 1.26 x 10 -4

Explanation:

The scientific theory is "an idea that is backed by data from many sources".

A scientific theory would be a justification for a feature of the natural world as well as the universe that already has undergone repeated testing and confirmation through using established procedures for observation and measurement but also outcome from evaluation.

The source would be defined as the origin of somebody else.

Therefore, the scientific theory is "an idea that is backed by data from many sources".

To know more about scientific theory and sources

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Answer:

0.004167 J/g°C is the specific heat of a substance.

Explanation:

[tex]Q=m\times c\times \Delta T[/tex]

[tex]Q=m\times c\times (T_{2}-T_1)[/tex]

Where:

Q =  heat absorbed(positive) or released (negative)

m = Mass of substance

c =  specific heat of a substance

[tex]T_1[/tex] = Initial temperature

[tex]T_2[/tex] = Final temperature

We have:

m = [tex]1.0\times 10^4 g[/tex]

c = ? , [tex]T_1=10^oC,T_2=70^oC[/tex]

Q = [tex]2.5\times 10^3 J[/tex]

[tex]2.5\times 10^3 J=1.0\times 10^4 g\times c\times (70^oC-10^oC)[/tex]

[tex]c=\frac{2.5\times 10^3 J}{1.0\times 10^4 g\times (70^oC-10^oC)}[/tex]

[tex]c=0.004167 J/g^oC[/tex]

0.004167 J/g°C is the specific heat of a substance.

Answer:

Explanation:

Information given about the element:

Number of protons = 74

Number of neutrons = 110

For the atomic number:

Neutral atoms such as this one would have their atomic number to be the same with their number of electrons and protons:

     atomic number = number of protons = number of electrons

The atomic number would therefore be 74

For the mass number:

The mass of an atom is centrally concentrated within the tiny nucleus. The mass number is the sum of protons and neutrons in an atom. Protons and neutrons are nuclear particles and are called nucleons:

     Mass number = number of protons + number of neutrons = 74+110=184

Is this a new element?

From the peroidic table, tungsten(W) perfectly fits this description of the atom. It has an atomic number of 74 and a mass number of approximately 184. The element is not a new element.

Is it solid, liquid, or gas?

The element is a hard metallic solid. It is a classified as a transition metal on the periodic table. Transition metals have very unique metals and are mostly solids.

Answer:

1) The atomic number of this element is 74, because number of protons = atomic number

2) Mass number of this element is 184

Ar=Z+N=74+110=184

3) It isn't a new element. An element with such atomic and mass numbers exists

4) It is Wolfram. Symbol: W

5) Solid

Sorry if I made mistakes. I started learning English recently

Answer:H20

Explanation:

because it is the base that contributes electrons

Answer : The Lewis-base in this reaction is, water [tex]H_2O[/tex]

Explanation :

According to the Lewis acid-base theory,

Lewis acid : It is a substance that can accepts pairs of electrons to form a covalent bond.

Lewis-base : It is a substance that can donates pairs of electrons to form a covalent bond.

The given balanced equation is:

[tex]Fe^{3+}+6H_2O\rightarrow [Fe(H_2O)_6]^{3+}[/tex]

In this reaction, [tex]Fe^{3+}[/tex] ion is Lewis-acid and [tex]H_2O[/tex] is a Lewis-base. The [tex]H_2O[/tex] donates electrons to [tex]Fe^{3+}[/tex] ion to form [tex][Fe(H_2O)_6]^{3+}[/tex].

Hence, the Lewis-base in this reaction is, water [tex]H_2O[/tex]

Answer:

A Mixture of two elements

Explanation:

Answer:

B

Explanation:

I looked it up and found the answer lol

Answer: Option (b) is the correct answer.

Explanation:

When Absalon stirred the solution which is containing salt in water then there will occur disturbance into solution due to stirring.

As a result, particles will come in motion and hence, they tend to gain more kinetic energy. Due to which there will be more number of collisions between the solute (salt) and solvent (water) particles.

Hence, rate of reaction will increase and because of this salt will readily dissolve into water.

Thus, we can conclude that the salt dissolve faster in Absalon's second experiment because stirring the salt and water increases particle motion, which causes more collisions to occur between the water and salt.

Answer:In science, a model is a representation of an idea, an object or even a process or a system that is used to describe and explain phenomena that cannot be experienced directly. Models are central to what scientists do, both in their research as well as when communicating their explanations.

Explanation:

Answer: 2.retains water, 4. are fine grained

Explanation:

Clay is a kind of soil. It exhibit fine grained particles. It retains the organic matter and inorganic minerals. The ability to retain water is because of fine grained size aggregate of clay. As this kind of soil can retain moisture and exhibit minerals it is suitable for the growth of plants.

Answer:

Resonance structures for the nitrate ion exist because there are more than one Lewis Structures for this ion.

Explanation:

How many bonds in each nitrate ion?

To answer this question, start by considering how many electrons each atom need for an octet.

The three O atoms and one N atom in each nitrate ion will need [tex]3\times 2 + 3 = 9[/tex] electrons in total to be stable. However, the ion carries a charge of [tex]-1[/tex]. In other words, atoms in the ion have already acquired one extra electron. Now they need only [tex]9 - 1 = 8[/tex] electrons.

Atoms share electrons by forming bonds. In effect, each chemical bond (a pair of shared electrons) adds two electrons to the bonding atoms. Atoms in the nitrate ion will form [tex]8/2 = 4[/tex] chemical bonds.

However, there are only three bonding position available. One of the three positions will see a double bond while each of the other two will see a single bond. However, the double bond can be at any of the three bonding position. There are thus three possible Lewis Structures. See the sketched. Note that the three structures are interconvertible by moving only the electrons but not any atoms. Hence the name resonance structures.

Keep in mind that in reality, the pi electrons from the double bond are delocalized across all three possible bonding positions. All three N-O bonds are of equal length.

Answer:

A

Explanation:

During fission, heavier unstable atoms are split into lighter and more stable atoms with the release of energy. Fission of Uranium-235 produces Barium and Krypton (which are lighter and more stable atoms) and neutrons. Barium has an atomic mass of 141 while that of Krypton is 92.

Answer:

a

Explanation:

Answer:

An atom becomes anion when it gains or loses electrons. The ions that are formed when an atom loses electrons are positively charged because they have more protons in the nucleus than electrons in the electron cloud.

Explanation:

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Answer: Sulfur atom will form a cation on loosing electrons.

Explanation:

There are 3 subatomic particles present in an atom. They are: protons, electrons and neutrons.

Protons carry positive charge, electrons carry negative charge and neutrons does not carry any charge.

Any neutral atom has equal number of protons and electrons.

An ion is formed when atom looses or gain electron.

If an atom gains electrons, it will have more number of electrons than protons. Thus, it will carry negative charge and form an anion.

If an atom looses electrons, it will have less number of electrons than protons. Thus, it will carry positive charge and forms a cation.

It is given that sulfur atom looses an electron. So, this atom will have more number of protons than electrons. Thus, it will form a cation.

Hence, sulfur atom will form a cation on loosing electrons.

Answer:

D. Changing the temperature will change Keq.

Explanation:

The equilibrium constant expresses the relationship between the molar concentration of reactants and products. This constant is the Keq. It is temperature dependent and constant at a given temperature.

A change in temperature of an equilibrium system shifts the system to a new equilibrium point. A rise in temperature shifts the equilibrium position to the direction that absorbs heat and vice versa.

In summary, a shift in equilibrium which results from temperature change is actually a change in value of the equilibrium constant.

Answer: D. changing the temperature will change the K eq

Explanation:

To determine which compounds an unknown sample could be, based on its percent composition, involves calculating the empirical formula from the given percentages and comparing it with the provided compound options.

The question involves determining which compounds an unknown sample could be, based on its percent composition of 52.14% carbon, 13.13% hydrogen, and 34.73% oxygen. This requires an understanding of percent composition and the ability to calculate an empirical formula based on the given percentages. Given the complexity of the sample compositions and potential empirical formulas, it's essential to evaluate each option through stoichiometric calculations and compare their empirical formulas derived from the provided compositions to the actual compounds mentioned.

Answer:

Saturated solution.

Explanation:

So, 10.0 g of KClO₃ forms a saturated solution.

When 10 g of KClO₃ are dissolved in 100 g of water at 30 degrees Celsius, a saturated solution is likely formed because the solubility of KClO₃ increases with temperature and is sufficient to dissolve this amount at 20 degrees Celsius.

The question is referring to the process of dissolving a chemical compound in water, which is a chemistry topic commonly studied in high school. When 10 g of KClO₃ (potassium chlorate) are dissolved in 100 g of water at 30℃, the type of solution that is formed depends on the solubility of KClO₃ at that temperature. Assuming the question implies 30 degrees Celsius, potassium chlorate has a solubility of about 7 g per 100 mL of water at 20℃. Since solubility generally increases with temperature, it's likely that the 10 g of KClO₃ will fully dissolve in 100 g of water at 30℃ to form a saturated solution. If all the solute dissolves, the solution is known as saturated; if the solute does not fully dissolve, any undissolved solute would result in a supersaturated solution if the excess was initially forced to dissolve under different conditions, or an unsaturated solution if there is still room for more solute to dissolve.

As a temperature of a fixed volume of a gas increases, the

pressure will also “INCREASE”

valence of magnesium is 2

and valence of sulfate-ion is 2 too

answer: MgSO4•7H2O

Answer: [tex]MgSO_4.7H_2O[/tex]

Explanation:

[tex]MgSO_4[/tex] is an ionic compound because aluminium element is a metal and hydrogen element is a non-metal. The bond formed between a metal and a non-metal is always ionic in nature.

The nomenclature of ionic compounds is given by:

1. Positive is written first.

2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written in case of [tex]SO_4^{2-}[/tex] is '-ate'.

Hence, the name of [tex]MgSO_4[/tex] is magnesium sulphate.

The water of crystallization is written as hydrate with the number of water molecules. As the name is heptahydrate, that means 7 water molecules are present.

Therefore, the correct answer is [tex]MgSO_4.7H_2O[/tex]

Answer:

- 90.6 kJ/mol.

Explanation:

ΔHrxn = ∑ΔHf(products) - ∑ΔHf(reactants)

∴ ΔHrxn = ∑ΔHf(products) - ∑ΔHf(reactants)

∴ ΔHrxn = [(2*ΔHf(KCl)) + (3*ΔHf(O₂))] - [(2*ΔHf(KClO₃))] = [(2*(- 436.7 kJ/mol)) + (3*(0)] - [(2*(- 391.4 kJ/mol)] = [- 873.4 kJ/mol] - [- 782.8 kJ/mol] = - 90.6 kJ/mol.

The enthalpy change of the reaction 2KClO3 -> 2KCl + 3O2 is calculated by subtracting the sum of the enthalpies of the reactants from the sum of the enthalpies of the products. The calculation results in an enthalpy change of 90.6 kJ, meaning the reaction is endothermic.

The enthalpy change of the reaction can be calculated by subtracting the sum of the enthalpies of the reactants from the sum of the enthalpies of the products. This is also known as Hess's law.

In this reaction, the reactants are 2 moles of KClO3 and the products are 2 moles of KCl and 3 moles of O2. Hence, the enthalpy of the reaction can be calculated as follows:

Enthalpy change = [2 * (-391.4 kJ/mol)] - [2 * (-436.7 kJ/mol) + 3 * 0 kJ/mol]

= (-782.8 kJ) - (-873.4 kJ)

= 90.6 kJ

Therefore, the enthalpy change of this reaction is 90.6 kJ. If the enthalpy change is positive, the reaction is endothermic meaning it absorbs heat from the surroundings.

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Answer:

In general, a scientific law is the description of an observed phenomenon. It doesn't explain why the phenomenon exists or what causes it. The explanation of a phenomenon is called a scientific theory. It is a misconception that theories turn into laws with enough research.

Explanation:

Answer:

A scientific law is a description of an observed phenomenon.this is not an explanation of a phenomenon but a description.

Hypothesis becomes a law when  they follow a line of reasoning and formulate a theory.then once a theory has been evaluated through a series of testing it becomes a law.

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