giving brainly for correct answer! :)

Answer:

B)

Explanation:

Taking into account the definition of pH and pOH, the mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.

First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.

The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:

pH= - log [H⁺]= - log [H₃O⁺]

Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:

pOH= - log [OH⁻]

The following relationship can be established between pH and pOH:

pOH + pH= 14

In this case, being pH= 12.40, pOH is calculated as:

pOH + 12.40= 14

pOH= 14 - 12.40

pOH= 1.60

Replacing in the definition of pOH the concentration of OH⁻ ions is obtained:

- log [OH⁻]= 1.60

Solving:

[OH⁻]= 10⁻¹ ⁶

[OH⁻]= 0.025 M

Then, the [OH⁻] is 0.025 M.  

Strong bases are bases that completely dissociate in water into the cation and OH - (hydroxide ion). LiOH is a strong base, so the OH- concentration is equal to the LiOH concentration:

[OH⁻]= [LiOH]= 0.025 M

Finally, Molarity or Molar Concentration is the number of moles of solute that are dissolved in a certain volume:

[tex]Molarity=\frac{number of moles}{volume}[/tex]

In this case, knowing that molarity is 0.025 M and the volume is 500 mL= 0.5 L, you can replace in the expression for molarity:

[tex]0.025 M=\frac{number of moles}{0.5 L}[/tex]

Solving:

number of moles= 0.025 M× 0.5 L

number of moles= 0.0125 moles

Finally, since the molar mass of LiOH is 23.95 [tex]\frac{g}{mol}[/tex], that is, the amount of mass that the substance contains in one mole, the mass of LiOH that 0.0125 mol contains can be calculated as:

0.0125 mol×23.95 [tex]\frac{g}{mol}[/tex]= 0.299375 g

The mass of LiOH needed to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40 is 0.299375 grams.

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Answer:

The amount of heat needed is 593.88 kJ.

Answer:

Explanation:

lead 3 is correct!!!!!

Answer:

can you include the choices?

Explanation:

Answer:

Answer b: The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants.

Explanation:

hope this helps

Answer:

I don't know what you're saying cuz give me the brainless answer please

Answer:

A, drawing a conclusion

Explanation:

Answer:

8

Explanation:

There are 8 carbon atoms in the reactants' side, because you multiply the 2 in front of C4H10 and the 4 under the C atom, and that gives you 8. So, 8 carbon atoms.

Answer:

Explanation:

1.08kg/50.5 cm^3(1000g/kg)=21.386 g/cm^3

Answer:

[tex]\boxed {\boxed {\sf 21.4 \ g/cm^3}}[/tex]

Explanation:

We are asked to find the density of an object.

The density of a substance is its mass per unit volume. It is calculated by dividing the mass by the volume.

[tex]\rho= \frac{m}{v}[/tex]

The mass of the object is 1.08 kilograms. The object displaced 50.50 cubic centimeters of water, so this value is its volume.

We are asked to give the density in grams per cubic centimeter, so we must convert the mass. There are 1000 grams in 1 kilogram. Set up a conversion factor.

[tex]\frac {1000 \ g}{1 \ kg}[/tex]

Multiply by the given mass: 1.08 kg

[tex]1.08\ kg *\frac{1000 \ g }{ 1\ kg}[/tex]

The units of kilograms cancel.

[tex]1.08*\frac{1000 \ g }{1}[/tex]

[tex]1.08*{1000 \ g } = 1080 \ g[/tex]

Now we know the mass in grams and the volume:

Substitute the values into the density formula.

[tex]\rho= \frac{1080 \ g }{50.50 \ cm^3}[/tex]

Divide.

[tex]\rho= 21.3861386 \ g/cm^3[/tex]

The original measurements of mass and density have 3 and 4 significant figures. Our answer must have the least number of significant figures, or 3.

For the number we found, that is the tenths place. The 8 in the hundredth place tells us to round the 3 in the tenths place up to a 4.

[tex]\rho \approx 21.4 \ g/cm^3[/tex]

The density of the object is approximately 21.4 grams per cubic centimeter.

Answer:

The one that burned longer because it burned longer

Explanation:

Answer:

Mark me as brainlest

Explanation:

Microorganisms present in our body Re viruses, bacteria, fungi, algae, and protozoa among which most of them cause immense benefits to the body. There are some harmful microorganisms too known as pathogens which cause disease and cause a threat to all existing life forms of the earth which can result in death at times.

Answer:

An example of microorganisms acting in a harmful way is a bacteria spoiling food.

Answer: It just haven’t been discovered yet

Explanation:

Because the periodic table was discovered long ago some elements haven’t been discovered thats why it maybe has 3 columns

Answer:

Explanation:

1 Electrolytes, particularly sodium, help maintain fluid balance through osmosis. Osmosis is a process where water moves through the wall of a cell membrane from a dilute solution (more water and fewer electrolytes) toward a more concentrated solution (less water and more electrolytes).

2 acid base balance in the body

our body's pH balance, also referred to as its acid-base balance, is the level of acids and bases in your blood at which your body functions best. The human body is built to naturally maintain a healthy balance of acidity and alkalinity. The lungs and kidneys play a key role in this process.

Answer:

The negative ion is larger than the original atom. but the same number of positive protons, the size of the ionic radius will increase. When an atom has its electrons attracted to another atom it becomes a positive ion. The positive ion is smaller than the original atom.

Answer:

boi i need the choices idiot

Explanation:

Nobody can add an answer without context.

But if this helps,

"Vaporization of an element or compound is a phase transition from the liquid phase to vapour. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomenon." - Wikipedia

https://en.wikipedia.org/wiki/Vaporization

Answer:

Melting and evaporation both represent changes in matter that involve behavior at the molecular level.

Answer:

well both disappear over time

Explanation:

The heat of vaporization of CH3CN is obtained from the question as 25 KJ/mol.

We can obtain the number of moles from;

PV = nRT

P = 1 atm

V = 1.17 L

n = ?

R = 0.082 atm LK-1mol-1

T = 81.6 °C + 273 = 354.6 K

n = PV/RT

Substituting values;

n =  1 atm × 1.17 L/0.082 atm LK-1mol-1 × 354.6 K

n = 0.04 moles

Using; q = n·ΔHv

q = Heat absorbed

n = number of moles

Hv  = Heat of vaporization

ΔHv = q/n

ΔHv = 1.00 × 10^3/0.04

ΔHv = 25 KJ/mol

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Answer:

4 covalent bonds

Answer:

YES

Explanation:

SO3 2-DOES  show delocalized bonding

delocalized bonding occurs when there is a resonance structure and the electronic bonds are a delocalised "cloud" around the species

The resonance effect of the sulfite sructures ithe folowing link:

https://www.chemistryscl.com/general/lewis-resonance-structure-of-SO32-/index.php

Ions can be made by single element or covalently bonded group of elements. The covalently bonded group of elements is called polyatomic ions or polyatomic atoms. Therefore SO₃²⁻ show delocalized bonding.

Any species that contain charge whether it is positive charge or negative charge is called ions. The example of polyatomic ions are sulfate, phosphate, nitrate etc.

Cation is the species that loose electron and attain positive charge while anion is a species which gain electron and attains negative charge so when anion and cation combine in fixed ration the the overall charge of the molecule is zero that is molecule is neutral, the charge over cation and anion is also called oxidation state.

SO₃²⁻ show delocalized bonding as there is a resonance structure and the electronic bonds are a delocalized "cloud" around the species

Therefore SO₃²⁻ show delocalized bonding.

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Not all acid-catalyzed conversions of alcohols to alkyl halides proceed through the formation of carbocations. Primary alcohols and methanol react to form alkyl halides under acidic conditions by an SN2 mechanism.

Not all acid-catalyzed conversions of alcohols to alkyl halides proceed through the formation of carbocations. Primary alcohols and methanol react to form alkyl halides under acidic conditions by an SN2 mechanism.

In these reactions the function of the acid is to produce a protonated alcohol. The halide ion then displaces a molecule of water (a good leaving group) from carbon; this produces an alkyl halide:

Again, acid is required. Although halide ions (particularly iodide and bromide ions) are strong nucleophiles, they are not strong enough to carry out substitution reactions with alcohols themselves. Direct displacement of the hydroxyl group does not occur because the leaving group would have to be a strongly basic hydroxide ion:

We can see now why the reactions of alcohols with hydrogen halides are acid-promoted.

Carbocation rearrangements are extremely common in organic chemistry reactions are are defined as the movement of a carbocation from an unstable state to a more stable state through the use of various structural reorganizational "shifts" within the molecule. Once the carbocation has shifted over to a different carbon, we can say that there is a structural isomer of the initial molecule. However, this phenomenon is not as simple as it sounds.

- BRAINLIEST answerer

Answer:  I think its in order, not really sure. First answer on top. Next answer on the left and the Last answer on the right.

Answer:

Covalent bond

Explanation:

All the characteristics of a Covalent bond are being described.

When, a substance boils at 45degree C. Then, the most likely bond type for the given substance is a covalent bond. Option A is correct.

Liquid at Room Temperature: The fact that the substance is a liquid at room temperature suggests that the intermolecular forces holding its molecules together are relatively weak. Covalent compounds often have weaker intermolecular forces compared to ionic or metallic compounds.

Doesn't Conduct Electricity When Dissolved in Water: Covalent compounds, in general, do not conduct electricity when dissolved in water. This is because they do not dissociate into ions in solution, which is necessary for electrical conductivity. Ionic compounds, on the other hand, typically dissociate into ions and can conduct electricity in solution.

Boils at 45°C: The relatively low boiling point (45°C) indicates that the intermolecular forces in the substance are weak. Covalent compounds tend to have lower boiling points compared to ionic or metallic compounds, which often have stronger bonding.

Considering these factors, the substance is likely held together by covalent bonds, which involve the sharing of electrons between atoms. This allows for the formation of discrete molecules with weak forces between them.

Hence, A. is the correct option.

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--The given question is incomplete, the complete question is

"The substance is a liquid at room temperature.-When you dissolve it into water, it doesn't conduct electricity.-The substance boils at 45 oC. Which is the most likely bond type for this substance? Choices: A) Covalent bond B) Metallic bond C) Ionic bond D) Hydrogen bonding E) Cation-pi bond."--

Explanation:

ano po topic nyo para maayos sagut

It's condensation in which gas particles have a higher kinetic energy..

Answer:

a because mass is converted into weight

Answer:

Non-redox, double displacement

Explanation:

it's the only answer that have double displacement

tell me if it was right

Answer:

there is two mixture homogeneous and heterogeneous mixture

ok

2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.

To determine the heat of neutralization, Chelsea used a coffee-cup calorimeter.

Initially, she had 2 solutions, NaOH and H₂SO₄, both at 29.5 °C. Upon mixing, the heat was evolved and the final temperature of the solution was 35.8 °C. The neutralization reaction was:

NaOH + H₂SO₄ ⇒ Na₂SO₄ + H₂O

The increase in temperature (ΔT) is equal to the difference between the final temperature and the initial temperature.

[tex]\Delta T = 35.8 \° C - 29.5 \° C = 6.3 \° C[/tex]

This data can be used to calculate the heat of neutralization (q) using the following expression.

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

where,

2 solutions of NaOH and H₂SO₄ at 29.5 °C are mixed in a coffee-cup calorimeter and after the reaction is completed the temperature is 35.8 °C. The increase in the temperature is 6.3 °C.

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