Help with this please :) will mark Brainlyist if right

The pH at the equivalence point for the titration of 0.25 M HCOOH versus 0.25 M NaOH is 8.5.

Let's consider the following neutralization reaction.

HCOOH + NaOH ⇒ HCOONa + H₂O

At the equivalence point, 0.25 M HCOOH completely reacted with 0.25 M NaOH to form 0.25 M HCOONa.

HCOONa undergoes hydrolysis. The net ionic equation is:

HCOO⁻(aq) + H₂O(l) ⇄ HCOOH(aq) + OH⁻(aq)

Given the concentration of HCOO⁻ is 0.25 M (Cb) and the basic dissociation constant of HCOO⁻ is 4.8 × 10⁻¹¹ (Kb), we can calculate the concentration of OH⁻ using the following expression.

[tex][OH^{-} ] = \sqrt{Kb \times Cb } = \sqrt{(4.8 \times 10^{-11} ) \times 0.25 } = 3.5 \times 10^{-6} M[/tex]

The pOH of the solution is:

[tex]pOH = -log [OH^{-} ] = -log (3.5 \times 10^{-6} ) = 5.5[/tex]

The pH of the solution is:

[tex]pH = 14 -pOH = 14 -5.5 = 8.5[/tex]

The pH at the equivalence point for the titration of 0.25 M HCOOH versus 0.25 M NaOH is 8.5.

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Answer:

13.C

14.B

15.C

16.Chemical element

Chemical Element are called substance or element that cannot be decomposed or broken down into simpler substances by ordinary chemical process.

Chemical elements are those elements which cannot be chemically broken down into simpler substances and are primary constituents of all matter. They are fundamental ingredients of all matter in existence which can be combined in reaction to create chemical substance each chemical element in the universe has unique properties that distinguish it from all of the Other chemical elements. For example hydrogen is an element.

Hope that helps

The alkaline earth element with the least massive atoms is beryllium (Be). Beryllium, located in Group 2 of the periodic table, possesses the lowest atomic number and atomic mass within the alkaline earth elements.

Among the alkaline earth elements, which are found in Group 2 of the periodic table, beryllium (Be) stands out for having the least massive atoms. The periodic table is organized in a way that elements are ordered by increasing atomic number, which corresponds to the number of protons in an atom's nucleus. For alkaline earth elements, the atomic numbers increase from beryllium (Be) with atomic number 4 to radium (Ra) with atomic number 88.

Atomic mass, on the other hand, takes into account the sum of protons and neutrons in an atom's nucleus, as electrons contribute very little to the overall mass. Since beryllium (Be) has the lowest atomic number in the alkaline earth group, it also has the fewest protons and neutrons among its isotopes, leading to a lower atomic mass compared to other elements in the same group.

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Answer:

Answer:

Aluminium atoms =  4.13 *10^22 aluminium atoms

Explanation:

Explanation:

Step 1: Data given

Mass of Al2O3 = 3.50 grams

Molar mass of Al2O3 = 101.96 g/mol

Number of Avogadro = 6.022 * 10^23 /mol

Step 2: Calculate moles Al2O3

Moles Al2O3 = mass Al2O3 / molar mass Al2O3

Moles Al2O3 = 3.50 grams / 101.96 g/mol

Moles Al2O3 = 0.0343 moles

Step 3: Calculate moles Aluminium

In 1 mol Al2O3 we have 2 moles Al

in 0.0343 moles Al2O3 we have 2*0.0343 = 0.0686 moles Al

Step 4: Calculate aluminium atoms

Aluminium atoms =  moles aluminium * Number of Avogadro

Aluminium atoms =  0.0686 * 6.022 * 10^23

Aluminium atoms =  4.13 *10^22 aluminium atoms

Answer:

Explanation:

Determine the treatments you’ll be using on your eggs, and prepare the substances you’ll need. You can make salt-water solutions by dissolving different amounts of table salt in containers of water (e.g. 100g, 200g, 300g of salt (NaCl) per liter). You can make solutions of food coloring by adding a few drops of each color into containers of  

The Eggsperiment with Vinegar solution. The first experiment conducted was the egg placed in vinegar solution which allowed the egg to become soft and bouncy . Vinegar is a weak acid which is 5% acetic acid in water (meaning vinegar is largely just water). The egg has a shell that is made up of calcium carbonate   an air cell forms at the large end of the egg. While the embryo is growing, the shell membranes surround and contain the white or albumen of the egg. The albumen provides the liquid medium in which the embryo develops, and it also contains a large amount of the protein necessary for proper development. I hope this was hopeful

Answer:

Hydrogen

Electronic notation

Explanation:

Answer:

the molar mass of Mg(NO3)2

the mass of the water added the density of the Mg(NO3)2

the volume of water used

Calculate the number of moles of Mg(NO3)2 used to make up this solution. 42.0 g of Mg(NO3)2 is equivalent to___ mol Mg(NO3)2.

Now calculate the molarity of the solution, giving your answer to the correct number of significant digits.

Molarity of Mg(NO3)2 = ___M

Answer:

k im silly frrr lol have a great day

According to conservation of matter, there should be equal amounts of all elements on both the reactant and product side.

Reactant:

1 Ca

1 C

1 O

Product:

1 Ca

1 C

3 O

Therefore, your friend is right because the law of conservation of matter is not followed in this chemical equation.

For a weak intermolecular bond, both the melting point and boiling point are lower.

A lesser energy is required to break bond of weak intermolecular forces while a greater energy is required to break bond of strong intermolecular forces.

E ∝ T

where;

A lesser energy means a lower temperature and a lower temperature will result in lower boiling point and melting point.

Thus, we can conclude that for a weak intermolecular bond, both the melting point and boiling point are lower.

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Answer:

red bone marrow contains blood stem cells that can become red blood cells ,white blood cells ,or platelets

Explanation:

Answer:

C6H5S^-

Explanation:

This is because you are removing the hydrogen to make it a conjugate base.

The formula for conjugate base of C6H5SH is C6H5S⁻.

Conjugate base is defined as the substance which is formed when an acid liberate its protons.

The acid donate protons and the acid changes into base.

Conjugate acid is defined as the pair of compound that differs by its protons by gaining protons.

Conjugate acid and base are based in acid base theory.

Thus, the formula for conjugate base of C6H5SH is C6H5S⁻.

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Answer: It is either C. or D.

Explanation: I did some reading about it and it talks about fuel but I know that it didn’t say all of them are used as fuels.  maybe I’m wrong

Petroleum is composed of hydrocarbons of various chain length. Different products can be extracted from petroleum but all products cannot be used as fuel.

Hydrocarbons in diesel have higher boiling point than that of gasoline.

Petroleum is a naturally occurring crude liquid mixture of hydrocarbons. Petroleum can be fractionated to different components such as gasoline, kerosene, diesel etc.

Each fraction vary in the number of carbons and hydrogens in it or called the difference in chain length. Kerosene contains 8-16 carbons where as gasoline and diesel have more carbons.

Not all products of petroleum fractionation can be used as fuel. Some of them with effective quality is taken as fuels.

The boiling point of hydrocarbons in diesel is greater (about 130-380 degree Celsius) than the hydrocarbons in gasoline which is having boiling point in he range 30-225 degree Celsius.

Therefore, the statement C is correct.

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this question is in reference to the formation and naming of ionic compounds. Specifically, they want you to give examples of three ionic compounds with a metal to nonmetal ratio of 2 to 1. That means we need to have two metal atoms to metal ions, which are typically cat ions for every one non metal atom or an ion. In order for this to occur, we need to have the metal with half the charge of the nonmetal or the non metal with double the charge of the metal. So an example might be something like sodium sulfide. Sodium has one valence electron. It can give up sulfur needs to valence electrons in order to achieve an octet. So we need to. Sodium seems to give up one electron each to total so that sulfide can achieve an octet. Another one might be potassium oxide. Similar scenario. We've got potassium giving up one valence electron oxygen requiring too. So we need to potassium to supply the to valence electrons that oxygen needs to achieve an octet and lithium. Also in Group one A and alkali metal wants to give up just one valence electron to achieve an octet well to achieve, I guess a duet to be more like helium, and so it gives up one. If we have two of them, then we can provide the to valence electrons that sulfur needs. So this is sodium sulfide, potassium oxide and lithium sulfide. Remember when we name Ionic compounds? We named the Cat Ion with the name of the element and the anti on with the name of the Element, but with the ending oven of ID, a suffix of ID because each one of the cat ions donated their valence electrons to the anti on so the an ion could achieve an octet. Then all of the's will have an octet of valence electrons. Sulfur had six sodium had one. There were two of them, so we have a total of eight.

The metals that can form only one type of ion are Li, Al, Ca, Ba, Rb, W,Na, Mg and  Sr. They are called alkali metals.

Cobalt, Co is stable in both +2 and +3 oxidation state. So it can variable.

Lithium, Li only have +1 charge. So it is invariable from one compound to other.

Lead, Pb is variable as it has +2, +4 charge in which it is stable.

Pd has +2, +4 charge in which it is stable. So, It is variable.

Copper, Cu has +1, +2 charge. It is also variable. Potassium, K has only +1 charge. It is invariable. Aluminum, Al has only +3 charge. It is invariable.

Cesium, Cs is only stable in +1 charge. It is invariable. Molybdenum, Mo is stable in +4 and +6. It is variable. Calcium, Ca and Barium Ba are stable in +2 charge. It is invariable.

Rubidium, Rb is stable in +1 charge. It is invariable. Tungsten, W is stable in +6 charge. It is invariable. Iron, Fe is stable in +2, +3 charge. It is variable. Sodium, Na is stable in +1 charge. It is invariable. Mg and Sr are stable in +2 charge. It is invariable. Vanadium, V has +2, +3, +4, +5 charges. So, It is variable.

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Answer:

40 hopefully right

Explanation:

Answer:

2 moles of C and no more

Explanation:

Consider the following reaction: 2A + 3B --> 2C If you have 2 moles of A and 6 moles of B, what is the maximum number of moles of C that can be made by the reaction

2A + 3B --> 2C '

2 of A make 2 of C if we have atleast 3 of B.

we ave more than enough B

2 of A will make 2 moles of C and no more

Explanation:

the chemicals are group 7 elements and one of their characteristics is that the melting and boiling point increase progressively

Answer:

3O2→ 2O3

Explanation:

by multiplying 2 by 3 we get 6 on both sides

identify keys concepts/terminologies about solutions or concentration of solutions.

They are the two basic solution concentration terms that you need to know.We always need to keep an account of the amount of solute in a solution.The amount of solute in the solvent is what is called the concentration of a solution.In chemistry,we define concentration of solution as the amount of solute in a solvent.

Depending upon amount of solute present,it is called a dilute, concentrated or a saturated solution.Different substances in a given solvent have a different solubilities at the same temperature.The most common method for expressing the concentration of a solution is the percentage method

Answer: mixture

Explanation: they are heterogeneous mixtures not homogeneous

It's Mixture

Reason:- Dirty water is a mixture of dirt and water. Mixture are made up of 2 or more different substance with different characteristics

Answer:

Rb, Zn, P, S, F, Ca, Co, Cr

Rb, Zn, P, S, F, Ca, Co, Cr elements in order of decreasing metallic character.

The metallic character of an element is defined as the properties typical of metal, especially the tendency to lose electrons in chemical reactions.

Metallic character depends on the ability of an element to lose its outer valence electrons. Examples of properties related to metallic character include thermal and electrical conductivity, metallic lustre, hardness, ductility, and malleability. The most "metallic" element is francium, followed by caesium.

Hence, Rb, Zn, P, S, F, Ca, Co, and Cr elements in order of decreasing metallic character.

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Answer:

C

Explanation:

Mixture of 2 or more metals is a compound

example is water which is made up of hydrogen and oxygen.

Answer:

LICL as an Ionic compounds has covalent ability and they are soluble in polar solvent such as CH3COCH3 but they are insoluble in non-polar solvents. Due to their polarity, CH3COCH3 will decreases the electrostatic forces of attraction thereby resulting in free ions in aqueous solution.

Water is the known as a polar solvent that can dissolve an ionic compounds very easy and as a polar solvent, the arrangement of oxygen and hydrogen atoms in water is in bent shape.

Ionic compounds like LICL that is very polar is soluble in the polar solvent water.

Polar solvents like CH3COCH3 will dissolve polar and ionic solutes because of the attraction of the opposite charges on the solvent and solute particles.

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Explanation:

Answer: 3.2 [D]

Explanation:

Use Boyles law

(Might want to rotate image, sorry!)

Answer:

1.68 atm (if temperature is constant)

Explanation:

p1 * v1 = p2 * v2

1 * 2.85 = p2 * 1.70

2.85 / 1.70 = p2

p2 = 1.6764

There are so many gas laws like Charles's law, Avogadro’s law and many more, out of which Boyle's law is one of the most important law among all gas laws. The pressure is required to compress the balloon to a volume of 1.70L is  1.6764 atm.

According to Boyle's law pressure is inversely proportional to volume at constant Temperature. It is applicable only on the ideal gases. Since temperature is constant here, we can apply this law.

Mathematically

P₁V₁=P₂V ₂

P₁= initial pressure of balloon =1.0atm

V₁= initial volume balloon =2.85L

P₂=final pressure balloon =?

V ₂=final volume balloon =1.70L

Putting all values

1 × 2.85 = P₂×1.70

2.85÷ 1.70 = P₂

P₂ = 1.6764 atm

Therefore, the pressure is required to compress the balloon to a volume of 1.70L is 1.6764 atm.

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Answer:

The answer is C) It is given off as heat

Explanation:

        Definition of unavailable energy : energy that cannot perform work while under the current conditions; see also available energy, energy deterioration, and entropy.

       Energy can transform from more useful forms into less useful forms, but it cannot be created or destroyed. It turns out that some energy gets transformed into an useless form in every real-world energy transfer or transformation.

    Entropy is the measurement of the amount of thermal energy per unit of temperature in a system that cannot be used for productive work. Entropy is a measure of a system's molecular disorder or unpredictability since work is produced by organized molecular motion.

   What is Mcq for McVisible Energy? Available energy is the largest portion of low-grade energy (heat) that is available for conversion. The smallest amount of heat that needs to be rejected is referred to as unavailable energy.

     For the system with two heat reservoirs undergoing this irreversible heat transfer, entropy increases. We'll see that this implies that the ability to use the transferred energy for work has been lost. Energy is no longer available to perform work due to the increase in entropy.

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Answer:

see below

Explanation:

1. particle motion

2. The particles of a liquid can slide past one another.

3. the kinetic energy required to break forces between particles

4. increasing its temperature until it transitions from a solid to a liquid

5. A liquid becomes a gas.

[quizlet: captncrun]

Thermal energy is in the form of heat and light is always associated with the random motion of atoms and molecules. That form of kinetic energy is used to the rise in temperature.

Hence the option B is correct.

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Answer:

34 grams

Explanation:

Assuming m/v means mass of solute / volume of solvent, then set up the equation:

1.7/100=m/2000, by cross multiplication, m=34 grams