pls that is the picture ​

Answer:

a. Kw = 1.0 × 10⁻¹⁴

Explanation:

a. Let's consider the self-ionization of water.

2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻

The ion-product of water (Kw) at 25 °C is:

Kw = [H₃O⁺][OH⁻] = 1.0 × 10⁻¹⁴

c. Considering [H⁺] = [H₃O⁺] = 4.0 × 10⁻⁹ M, the concentration of OH⁻ is:

[OH⁻] = 1.0 × 10⁻¹⁴/[H₃O⁺] = 2.5 × 10⁻⁶ M

b. We can calculate the pOH using the following expression.

pOH = -log [OH⁻] = -log 2.5 × 10⁻⁶ = 5.6

d. We can calculate the pH using the following expression.

pH = -log [H⁺] = -log 4.0 × 10⁻⁹ = 8.4

When [H+] = 4.0 × 10–9 M in water at 25°C, then the [tex]Kw =1.0\times 10^-^1^4.[/tex]

Kw is the dissociation constant or ionization constant of water.

The self-ionization of water will be

[tex]\rm 2 H_2O(l) = H_3O^+(aq) + OH^-[/tex]

The dissociation constant of the water at 25°C will be

[tex]\rm Kw = [H_3O^+][OH^-] = 1.0 \times 10^-^1^4[/tex]

Thus, the correct option is a. [tex]Kw =1.0\times 10^-^1^4.[/tex]

Learn more about dissociation constant

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Answer:electron

Explanation:

The answer would be metals :)

Answer:

B) Na3BO3.

Explanation:

Hello!

In this case, since percent compositions are used to identify the empirical formula of an unknown compound, we can assume we have 54.0 g of sodium, 8.50 g of boron and 37.5 g of oxygen, and we compute the moles of each one:

[tex]n_{Na}=54.0g*\frac{1mol}{23g} =2.35mol\\\\n_B=8.50g*\frac{1mol}{11g}=0.773mol\\\\n_O=37.5g*\frac{1mol}{16g}=2.34mol[/tex]

Now, we divide by the moles of boron as those are the fewest:

[tex]Na:\frac{2.35}{0.773}=3\\\\B:\frac{0.773}{0.773}=1\\\\O=\frac{2.34}{0.773}=3[/tex]

Thus, the empirical formula is B) Na3BO3.

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Answer:

Q = 802.6 J

Explanation:

Given data:

Specific heat capacity of water = 4.18 J/g.°C

Mass of water = 12 g

Initial temperature = 23°C

Final temperature = 39°C

Heat required = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 39°C - 23°C

ΔT = 16 °C

Q = 12 g× 4.18 J/g.°C × 16 °C

Q = 802.6 J

Answer:

I think the answer is letter C

Answer: FeO

Explanation:

Answer:

This is not worth 50 points liar

Explanation:

Answer:

4.04433566 L (433566 repeating)

Explanation:

2.52 is divided by 28.6 is 0.0881118 (881118 repeating). multiply 0.0881118 (881118 repeating) by 45.9 to get 4.04433566 L (433566 repeating).

Answer:

The given substance is cast iron.

Explanation:

Given data:

Mass of substance = 50 g

Heat absorbed = 23000 J

Initial temperature = 250°C

Final temperature = 1250°C

Which metal is this = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 1250°C -  250°C

ΔT = 1000°C

23000 j = 50 g ×c ×1000 °C

23000 J = 50,000 g. °C×c

c = 23000 J /50,000 g. °C

c = 0.46 J/g.°C

The given substance is cast iron.

Answer:

joe.......

Explanation:

mama......

Answer:

need points

Explanation:

Answer:

A. The seeds on the ground are going to grow into new trees.

Explanation:

Trees are renewable resources.

Answer:

Mass percentage does not have any unit as numerator and denominator contains the same unit. The percent by mass of Ca in CaCl[tex]_2[/tex] is equal to (40/111) x 100. The correct option is option A.

Mass percentage represents the the percentage of each element that is making a particular compound.

Mathematically,

Percentage of mass = (component’s mass ÷ total mass) x 100%

Atomic weight of different element of calcium chloride{ CaCl[tex]_2[/tex]} are

Ca = 40 ; Cl = 35

Total mass of Calcium element in calcium chloride = 40g/mol

Total mass of Chlorine atom in calcium chloride = 35× 2= 71g/mol

Total molar mass of calcium phosphate = 40 +71= 111g/mole

Percentage of calcium in calcium chloride =40÷111 = 36%

Therefore, the percent by mass of Ca in CaCl2 is equal to (40/111) x 100. The correct option is option A.

To learn more about mass percentage, here:

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Answer:

B. Influenza affects one system, but multiple systems must interact in order to restore homeostasis.

Explanation:

According to the CDC, influenza is a respiratory illness caused by the flu virus of which some symptoms include cough, sore throat, muscle aches, and vomiting.

The statement that represents a reasonable claim about the effects of the flu virus on the body’s ability to maintain homeostasis is that it affects one system which is the RESPIRATORY SYSTEM but multiple systems must intervene in other to maintain homeostatis.

*Homeostatis is the unique way a human body or organism stabilises its internal state despite the changes on the external.

Answer:

1. Alkali metals (group 1)

2. halogens (Group 17)

3. noble gasses (group 18)

Explanation:

1. alkali metals only have one valence electron meaning that they really want to lose that one valence electron to get a full octet.

2. halogens have 7 valence electrons meaning that they just need to gain 1 to get a full octet.

3. Nobel gasses already have a full octet meaning that they don't want to react. (atoms only react to get a full octet)

I hope this helps.  Let me know if anything is unclear.

Answer:

Ionic compounds are neutral compounds made up of positively charged ions called cations and negatively charged ions called anions. For binary ionic compounds (ionic compounds that contain only two types of elements), the compounds are named by writing the name of the cation first followed by the name of the anion.

Explanation:

Hope this helps.

Answer: State of matter, Subcategory in the metal-metalloid-nonmetal trend, and electrons per shell.

Explanation:

Answer:

Explanation:it is c

Answer:

C The amount of empty space between the water particles will decrease

Explanation:

I just took the quiz, have a nice day!

Answer:

Arthropod (3)

Annelids (2)

Cnidarians (1)

Echinoderms (4)

Explanations:

I hope all this helps if u don't understand it let me know.

Answer:

A

Explanation:

Answer:

Yes the given equation is balanced.

Explanation:

Chemical equation:

Fe + O₂       →     Fe₂O₃

Balanced chemical equation:

4Fe + 3O₂       →     2Fe₂O₃

There are four iron and six oxygen atoms on both side of equation thus the given equation is balanced.

The given reaction also follow the law of conservation of mass.

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

This reaction is synthesis reaction:

Synthesis reaction:

It is the reaction in which two or more simple substance react to give one or more complex product.

A + B      →   AB

Answer:

8

Explanation:

u can find it on ur chemistry book

Answer:

C. 8

Explanation:

Check chemistry textbook

Answer:

An electrical phenomenon is caused by flow of free electrons from one atom to another. The characteristics of current electricity are opposite to those of static electricity. Wires are made up of conductors such as copper or aluminum.

Explanation:

from google

Answer:

To avoid variation due to concentration

Explanation:

Hope this helps :)

Answer:

Explanation:

2.2 g/mL is the answer.

Answer:

Aluminum even after being an active metal is used as a structural metal due to its toughness, high strength, lightweight, and resistance to the process of corrosion. It is resistant to corrosion as its reactivity gets suppressed due to the formation of an aluminum oxide film which is protective in nature, on its surface. Passivation is the term for the formation of the protective coating.