I’m confused and I don’t understand this can someone help?

Answer: pH = 2.68

Explanation: pH = - log[H3O^+] .

 HCl reacts with water : HCl + H2O ->  Cl^- + H3O^+

So [H3O^+] = c(HCl) = 0.0021 M

pH = - log(0.0021) = 2.68

Answer:

0.244 M.

Explanation:

From the question given above, the following data were obtained:

Molarity of stock solution (M₁) = 1 M

Volume of stock solution (V₁) = 0.305 L

Volume of diluted solution (V₂) = 1.25 L

Molarity of diluted solution (M₂) =?

The molarity of the diluted solution can be obtained by using the dilution formula as illustrated below:

M₁V₁ = M₂V₂

1 × 0.305 = M₂ × 1.25

0.305 = M₂ × 1.25

Divide both side by 1.25

M₂ = 0.305 / 1.25

M₂ = 0.244 M

Thus, the molarity of the diluted solution is 0.244 M

Answer:

A

Explanation:

A scientist is a person who conducts scientific research to advance knowledge in an area of interest.

In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophical study of nature called natural philosophy, a precursor of natural science. It was not until the 19th century that the term scientist came into regular use after it was coined by the theologian, philosopher, and historian of science William Whewell in 1833.

examples are

Answer: they do this because if they do they can easily find new viruses to stay safe from

Explanation: i took test on it recentley

Answer:

element has this explanation and is actually the smallest unit with chemical properties

A DRY ICE is hole were the steam looks a lot a smoke

Answer:

A

Explanation:

A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from tri- and glyceride). Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as vegetable fat.

The structure of option A shows a triglyceride.

Triglycerides are a kind of fat present in the blood. Triglycerides are the types of stored fats, which are not in use currently.

The structure of triglyceride is TRI esters containing glycerol bound to three fatty acid molecules.

Thus, the correct option is A.

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We are given:

Initial Temperature = 90°c

Final Temperature = 120°c

Heat applied(ΔH) = 500 Joules

Specific heat(c) = 0.9 Joules / g°C

Mass of Aluminium(m) = ?

Change in temperature:

ΔT = Final temp. - Inital Temp.

ΔT = 120 - 90

ΔT = 30°c

Calculating the mass:

We know the formula:

ΔH = mcΔT

replacing the values:

500 = m(0.9)(30)

500 = m(27)

m = 500/27

m = 18.52 grams

Answer:

Please find the report on the comet below

Explanation:

Specifically in the year 1993, a comet was discovered by three individuals namely: Eugene Shoemaker, Carolyn Shoemaker, and David Levy. The comet was named after the first discoverers as; Shoemaker-Levy 9.

Shoemaker-Levy 9 was reported to have already been in pieces as at the time of discovery. It was believed to have been torn apart by the gravitational force emanating from the biggest of the planets called JUPITER.

In July 1994, Shoemaker-Levy 9 came in contact with Jupiter in what seemed to be the end of the discovered comet. This collision of Shoemaker-Levy 9 with planet Jupiter was said to be the first ever solar systems collision observed.

Answer:

K2S(aq) + BaCl2(aq) = 2KCl(aq) + BaS(s)

In the image attached, it is explained how the solution is balanced.

The number of atoms of any element in the given chemical formula is the number that is written on the foot of the symbol of that element. The   balanced equation is

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq)[tex]\rightarrow[/tex]2KCl(aq) + BaS(s)

Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side.

The unbalanced equation is

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq) [tex]\rightarrow[/tex]KCl(aq) + BaS(s)

The number of atoms of K on reactant side is 2 while on product side it is 1, so to balance K we need to multiply KCl by 2

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq) [tex]\rightarrow[/tex]2KCl(aq) + BaS(s)

The atoms of sulfur on reactant and product side is 1, so it is balanced.

The atoms of Ba on reactant and product side is 1, so it is balanced.

The atoms of Cl on reactant and product side is 2, so it is balanced.

Therefore the balanced equation is

K[tex]_2[/tex]S(aq) + BaCl[tex]_2[/tex](aq)[tex]\rightarrow[/tex]2KCl(aq) + BaS(s)

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Answer:

No of molcules(N)= 1.98×10^22

Explanation:

m=5.5, Mm= 167, NA= 6.02×10^23

Moles(n)= m/M= N/NA

5.5/167 = N/6.02×10^23

SIMPLIFY

N=1.98×10^22molecules

Answer:

The De Broglie hypothesis proposes that all matter exhibits wave-like properties and relates the observed wavelength of matter to its momentum. After Albert Einstein's photon theory became accepted, the question became whether this was true only for light or whether material objects also exhibited wave-like behavior.

Answer:

- Identify the acid and base in the reaction.

- What is left of the base after the reaction is known as the conjugate acid, while what is left of the acid after the reaction is known as the conjugate base.

Explanation:

Types of acids and bases:

When we are looking at conjugate acid and base, the type of acid and base we should focus on are Brønstead acid and base.

Brønsted acid: proton donor

Brønsted base: proton acceptor

Do note that proton here refers to hydrogen ion, H⁺.

Other types of acids and bases includes arrhenius acid/base and Lewis acid/base.

Definition:

Conjugate acid is what remains of the acid when a Brønsted acid donates a proton, while conjugate base is the newly formed protonated species when a Brønsted base accepts a proton.

Example:

Let's look at an example of a Brønsted acid-base reaction:

NH₃(aq) +H₂O(l) ⇌ NH₄⁺(aq) +OH⁻(aq)

Here, the base is NH₃ and the acid is H₂O.

NH₄⁺ is the conjugate acid, while OH⁻ is the conjugate base.

Note:

For a Brønsted acid- base reaction, whether a substance behaves as an acid or a base depends on what it is reacting with. Although H₂O behaves as an acid in this example, it behaves as a base when reacting with HCl.

Answer:

The answer would be charged particles.

Explanation:

Electric force exists as one of the most fundamental forces in the universe, it occurs between all charged particles.

Answer:

7,491 lb/cu ft.

Explanation:

Answer:

[Kr] 4d4 5s1

Explanation:

Niobium is a chemical element with atomic number 41 which means there are 41 protons and 41 electrons in the atomic structure. The chemical symbol for Niobium is Nb. Neutron Number and Mass Number of Niobium Mass numbers of typical isotopes of Niobium are 93.

Name of Element : Niobium

Atomic Weight : 92.9

Atomic Number : 41

Group : Transition Elements

Electron Configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d3

Answer:  The coefficient we should change first is for [tex]NO_{3}[/tex].

Explanation:

The given reaction equation is as follows.

[tex]Al + Ni(NO_{3})_{2} \rightarrow Al(NO_{3})_{3} + Ni[/tex]

Here, number of atoms present on reactant side are as follows.

Number of atoms present on the product side are as follows.

To balance this equation, multiply Al by 2 and [tex]NO_{3}[/tex] by 3 on reactant side. Also, multiply [tex]Al(NO_{3})_{3}[/tex] by 2 and Ni by 3 on the product side.

Hence, the equation can be rewritten as follows.

[tex]2Al + 3Ni(NO_{3})_{2} \rightarrow 2Al(NO_{3})_{3} + 3Ni[/tex]

Now, number of atoms present on reactant side are as follows.

Number of atoms present on product side are as follows.

Since, the atoms on both reactant and product side are same. Hence, it is now a balanced chemical equation.

Thus, we can conclude that the coefficient we should change first is for [tex]NO_{3}[/tex].

Answer:

Kind of like DNA or a part of DNA

Explanation:

They are what make you a person, no they aren't the same

Answer:

2, 8, 10, 2

Explanation:

Answer:

2, 8, 10, 2

Explanation: Titanium/Electrons per shell

Answer:

Substances over 7 are categorized as basic, with 7 being the neutral point. Water has a pH level of 7. Substances with pH levels under 7 are categorized as acidic. Vinegar is acidic.

Explanation:

You can change it a little if you want. Hope this helps!

Vinegar is acidic. The only vinegar that has alkaline is apple cider vinegar, but all types of vinegar are acidic.

Answer:

Precipitation reactions are ones in which at least one of the reactants is in the aqueous phase (i.e., dissolved in water), and a solid forms on the product side which was not present on the reactant side. If all the reactants are solid, then a solid product forming should not be called a precipitate. To be called a precipitate, an insoluble product must form from within solution, either from a solid and solute interacting, or from an interaction strictly between solutes.

Explanation:

Answer:

a. decrease the amount of the common ion in the system

Explanation:

The correct option is - a. decrease the amount of the common ion in the system

Reason -

Adding a common ion decreases solubility, as the reaction shifts toward the left to relieve the stress of the excess product.

Adding a common ion to a dissociation reaction causes the equilibrium to shift left, toward the reactants, causing precipitation.

Answer:  Okay so i don't know how i can explain this but.. OK so Steven placed an ice cream scoop right? and put it under hot water so i would say it would make the ice cream scoop hot? and then using it to scoop the ice cream i could say it would be a melting affection i think

Explanation:

im am so sorry pls forgive me is i am wrong i tried my best so at least give me a like for effort.. i hope u have a great day :)

Answer:answer in explanation try to understand dear

Explanation:Air pollutants have a negative impact on plant growth, primarily through interfering with resource accumulation. Once leaves are in close contact with the atmosphere, many air pollutants, such as O3 and NOx, affect the metabolic function of the leaves and interfere with net carbon fixation by the plant canopy.

Answer:

Antarctic Peninsula, is one of the most important fossil sites on Earth.

hope this helps you ☺️☺️

Fossils that would be expected to be found in Antarctica from more recent times, after it had moved much closer to the South Pole is Antartica peninsula.

Fossils are the preserved remains, impression, or trace of any once-living thing from many years ago. Examples of the fossils include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants.

There are four different types of fossils-

Mold fossils

Cast fossils

Trace fossils or Ichnofossils

True form fossils

Imprints, tracks, and trails can also become fossilized and are called Trace fossils. Dinosaur footprints or worm burrows are the examples.

Living things when get decomposed from the so many years ago and become dirt and rocks are fossils.

Therefore, Fossils that would be expected to be found in Antarctica from more recent times, after it had moved much closer to the South Pole is Antartica peninsula.

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Answer:

sever and over

Answer:

I THINK IT IS TRUE  BECAUSE THEY ERE FIRST FOUND TO DEMOCRITUS ARISTOTLE AND PLATO THE ROMANS AND GREEK CHEMISTS .

Explanation:

Answer:

1.0 mole

Explanation:

From the question given above, the following data were obtained:

Volume (V) = 5 L

Temperature (T) = 205 K

Pressure (P) = 340 KPa

Gas constant (R) = 8.31 KPa.L/Kmol

Number of mole (n) =?

Using the ideal gas equation, the number of mole of the gas in the container can be obtained as follow:

PV = nRT

340 × 5 = n × 8.31 × 205

1700 = n × 1703.55

Divide both side by 1703.55

n = 1700 / 1703.55

n = 1.0 mole

Thus, the number of mole of the gas in the container is 1.0 mole