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vodomira [7]
3 years ago
9

Someone pls help me I will mark you as brain

Chemistry
1 answer:
gavmur [86]3 years ago
4 0

Answer:

1st one is the answer water cannot be purified by nature pls add me in brainliest

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lilavasa [31]

1.66 M is the concentration of the chemist's working solution.

<h3>What is molarity?</h3>

Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution. Molarity is also known as the molar concentration of a solution.

In this case, we have a solution of Zn(NO₃)₂.

The chemist wants to prepare a dilute solution of this reactant.

The stock solution of the nitrate has a concentration of 4.93 M, and he wants to prepare 620 mL of a more dilute concentration of the same solution. He adds 210 mL of the stock and completes it with water until it reaches 620 mL.

We want to know the concentration of this diluted solution.

As we are working with the same solution, we can assume that the moles of the stock solution will be conserved in the diluted solution so:

n_1= n_2  (1)

and we also know that:

n = M x V_2

If we replace this expression in (1) we have:

M_1 x V_1= M_2 x V_2

Where 1, would be the stock solution and 2, the solution we want to prepare.

So, we already know the concentration and volume used of the stock solution and the desired volume of the diluted one, therefore, all we have to do is replace the given data in (2) and solve for the concentration which is M_2:

4.93 x 210 =  620 xM_2

M_2 = 1.66 M

This is the concentration of the solution prepared.

Learn more about molarity here:

brainly.com/question/19517011

#SPJ1

6 0
2 years ago
PLS ANSWER ALL QUESTIONS FOR 67 POINTS
Elena L [17]

Explanation:

1. subatomic particles. 

2.proton, electron and neutron

3.The atomic mass of an element is actually the sum of the MASSES of protons and neutrons in AN atom of that element

4.An element's atomic number is equal to the number of protons in the nuclei of any of its atoms

5. Number of Protons = Atomic Number

Number of Electrons = Number of Protons = Atomic Number

Number of Neutrons = Mass Number - Atomic Number

For krypton:

Number of Protons = Atomic Number = 36

Number of Electrons = Number of Protons = Atomic Number = 36

Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48

6. electron, lightest stable subatomic particle known. It carries a negative charge of 1.602176634 × 10−19 coulomb, which is considered the basic unit of electric charge. The rest mass of the electron is 9.1093837015 × 10−31 kg

7.The center of the atom is called a nucleus

8. Negatively charged particles are found in multiple layers outside the nucleus of the atom. These particles are called electrons, and they orbit in various energy levels around the atom's nucleus.

9. A charged particle is also called an ion

3 0
2 years ago
Which elements have the most similar chemical properties
gtnhenbr [62]

Answer:

Elements that belong to the <em>same </em><em>GROUP</em><em> </em>of the periodic table have the most similar chemical properties.

Explanation:

A GROUP in the periodic table is a column of elements with the same number of valence electrons. Since electrons are exchanged/shared during a chemical reaction, then elements with similar valence electrons, will react similarly. Thus elements belonging to the <em>same GROUP</em> are most similar in the way they react.

For example: Sodium and Lithium are group 1 elements while fluorine and chlorine are group 17 elements. In a reaction under normal conditions, Sodium and Lithium will both try to give up their single valence electron to form cations. In doing so they will react more similarly. On the other hand, Fluorine and Chlorine who are more inclined to accept a single electron to form cations react less like the group 1 elements and more like each other.

6 0
3 years ago
What are two different kinds of rock that are easily weathered by carbonic acid?
horsena [70]
Limestone and marble are the two rocks that are easily weathered by carbonic acid. Two kinds of weathering mostly affect the rocks. and they are physical weathering and chemical weathering. The above mentioned two rocks are highly affected by carbonic acid. The appeareance of these kind of rocks change their structure due to erosion very regularly. Caronation is the type of chemical weathering that affects the rocks limestone and marble. The carbonic acide is formed by the reaction of carbon dioxide in the air and water in the rivers. This carbonic acid results in weathering.
8 0
3 years ago
Are properties such as odor, color, density, and solubility physical or chemical properties?
storchak [24]
Physical properties- color, density, solubility.
<span>Chemical property- odor.

</span>You see, a physical property<span> is any property that can be </span>measured<span> , and a one that </span><span>describes the state of the physical system.
</span>
https://socratic.org/questions/are-properties-such-as-odor-color-density-and-solubility-physical-or-...
8 0
3 years ago
Read 2 more answers
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