if you know the answer to any of these pls help out I'll give brainiest. also a lot of points​

Answer:

0.8M

Explanation:

Given parameters:

Number of moles of KNO₃  = 0.2mol

Volume of KNO₃ = 250mL

Unknown:

Molarity of the solution  = ?

Solution:

The molarity of a solution is the number of moles in a given volume of a solution;

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

 We need to convert the given volume to L;

                1000mL  = 1L

        250mL will give  250 x 10⁻³L = 0.25L

So;

        Molarity  = [tex]\frac{0.2}{0.25}[/tex]   = 0.8M

Answer:

0.8 M

Explanation:

The formula is mol divided by liters. Converting 250 ml to .25 liters is important. Dividing .2 by .25 gets the answer. (I swear it’s right but it’s graded wrong so take this with a grain of salt)

0.04350179862

Explanation:

Make sure to check for sig figs though. Basically, you have 2.54 mL and you multiply that by the 0.789 g/mL and mL cancels out and you are left with 2.00406g. There are 46.06844 grams per mol of ethanol, so to cancel out grams we multiply by 1/46.06844. And then we are left with 0.04350179862 mol

Answer:

Methanol

Explanation:

Answer:

6 oxygen atoms

Explanation:

Step 1: Given data

Number of dinitrogen monoxide molecules (N₂O): 6

Number of oxygen atoms (O): ?

Step 2: Calculate the appropriate ratio

The ratio of dinitrogen monoxide molecules to oxygen atoms is 1:1.

Step 3: Use the ratio to calculate the number of oxygen atoms

6 molecule N₂O × (1 atom O/1 molecule N₂O): 6 atom O

Answer:

x

Explanation:

becaue neutron equal to mass num -atomic num

Answer:

True

Explanation:

A chemical reaction will always result in a new product or substance being formed

that is what makes it a chemical reaction.

Answer:

zygote

Explanation:

In human beings, each gamete contains 23 chromosomes, half the number found in the other cells of the body. When the male and female gametes fuse, they become a zygote containing the full 46 chromosomes, half of which came from the father and half from the mother.

Answer:

zygote

Explanation:

In human beings, each gamete contains 23 chromosomes, half the number found in the other cells of the body. When the male and female gametes fuse, they become a zygote containing the full 46 chromosomes, half of which came from the father and half from the mother.

Answer:

No simple relationship exists between population size and environmental change. However, as global population continues to grow, limits on such global resources as arable land, potable water, forests, and fisheries have come into sharper focus.

Explanation:

Answer:

A. how cholesterol works in the body.

Explanation:

If we know the precise structure of a molecule (by X-ray crystallography), we can understand more about how it interacts with cells, proteins, and other molecules. It can also tell us what reactions it might take part in.

Therefore, we can learn more about how it works in the body and what activities it takes part in in the cells of the body.

Answer:

A

Explanation:

nuityyy

Answer:it do not states

Explanation:

355 volcanoes in the Philippines are inactive.

24 volcanoes are active

Answer:

TAAL ACTIVE

MAOUNT BALUGAO INACTIVE

Explanation:

Answer:

Electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions

Explanation:

In accordance with VSEPR theory, the electron domains or electron pairs on the valence shell of the central atom in a molecule always position themselves as far apart in space as possible in order to minimize repulsions.

Recall that according to VSEPR theory, the shape of a molecule depends on the number of electron pairs or electron domains on the valence shell of the central atom of the molecule, both lone pairs and bond pairs. Lone pairs are known to cause more repulsions than bond pairs.

Answer:

80.80amu

Explanation:

multiple each value by its percentage (in decimal form) and take the sum.

80.65x.2191 + 83.67x.2335 + 79.64x.5474 = 80.802296 sig figs = 80.80

Answer:

Bromine

Explanation:

Cuz it has bro in it :)

Answer:

2.04 x 10⁻¹⁹J

Explanation:

Given parameters:

  Frequency = 3.08 x 10¹⁴Hz

Unknown:

The energy of the photon  = ?

Solution:

 The energy of a photon is given as;

          E = hf

Where h is the planck's constant

            f is the frequency

Insert the parameters and solve;

           E = 6.63 x 10⁻³⁴ x 3.08 x 10¹⁴

          E = 20.4 x 10⁻³⁴⁺¹⁴

           E = 20.4 x 10⁻²⁰  = 2.04 x 10⁻¹⁹J

Answer:

2.97*10-19 j

Explanation:

E=Energy of photon

H=Planck constant=6.626*10-34

V=Frequency of photon

we can plug what we already know E=(6.626*10-34)(4.48*10 14)

Answer:

Explanation:1. A 2.650-g sample of a gas occupies a volume of 428 mL at 0.9767 atm and 297.3 K. What is its molar mass?

2.

a. A sample of nitrogen gas has a volume of 10.0 L at 2.50atm and 50.0℃. If the pressure is increased to 5.00 atm and the temperature decreases to 25.0℃, what volume does the gas occupy?

(a). 5.00L, (b).4.61L, (c).2.50L, (d).5.42L

b. Using the average bond energy, calculate the enthalpy of the above reaction. draw Lewis structures of the reactants and products first to determine the exact bond order. N2(g)+3H2(g)→2NH3(g)

Answer:

0.70 J/g.°C

Explanation:

Step 1: Given data

Step 2: Calculate the specific heat of graphite

We will use the following expression.

Q = c × m × ΔT

c = Q / m × ΔT

c = 1136 J / 402 g × (30°C - 26°C)

c = 0.70 J/g.°C

Answer:

4.5 × 10²³ number of atoms Al

Explanation:

Given data:

Mass of Al = 20 g

Number of atoms of Al = ?

Solution:

The given problem will solve by using Avogadro number.

'It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance" .The number 6.022 × 10²³ is called Avogadro number.

We will calculate  the number of moles of Al first:

Number of moles = mass/molar mass

Number of moles = 20 g/ 27 g/mol

Number of moles = 0.74 mol

1 mole = 6.022 × 10²³ number of atoms

0.74 mol ×  6.022 × 10²³ number of atoms / 1 mol

4.5 × 10²³ number of atoms Al

The required number of atoms is [tex]4.46\times 10^{23}[/tex]

Atomic weight, also called relative atomic mass, ratio of the average mass of a chemical element’s atoms to some standard.

Given that,

Mass=[tex]20[/tex] grams

1 mole of aluminum [tex]= 27g = 6.023\times10^{23}[/tex] number of atoms 27g of aluminum contains [tex]6.023\times10^{23}[/tex] a number of atoms.

Therefore,20 grams the number of atoms is,

[tex]6.023\times10^{23}\times\frac{20}{27} =4.46\times10^{23}[/tex]

Learn more about the topic of atomic weight:

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Answer:d

Explanation:took the test

The arrow in the statement  is likely pointing to the atomic symbol of manganese, which is the letter "Mn."  Therefore, option (D) is correct.

In the periodic table, elements are organized based on their atomic number, which corresponds to the number of protons in the nucleus of an atom. Manganese has an atomic number of 25, indicating that it has 25 protons. The atomic symbol is a shorthand representation of the element's name, allowing for easy identification and reference.

Therefore, the arrow is pointing to the atomic symbol of manganese, "Mn," indicating its position in the periodic table and distinguishing it from other elements. The atomic symbol is a fundamental component of the periodic table, enabling scientists to communicate and study elements and their properties more efficiently.

Learn more about atomic symbol, here:

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Answer:

evaporation

Explanation:

Answer:

boiling (or vaporization)

Explanation:

At a certain temperature, the particles in a liquid have enough energy to become a gas. This process of a liquid becoming a gas is called boiling (or vaporization.)

Answer:

(1) the same chemical properties .

Explanation:

Hello!

In this case, among the options:

(1) the same chemical properties

(2) the same volume

(3) different temperatures

(4) different empirical formulas

We can see that they have the same chemical properties as they at the same conditions, same type of bond (polar), molecular geometry, bond angle (104.5 °) and so on. Nevertheless, at STP (1 atm and 273.15 K) they do not have the same volume since the larger the mass, the larger the volume, they have the same temperature and the both of them are H₂O.

It means that the answer is (1) the same chemical properties .

Best regards.

Answer: To examine whether one variable causes a change in another

Explanation:

Answer:

S–34

Explanation:

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

Neutron number = 18

The isotope of sulphur still retains its atomic number of 16.

Recall:

Atomic number = proton number

Atomic number of sulphur (S) = 16

Therefore,

Proton number = 16

Next, we shall determine the mass number of the sulphur isotope. This can be obtained as follow:

Proton number = 16

Neutron number = 18

Mass number =.?

Mass number = Proton + Neutron

Mass number = 16 + 18

Mass number = 34

The symbol for sulphur is S.

Thus, the symbol of sulfur isotope that contains 18 neutrons is S–34

Answer:

Density of Radon is  5.44 g/.

Explanation:

Given data:

Temperature of gas = 100°C (273+100 = 373 K)

Pressure of gas = 0.75 atm

Density of gas = ?

Solution:

First of all we will derive the formula.

We know that,

PV = nRT

and

n = m/M    (m = mass, M = molar mass)

PV = (m/M) RT

PVM =  (m/M) RT ×M

PVM = mRT

PVM/V = mRT/V

PM = dRT            (m/V = d)

Now we will put the values in formula:

Molar mass of Radon is 222 g/mol .

0.75 atm ×222 g/mol = d× 0.0821 atm.L/mol.K ×373 K

166.5 atm.g/mol = d×30.62 atm.L/mol

d = 166.5 atm.g/mol / 30.62 atm.L/mol

d = 5.44 g/L

Answer:

it's A. if the force of gravity is greater than the buoyant force, the object will sink.

Explanation:

just took the quiz on a p e x

Answer:

im not good at chem

Explanation:

sorry bro

The empirical formula for the compound containing 40.05 % sulfur and 59.95 % oxygen is SO₃

The empirical formula of the compound can be obtained as follow

Divide by their molar mass

S = 40.05 / 32 = 1.25

O = 59.95 / 16 = 3.75

Divide by the smallest

S = 1.25 / 1.25 = 1

O = 3.75 / 1.25 = 3

Thus, the empirical formula of the compound is SO₃

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Answer:

Explanation:

To find the original pressure we use the formula for Boyle's law which is

[tex]P_1V_1 = P_2V_2[/tex]

where

P1 is the initial pressure

P2 is the final pressure

V1 is the initial volume

V2 is the final volume

Since we are finding the original pressure

[tex]P_1 = \frac{P_2V_2}{V_1} \\[/tex]

From the question

V1 = 20 L = 20,000 mL

P2 = 560.0mmHg

V2 = 15700mL

We have

[tex]P_1 = \frac{560 \times 15700}{20000} = \frac{8792000}{20000} = \frac{2198}{5 } \\ [/tex]

We have the final answer as

Hope this helps you