Calculate the molarity of a solution prepared by dissolving 2.50 mol of KCl into 2.00 L of solution.
________ M​

Answer:

- A new substance was formed in the chemical change while no be substance was formed in the physical change

- The chemical change involved a change in chemical composition while the physical change involved no change in chemical composition

Please find the explanation below.

Explanation:

A physical change is a change that does not alter the chemical content of the substances involved, hence, no new substances are produced while a chemical change alters the chemical composition, hence, new substances results.

In this question,

- Water is heated till it forms steam is characterized as a physical change

- Lighted splint is applied to hydrogen gas to produce water in the form of steam is characterized as a chemical change.

- The first process is a PHYSICAL CHANGE because it involved only a change of state i.e. from liquid to gas, hence, no alteration to the chemical composition of the molecule and also no new substance is produced.

- The second process is a CHEMICAL CHANGE because there was a chemical combination of hydrogen gas and the oxygen in the lighted splint to yield water molecules ( a new substance). Therefore, it involved a chemical reaction and formation of a new substance

Answer:

is there a picture.....????

Answer:

See note in Explanation

Explanation:

The modern periodic table of the elements is arranged in order of increasing atomic numbers which is also in terms of the number of protons in the nucleus. That is, for any element listed on the periodic table its atomic number equals the number of protons in the nucleus. Thus, the element with 2 protons in its nucleus would be element #2 (Helium), element #3 (Lithium) has 3 protons in its nucleus and element #4 (Beryllium) has an atomic number 4 and contains 4 protons in its nucleus.

Also, this arrangement of elements finds that elements below elements 2, 3 & 4, Neon #10; sodium #11 & magnesium #12 have similar chemical and physical properties as does elements #2, #3 & #4. Such gives rise to the 'Periodic Law' => the chemical and physical properties of the elements is a periodic function of their atomic number (or, number of protons in the nucleus).

Answer:

kilograms

Explanation:

hope this helps, pls mark brainliest :D

Answer:kilogram

Explanation:

I got the smarts

Answer:

5

Explanation:

Answer:

2 in the first and 4 in the second

Explanation:

in an atom the first energy level has only 2 spaces for electrons, as the number electrons goes up so does the amount of energy levels

Answer:

2.5

Explanation:

Answer:

1.301 × 10⁻¹² m

Explanation:

Step 1: Given and required data

Step 2: Calculate the wavelength (λ) of the electromagnetic wave

We can calculate the wavelength of the electromagnetic wave using the Planck-Einstein's relation.

E = h × c / λ

λ = h × c / E

λ = (6.626 × 10⁻³⁴ J . s) × (3.00 × 10⁸ m/s) / 1.528 × 10⁻¹³ J

λ = 1.301 × 10⁻¹² m

The wavelength of this wave is equal to: D. [tex]1.301 \times 10^{-12}\;meter[/tex]

Given the following data:

To determine the wavelength of this wave, we would apply Einstein's equation for photon energy:

Mathematically, Einstein's equation for photon energy is given by the formula:

[tex]E=\frac{hc}{\lambda}[/tex]

Where:

Making [tex]\lambda[/tex] the subject of formula, we have:

[tex]\lambda = \frac{hc}{E}[/tex]

Substituting the given parameters into the formula, we have;

[tex]\lambda = \frac{6.626 \times 10^{-34}\; \times \;3.0 \times 10^{8}}{1.528 \times 10^{-13} }\\\\\lambda = \frac{1.99 \times 10^{-25}}{1.528 \times 10^{-13} }\\\\\lambda =1.301 \times 10^{-12}\;meter[/tex]

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Answer:Read explanation

Explanation:

A polar molecule has a net dipole as a result of the opposing charges (i.e. having partial positive and partial negative charges) from polar bonds arranged asymmetrically. Water (H2O) is an example of a polar molecule since it has a slight positive charge on one side and a slight negative charge on the other. A non polar substance we be the opposite of what I said

Answer:

That's because the glass walls of the greenhouse trap the Sun's heat. The greenhouse effect works much the same way on Earth.

Explanation:

Gases in the atmosphere, such as carbon dioxide, trap heat just like the glass roof of a greenhouse. These heat-trapping gases are called greenhouse gases.

Answer:

113 kJ or 113,000J

Explanation:

Since we are condensing it, a physical change in the state of matter is occurring. 113 kJ or 113,000J because of the following equation: Q = 2260 times 50.  2260 is the Heat of Vaporization constant.

Actual yield : 45.752 g ⇒no option

Given

The theoretical yields of Cl₂ : 65.35 g and 68.08 g

Required

The actual yield

Solution

Reaction

4 HCl (aq) + MnO₂ (s) → MnCl₂ (aq) + Cl₂ (g) + 2H₂O (l)

Because there are two theoretical yields, then we can choose the smallest one because the value is usually determined from the limiting reactant (in this reaction the limiting reactant is MnO₂)

So 65.36 g is The theoretical yields of Cl₂

Then the actual yield :

[tex]\tt \%yield=\dfrac{actual}{theoretical}\times 100\%\\\\actual=\%yield\times theoretical\\\\actual=70\%\times 65.36=45.752[/tex]

Answer:

CT Scan

Explanation:

Radiology is a branch of medicine that uses imaging technology to diagnose and treat disease. So, an example of a radiology technology that is useful for viewing tumors is Computed Tomography (CT)Scan. Others include Magnetic resonance imaging (MRI), X-rays etc.

Answer:

The water is the medium of the wave

Answer:

Elephant Toothpaste

Extra

Make Elephant Toothpaste

Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food coloring into the bottle. Swish the bottle around to mix the ingredients. Set the bottle in a sink or outdoors or some other place where you won't mind getting wet foam everywhere.

In a separate container, mix a packet of active yeast with a little warm water. Give the yeast about five minutes to activate before proceeding to the next step.

When you are ready to do the demo, pour the yeast mixture into the bottle. The reaction occurs immediately upon the addition of the yeast.

I don't know if this will help but here you go.

Answer:

Instructions on balancing chemical equations:

Enter an equation of a chemical reaction and click 'Balance'. The answer will appear below

Always use the upper case for the first character in the element name and the lower case for the second character. Examples: Fe, Au, Co, Br, C, O, N, F.     Compare: Co - cobalt and CO - carbon monoxide

To enter an electron into a chemical equation use {-} or e

To enter an ion specify charge after the compound in curly brackets: {+3} or {3+} or {3}.

Example: Fe{3+} + I{-} = Fe{2+} + I2

Substitute immutable groups in chemical compounds to avoid ambiguity.

For instance equation C6H5C2H5 + O2 = C6H5OH + CO2 + H2O will not be balanced,

but PhC2H5 + O2 = PhOH + CO2 + H2O will

Compound states [like (s) (aq) or (g)] are not required.

If you do not know what products are enter reagents only and click 'Balance'. In many cases a complete equation will be suggested.

Reaction stoichiometry could be computed for a balanced equation. Enter either the number of moles or weight for one of the compounds to compute the rest.

Limiting reagent can be computed for a balanced equation by entering the number of moles or weight for all reage

Explanation:

Answer:

somebody please help her or him please please

Explanation:

kind of ion formed (anion or cation) and the size of the ionic charge. ... O-‐2 oxide. S-‐2 sulfide. N-‐3 nitride. P-‐3 phosphide. Table 3.1. Common, simple anions. It is critically important that you distinguish between ...

Ions and Ionic Compounds – Introductory Chemistry – 1st Canadian Edition - BC Open Textbooks

opentextbc.ca › chapter › ions-and-ionic-...

The formula Na 2Cl 2 also has balanced charges, but the convention is to use the lowest ratio of ions, which ... For the ionic compound between magnesium cations (Mg 2+) and oxide anions (O 2−), again we need only ...

[PDF] Tutorial 2 FORMULAS, PERCENTAGE COMPOSITION, AND THE MOLE FORMULAS: A chemical formula shows the elemental composition of a sub

www.eiu.edu › eiuchem › forms › t...

Ba2+ barium. HSO3. – hydrogen sulfite. MnO4. – permanganate. Al3+ aluminum. SO4. 2– sulfate. NO2. – nitrite. Sn2+ tin(II). HSO4. – hydrogen sulfate. NO3. – nitrate. Sn4+ tin(IV). S2O3. 2– thiosulfate. OH– hydroxide.

Symbols and Charges for Monoatomic Ions

www.edu.xunta.es › portal › Nomenclature

Cs+ cesium ion O2- oxide. Be2+ beryllium ion S2- sulfide. Mg2+ magnesium ion Se2- ... one K+ and one Cl¯ are required. The resulting formula is KCl. Example 3: Write the formula from the following name: barium

Barium chloride salts has a 3 to 2 ratio of cations to anions. thus option C is correct.

Barium Chloride an inorganic salt which is composed up of barium cations (Ba2+) and chloride anions (Cl–), otherwise named as  Barium Muriate or Barium dichloride.

It is a white solid , water-soluble, hygroscopic and gives a slight yellow-green color to a flame,  extensively used in the industry mainly The sulfate is used in white paints where as Barium chloride is poisonous in nature.

It is soluble in water which dissociate into barium cations and chloride anions in its dissolved state, However, the solubility of this compound in water is temperature-dependent.

For more details barium chloride,  visit

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Answer: Metal atoms lose electrons from their outer shell when they form ions: the ions formed are positive, because they have more protons than electrons.

Protons

Explanation: the atomic number is the same as the number of protons

Answer:

P = 6

O = 15

Explanation:

for the phosphorus you multiply the mole number which number of atom present, same thing applicable to the oxygen atom

Answer:

A option

Explanation:

Because recatants are in solid form having less enetropy and products are liquid form having more entropy

While other options reactants and products are in same phase gas phase having same entropy

The reaction that would result in increased entropy is the combustion reaction;

KNO3(s)--->K+(aq)+NO3-(aq). Option A

This is further explained below

Generally, a combustion reaction is simply a combustion process that occurs when a material combines with oxygen gas, producing energy as light and heat.

In conclusion, the chemical reaction KNO3(s)--->K+(aq)+NO3-(aq) is has all properties of a combustion reaction as the solid reactants gives an aq solution.

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Answer:

d

Explanation:

Answer:

V = 20.1 L

Explanation:

Given data:

Volume of flask = ?

Number of moles of nitrogen gas = 0.730 mol

Pressure = 698 mmHg (698/760 = 0.92 atm)

Temperature = 35.4°C

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

35.4+273 = 308.4 K

by putting values,

0.92 atm× V = 0.730 mol ×0.0821 atm.L/ mol.K × 308.4 K

V = 18.48 atm.L / 0.92 atm

V = 20.1 L

Explanation:

mass H2O2 = 55 mL(1.407 g/mL) = 80.85 g

molar mass H2O2 = 2(1.01 g/mol) + 2(16.00 g/mol) = 34.02 g/mol

moles H2O2 = 80.85 g/34.02 g/mol = 2.377 moles H2O2

For each mole of H2O2 you obtain 0.5 mole of O2 (see the equation).

moles O2 = 2.377 moles H2O2 (1 mole O2)/(2 moles H2O2) = 1.188 moles O2

Now, you need the temperature.  If you are at STP (273 K, and 1.00 atm) then 1 mole of an ideal gas at STP has a volume of 22.4 L.  Without temperature you are not really able to continue.  I will assume you are at STP.

Volume O2 = 1.188 moles O2(22.4 L/mole) = 0.0530 L of O2.

which is  53 mL.

Answer:

3.06 m

Explanation:

Time of fall be t .

h = ut + 1/2 g t² , h is height , u is initial vertical velocity = 0

h = 1/2 g t²

32 = .5 x 9.8 x t²

t = 2.55 s

During this period , diver will move in horizontal direction also .

Horizontal displacement during fall

=  horizontal velocity x time

= 1.2 x 2.55

= 3.06 m  

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Answer:

1 oxygen from the lungs

Explanation:

maybe too help you breath better

Answer:

See explanation

Explanation:

Dalton's atomic theory furnished us with a basis to discuss the theory of atoms. However, not all his ideas holds up under the scruitiny of morden science.

He postulated that atoms were 'indivisible' the discovery of subatomic particles indeed show that there are smaller particles than atoms.

His postulation that atoms can neither be created nor destroyed does not hold water today because atoms are being created in nuclear reactors.

He said that atoms of all elements are exactly alike. Today we know there are isotopes of elements which are not exactly alike.

We can see that the Dalton's atomic theory did not take cognisance of the important role of subatomic particles in studying the structure of the atom. Modern atomic theory tries to look at the importance of these particles in the understanding the structure of the atom.