NEED HELP ASAP
You need to prepare a 100. mL of a 0.050M solution of CaCl2. How many grams of CaCl2 are needed?

Answer:

Chromatography

Distillation

Evaporation

Filtration

Explanation:

Chromatography involves solvent separation on a solid medium.

Distillation takes advantage of differences in boiling points.

Evaporation removes a liquid from a solution to leave a solid material.

Filtration separates solids of different sizes.

Mixtures can be physically separated by using methods that use differences in physical properties to separate the components of the mixture, such as evaporation, distillation, filtration and chromatography.

Answer:

Conservation of Charge is the principle that the total electric charge in an isolated system never changes. The net quantity of electric charge, the amount of positive charge minus the amount of negative charge in the universe, is always conserved.

5.25 moles

Chemistry

Atomic Structure

Aqueous Solutions

Stoichiometry

Step 1: Define

[RxN - Balanced] 2KClO₃ (s) → 2KCl (s) + 3O₂ (g)

[Given] 3.50 mol KClO₃

[Solve] mol O₂

Step 2: Identify Conversions

[RxN] 2 mol KClO₃ (s) → 3 mol O₂ (g)

Step 3: Stoichiometry

Answer:

cell, nucleus , chromosome, DNA, gene

Answer:

9.05 g

Explanation:

PV=nRT

Use the ideal gas equation. Substitute values.

P = 5 atm

V = 1.50 L

n = ?

R (gas constant) = 0.08206 L-atm/mol-K

T = 20.0°C

*Always convert °C to K.

T = 20.0° + 273 = 293K

Substitute values.

(5 atm)(1.50 L) = n(0.08206 L-atm/mol-K)(293K)

n = (5 atm)(1.50 L) / (0.08206 L-atm/mol-K)(293K)

n = 0.3119335... mol

Convert to grams with the given average mass of air.

0.3119335... mol x (29.0 g/1 mol) = 9.05 g

Explanation:

Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves.

This means that if you know how many moles of solute you have in the target solution, you also know how many moles of solute were present in the stock solution sample.

Use the molarity and volume of the target solution to determine how many moles of hydrochloric acid,

HCl

, you need in that solution

c

=

n

V

⇒

n

=

c

⋅

V

n

HCl

=

0.10 M

⋅

500

⋅

10

−

3

L

=

0.050 moles HCl

Now the question is - what volume of stock solution would contain this many moles of hydrochloric acid?

c

=

n

V

⇒

V

=

n

c

V

stock

=

0.050

moles

12

moles

L

=

0.0041667 L

I'll leave the answer rounded to two sig figs, despite the fact that you only gave one sig fig for the volume of the target solution

V

stock

=

4.2 mL.follow me

Answer:

Balloon filled with helium is not a mixture because the gas in it consists of solely helium atoms.

Explanation:

Explanation:

An element is a pure substance as well, because if we fill up a balloon with just helium gas, it will only contain helium atoms.

Answer:

7. Ionization energy

8. Lattice energy

9. Free energy

10. Activation energy

Explanation:

I. Ionization energy: The energy required to convert a ground-state atom in the gas phase to a gaseous positive ion. Thus, it is the minimum energy required to remove or detach an electron from a neutral atom in a gaseous state. Generally, atoms with relatively large atomic radii tend to have a low ionization energy.

II. Lattice energy: The energy change that occurs in the conversion of an ionic solid to widely separated gaseous ions. This ultimately implies that, it is the energy generated during the conversion of an ionic solid into gaseous ions and as such is a measure of the cohesive force binding the ions of an ionic compound using the Born-Haber cycle.

III. Free energy: the energy in a chemical or physical change that is available to do useful work. Thus, it is a thermodynamic quantity that measures the maximum capacity of a system to do work at constant temperature and pressure.

IV. Activation energy: The energy required to form the transition state in a chemical reaction. When the activation energy of a reaction is low, the rate of the reaction would be faster. Therefore, an enzyme speeds or catalyzes the rate of a reaction by lowering its activation energy.

Answer: it think the answer is c.) The cell gets help from white blood cells or b.) The cell gets help from its neighbor cells.

Explanation:

Answer: 15 grams of salt are there in 5 L of solution.

Explanation:

Concentration of a solution is defined as the number of grams of solute dissolved per liter of the solution.

Given : Concentration of solution : 3 g/L

1 Liter of solution contains = 3 gram of salt

Thus 5 L of solution contains = [tex]\frac{3g}{1L}\times 5L=15g[/tex]

Thus 15 grams of salt are there in 5 L of solution.

Answer:

it is closer to the south pole

Explanation:

Answer:

True

Explanation:

Answer:

i dont know i do this for points

Explanation:

h^ ar hidrojen oksijen azot helyum

Answer:

ok i dont get your question fully but i'll answer

When copper sulfate is dissolved in water in a beaker, a bright blue liquid or solution is formed. If copper sulfate is added until no more will dissolve, a saturated solution is formed. And some blue crystals will remain at the bottom of the beaker due to crystallization reaction. It is the process by which a solid form, where the atoms or molecules are highly organized into a structure known as a crystal.

Answer:

See explanation

Explanation:

Usually, when we write a chemical formula for any compound or other chemical specie, we use subscripts to;

Hence, the subscripts written after chemical formulas have more than one function as described above.

In H2SO4 for instance, there are two hydrogen atoms, one sulphur atom and four oxygen atoms as shown in the chemical formula.

Answer:

8.11

Explanation:

pH = -log[H+]

pH = -log[7.8 x [tex]10^{-9}[/tex]]

pH = 8.107905...

pH = 8.11

Answer:

[tex]T_{EQ}=37\°C[/tex]

Explanation:

¡Hola!

En este caso, para los problemas de equilibrio térmico, consideramos que la energía liberada por la sustancia que inicialmente está caliente (agua), es absorbida por la sustancia que inicialmente está fría (alcohol); thus, we can write:

[tex]Q_{agua}=-Q_{alcohol}[/tex]

La cual puede ser escrita en términos de masa, calor specifico y temperaturas:

[tex]m_{agua}C_{agua}(T_{EQ}-T_{agua})=-m_{alcohol}C_{alcohol}(T_{EQ}-T_{alcohol})[/tex]

De este modo, al resolver para la temperature de equilibrio térmico, obtenemos la siguiente expresión:

[tex]T_{EQ}=\frac{m_{agua}C_{agua}T_{agua}+m_{alcohol}C_{alcohol}T_{alcohol}}{m_{agua}C_{agua}+m_{alcohol}C_{alcohol}}[/tex]

Así, al reemplazar los valores en esta, obtenemos:

[tex]T_{EQ}=\frac{(20g)(1cal/g\°C)(40\°C)+(15g)(0.58cal/g\°C)(30\°C)}{(20g)*(1cal/g\°C)+(15g)(0.58cal/g\°C)} \\\\T_{EQ}=37\°C[/tex]

¡Saludos!

Answer:

The volume of the gas will be 814 mL.

Explanation:

An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.

Charles's Law consists of the relationship that exists between the volume and the temperature of a certain quantity of ideal gas, which is kept at a constant pressure, by means of a constant of proportionality that is applied directly. For a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement of the gas molecules. .

In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the quotient that exists between the volume and the temperature will always have the same value:  

[tex]\frac{V}{T} =k[/tex]

It is desired to study two different states, an initial state and an final state. You have a gas that is at a volume V1 and at a temperature T1 at the beginning of the experiment. When the temperature varies to a new T2 value, then the volume will change to V2, and the following will be true:

[tex]\frac{V1}{T1} =\frac{V2}{T2}[/tex]

In this case:

Replacing:

[tex]\frac{752 mL}{298 K} =\frac{V2}{323 K}[/tex]

Solving:

[tex]V2= 323 K*\frac{752 mL}{298 K}[/tex]

V2= 815 mL

The volume of the gas will be 814 mL.

Answer: 46.66 Grams

Explanation:

Credits to jasminealexismacias, Enjoy your CK12

Answer:

An element's mass number (A) is the sum of the number of protons and the number of neutrons. The small contribution of mass from electrons is disregarded in calculating the mass number.

Answer:

c

Explanation:

A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.

chemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances.

A chemical reaction is one in which  two or more reactants will react to form a new substance. When new substance will form it will produce heat. Therefore, when science teacher was mixing two liquids it was generating heat.

Heating a substance allow molecules to move faster. When heat is given to the object it will move fast. When heat will apply to a solid it will turn into liquid. When heat is supplied to the liquid it will turn into gas.

Therefore, A chemical reaction produced a new substance. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.

To learn more about chemical reaction, refer to the link:

https://brainly.com/question/22817140

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Answer:

The variable Q

Explanation:

i just took the test and got it right.... i hope this helps :)

The variable Q represents thermal energy in the equation Q = mcΔT. Hence, option B is correct.

The specific heat capacity is defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases by 1 K (or 1 °C), and its units are J/(kg K) or J/(kg °C).

Q =  mcΔT

Q = heat energy

m = mass

c = specific heat capacity

ΔT = change in temperature

Hence, option B is correct.

Learn more about specific heat capacity here:

brainly.com/question/2530523

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Answer:

A. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

B. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

C. Particle emitted = beta particles; protons gained = 1; Change in mass = 0

D. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

E. Particle emitted = gamma ray; protons gained = 0; Change in mass = 0

F. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

Explanation:

Radioactivity is the spontaneous disintegration of nucleus of an atom resulting in emission of particles and radiation unyil a stable atomic nuclei is obtained. Substances that are exhibit radioactivity are known as radioactive substances and are usually isotopes of stable atoms.

The types of radiation emitted by a radioactive substances include alpha rays, beta rays, and gamma rays.

Alpha rays or particles are fast moving positively charged particles with a mass number of four and atomic number of two. Thus, each alpha particle is a helium nucleus.

Beta rays or particles are vary fast moving stream of electrons having a mass number of zero and a charge of -1.

Gamma rays are not particles but are electromagnetic waves similar to visible light and X-rays but with shorter wavelengths. They have no mass or charge.

An atom emitting alpha particles has its mass reducing by 4 units and its atomic number decreasing by 2.

An atom emitting beta particles as it decays has no change in mass but its atomic number increases by 1.

From the table:

A. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

B. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

C. Particle emitted = beta particles; protons gained = 1; Change in mass = 0

D. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

E. Particle emitted = gamma ray; protons gained = 0; Change in mass = 0

F. Particle emitted = alpha particle; Protons lost = 2; Change in mass = -4

Answer:

C: Warm water is denser than cold water

N2 +H2 →2 NH3

"Reactants Products Nitrogen 2 2 Hydrogen 2 6 Since NH3 is multiplied by a coefficient of 2 there are now 2 nitrogens and 6 hydrogens. The 6 hydrogens come from the 2 multiplied by the subscript of 3."