Please help I will mark brainy

Answer:

117g

Explanation:

Given parameters:

Number of moles = 2moles

Unknown:

Mass of NaCl  = ?

Solution:

To solve the problem, we need to use the expression below;

    Mass of NaCl  = number of moles x molar mass

Molar mass of NaCl  = 23 + 35.5  = 58.5g/mol

So;

Insert the parameters and solve;

     Mass of NaCl  = 2 x 58.5  = 117g

Answer:

Volume

Mass

Size

Weight

Length

Explanation:

Extensive properties do depend on the amount of matter that is present. An extensive property is considered additive for subsystems. Examples of extensive properties include:

Volume

Mass

Size

Weight

Length

1. solute is the substance that is being dissolve,while solvent is dissolving medium

2.saturated is solution that contain maximum amount of solut that capable of being dissolve and supersaturated is solution that contain less amount or medium of solut that capable being dissolve : example vinger

3. is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2 H2, and two molecules of water would be written 2 H2O . yes it's can be change only in caseWhen you balance an equation you can only change the coefficients

Answer:

630gC₆H₁₂

Explanation:

How many grams are in 7.5 moles of C₆H₁₂?

C₆:12.011×6=72.066

H₁₂:1.008×12=12.096

72.066+12.096=84.162

84.162g/mol C₆H₁₂

7.5 molC₆H₁₂ ×84.162g/molC₆H₁₂= 631.215gC₆H₁₂

Answer:

First question

       [tex]Q = 36826 \ J[/tex]

Second  question  

       [tex]Q = 52299.7 \ J[/tex]

Explanation:

From the question we are told that

     The melting point of Ethanol is  [tex]T_m = -114 ^oC[/tex]

      The boiling point of Ethanol is  [tex]T_b = 78^ oC[/tex]

       The enthalpy of fusion of Ethanol is [tex]F = 5.02 \ kJ / mol = 5.02 *10^{3}\ kJ / mol[/tex]

        The enthalpy of vaporization  of Ethanol is [tex]L = 38.56 \ kJ / mol = 38.56 *10^{3} \ J / mol[/tex]

         The specific heat of solid Ethanol is  [tex]c_e = 0.97 \ J/ g \cdot K[/tex]

          The specific heat of liquid  Ethanol is [tex]c_l = 2.3 \ J / g \cdot K[/tex]

           The mass of the Ethanol given is  [tex]m = 35.0 \ g[/tex]

Considering the first question

           The initial  temperature is [tex]T_i = 27^oC[/tex]

             The final  temperature is  [tex]T_f = 120^oC[/tex]

Generally the heat required too raise the Ethanol to its boiling point is mathematically represented as

       [tex]Q_1 = m * c_l * (T_b - T_i)[/tex]

=>      [tex]Q_1 = 35.0 * 2.3 * ( 78 - 27)[/tex]

=>      [tex]Q_1 =4106 \ J[/tex]

Genially the number of moles of Ethanol given is mathematically represented as

         [tex]n = \frac{m}{Z}[/tex]

Here Z  is the molar mass of Ethanol  with value  [tex]Z = 46 g/mol[/tex]

So

         [tex]n = \frac{35}{46 }[/tex]

=>      [tex]n = 0.7609 \ mol[/tex]

Generally the heat of vaporization of the Ethanol is mathematically represented as

         [tex]Q_2 = n * L[/tex]

=>        [tex]Q_2 =0.7809 * 38.56 * 10^{3}[/tex]

=>        [tex]Q_2 =29339 \ J[/tex]

Generally the heat required too raise the Ethanol from  its boiling point to  [tex]T_f[/tex]  is  mathematically represented as

       [tex]Q_3 = m * c_l * (T_f - T_b)[/tex]

=>     [tex]Q_3 = 35 * 2.3 * (120 - 78 )[/tex]

=>     [tex]Q_3 = 3381 \ J[/tex]

Generally the total heat required is  

     [tex]Q = Q_1 + Q_2 + Q_3[/tex]

=>   [tex]Q = 4106 + 29339 + 3381[/tex]

=>   [tex]Q = 36826 \ J[/tex]

Considering the second question

           The initial  temperature is [tex]T_i = -120^oC[/tex]

             The final  temperature is  [tex]T_f = 120^oC[/tex]

Generally the heat required too raise the Ethanol to its melting  point is mathematically represented as

       [tex]Q_1 = m * c_e * (T_m - T_i)[/tex]

=>      [tex]Q_1 = 35.0 * 0.97 * ( -114 - (- 120) )[/tex]

=>      [tex]Q_1 = 203.7 \ J[/tex]

Generally the heat of fusion  of the Ethanol is mathematically represented as

                 [tex]Q_2 = n * F[/tex]

=>        [tex]Q_2 =0.7809 * 5.02 *10^{3}[/tex]

=>        [tex]Q_2 =3920 \ J[/tex]

Generally the heat required too raise the Ethanol to its boiling point is mathematically represented as

       [tex]Q_3 = m * c_l * (T_b - T_m)[/tex]

=>      [tex]Q_3 = 35.0 * 2.3 * ( 78 - (- 114) )[/tex]

=>      [tex]Q_3 =15456 \ J[/tex]

Generally the heat of vaporization of the Ethanol is mathematically represented as

         [tex]Q_4 = n * L[/tex]

=>        [tex]Q_4 =0.7809 * 38.56 * 10^{3}[/tex]

=>        [tex]Q_4 =29339 \ J[/tex]

Generally the heat required too raise the Ethanol from  its boiling point to  [tex]T_f[/tex]  is  mathematically represented as

       [tex]Q_5 = m * c_l * (T_f - T_b)[/tex]

=>     [tex]Q_5 = 35 * 2.3 * (120 - 78 )[/tex]

=>     [tex]Q_5 = 3381 \ J[/tex]

Generally the total heat required is  

     [tex]Q = Q_1 + Q_2 + Q_3+Q_4 + Q_5[/tex]

=>   [tex]Q = 203.7 + 3920 + 15456 +29339+3381[/tex]

=>   [tex]Q = 52299.7 \ J[/tex]

Answer:

to find the number of electrons an element has locate it on the periodic table of elements find the atomic number and note the number of protons because they are naturally electrically neutral

Answer:

M-A=N

Explanation:

M-A=N

Here is an example.

The equation above means that the atomic number (A) subtracted from the average atomic mass (M) equals the combined amount of neutrons and protons. Since we know that 35 17Cl is Chlorine (this is because Chlorine (Cl) is the 17th number on the periodic table and has the average atomic mass of 35), we can insert our data into the equation and end up with the following:

35-17=18.

From here, we can tell that we have a mix of neutrons and protons, with the total being 18. Since the atomic number is 17, we can reasonably assume that there are 17 protons and 1 neutron.

But we still need to find the number of electrons. Fortunately, the number of electrons is always equivilant to the number of protons and the atomic mass, so we know that the number of electrons is 17.

So, we have;

17 Protons

1 Neutron

17 Electrons

Answer:

The laboratory demonstration consists of the following;

The compounds present in the combustion reaction = Methane, CH₄ and Oxygen, O₂

The chemical equation for the combustion reaction is given as follows;

CH₄ + 2O₂ → CO₂ + 2H₂O

Therefore;

A. The equation given as CH₄ + O → CO₂ is not correct because;

1) Oxygen gas exist as diatomic molecules, O₂, and given that the experiment involves the mixture of gases, the oxygen gas present which can exist as a separate compound, should be represented as O₂

2) The number of oxygen molecules in the reaction is two rather than one

3) The product also includes two molecules of water (vapor) H₂O

B. The correct equation for the reaction should be given as follows;

CH₄ + 2O₂ → CO₂ + 2H₂O

B i) The constituents of the equation is obtained by the knowledge of the fact that the combustion reaction of an organic substance such as methane in the presence of oxygen yields, carbon dioxide and water (vapor)

The equation showing the relative amounts the reacting compounds is by balancing the basic equation of the combustion of methane in the presence of oxygen

Explanation:

Explanation:

I think its a solution just me tell me in comments if right

Answer:

A solution

Explanation:

Sugar is soluble in water and would dissolve into the water to form a solution.

Answer:

B. Most potential energy

Explanation:

brainest plz

Answer:

The answer would either be Carbon or Silicon.

Explanation:

Answer:

I believe they can if it's a small town/village

Explanation:

Answer:

"A combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat. Combustion reactions must involve O2 as one reactant. The combustion of hydrogen gas produces water vapor." and "A synthesis reaction occurs when two or more reactants combine to form a single product. ... In a double replacement reaction, two compounds exchange elements. A combustion reaction occurs when a substance reacts quickly with oxygen. Combustion is commonly called burning"

Explanation:

I tried

Answer:

the full viral genome is retained in the host cell, but its expression is dramatically restricted, such that few viral antigens and no viral particles are produced.

Explanation:

Answer:

alpha decay, beta decay, gamma decay

Explanation:

i believe you meant particles*

Answer:

Elements are made of only one kind of atom

Compounds are made of 2 or more elements chemically bonded together

Explanation:

Its right there????

Answer:

They show you  how to do it sweetie

Explanation:

123456789 Common math

A “supersaturated” solution contains more dissolved material. supersaturated solutions lies in the temperature of the water. more sugar will dissolve in hot water than in cold. Meaning that by separating the 2, only the supersaturated sugar would dissolve leaving the regular sugar untouched.

Answer:

The official measurement unit for energy is the Joule (J). Among the most common units measuring energy mention should be made of the kilowatt/hour (kWh), used especially for electric energy (in fact it is used to calculate electricity bills).

Answer:

I believe its A. Mass

Explanation:

An intensive property is a property of matter that depends only on the type of matter in a sample and not on the amount. For example, the electrical conductivity of a pure substance is a property that depends only on the type of substance. Silver, gold, and copper are excellent conductors of electricity, while glass and plastic are poor conductors.. Other intensive properties include color, temperature, density, and solubility.

Answer:

B. Magnetism

Explanation:

Hope this helps! :))
Sorry for late answer

Answer:

a1

The main difference between SPECT and PET scans is the type of radiotracers used. While SPECT scans measure gamma rays, the decay of the radiotracers used with PET scans produce small particles called positrons. A positron is a particle with roughly the same mass as an electron but oppositely charged.

Explanation:

a2

While imaging tests such as X-rays can show what the structures inside your body look like, a SPECT scan produces images that show how your organs work. For instance, a SPECT scan can show how blood flows to your heart or what areas of your brain are more active or less active.

a3

PET and SPECT have been extensively evaluated as diagnostic procedures for dementia. Substantial progress has been made in developing radioligands that bind to amyloid deposits in the brain, which should provide new opportunities for early diagnosis and treatment monitoring in Alzheimer's disease

a4

What are the disadvantages of spect as compared to pet?

However, SPECT has issues, including long scan times and low-resolution images prone to artifacts and attenuation. Some artifacts can easily be misidentified as perfusion defects. SPECT also does not provide a quantifiable estimate of the blood flow, whereas PET does, experts say.

Answer:

not sure about the first one, but i know SDS provides information about the last 3.

Explanation:

The molecular mass​ : 81.72 g/mol

In general, the gas equation can be written  

[tex]\large {\boxed {\bold {PV = nRT}}}[/tex]

where  

P = pressure, atm , N/m²

V = volume, liter  

n = number of moles  

R = gas constant = 0.082 l.atm / mol K (P= atm, v= liter),or 8,314 J/mol K (P=Pa or N/m2, v= m³)

T = temperature, Kelvin  

P = 760 mmHg=1 atm

T = 300 K

V = 0.3 L

Number of moles :

[tex]\tt n=\dfrac{PV}{RT}\\\\n=\dfrac{1\times 0.3}{0.082\times 300}\\\\n=0.0122[/tex]

The molecular mass (MW) :

[tex]\tt MW=\dfrac{mass}{n}\\\\MW=\dfrac{0.997~g}{0.0122}\\\\MW=81.72~g/mol[/tex]

Answer:

See explanation

Explanation:

If we look at the electron configuration closely, we will discover that the element must have had a ground state electron configuration of 2,4.

This is because, the innermost shell usually holds two electrons while the outer shells hold eight electrons each. The four electrons must be accommodated in the second shell in the ground state configuration of the compound.

However, when the atom is excited, one electron from this shell may move to the third shell to give the excited state configuration 2-3-1 as shown in the question.