A student conducted an experiment 4 times. His results were very close to each other each time he ran the experiment and
were very close to the true or actual value. His results showed
A. None of these answers are correct
B. poor accuracy and poor precision
C. good accuracy and good precision
D. poor accuracy and good precision
E. good accuracy and poor precision

Answer:

It is difficult because of C

Explanation:

The correct answer is:Some substances keep the same molecular structure when they break down, and others do not.

Some substances change their form when they dissolve and some do not. Dissolution can sometimes be regarded as a sort of reaction between a chemical substance and water.

Usually, we can consider dissolution of a substance in water as a sort of chemical reaction for some substances. For instance, an ionic substance interacts with water to form ions. similarly, some salts become hydrolysed in water and give acidic/basic solutions as  result of that.

However, some substances do not interact with water upon dissolution. They rather remain as molecular entities because they are not composed of ions.

We can see that some substances keep the same molecular structure when they break down, and others do not keep the same molecular structure  when they dissolve hence it is difficult to classify dissolving as a physical or a chemical change.

https://brainly.com/question/1161517

The Adsorbent is used as part of the stationary phase and has an affinity for the solvent and the chemical components of the mixture.

The adsorbent has a high affinity for solvent and the chemical components of the mixture.

Chromatography is a method of separation in which the mixture of substances is introduced into a mobile phase (solvent). The separation occurs as the solvent interacts with an adsorbent(stationary phase).

The extent of separation of the components of the mixture depends on the extent of interaction between the mobile and the stationary phase . This interaction also determines the retention factor (Rf) of the separation.

For a definition of chromatography, see

https://brainly.com/question/19334271

Answer:

"[tex]N^+(g) \rightarrow N^{2+}(g) + e^-[/tex]" is the appropriate answer.

Explanation:

Thus the above is the correct answer.

Answer:

Explanation:

We are to match each land resource to what they are being used for.

Clay             →→→  used to make pottery and tiles

iron ore       →→→  used to make steel

Salt              →→→   used as a flavoring in food

aggregate   →→→   used in construction

graphite       →→→ used to make batteries

Clay is a kind of soil particle that forms as a result of weathering processes. Examples include; pottery clays, glacial clays, and deep-sea clays e.t.c. The presence of one or more clay minerals, as well as variable quantities of organic and detrital components, characterizes all of them. Clay is usually sticky and moist when wet, but hard when dry. They are used in the making of tiles and potteries.

Iron ore:  The iron ore deposits are found in the Earth's crust's sedimentary rocks. They're made up of iron and oxygen that mix during the chemical process in marine and freshwater. iron ores are used to produce almost every iron and steel product that we use today.

Aggregate: are utilized in construction activities. It is a material used to mix cement, gypsum, bitumen, or lime to produce concrete in the construction industry.

Graphite: Graphite is a mineral that occurs in both igneous and metamorphic rocks. It is generally generated on the earth's surface when carbon is exposed to high temperatures and pressures. It is mainly used in the production of batteries and electrodes,

Answer:

Explanation:

I am almost sure that the products are identical.

Answer:

boiling point is the physial property of matter

The option that is showing the physical property of the matter is boiling point, the correct option is C.

A physical property is any measurable property whose value describes the state of a physical system.

Changes in a system's physical properties can be used to describe its transitions between momentary states. Physical properties are also known as observables. They do not have modal properties.

Physical properties include color, phase, odor, and boiling point. Since reactivity with oxygen is dependent on the chemical nature of the object, it is not a physical property.

A compound's physical property is one that can be observed and measured. The chemical composition of a compound is unaffected by a physical property.

Thus, the correct option is C.

For more details regarding physical property, visit:

https://brainly.com/question/18327661

#SPJ6

Answer:

liquid will be evaporated while solid remains

Answer:

Explanation:

Your mom

Answer:

isn’t it reactants and products?

Explanation:

Answer: reactants and products

Explanation:

Explanation:

They are called or known as cations

Answer:

1)In organic chemistry, the bromine test is a qualitative test for the presence of unsaturation (carbon-to-carbon double or triple bonds), phenols and anilines. ... The more unsaturated an unknown is, the more bromine it reacts with, and the less coloured the solution will appear.

2)The equation for incomplete combustion of propane is: 2 C3H8 + 9 O2 → 4 CO2 + 2 CO + 8 H2O + Heat. If not enough oxygen is present for complete combustion, incomplete combustion occurs. The result of incomplete combustion is, once again, water vapour, carbon dioxide and heat. But it also produces carbon monoxide.

Explanation:

3)Propene, also known as propylene, is an unsaturated organic compound with the chemical formula {\displaystyle {\ce {CH3CH=CH2}}}. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor. 

Formula: C3H6

IUPAC ID: Propene

4)Margarines are chemically created during hydrogenation which, until January 1, 2006, relied upon trans fats to solidify their vegetable oils. Food companies have been exploring options for replacing trans fat in partially hydrogenated margarine.

Answer:

One can draw the 3-dimensional structure of an atom once they have the Lewis Structure of an atom. The 3-dimensional geometrical structure of ammonium, NH4+ is referred to as Tetrahedral. ... But the + sign decrees that NH4+ has 8 valence shell electrons, due to the positive ion.

Explanation:

Answer:

5.37% w/w is the mass percent of vinegar assuming a molarity of 0.8935mol/L

Explanation:

Assuming the molarity of vinegar is 0.8935mol/L:

Mass percent is defined as 100 times the ratio between mass of solute (In this case, acetic acid), and the mass of the solution

To solve this question we need to find the mass of acetic acid from the moles using the molar mass and the mass of the solution from the volume in liters using the density:

Mass Acetic acid -Molar mass: 60.052g/mol-

0.8935mol * (60.052g / mol) = 53.656g Acetic Acid

Mass Solution:

1L = 1000mL * (1.00g/mL) = 1000g Solution

Mass Percent:

53.656g Acetic Acid / 1000g Solution * 100 =

The mass percent of acetic acid in the original sample of vinegar of molarity 0.8935mol/L is 5.37% w/w.

Mass percent of any solute present in any solution will be calculated as the:

Mass % of solute = (mass of solute / mass of solution) × 100

Let the molarity of vinegar = 0.8935mol/L

Means 0.8935 moles of vinegar present in the 1 liter of the solution.

Now we calculate mass from moles as:

n = W/M, where

W = required mass

M = molar mass = 60.052g /mol

W = (0.8935mol)(60.052g/mol) = 53.656g

Mass of solution = 1L = 1000mL×(1.00g/mL) = 1000g Solution

Then the mass % of acetic acid:

Mass % = (53.656g / 1000g) × 100 = 5.37% w/w

Hence the required % mass is 5.37% w/w.

To know more about mass percent, visit the below link:
https://brainly.com/question/26150306

Answer:

[tex]\%diff=24.0\%[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out firstly necessary for us to set up the van der Waals' equation as shown below:

[tex]p=\frac{RT}{v-b}-\frac{a}{v^2}[/tex]

Thus, we secondly calculate the molar volume as:

[tex]v=\frac{0.8311L}{9.998mol} =0.083L/mol[/tex]

Then, we plug in the entire variables in the vdW equation to get such pressure:

[tex]p=\frac{0.08206\frac{atm*L}{mol*K}*502.7K}{0.08313L/mol-0.03219L/mol}-\frac{1.345L*atm/mol}{(0.08313L/mol)^2}\\\\p=615.2atm[/tex]

And the ideal gas pressure:

[tex]p=\frac{0.08206\frac{atm*L}{mol*K}*502.7K}{0.08313L/mol}\\\\p=496.2atm[/tex]

Finally, the percent difference:

[tex]\%diff=\frac{|496.2atm-615.2atm|}{496.2atm} *100\%\\\\\%diff=24.0\%[/tex]

Regards!

Answer:

6.63 M

Explanation:

NaCl(s) ---> Na^+(aq) + Cl^-(aq)

Given that [Na^+] = [Cl^-] = s

Where s= concentration of the both ions

Ksp = s^2

s= √Ksp

s= √43.9

s= 6.63 M

The concentration of Na (in M) obtained when it begins to crystallize out of solution is 6.63 M

The solubility of product (Ksp) is defined as the concentration of products raised to their coefficient coefficients. This is illustrated below:

mX <=> nY + eZ

Ksp = [Y]^n × [Z]^e

NaCl(aq) → Na⁺(aq) + Cl¯(aq)

Ksp = [Na⁺] × [Cl¯]

43.9 =  y × y

43.9 = y²

Take the square root of both side

y = √43.9

y = 6.63 M

Thus, the concentration of Na⁺ is 6.63 M

Learn more about solubility of product:

https://brainly.com/question/4530083

Explanation:

here's the answer to your question

Iodine's neutral atom has the following electronic configuration: 1 s² 2 s² 2 p⁶ 3 s² 3 p⁶ 4 s² 3 d¹⁰ 4 p⁶ 5 s² 4 d¹⁰ 5 p⁵. The complete ground-state electron configuration of I⁻ is  [Kr]5s² 4d¹⁰ 5p⁶.

Electronic configuration is defined as each electron moves individually within an orbital while being surrounded by an average field produced by all other orbitals. The electron configuration is used to describe an atom's ground state orbitals, but it may also be used to depict an atom that has ionized into a cation or anion by making up for any lost or gained electrons in the orbitals after it.

The ground state electronic configuration is defined as the configuration of lower energy electrons surrounding an atom's nucleus. Ground state is defined as the least energetic state feasible for a physical system.  It is important because permits us to determine the location of the excited electrons' departure and return when they release a photon.

Thus, iodine's neutral atom has the following electronic configuration: 1 s² 2 s² 2 p⁶ 3 s² 3 p⁶ 4 s² 3 d¹⁰ 4 p⁶ 5 s² 4 d¹⁰ 5 p⁵. The complete ground-state electron configuration of I⁻ is  [Kr]5s² 4d¹⁰ 5p⁶.

To learn more about electronic configuration, refer to the link below:

https://brainly.com/question/14283892

#SPJ2

Answer:

1.1 × 10²¹ NH₃ molecules

Explanation:

From the given information:

We were being told that the number of the hydrogen (H) atoms present in the sample of NH3 = 3.3 × 10²¹ hydrogen.

However, it signifies that each molecule of ammonia harbors 3hydrogen (H) atoms.

Hence,  the number of  molecules of NH₃ present;

[tex]\mathsf{=\dfrac{3.3\times 10^{21}}{3} \ molecules \ of \ {NH_3}}[/tex]

= 1.1 × 10²¹ NH₃ molecules

Explanation:

Following are the kinetic theory of gases postulates:

1) Space-volume to molecules ratio is negligible.

2)There is no force of attraction between the molecules at normal temperature and pressure. The force of attraction between the molecules build when the temperature decreases and the pressure increases.

3) There is large space between the molecules resulting in continuous motion.

4) The free movement of molecules results in collision which is perfectly elastic.

5) The molecules have kinetic energy due to random movement. But the average kinetic energy of these molecules differs with temperature.

6) Molecules exert pressure on the walls of the container.

This question is incomplete, the complete question is;

Five kg of carbon dioxide (CO2) gas undergoes a process in a well-insulated piston-cylinder assembly from 2 bar, 280 K to 20 bar, 520 K. If the carbon dioxide behaves as an ideal gas, determine the amount of entropy produced, in kJ/K. Assuming;

a) constant specific heats Cp = 0.939 kJ/Kg K

b) variable specific heats

Answer:

a) the amount of entropy produced is 0.731599 kJ/K

b) the amount of entropy produced is 0.69845 kJ/K

Explanation:

Given the data in the question;

5 kg of carbon dioxide (CO₂) gas undergoes a process in a well-insulated piston-cylinder assembly.

m = 5 kg

Molar mass M = 44.01 g/mol

P₁ = 2 bar, P₂ = 20

T₁ = 280 K, P₂ = 520 K

Since its insulated { q = 0 } ( kinetic and potential energy effects = 0 )

Now,

a) the amount of entropy produced, in kJ/K, Assuming constant specific heats with Cp = 0.939 kJ/Kg K

S[tex]_{Generation[/tex] = m × ((Cp × In( T₂/T₁) - R × In( P₂/p₁ ))

we substitute

S[tex]_{Generation[/tex] = 5 × (( 0.939  × In( 520/280) - 0.1889 × In( 20/2 ))

= 5 × ( 0.5812778 - 0.434958 )

= 5 × 0.1463198

= 0.731599 kJ/K

Therefore, the amount of entropy produced is 0.731599 kJ/K

b) the amount of entropy produced, in kJ/K, Assuming variable specific heats.

Now, from  Table A-23: Ideal Gas Properties of Selected Gases;

T₁,T₂ : s₁⁰ = 211.376 kJ/kmol-K, s₂⁰ = 236.575 kJ/kmol-K

now, s₁ = s₁⁰ / M and s₂ = s₂⁰ / M

we substitute

s₁ = s₁⁰ / M = 211.376 / 44.01  = 4.8029 kJ/kg

s₂ = s₂⁰ / M = 236.575 / 44.01 = 5.37548 kJ/kg

S[tex]_{Generation[/tex] = m × (( s₂ - s₁ ) - R × In( p₂ / p₁ ))

we substitute

S[tex]_{Generation[/tex] = 5 × (( 5.37548 - 4.8029  ) - 0.1880 × In( 20 / 2 ))

= 5 × ( 0.57258 - 0.432885997 )

= 5 × 0.13969

= 0.69845 kJ/K

Therefore, the amount of entropy produced is 0.69845 kJ/K

Answer:

fossil fuels are non-renewable resources .

Answer:

It is known that 1 mol of a molecule contains 6.023×1023 6.023 × 10 23 number of molecules. So, 0.25 moles of CO2 C O 2.

The correct option for the given question about Mole Concept is Na / 2 atom of oxygen.

In 1 mole number of molecules of CO₂ = Na (Avagadro Number)

In 0.25 mole number of molecules of CO₂ = 0.25 × Na molecules

In 1 molecule number of oxygen atom = 2 atom

In 0.25 × Na molecules number of oxygen atom = 2 × 0.25 × Na atom

In 0.25 × Na molecules number of oxygen atom = 0.5 × Na atom

So in 0.25 mole of CO₂ number of oxygen atom = Na / 2 atom

Thus we can conclude that in 0.25 mole of CO₂ number of oxygen atom will be Na / 2, where Na is Avagadro Number.

Learn more about Mole Concept here:

https://brainly.com/question/16488605

#SPJ2

Answer: c

Explanation:   Filtration is technically defined as the process of separating suspended solid matter from a liquid

Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops .

Many commercial juices are filtered to remove fiber or pulp.

The correct answer is C, Pulp.

Orange is an example of a citrus fruit. Every citrus fruit has a pulp. The of pulp a citrus fruit is that stringy content in the endocarp of the fruit .

The pulp of a citrus fruit is where its juice is found.

When you want to prepare orange juice, you need to remove the pulp of the citrus fruit. This is done by filtering out the pulp from the juice.

Filtration is the process of removing larger particles. For a liquid juice, filtration is the process of removing solid particles from the orange juice.

https://brainly.com/question/11403039

Answer:

Propilen là một chất khí không màu với mùi giống như dầu mỏ. Propilen nhẹ hơn nước và tan rất ít trong nước 0.61 g/ . Không hòa tan trong các dung môi phân cực như nước, chỉ tan trong dung môi không phân cực hay ít phân cực.. Propilen không có tính dẫn điện.

Answer:5m

Explanation:Because in the question it say per minute so it would be 5 times m

Answer:

This is an acid-base reaction (neutralization): Ba(OH) 2 is a base, H 2SO 4 is an acid. This is a precipitation reaction: BaSO 4 is the formed precipitate.

Answer:

a. 7.24m

b. 5.15M

c. 53.4mL of the solution would contain this amount of ethanol.

Explanation:

Molality, m, is defined as the moles of solute (ethanol, in this case) per kg of solvent.

Molarity, M, are the moles of solute per kg of solvent

To solve this question we need to find the moles of solute in 100g of solution and the volume using its density as follows:

a. Moles ethanol -Molar mass: 46.07g/mol-:

25g ethanol * (1mol/46.07g) = 0.54265 moles ethanol

kg solvent:

100g solution - 25g solute = 75g solvent * (1kg / 1000g) = 0.075kg

Molality:

0.54265 moles ethanol / 0.075kg = 7.24m

b. Liters solution:

100g solution * (1mL / 0.950g) = 105.3mL * (1L / 1000mL) = 0.1053L

Molarity:

0.54265 moles ethanol / 0.1053L = 5.15M

c. 0.275 moles ethanol * (1L / 5.15moles Ethanol) = 0.0534L =

53.4mL of the solution would contain this amount of ethanol

Explanation:

The given balanced chemical equation is:

[tex]2 HI(g) <--> H_2 (g) + I_2 (g)[/tex]

The value of Kc at 445oC is 0.020.

[HI]=1.5M

[H2]=2.50M

[I2]=0.05M

The value of Qc(reaction quotient ) is calculated as shown below:

Qc has the same expression as the equilibrium constant.

[tex]Qc=\frac{[H_2][I_2]}{[HI]^2} \\Qc=(2.50Mx0.05M)/(1.5M)^2\\Qc=0.055[/tex]

Qc>Kc,

Hence, the backward reaction is favored and the formation of Hi is favored.

Among the given options, the correct answer is option d. Qc is greater than Kc; more HI will be produced.

Answer:

A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.

Explanation:

You have to put energy into a molecule to break its chemical bonds. The amount needed is called the bond energy. After all, molecules don't spontaneously break