Having a control group is important when doing an investigation why?

Answers

Answer 1

Answer:to help understand the stuff more

Explanation:

Answer 2
Mark Brainliest please

Answer :

Dependent variable depends on the independent variable. ... In a control group in an experimental investigation the independent variable is omitted. Thus the goal is to test if the dependent variable shows any change in the absence of the independent variable.

Related Questions

Question 3: Functional Groups
Identify the type of molecule from the name of the molecule.

Answers

Answer:

1. Organic Alcohol

2. Ester (specifically acetate ester)

3. Organic Alcohol

4. Carboxylic acid

5. Ketone

6. Ether

7. Amine

Explanation:

You can tell what type it is both from the nomenclature and looking at the functional group on the molecular structure. Hope this helps!

Mother is frying fish in the kitchen. The aroma of fried fish can be smelled by Sofea who is sitting in the living room. Explain how the aroma of the fried fish reach the living room.​

Answers

Answer:

through process of diffusion

Explanation:

air particles and odours move freely in all directions and eventually spreads out thus reaching the sitting room

The process of diffusion causes the particles of the aroma of the fried fish to reach the living room.

What is diffusion?

Diffusion can be described as the net movement of anything such as molcules, or energy from a region of higher concentration to a region of lower concentration. Diffusion is generally driven by a gradient in Gibbs free energy or chemical potential.

The concept of diffusion can be used in fields such as physics, chemistry, biology, sociology, economics, and finance. The central idea of diffusion is common that a substance undergoing diffusion spreads out from a point or location at which there is a higher concentration of that substance.

A gradient can be defined as the change in the value of an amount such as concentration, pressure, or temperature with a change in another variable, distance.

A change in concentration over a distance is known as a concentration gradient, and a change in pressure over a distance is known as a pressure gradient.

The Latin word diffusion means "to spread out." Therefore, the aroma of the fried fish diffuses and reaches to lining room.

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Realiza los cálculos para determinar la cantidad de KOH 90%, que se necesita para preparar 100 ml de solución 1N.

Answers

Answer:

6.23 KOH 90% son necesarios

Explanation:

Una solución 1N de KOH requiere 1equivalente (En KOH, 1eq = 1mol) por cada litro de solución.

Para responder esta pregunta se requiere hallar los equivalentes = Moles de KOH para preparar 100mL = 0.100L de una solución 1N. Haciendo uso de la masa molar de KOH y del porcentaje de pureza del KOH se pueden calcular los gramos requeridos para preparar la solución así:

Equivalentes KOH:

0.100L * (1eq / L) = 0.100eq = 0.100moles

Gramos KOH -Masa molar: 56.1056g/mol-:

0.100moles * (56.1056g/mol) = 5.61 KOH se requieren

KOH 90%:

5.61g KOH * (100g KOH 90% / 90g KOH) =

6.23 KOH 90% son necesarios

2.
In photosynthesis, which substances are used up, which are produced and which are necessary
but remain unchanged after the reaction?
used up
produced
remain
A
carbon dioxide
water
oxygen
A
8
chlorophylt
carbon dioxide
water
с
oxygen
starch
cellulose
D
water
oxygen
chlorophyll

Answers

D. Water is used up, Oxygen is produced and Chlorophyll is necessary, but remains unchanged.

balance the equation:2Na+3H2O-2NaOH+H2​

Answers

Answer:

2Na + 2H2O → 2NaOH + H2

Explanation:

A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge are the same for both the reactants and the products.

My theoretical yield is 14 grams of water. I actually produced 6 grams of water. What is my percent yield?

Answers

Answer:

Pertaining to the interrogate, the answer to such is acknowledged and henceforth disseminated as 43.0%

Explanation:

To evaluate such, the following must be comprehended:

Percent Yield Calculator:

% Yield = (What You Actually Got / What You Should Theoretically Get) * 100

The following variables may be denoted, as stated within the interrogate:

Yielded/Produced: 6 grams.

Theoretical Yield: 14 grams.

(6 g/14 g) * 100 = 42.8571428571

*Grams measurement cancels*

42.8 ==> 43.0%

Thus, if rounded to the nearest tenth, the percent yield is equivalent to 43.0%.

What is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water?

Answers

The answer is 29.7% view on how to solve

The mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water is 29.7%.

What is mass percent ?

Mass percent is a means to describe a component in a specific combination or to convey a concentration. The mass percentage used to describe the solution composition indicates the mass of solute contained in a given mass of solution.

To determine the mass percent of an element in a compound, we divide the mass of the element in one mole of the compound by the compound's molar mass and multiply the result by 100.

Given:

Number of moles = 0.64 moles

Moles of sodium fluoride = Given mass/molar mass

0.64 moles = Mass / 42

Mass = 26.88gram

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

= 26.88/90.48 × 100

= 29.7 %

Thus, 29.7 % is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water

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Suggest why a young baby needs a lot of calcium

Answers

Babies often need calcium as they prevent bone loss in their later lives. Vitamin D and calcium also helps prevent babies from rickets which causes bow legs, softening of bones, stunted growth and weak muscles.

I need help getting this done

Answers

Answer:

I put the right structures in the pictures for you

A block of dry ice (-40°C) is placed in contact with an ice cube (-10°C).
What will happen, assuming no chemical reactions occur?
O Heat will flow from the ice cube to the dry ice.
O Heat will flow from the dry ice to the ice cube.
O There is no way to tell without a thermometer
O No heat will flow.​

Answers

Explanation:

Answer is that : no heat will flow

Answer:

Heat will flow from the ice cube to the dry ice

Explanation:

Fe + HNO₃ -> Fe(NO₃)2 + H₂​

Answers

Fe + 2HNO3 -> Fe(NO3)2 + H2

what is the gram formula of na2co3

Answers

Answer:

106 gfm

Explanation:

element. number masses

Na. 2 23×2

C. 1. 12

O. 3. 16×3

then add

106 gfm

why atoms of magnet differ from normal atoms?

Answers

Answer:

ones in magnets r close together while others can be spread apart

6.25 g of HCl(g), a strong acid, is dissolved in water to make a 280-ml solution.
Calculate the pH of the resulting solution.

Answers

pH= -log[0,611]= 0,21

Xà phòng hoá hoàn toàn 22,2g hỗn hợp gồm 2 este HCOOC2h5 và ch3cooch3 bằng dung dịch naoh 1m ( đun nóng) thể tích dung dịch naoh tối thiểu cần dùng là

Answers

Answer:

I can't understand your language? can you write in English

I'm sorry

I forgot to add the answers i had to my question (While a balloon is being filled, if the temperature of the air in the balloon increases, what happens to it’s volume)
A) It stays the same
B) It deflates
C) It decreases
D) It increases

Answers

The correct answer is D ... and if the answer was added to the word "explode" .. it would have been more correct .

Formation of HCl from H₂and Cl₂ is example of

photochemical

electrochemical

displacement​

Answers

Answer:

Combination reaction.

Explanation:

The reaction depicted in the question is;

H2 (g) + Cl2 (g) ⟶ 2HCl (l)

Now, this reaction shows that two reactants namely hydrogen and chlorine react to form a single product named Hydrogen chloride. This process is called combination reaction.

calculate molarity, molality and mole fraction of 28 percent aqueous solution of a solute with molar mass 11.5 g per mole and density is 1.25 g per mole

Answers

Explanation:

Aight, I'mma give tell ya an easy way for this question. look at this Forumla

M=

[tex] \frac{10ad}{m} [/tex]

a explains the percentage of aqueous solution

d is the density

m is the molar mass

right, let's just hop to it

M=10×28×1.25/11.5====> M=30.43

The addition of solute particles into a solution causes:

A. the solvent particles to be attracted to the solute particles and to have less kinetic energy.
B. the solute particles to bump the solvent particles out of the solution, making it easier to boil.
C. the solute particles to form seed crystals and make the solution freeze more easily.
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.

Answers

Answer:

D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.

Explanation:

The addition of solute particles results in an increased boiling point.  As the solutes increases so does the energy inside as the solutes add and occupies more space near the surface of the liquid.

How many molecules are in 35.5 grams of carbon dioxide?

Answers

Answer:

you have to use the avogadro's constant of 6.023×10^23 to calculate the number of molecules of carbon dioxide.and you also have to use the molecular mass which is 44.

35.5/44×6.023×10^23

=4.85×10^23

I hope this helps and sorry if it's wrong

What is the energy of a photon emitted with a wavelength of 448 nm?
O A. 2.97 x 10-22 J
O B. 4.44 x 10-19 J
O C. 8.91 x
10-23 J
O D. 1.48 x 10-27 J

Answers

Answer: B is the correct answer

Explanation:

The energy of a photon is 4.44×[tex]10^{-19}[/tex]J for the wavelength of 448 nm.

So, option (B) is correct. This can be calculated by using the energy formula.

The energy of a photon:

The energy of a photon is said to be photon energy. It is directly proportional to the photon's electromagnetic frequency and inversely proportional to the wavelength. If the frequency of the photon is high then its energy is also high.

The energy of a photon, E=hc/λ

Given data:

Given that,

λ = 448nm

h= 6.63×[tex]10^{-34}[/tex]J/s

Calculating the energy:

E = 6.63×[tex]10^{-34}[/tex]×3×[tex]10^8[/tex]/448×[tex]10^-^9[/tex]

E = 4.44×[tex]10^{-19}[/tex] J

Hence option (B) is correct.

Therefore, the energy of a photon emitted with a wavelength of 448nm is  4.44×[tex]10^{-19}[/tex] J.

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Name three metals on the periodic table and their uses
PLS HELP​

Answers

The three main types of metals are
Ferrous metals
Non ferrous metals
And
Alloys

Currently, nuclear energy provides only a small fraction (~10%) of energy used in the United States. In some other places, like France, it is close to 80%. Do you think nuclear energy will ever be a more widely used source of energy in the United States? Why or why not?
PLEASE HELP ASAP PLEASEEE

Answers

Nuclear energy is currently within almost every country becoming a growing source of energy use since it can provide a lot of energy within a short amount of time with little resources used to create it. It is quite possible that within the next few generations that nuclear energy could become a much larger source of energy within the United States. Although, many countries after the leak have resorted to other means of energy sources learning from the mistakes of Japan.

Hope this helps :)

PLZ HELP ME WITH MY WORK​

Answers

Answer:

c. H2 andO2

I think this is the answer not sure ok

Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 0.4 Hg/mL, what is the total mass in kilograms of mercury in the lake

Answers

Answer:

The total mass of mercury in the lake is 631,542.7 kg

Explanation:

Question: The given dimensions of the lake as obtained from a similar question posted online are;

The surface area of the lake, A = 100 mi²

The lake's average depth, d = 20 ft.

The concentration of the mercury, C = 0.4 μg Hg/mL = 0.4 × 10⁻⁶ kg Hg/L

Therefore, we have;

The volume of water mixture in the lake, V = A × d

∴ V = 100 mi² × 20 ft. = 2,787,840,000 ft.² × 20 ft. = 55,756,800,000 ft.³

1 ft³ = 28.31685 L

∴ 55,756,800,000 ft.³ = 55,756,800,000 ft.³ × 28.31685 L/ft.³ = 1.57885675 × 10¹² L

The total mass of mercury in the lake, m = C × V

∴ m = 0.4 × 10⁻⁶ kg Hg/L × 1.57885675 × 10¹² L = 631,542.7 kg

The total mass of mercury in the lake, m = 631,542.7 kg.

Explain which intermolecular force is primarily responsible for the unusually high boiling point of H2OH2O. Compare the strengths of intermolecular forces of attraction present in a sample of liquid water to the strengths of intermolecular forces of attraction present in liquid samples of H2SH2S, H2SeH2Se, and H2TeH2Te. Justify your answer using the information presented in both tables, and complete the statements below.

Answers

Answer:

See explanation

Explanation:

Intermolecular forces are forces of attraction that exist between molecules of a substance in a particular state of matter.

The dominant intermolecular force of attraction in H2O is the hydrogen bond. The hydrogen bond exists between molecules of a substance when the substance is made of hydrogen atoms bonded to atoms of a highly electronegative element. Hence, strong hydrogen bonding accounts for the high boiling point of water.

The magnitude of hydrogen bonding between molecules depends on the electro negativity of the atoms to which hydrogen is bonded.

The more the electro negativity of the atoms to which hydrogen is bonded, the greater the magnitude of intermolecular hydrogen bonding.

Since the electro negativity of elements decrease down the group, the strength of intermolecular hydrogen bonding between the molecules decreases as follows;

H2O> H2S> H2Se> H2Te

How does knowing the reactants and
help you classify a chemical reaction?

Answers

if you know what kind of chemical a reactant is, it can help you to quickly distinguish the chemical reaction.

Ex:

HCl + KOH <---> KCl + H2O

We can look at the reactants and identify that this reaction is an acid-base reaction because HCl is an acid (it gave a proton) and KOH is a base (it accepted the proton)

Answer:

Products

Explanation:

I just got it right.

According to the kinetic molecular theory, what happens to a liquid when it is transferred from one container to another?
ОООО
O The volume and the shape stay the same.
The volume increases to fill the new container, but the shape stays the same.
The volume stays the same, but the shape changes to fit the new container.
The volume and the shape change to fill the new container.

Answers

Answer:

C. The volume stays the same, but the shape changes to fit the new container.

Explanation:

It changes shape to fit the container since it's a liquid.

Calculate the amount of solute excess out when the 60 gm of saturated solution of

NH4Cl having solubility of 57 at 60 ℃ is cooled to 20 ℃ , the solubility being 35.

Answers

Answer:

weight of salt = 90 gram,

solubility = 50

sing formula

solubility of solute =

weightofsolventinsaturatedsolution

weightofsoluteinsaturatedsolution

×100

or 50=

weightofsolventinsaturatedsolutio

90gm

×100

so weight of solvent in saturated solution =

50

90gm

×100=180gm

Hence 180 gm of water is required to prepare a saturated solution.

Although tom was a poor student, he studied very well

Answers

Tom. The ‘T’ should be in capital. Every sentence should end with a full stop ‘.’ . This also has nothing to do with Chemistry. So yeah. Mark me brainliest please.
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