A new student is planning to use thin layer chromatography (TLC) for his research project. After setting up the apparatus the student forgets to place a lid on the TLC jar. He obtains poor results after running the TLC experiment. Which of the following can best explain his bad results?
A. The open system evaporates the solvent on the TLC plate
B. The open system prevents the evaporation of the solvent in the solution
C. The open system prevents the evaporation of the solvent on the TLC plate
D. The open system evaporates the solvent in the solution

Answer:

the TWO characteristics of an effective collision are:

1.Molecules collide with sufficient energy

2.Molecules collide with the proper orientation.

Answer:

Wide melting point range - impure sample with multiple compounds

Experimental melting point is close to literature value - pure sample of a single compound

Experimental melting point is below literature value - impure sample with multiple compounds

Narrow melting point range - pure sample of a single compound

Explanation:

The melting point of substances are easily obtainable from literature such as the CRC Handbook of Physics and Chemistry.

A single pure substance is always observed to melt within a narrow temperature range. This melting temperature is always very close to the melting point recorded in literature for the pure compound.

However, an impure sample with multiple compounds will melt over a wide temperature range. We also have to recall that impurities lower the melting point of a pure substance. Hence, the experimental melting point of an impure sample with multiple compounds is always below the literature value.

Answer:

"The total pressure in a mixture of gases is equal to the sum of partial pressures of each gas"

Explanation:

Dalton's law of partial pressures state that, in a mixture of gases, the total pressure is equal to the sum of the partial pressure exerted by each gas of the mixture. The equation is:

Total pressure = Partial pressure Gas 1 + Partial pressure Gas 2 + .... + Partial pressure Gas n

To complete the sentence we can say:

"The total pressure in a mixture of gases is equal to the sum of partial pressures of each gas"

Considering the Dalton's partial pressure, the total pressure in a mixture of gases is equal to the sum of partial pressures of each gas.

The pressure exerted by a particular gas in a mixture is known as its partial pressure. So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone:

[tex]P_{T} =P_{A} +P_{B}[/tex]

This relationship is due to the assumption that there are no attractive forces between the gases.

Dalton's partial pressure law can also be expressed in terms of the mole fraction of the gas in the mixture. The mole fraction is a dimensionless quantity that expresses the ratio of the number of moles of a component to the number of moles of all the components present.

So in a mixture of two or more gases, the partial pressure of gas A can be expressed as:

[tex]P_{A} =x_{A} P_{T}[/tex]

In summary, the total pressure in a mixture of gases is equal to the sum of partial pressures of each gas.

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Characteristic properties are used because the sample size and the shape of the substance does not matter.

Answer:

Hence, option B is correct. 1 and 2

Explanation:

NH 4 Cl is a weak base-strong acid salt.

NaCN is a salt of a strong base (NaOH) and weak acid (HCN).In water,

1. NH 4 Cl produces acidic solution

2. KHSO 4 produces acidic solution

because the neutral salt of strong base KOH and strong acid H 2 SO 4 is K 2 SO 4

3. NaCN produces basic solution

4. KNO

3 produces neutral solution

I think this is right but I hope its help ,ur welcome ♥️♥️

Answer:

H+

Explanation:

I took the test :)

Answer:

C. To remove any source of bias in an experience

Answer:

CuCo3+CaSo4

Explanation:

when they react they form that compound in the reaction called double displacement.

Answer:

A) 1.3 × 10⁻⁵ mol/L

Explanation:

Step 1: Write the balanced equation for the solution of AgCl

AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)

Step 2: Make an ICE Chart

        AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)

I                           0             0

C                        +S            +S

E                          S              S

If we replace the solubility (S) in the Ksp expression, we get,

Ksp = [Ag⁺] [Cl⁻] = S × S = S²

S = √Ksp = √1.8 × 10⁻¹⁰ = 1.3 × 10⁻⁵ mol/L

Answer:

7 L of H₂.

Explanation:

The balanced equation for the reaction is given below:

2H₂ + O₂ —> 2H₂O

From the balanced equation above,

1 L of O₂ required 2 L of H₂.

Finally, we shall determine the volume of H₂ required to react with 3.5 L of O₂. This can be obtained as follow:

From the balanced equation above,

1 L of O₂ required 2 L of H₂.

Therefore, 3.5 L of O₂ will require

= 3.5 × 2 = 7 L of H₂.

Thus, 7 L of H₂ is required to for the reaction.

Answer:

Explanation:

The pH of a solution can be found by using the formula

[tex]pH = - log [ { H_3O}^{+}][/tex]

From the question we have

[tex]ph = - log(7.8 \times {10}^{ - 13} ) \\ = 12.1079...[/tex]

We have the final answer as

Hope this helps you

The pH of this solution with a 7.8 × 10⁻¹³ M concentration of hydronium ion is equal to: D. 12.

Given the following data:

Concentration of hydronium ion = 7.8 × 10⁻¹³ M.

pH is literally the power of hydrogen ions and it can be defined as a measure of the molar concentration of hydrogen ions in a given solution.

We would determine the pH of this solution by using this formula;

pH = -log[H⁺]

pH = -log(7.8 × 10⁻¹³).

pH = -(-12.1)

pH = 12.1 ≈ 12.

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Answer:

tge answer is a

Explanation:

I'm smart like that

Answer:

soy....plant protein also is found in vegtables and grain products.

The protein that is derived from the plant is soyabean. Protein-rich foods have a rich source of amino acids. Amino acids are required by the body for different cellular activities.

Proteins are present in plant-based foods and animal-based foods. In nature, the plant-based foods that are rich in proteins are soybeans, beans etc. Animal products such as dairy products, milk, and cheese are rich sources of proteins.

Animal-based foods such as eggs, meat, and fish have a good amount of protein. The proteins are made up of amino acids. Peptide bonds connect each amino acid to the next.

Proteins are necessary for the body, as cells need amino acids for both structural and functional support. Not all cells of the body synthesise all amino acids. Some essential amino acids are required by the body and can be taken from external sources such as plants.

Hence, the plant-based protein is soyabean.

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The question is incomplete; the complete question may be the following:

1) Which of the following is a protein source of plant origin?

A)egg

B) Soyabean

C)cheese

D)Milk

Answer:

Exothermic

1771 g

Explanation:

Step 1: Write the balanced thermochemical equation

2 S(s) + 3 O₂(g) ⇒ 2 SO₃(g)   ΔH° = -791.4 kJ

Since ΔH° < 0, the reaction is exothermic.

Step 2: Calculate the moles of SO₃ produced when 8753 kJ of energy are released

According to the thermochemical equation, -791.4 kJ are released every 2 moles of SO₃ that are formed.

-8753 kJ × 2 mol/(-791.4 kJ) = 22.12 mol

Step 3: Calculate the mass corresponding to 22.12 moles of SO₃

The molar mass of SO₃ is 80.06 g/mol.

22.12 mol × 80.06 g/mol = 1771 g

Answer:

Hi so your answer is that to helping fix the climate change you have to : speak up , power your home with renewable engery , reduce water waste , dont waste food , and finally invest energy .

Explanation:

Really hope i helped , have a nice day :)

Answer:

we can reduce air pollution,which is one of the main cause of climate change.Climate change is not a hoxe if it is not attending the upcoming generations will suffer greatly.

4,032

BT electron

nSO2= 3nFe/

Answer:

Below

Explanation:

Got it right

Check the periodic table, then click electrons

Answer:

A

Explanation:

Explanation:

the answer is in the above image

Answer:

the mass of salt

Explanation:

In an experiment, we have an independent variable and dependent variable. The independent variable is the variable that is manipulated to cause changes in other variable while the dependent variable is the variable that responds to the changes made to the independent variable and is measured.

In this case of experiment, the mass of the salt is the DEPENDENT VARIABLE while the different temperatures is the INDEPENDENT VARIABLE. In a graphical representation, the independent variable is always plotted on the x-axis or horizontal axis while the dependent variable is always plotted on the y-axis or vertical axis.

Since the dependent variable is the mass of the salt, it should be plotted on the y axis.

Answer:

The temperature of water

Explanation:

I took the test

Answer:

Explanation:

1 Mole of Aluminum with mass 26.98g contains 6.02*10^23 atoms.

In 2.88g of Aluminum, there are 2.88/26.98*6.02*10^23 = 6.426*10^22 atoms.

Answer:

Explanation:

no of Al atoms = 2.88/26.98*6.02*10^23

= 6.426*10^22

= 6.43*10^22

Answer:

hey there

Explanation:

CN- (aq) + H+ (aq) → HCN(I)

The reactants are aqueous solutions:

NaCN(aq) and HBr(aq)

When you mix these compounds you make pure HCN (I)

The molecular equation is:

NaCN(aq) + HBr(aq) → NaBr(aq) + HCN(I)

When you dissociate the reactants, you have: Nat(aq) +CN¯(aq) + H*(aq) + Br−(aq) → Nat(aq) + ->

Br (aq) + HCN(I)

Sodium bromide, it is a salt, that can also be

dissociated in the solution

To make, the net ionic equation you remove the repeated ions

CN- (aq) + H+ (aq) → HCN(I)

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Answer:

MgO

Explanation:

Explanation:

the answer is in the image above

Answer:

you don't know the answer?ha me too

Hydrogen sulfide ions, dihydrogen phosphate, and water are amphoteric. Therefore, option (a), (c), and (d) are correct.

Amphoteric can be stated as any compound that can be mixed with other compounds both as a base and an acid. Water is amphoteric as it can be transformed into a compound that can be mixed as an alkali or an acid.  

Amphoterism is explaining the reactivity of a compound that indicates alkaline nature when mixed with an acid and describes acidic characteristics in an alkaline environment.

When acid reacts with water, it forms H₃O⁺ ion adding an H⁺ ion from the acid. When water is combined with a base, it donates a hydrogen H⁺ ion to the base and releases a hydroxide ion.

Besides water, there are many oxides and hydroxides are utilized in amphoterism. The substances that have both characteristics acids are proton donors and bases are proton acceptors are identified as amphoteric substances.

Therefore, HS⁻, H₂O, and H₂PO₄⁻ are amphoteric in nature.

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Answer:

C it requires a specific glycoprotein for its absorption.

Out of the following statements concerning vitamin B12 the only statement which is correct- it requires a specific glycoprotein for its absorption.

Let's study some facts about vitamin B12:

⇒First, hydrochloric acid in the stomach separates vitamin B12 from the protein that it's attached to.

⇒Second, the freed vitamin B12 then combines with a protein made by the stomach, called intrinsic factor, and the body absorbs them together.

⇒intrinsic factor, transcobalamin (also known as transcobalamin II), and haptocorrin (also known as the R-protein or transcobalamin I).

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