Separating techniques - Chromatography
Someone has written rude words in graffiti ink all over the back bench in the Science
classroom where three students usually sit. Miss has said the whole class will forfeit
their lunchtime unless you can find out who the culprit is.
Your task is to plan a detailed investigation into the colours in the graffiti ink and the ink
used by the culprits to find out whose ink wrote the graffiti
You should include:
a List of apparatus required
description of the method used
a labelled diagram of your results
any hazards or risks
a conclusion and evaluation
.
Keywords: soluble solvent chromatography chromatogram separate mixtures colours
To get a higher
mark:
You need to have:
.
.
.
.
Described a method of separation of ink using most of the key words.
Drawn and labelled a diagram of results.
Conducted a full risk assessment.
Described how chromatography is useful
Explained your results and drawn a conclusion
Explained how chromatography works and the uses of chromatography
Explained your choice of separation technique, stating other types of separation
techniques
Suggested any possible problems with the method or in using the results.
• Suggested how the investigation could have been improved.
Compared the distance moved and Rf values for the different pigments in different
solvents and used this data to draw conclusions
Evaluated how good the evidence was in supporting the conclusion

At equilibrium, the number of moles of \(Cl_2\) (g) will be 0.2025 mol.

1: Write the balanced chemical equation:

\(C_O\)(g) + \(Cl_2\)(g) ⟶ \(C_OCl_2\)(g)

2: Set up an ICE table to track the changes in moles of the substances involved in the reaction.

Initial:

\(C_O\)(g) = 0.3500 mol

\(Cl_2\)(g) = 0.05500 mol

\(C_OCl_2\)(g) = 0 mol

Change:

\(C_O\)(g) = -x

\(Cl_2\)(g) = -x

\(C_OCl_2\)(g) = +x

Equilibrium:

\(C_O\)(g) = 0.3500 - x mol

\(Cl_2\)(g) = 0.05500 - x mol

\(C_OCl_2\)(g) = x mol

3: Write the expression for the equilibrium constant (Kc) using the concentrations of the species involved:

Kc = [\(C_OCl_2\)(g)] / [\(C_O\)(g)] * [\(Cl_2\)(g)]

4: Substitute the given equilibrium constant (Kc) value into the expression:

1.2 x \(10^3\) = x / (0.3500 - x) * (0.05500 - x)

5: Solve the equation for x. Rearrange the equation to obtain a quadratic equation:

1.2 x \(10^3\) * (0.3500 - x) * (0.05500 - x) = x

6: Simplify and solve the quadratic equation. This can be done by multiplying out the terms, rearranging the equation to standard quadratic form, and then using the quadratic formula.

7: After solving the quadratic equation, you will find two possible values for x. However, since the number of moles cannot be negative, we discard the negative solution.

8: The positive value of x represents the number of moles of \(Cl_2\)(g) at equilibrium. Substitute the value of x into the expression for \(Cl_2\)(g):

\(Cl_2\)(g) = 0.05500 - x

9: Calculate the value of \(Cl_2\)(g) at equilibrium:

\(Cl_2\)(g) = 0.05500 - x

\(Cl_2\)(g) = 0.05500 - (positive value of x)

10: Calculate the final value of \(Cl_2\) (g) at equilibrium to get the answer.

Therefore, at equilibrium, the number of moles of \(Cl_2\) (g) will be 0.2025 mol.

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Answer: 55.5 oC is 0.014 atm (3rd decimal point)

Explanation:

The Clausius-Clapeyron equation is given as:

ln(P2/P1) = -(ΔH_vap/R) * (1/T2 - 1/T1)

where:

P1 = vapor pressure at temperature T1

P2 = vapor pressure at temperature T2

ΔH_vap = enthalpy of vaporization

R = gas constant = 8.314 J/(mol*K)

Converting the enthalpy of vaporization to J/mol:

ΔH_vap = 35.2 kJ/mol = 35,200 J/mol

Converting temperatures to Kelvin:

T1 = 64.7 + 273.15 = 337.85 K

T2 = 55.5 + 273.15 = 328.65 K

Substituting the values into the equation and solving for P2:

ln(P2/1 atm) = -(35,200 J/mol / 8.314 J/(mol*K)) * (1/328.65 K - 1/337.85 K)

ln(P2/1 atm) = -4.231

P2/1 atm = e^(-4.231)

P2 = 0.014 atm

Therefore, the vapor pressure for methanol at 55.5 oC is 0.014 atm, to the third decimal point.

Answer:

In the basic version, students learn about the atom, its structure, the particles. ... They will also learn how to calculate the atomic mass and find the number of protons, neutrons, and electrons. In the advanced version, students learn about isotopes and ions.

Answer:

a and b

Explanation:

Opals are formed when water in oceans dribble through the Earth, picking up silica from sandstone along the way. And really, that only happens when the ocean water touches the land.

The maximum mass of fructose that can be added to 2.50 kg of pure water and still have the solution freeze at -12.5°C is 0 grams (or essentially 0).

To determine the maximum mass of fructose (C6H12O6) that can be added to 2.50 kg of pure water and still have the solution freeze at -12.5°C, we need to consider the concept of freezing point depression.

The freezing point depression is given by the equation:

ΔT = Kf × m

Where:

ΔT is the change in freezing point,

Kf is the cryoscopic constant for the solvent (water),

m is the molality of the solute (fructose).

Since we know the freezing point depression (ΔT) and the cryoscopic constant (Kf) for water, we can calculate the molality (m) of the fructose that will result in the desired freezing point depression.

The cryoscopic constant for water is approximately 1.86°C·kg/mol.

Given that the freezing point depression is -12.5°C, we can calculate the molality as follows:

ΔT = Kf × m

-12.5°C = (1.86°C·kg/mol) * m

Solving for m:

m = -12.5°C / (1.86°C·kg/mol)

m ≈ -6.72 mol/kg

Since molality (m) is expressed in moles of solute per kilogram of solvent, we need to convert the molality into mass of fructose.

To do this, we need to know the molar mass of fructose, which is approximately 180.16 g/mol.

Using the molality and the molar mass, we can calculate the maximum mass of fructose as follows:

Mass of fructose = m × (mass of water)

Mass of fructose = -6.72 mol/kg * 2.50 kg

Mass of fructose ≈ -16.8 mol

However, it is not physically meaningful to have a negative mass. This indicates that adding any amount of fructose will result in the solution freezing, as the fructose would further depress the freezing point below -12.5°C.

Therefore, the maximum mass of fructose that can be added to 2.50 kg of pure water and still have the solution freeze at -12.5°C is 0 grams (or essentially 0).

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Answer:ionic

Explanation:

Answer:

4 significant figures

Explanation:

____

Answer:

3.89

Explanation:

the specific heat is usually quoted at constant pressure but in some applications where pressure changes it is quoted at quoted at constant volume

Answer:

A carbon dioxide

its how carbon is transferred

Carbon cycle is the process of balancing the amount of carbon in the atmosphere and what is present in plants and animals. In carbon cycle, carbon is transferred in the form of carbon dioxide from animals to plants.

Carbon cycle is a geochemical cyclic process by which the carbon gas is exchanged between the atmosphere and biosphere. Carbon is the main content of all biological materials as well as living.

These events in carbon cycle balance the amount of carbon in atmosphere and biosphere to sustain life. Thus the wasted carbon from animals are recycled back to the atmosphere in the form of carbon dioxide.

We intake oxygen and release carbon dioxide. The released carbon dioxide is uptaken by plants and used for photosynthesis. By the process of photosynthesis, plants are making glucose and energy.

Therefore, In the carbon cycle, carbon is transferred from animals to plants in the form of A. carbon dioxide.

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Answer:

Warm front

Explanation:

Warm front forms widespread clouds, rain, or snow.

Answer:

Warm front

Explanation:

Just took the quiz

Answer:

To determine the number of moles of NO produced, we need to use the balanced chemical equation and the stoichiometric coefficients.

First, we need to identify the stoichiometric coefficient of HNO3 in the equation, which is 8. This means that 8 moles of HNO3 react with 2 moles of NO.

To find the number of moles of NO produced from 83 moles of HNO3, we can use a proportion:

8 moles HNO3 / 2 moles NO = 83 moles HNO3 / x moles NO

Solving for x, we get:

x = (2 moles NO x 83 moles HNO3) / 8 moles HNO3

x = 20.875 moles NO

Therefore, 20.875 moles of NO can be made when 83 moles of HNO3 are consumed.

The molecular clocks show the species that were diverged by evolution.

Scientists use the molecular clock of mutation to estimate the timing of evolutionary events and to infer the relationships between organisms. The molecular clock is based on the idea that mutations accumulate in DNA at a roughly constant rate over time, and that this rate can be used to estimate the time since two organisms diverged from a common ancestor.

To use the molecular clock, scientists first identify a gene or a set of genes that are present in both organisms and that are evolving slowly enough to be informative. They then compare the DNA sequences of these genes between the two organisms and calculate the number of differences or mutations that have accumulated over time.

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Answer:

1.234 × 10^3

Explanation:

hope this helps. . .<3

Answer:Bohr's model is one of the earliest model of atom in history, modified from Rutherford's model. ... As for the Lewis Dot Structure, it is the model of an atom that has the chemical symbol for the element surronded by dots to represent the valence electron of the element.

Explanation:

Answer:

The one cell of a unicellular organism must be able to perform all the functions necessary for life. These functions include metabolism, homeostasis and reproduction. Specifically, these single cells must transport materials, obtain and use energy, dispose of wastes, and continuously respond to their environment.

Answer:

A single celled Organism is able to get energy from complex molecules, to move, and to sense their environment.

Explanation:

The ability to perform these and other functions is part of their organization.

6 moles of water will be produced. after analyzing the stoichiometry of the equation, where the number of water molecules is divided by the molecular mass of water which is 18 grams.

What are Moles?

Standard scientific unit for calculating the number of atoms, molecules, or other specific particles in vast amounts. The mole designates 6.02214076 × \(10^{23}\) units, which is a very large number.

What is Stoichiometry?

To calculate the appropriate quantitative data, a chemistry concept known as stoichiometry uses relationships between the reactants and/or products of a chemical reaction. Understanding the relationships that exist between products and reactants and why they exist, which necessitates understanding how to balance reactions, is crucial before using stoichiometry to perform calculations regarding chemical reactions.

6 moles of water will be produced.

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Answer:

843.75

Explanation:

ok so the moon radius is 1,350,000meters right so meters to miles

1 mile=1600meters

1,350,000/1600=843.75

843.75 miles

Hope that helps!

Merry Christmas!

Answer:

106.905 amu is the mass of the other isotope

Explanation:

The atomic mass of an element is the sum of the masses of the isotopes multiplied by its abundance. The atomic mass of an element X with 2 isotopes is:

X = X-109*i + X-107*i

Where X is the atomic mass = 107.868 amu

X-109 = 108.905amu, i = 48.16% = 0.4816

X-107 = ?, i = 1-0.4816 = 0.5184

Replacing:

107.868amu = 108.905amu*0.4816 + X-107*0.5184

55.4194 = X-107*0.5184

106.905 = X-107

Theoretical yield

Percent yield

The answer is theoretical yield = 22.6 grams of ammonia and percent yield = 77.4 %

Answer:

Discovered two new radioactive elements They came up with the term radio activity.conducted experiments with uranium-containing

Explanation:

Answer:

+1

Explanation:

A sodium atom can lose its outer electron. It will still have 11 positive protons but only 10 negative electrons. So, the overall charge is +1.

Answer:

lemme slurp them juices out of that p*ssy. You must taste sweet.

Explanation:

Answer:  3.142 M

Explanation:

use the dilution formula

M1V1=M2V2

M2= 5.9 X 4.1 / 7.7  = 3.142 M  if need to correct sig figs its 3.1 M

Answer:

see below

Explanation:

1) here we are given that one mole of propane releases 2221kJ of energy.

now use unitary method as ,

to burn 1 mol (44g) propane 2221kJ of energy is required

to burn 1g of propane 2221kJ/44g of energy is required

therefore to burn 25g of propane 2221/44*25kJ of energy is required= 1261.93kJ ≈ 1262 kJ

Hence 1262kJ of energy is required to burn 25g propane.

2) amount of heat absorbed= 25kJ

amount of work done = 12J

change in energy= (25-12)kJ = 13kJ

Hence the value of ∆E is 13kJ .

and we are done!