A student in CEM143 was doing a fractional distillation when she noticed that the temperature suddenly started to drop. What could have caused the decrease in the temperature

Answers

Answer 1

Explanation:

A process where two or more number of miscible liquids present in different fractions are separated by boiling at different temperatures is called fractional distillation.

The sudden decrease in temperature is because the compounds having lower boiling point have completed the distillation before vapor of the higher boiling point can actually fill the distillation head.


Related Questions

Write the Ka expression for an aqueous solution of hypochlorous acid: (Note that either the numerator or denominator may contain more than one chemical species. Enter the complete numerator in the top box and the complete denominator in the bottom box. Remember to write the hydronium ion out as , and not as )

Answers

Answer: The Ka expression for an aqueous solution of hypochlorous acid is [tex]K_{a} = \frac{[H_{3}O^{+}][OCl^{-}]}{[HClO]}[/tex].

Explanation:

The chemical formula of hypochlorous acid is HClO. So, when it is added to water (solvent) then its dissociation is as follows.

[tex]HClO + H_{2}O \rightarrow H_{3}O^{+} + Cl^{-}[/tex]

When we write the equilibrium constant for this reaction then it is called acid acid dissociated constant.

Hence, the expression for acid dissociation constant of this reaction is as follows.

[tex]K_{a} = \frac{[H_{3}O^{+}][OCl^{-}]}{[HClO]}[/tex]

Thus, we can conclude that the Ka expression for an aqueous solution of hypochlorous acid is [tex]K_{a} = \frac{[H_{3}O^{+}][OCl^{-}]}{[HClO]}[/tex].

gabriel created 270 grams of aluminum oxide from 145 grams of aluminum. what was his percent yield?

A. 99.1%
B. 98.6%
C. 97.2%
D.96.5%

( it’s not “D” because I got it wrong lol) pls help tho

Answers

Answer:

% yield = 200%

Explanation:

By using 145 gram of aluminium

Using 26.982 g/mol of Al, 101.96 g/mol of Aluminium oxide is produced

Using 145 grams of aluminium, the yield of Aluminium oxide  would have been = (101.96 g/mol/26.982 g/mol)/145 grams

= 547.9282485 gram

Now % yield = actual yield /theoretical yield * 100

Substituting the given values, we get -

% yield = (547.928/270) *100

% yield = 200%

balance this equation plz
SO2+O2+H2O------->H2SO4​

Answers

Answer: The balanced equation is [tex]2SO_{2} + O_{2} + 2H_{2}O \rightarrow 2H_{2}SO_{4}[/tex].

Explanation:

A chemical equation which contains same number of atoms on both reactant and product side is called a balanced chemical equation.

For example, [tex]SO_{2} + O_{2} + H_{2}O \rightarrow H_{2}SO_{4}[/tex]

Here, number of atoms present on reactant side are as follows.

S = 1O = 5H = 2

Number of atoms present on product side are as follows.

S = 1O = 4H = 2

To balance this equation, multiply [tex]SO_{2}[/tex] by 2 and [tex]H_{2}O[/tex] by 2 on reactant side. Also, multiply [tex]H_{2}SO_{4}[/tex] by 2 on product side.

Hence, the equation can be re-written as follows.

[tex]2SO_{2} + O_{2} + 2H_{2}O \rightarrow 2H_{2}SO_{4}[/tex]

Now, the number of atoms present on reactant side are as follows.

S = 2O = 8H = 4

Number of atoms present on product side are as follows.

S = 2O = 8H = 4

Since, the atoms present on both reactant and product side are equal. Hence, the equation is now balanced.

Thus, we can conclude that the balanced equation is [tex]2SO_{2} + O_{2} + 2H_{2}O \rightarrow 2H_{2}SO_{4}[/tex].

You calculate that 0.000345 m is the answer to a problem. You are asked to write
your answer in scientific notation. Which answer is correct? *
A~ 34.5 x 10^-5m
B~ 345 x 10^6m
C~ 3.45 x 10^-5 m
D~ 3.45 x 10^-4 m

Answers

Mark Brainliest please

Answer: D

Explanation :

0.000345 = 3.45 × 10^−4

Explanation:
The number is a small decimal which tells us we have divided by 10 and we are working with a negative index of 10.
Scientific notation has one digit nefore the decimal point..
0.000345 p= 3.45 ×10^−4

g An ionic bond involves ____ a. molecules that gain or lose an atom to develop a bonding charge b. molecules that bond together through a weak force c. atoms that either lose or gain an electron in order to bond d. atoms that share an electron to tightly bond

Answers

Answer:

a. molecules that gain or lose an atom to develop a bonding charge

Explanation:

Write the balanced COMPLETE ionic equation for the reaction when aqueous NiCl₂ and aqueous Na₂S are mixed in solution to form solid NiS and aqueous NaCl. If no reaction occurs, simply write only NR.

Answers

Answer:

Explanation:

The chemical reaction of the well-balanced equation is as follows:

[tex]\mathbf{2NiCl_{2(aq)}+2Na_2S_{(aq)} \to 4NaCl_{(aq)}+2NiS_{s}}[/tex]

The aforementioned reaction's ionic equation is:

[tex]\mathbf{2Ni^{2+}_{(aq)}+4Cl^-_{(aq)}+ 4Na^+_{(aq)}+2S^{2-}_{(aq)} \to 4Na^+_{(aq)}+4Cl^-_{(aq)}+2NiS_{(s)}}[/tex]

From above; Na⁺ and Cl⁻ appear on both sides;

Hence, the net ionic equation is:

[tex]\mathbf{2Ni^{2+}_{(aq)}+2S^{2-}_{(aq)} \to 2NiS_{(s)}}[/tex]

PLS HELP THESE ARE RHE ONLY QUESTIONS I HAVE LEFT DUE SOON

Answers

Explanation:

Magnesium reacts with dilute hydrochloric acid in a conical flask which is connected to an inverted measuring cylinder in a trough of water. The volume of hydrogen gas produced is measured over a few minutes, and the results are used to plot a graph

This is intended as a class practical. It is best if the students work in pairs because setting up and starting the experiment requires more than one pair of hands. One student can add the magnesium ribbon to the acid and stopper the flask, while the other starts the stopclock. During the experiment, one student can take the readings while the other records them. The experiment itself takes only a few minutes. But allow at least 30 minutes to give students time to set up, take readings and draw graph.

please mark as brainliest

One gram of a compound requires the following quantities of solvent to dissolve: 47 mL of water, 8.1 mL of chloroform, 370 mL of diethyl ether, or 86 mL of benzene. Calculate the solubility of the compound in these four solvents (as g/100 mL). Estimate the partition coefficient of the compound between chloroform and water, ethyl ether and water, and benzene and water. Which solvent would you choose to extract the compound from an aqueous solution

Answers

Answer:

Chloroform.

Explanation:

Given,

Solvent requires 1g of compound per 100 mL

For water,

= 1g/47ml

= 2.1

For Chloroform,

= 1 g/8.1 mL

= 12.345679

For Diethyl ether,

= 1 g/370 mL

= 0.27

For Benzene,

=  1 g/86 mL

= 1.2

Partition coefficients:

Water = -

chloroform = 5.9

Diethyl = .13

Benzene  = .57

The solvent chloroform would be chosen for drawing out the compound out of an aqueous solution as it has the maximum solubility.

Suppose a soap manufacturer starts with a triglyceride that has the fatty acid chains arachidic acid, palmitic acid and palmitic acid attached to the three backbone carbons. The manufacturer saponifies the triglyceride with NaOH. What are the fatty acid soaps that are produced in the process

Answers

Answer:

Sodium arachidate; Sodium palmitate and Sodium palmitate

Explanation:

Triglycerides are esters of fatty acids with glycerol. In triglycerides, three fatty acid molecules are linked by ester bonds to each of the three carbon atoms in a glycerol molecule. The fatty acids may be same or different fatty acid molecules. Hydrolysis of triglycerides yields the three fatty acid molecules and glycerol.

Saponification is the process by which a base is used to catalyst the hydrolysis of the ester bonds in glycerides. The products of this base-catalyzed hydrolysis of triglycerides are the metallic salts of the three fatty acids and glycerol. The salts of the fatty acids are known as soaps.

For a triglyceride that has the fatty acid chains arachidic acid, palmitic acid and palmitic acid attached to the three backbone carbons glycerol, the saponification of the triglyceride with NaOH will yield the sodium salts or soaps of the three fatty acids as well as glycerol.

Arachidic acid will react with NaOH to yield sodium arachidate.

The two palmitic acid molecules will each react with NaOH to yield sodium palmitate.

The osmotic pressure exerted by a solution is equal to the molarity multiplied by the absolute temperature and the gas constant . Suppose the osmotic pressure of a certain solution is measured to be at an absolute temperature of .

Answers

Answer:

c = π/T*R

c = 0.199M

Explanation:

Is measured to be 5.1 atm at an absolute temperature of 312. K. Write an equation that will let you calculate the molarity c of this solution. Your equation should contain only symbols. Be sure you define each symbol other than R.

The osmotic pressure of a solution, π, is defined as:

π = c*T*R

As we know osmotic pressure π = 5.1atm, T = 312K and R = 0.082atmL/molK

we can replace in the equation as follows:

π= c*T*R

c = π/T*R

c = 5.1atm/312K*0.082atmL/molK

c = 0.199M

1.Consider the molecule azulene and
a) set the secular determinant for azulene within the huckel approximation and using the out of plane C2p orbitals as basis set.
b) Estimate pi electron binding energy within the Huckel approximation
c) Approximate the delocalization energy

Answers

Mark Brainliest please

Answer :

The Hückel approximation is used to determine the energies and shapes of the π
π
molecular orbitals in conjugated systems. Within the Hückel approximation, the covalent bonding in these hydrocarbones can be separated into two independent "frameworks": the σ
σ
-bonding framework and the the σ
σ
-bonding framework. The wavefunctions used to describe the bonding orbitals in each framework results from different combinations of atomic orbitals. The method limits itself to addressing conjugated hydrocarbons and specifically only π
π
electron molecular orbitals are included because these determine the general properties of these molecules; the sigma electrons are ignored. This is referred to as sigma-pi separability and is justified by the orthogonality of σ
σ
and π
π
orbitals in planar molecules. For this reason, the Hückel method is limited to planar systems. Hückel approximation assumes that the electrons in the π
π
bonds “feel” an electrostatic potential due to the entire σ
σ
-bonding framework in the molecule (i.e. it focuses only on the formation of π
π
bonds, given that the σ
σ
bonding framework has already been formed).

Someone pls help me ::/:/

How much energy must be added to 250.0 g of ice at 0.00 °C to raise the
temperature of the water to 50.0 °C? The heat of fusion for water is 334
J/g. The specific heat of water is 4.184 J/g.K.

Answers

Answer:

136 KJ

Explanation:

We'll begin by calculating the heat required to melt the ice. This can be obtained as follow:

Mass (M) = 250 g

Heat of fusion (Hբ) = 334 J/gºC

Heat (Q₁) required to melt the ice =?

Q₁ = MHբ

Q₁ = 250 × 334

Q₁ = 83500 J

Next, we shall determine the heat required to change the temperature. This can be obtained as follow:

Mass (M) = 250 g

Initial temperature (T₁) = 0 °C

Final temperature (T₂) = 50 °C

Specific heat capacity (C) = 4.184 J/gºC

Heat (Q₂) required to change the temperature =?

Q₂ = MC(T₂ – T₁)

Q₂ = 250 × 4.184 (50 – 0)

Q₂ = 1046 × 50

Q₂ = 52300 J

Next, we shall determine the total heat required.

Heat (Q₁) required to melt the ice = 83500 J

Heat (Q₂) required to change the temperature = 52300 J

Total heat (Qₜ) required =?

Qₜ = Q₁ + Q₂

Qₜ = 83500 + 52300

Qₜ = 135800 J

Finally, we shall convert 135800 J to KJ. This can be obtained as follow:

1000 J = 1 KJ

Therefore,

135800 J = 135800 J × 1 KJ / 1000 J

135800 J ≈ 136 KJ

Thus, the total heat required is 136 KJ.

A 59.0 mL portion of a 1.80 M solution is diluted to a total volume of 258 mL. A 129 mL portion of that solution is diluted by adding 183 mL of water. What is the final concentration

Answers

Answer:

0.170 M

Explanation:

As this is a series of dilutions, we can continuosly use the C₁V₁=C₂V₂ formula to solve this problem:

For the first step:

59.0 mL * 1.80 M = 258 mL * C₂C₂ = 0.412 M

Then for when 129 mL of that 0.412 M are diluted by adding 183 mL of water:

V₂ = 129 mL + 183 mL = 312 mL

Using C₁V₁=C₂V₂:

129 mL * 0.412 M = 312 mL * C₂C₂ = 0.170 M

1. An ion has a net charge of - 3, and 12 electrons, what is its atomic number? What element has that atomic number?

2. An ion of Celsius has a net charge of -5, how many electrons does it have?

3. Some atom has an atomic number of 46, how many electrons does it have if it has a net charge of +2?

4. How many neutrons are in an atom of Helium, and what is its mass number?

5. There are 3 neutrons in an isotope of Helium, what is its mass number?

6. n isotope has 83 neutrons and a mass number of 167, what is its atomic number? What element is defined by that atomic number?

7. What element has 54 neutrons and a mass number of 112?

8. What element has 10 electrons, a net charge of -2?

Answers

Answer:

19 because it gained 3 electron so 12-3=9 beryllium

2

3 is 46-2=44

4 is 2

5 is 5

6 84 polonium

7

8 oxygen

Explanation:

plz let me know if they are right or wrong:)

. Which is instinctive behavior? A. A puppy cuddling its human owner.C. A young child learned how to read. B. A duckling swimming after its mother.D. A kitten learning to use a litter box.

Answers

Answer:

A duckling swimming after its own mother

Explanation:

How many grams of 02 are present in 7.49 L of oxygen gas?

Answers

Answer:

10.70grams

Explanation:

Density of a substance = mass/volume

At STP of a gas (standard temperature and pressure), the density of oxygen gas is 1.429 g/L

Hence, according to this question, in 7.49 L of oxygen gas, there would be:

Using D = m/V

1.429 = m/7.49

m = 1.429g/L × 7.49L

m = 10.70g

A solution has a pH of 2.5. what is the H+

Answers

Answer: The concentration of [tex]H^+[/tex] in the solution is [tex]3.16\times 10^{-3}M[/tex]

Explanation:

pH is defined as the negative logarithm of hydrogen ion concentration present in the solution.

[tex]pH=-\log [H^+][/tex]      .....(1)

We are given:

pH of solution = 2.5

Putting values in equation 1, we get:

[tex]2.5=-\log [H^+][/tex]

[tex][H^+]=10^{-2.5}[/tex]

[tex][H^+]=3.16\times 10^{-3}M[/tex]

Hence, the concentration of [tex]H^+[/tex] in the solution is [tex]3.16\times 10^{-3}M[/tex]

What mass of sodium hydroxide is needed to make 12.5 L of a 0.150M solution?
a) 1.88g
b) 40.0g
c) 75.0g
d) 83.0g

Answers

Answer:

75g

Explanation:

n=Cmxv

=0,15x12,5

=1,875 mol

m=nxM

=1,875x40

=75g

When aqueous solutions of AgNO3 and MgCl2 are mixed, a precipitate forms. What is the correct formula for the precipitate

Answers

Answer:

AgCl

Explanation:

The reaction that takes place is:

2AgNO₃ (aq) + MgCl₂ (aq) → Mg(NO₃) (aq) + 2AgCl (s)

The precipitate (meaning a solid substance) formed is silver chloride, AgCl.

All salts formed with silver and a halogen (F, Cl, Br, I) are insoluble in water, meaning that when working with aqueous solutions they will be precipitates.

Provide the IUPAC names for
the following structures
CH2CH3
w
CH2CH:
(b) H-C-N
CH.CH
H-EN
N
H
(c)
OCH2CH3

Answers

Answer:

For a: The IUPAC name of the compound is N-ethylethaneamide.

For b: The IUPAC name of the compound is N,N-diethylmethaneamide.

For c: The IUPAC name of the compound is ethyl pentanoate

Explanation:

To name a compound, first look for the longest possible carbon chain.

For a:

Amide group is a type of functional group where an amine group is attached to a carbonyl group. The general formula of amide is [tex]R-CO-NH_2[/tex], where R is an alkyl or aryl group.

In part (a), the alkyl group has 2 carbon atoms and thus, the prefix used is 'eth-'

Also, an ethyl substituent is directly attached to N-atom. It is an alkane structured hydrocarbon thus, the suffix used will be '-ane'

Hence, the IUPAC name of the compound is N-ethylethaneamide.

For b:

Amide group is a type of functional group where an amine group is attached to a carbonyl group. The general formula of amide is [tex]R-CO-NH_2[/tex], where R is an alkyl or aryl group.

In part (b), the alkyl group has 1 carbon atoms and thus, the prefix used is 'meth-'

Also, two ethyl substituents are directly attached to N-atom. It is an alkane structured hydrocarbon thus, the suffix used will be '-ane'

Hence, the IUPAC name of the compound is N,N-diethylmethaneamide.

For c:

Esters are a kind of organic molecules having functional groups, [tex]R-COO-R'[/tex] where R and R' are the alkyl or aryl groups. They are formed by the combination of alcohol and carboxylic acid.

These functional group compounds are named in two words which is alkyl alkanoates, where alkyl refers to the alcoholic part and alkanoate refers to the carboxylic acid part of the molecule. The numbering of the parent chain in esters is done from the carboxylic carbon. The alkyl part is not given any numbers.

In part (c), there are 5 carbon atoms present in a straight chain and thus, the prefix used is 'pent-'

Also, an ethyl group forms the alcoholic part.

Hence, the IUPAC name of the compound is ethyl pentanoate


Gasoline and motor oil are chemically similar. They are both mixtures of nonpolar hydrocarbons
containing carbon and hydrogen atoms. However, motor oil is much more viscous than gasoline. Which
substance probably has the higher average molar mass?

Answers

Answer:

motor oil

Explanation:

According to Oxford dictionary, viscosity refers to ''a quantity expressing the magnitude of internal friction in a fluid, as measured by the force per unit area resisting uniform flow.''

The higher the molecular weight of a substance, the greater its viscosity. This is because, the long chains in the viscous substance become entangled thereby increasing the internal friction in the liquid.

Motor oil is a heavier hydrocarbon than gasoline hence it is more viscous than gasoline.

Answer:

Motor oil

Heat it

Water

Explanation:

The pH of the ocean is 8.1. What is the concentration of hydronium ions?

Answers

Answer:

7.9 × 10⁻⁹ M

Explanation:

Step 1: Given data

pH of the ocean: 8.1

Step 2: Calculate the concentration of hydronium ions

We will use the definition of pH.

pH = -log [H⁺] = -log [H₃O⁺]

[H₃O⁺] = [H⁺] = antilog -pH

[H₃O⁺] = antilog -8.1 = 7.9 × 10⁻⁹ M

Since [H₃O⁺] < 10⁻⁷ M, the solution is basic.

How many molecules are in 4.44 mol of CF4? 4.44 mol CF4 =

Answers

Mark Brainliest please

Answer

Molecular Mass for CF4 = 88.004349 Da

I am not sure abt the ans

molar mass= 88

1 molecule = 6.022×10^23

4.44 moles = 6.022×10^23×4.44/88

= 26.73768 × 10^23/88

= 0.3038372727 ×10^23

Which example shows a double replacement reaction?

Answers

Answer:

KCl + AgNO₃ —> AgCl + KNO₃

Explanation:

To answer the question correctly, we must understand the definition of a double displacement reaction.

A double displacement reaction is a reaction in which the ions of the two reacting compounds exchange to form new compounds different from the two reacting compounds. Example is given below:

XY + AB —> XB + AY

Considering the options given in the question above, only the equation:

KCl + AgNO₃ —> AgCl + KNO₃

Satisfy the definition of a double displacement reaction.

Define solubility. the amount of a substance that will dissolve in a given amount of solvent a solid mixed with another solid a liquid that does not dissolve in another liquid the amount of a substance that will dissolve in a given amount of solute a solid that does not dissolve in a gas

Answers

Answer:

You answered your own question

The solubility of a substance is the amount of the substance that can be dissolved in a given amount of solvent at a specified temperature. Hence, option A is correct.

What is solubility ?

Solubility of a substance can be defined as the fraction of concentration of the substance which can be dissolved in a particular amount of a solvent at a specified temperature.

Solubility of a substance depends on the bond type, temperature, pressure and presence of impurities if any. If the bond strength is greater, less will be the solubility because, greater energy is needed to weaken the bonds in the salt.

Similarly, for most of the salts, as the temperature increases, solubility increases, but some salt's solubility is independent of the temperature such as for NaCl. Therefore, the correct definition of solubility is option A.

Find more on solubility ;

https://brainly.com/question/28170449

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Which additional product balances the reaction h2so4+2naoh>na2so4

Answers

Answer:

H 4so8 is the answer of balance the reaction

what will happen to the initial rate of the reaction if the concentration of iron(III) chloride is tripled

Answers

Answer:

Concentration and reaction rate is directly proportional

Explanation:

Basically, concentration is directly proportional to the concentration, so the higher the concentration, the higher the reaction rate.

Once the concentration is increased, more chemical will be added hence the reaction rate will increase

Why should a science teacher know how to prepare stock solution

Answers

Answer:

because they were thought in college

Explanation:

hope that helps

Which of the following is most likely to make a -3 ion?

P
Se
Be
All

Answers

The element whose atom may likely make a -3 ion is P.

Elements in the periodic table are classified into groups and periods. The elements in the same group have similar physical and chemical properties.

Phosphorus (P) is a member of group 15 in the periodic table. The most common ion formed by the members of this group is the -3 ion.

It is formed by accepting three electrons to complete their octet since they have five electrons on their outermost shell.

Hence P is most likely to form a -3 ion.

Learn more: https://brainly.com/question/11155928

What is the pH of a 0.086 M HCl solution?

Answers

Answer: pH = 1.066

Explanation: HCl is strong acid and it protolyzes totally:

HCl + H2O  ⇒ H3O+ + Cl-

Concentrations are same:  [H3O+] = c(HCl)

pH = - log[H3O+] = - log(0.086) = 1.0655

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