#19.
An unknown sample weighs 45.2 g and takes 58.2 kJ to vaporize. What is
its heat of vaporization?

#19. An Unknown Sample Weighs 45.2 G And Takes 58.2 KJ To Vaporize. What Isits Heat Of Vaporization?

Answers

Answer 1
The answer above is correct:)

Related Questions

What is the molecular formula of following show how it is done.1 nitric acid 2 Sulphuric acid 3 Methane 4 Potassium oxide 5 Silver chloride 6 Limestone . Answer it ASAP.Thank u​

Answers

Answer:

1.HNO₃

Nitric acid is a nitrogen oxoacid of formula HNO3 in which the nitrogen atom is bonded to a hydroxy group and by equivalent bonds to the remaining two oxygen atoms.

2.H₂SO₄

3.CH₄

Methane (US: , UK: ) is a chemical compound with the chemical formula CH4 (one atom of carbon and four atoms of hydrogen). It is a group-14 hydride and the simplest alkane and is the main constituent of natural gas.

4.K₂O

5.AgCl

6.CaCO3

Limestone consists of calcium carbonate, which has the chemical formula CaCO3. Limestone exists in sedimentary and crystalline form.

Explanation:

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What is the balanced equation for the reaction of lithium metal with fluorine gas? Li ( s ) + F ( g ) → LiF ( s ) Li ( s ) + F 2 ( g ) → LiF ( s ) 2 Li ( s ) + F 2 ( g ) → 2 LiF ( s ) Li ( s ) + F 2 ( g ) → LiF

Answers

Answer:

2Li(s) + F2(g)→2LiF(s)

Explanation:

How is the rate of a reaction affected when the temperature increases?
A. The rate decreases because the reactant particles move too
quickly to react.
B. The rate increases because the equilibrium constant increases.
C. The rate increases because the reactant particles collide more
often.
D. The rate decreases because the products reform the reactants more quickly
more quickly.

Answers

D the rate decreases because the products reform the reactants more quickly more quickly.

The rate of reaction increases when the temperature increases because the reactant particles collide more often and the correct option is option C.

What is Rate of reaction?

The rate of reaction refers to the speed at which the products are formed from the reactants in a chemical reaction. It gives some insight into the time frame under which a reaction can be completed.

The rate or speed of reaction can be defined as the change in the concentration of any one of the reactants or products per unit time.

The rate is higher at higher temperatures because colliding particles will have the required activation energy at high temperature and more successful collisions will take place.

Therefore, The rate of reaction increases when the temperature increases because the reactant particles collide more often and the correct option is option C.

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the nutrition label on rice lists the amounts of protein, carbohydrates and fats in one serving. these substances are important for human nutrition

Answers

Answer:

Carbohydrates, proteins, and fats are biological macromolecules that are made up of chemical elements which are inherent to chemistry.

Chemistry explain how these macromolecules are bonded together at the molecular level and give an explanation for their behavior.

Explanation:

HBr can be added to an alkene in the presence of peroxides (ROOR). What function does the peroxide serve in this reaction

Answers

Answer:

Radical chain initiator

Explanation:

The peroxide here serves as a radical chain initiator. In the field of chemistry the radical initiatives are those substances that are used in industrial processes like polymer synthesis. These initiatives have weak bonds generally and they're mostly used to create free radicals. These radicals are atoms that have odd numbers of electrons. Peroxide is an example of such.

what is the complete ionic equation between the reaction of sodium carbonate and calcium hydroxide to form a precipitate ​

Answers

Answer:

CaCl2(aq) + Na2CO3(aq) → CaCO3(s) + 2NaCl(aq)

Reference:

H.W. Hanna and A. Dittmar; Laboratory Manual for General Chemistry, 4th ed.; Morton Publishing Company, Denver, Colorado

Do you think that people decide their destiny, or that their destiny has already been decided and they cannot change ,they only discover it ?

Answers

i don't know if this is for school or what. but I believe that your destiny is set out but you do have the power to change it. you decide what path you want to go down with your actions

Which of the following chemical equations depicts a balanced ionic equation?
A. 2OH−+Ca2+−>Ca(OH)2
B. OH−+Ca2+−>Ca(OH)2
C. 2OH−+Ca2+−>2Ca(OH)2
D. OH−+2Ca2+−>Ca(OH)2

Answers

Answer:

[tex]{ \sf{A. \: 2OH {}^{ - } _{(aq)} +Ca {}^{2 + } _{(aq)} −>Ca(OH) _{2(s)} }}[/tex]

The chemical equations depict a balanced ionic equation is  2OH−+Ca2+−>Ca(OH)2. option A is correct.

What is the ionic equation?

An ionic equation is a chemical equation in which the electrolytes in an aqueous solution are expressed as dissociated ions. The ions in aqueous solutions are stabilized by ion-dipole interactions with water molecules

Strong acids, strong bases, and soluble ionic compounds (usual salts) exist as dissociated ions in an aqueous solution, and Weak acids and bases and insoluble salts are usually written using their molecular formulas because only a small amount of them dissociates into ions.

Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) → AgCl(s) + Na+(aq) + NO3-(aq) is an ionic equation example.

Therefore, the balanced ionic reaction will be  2OH−+Ca2+−>Ca(OH)2. option A is correct.

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China is the leading producer of​

Answers

Answer:

Production of some products is highly concentrated in a few countries, China, the leading producer of wheat and ramie in 2013, produces 6% of the world's ramie fiber but only 17% of the world's wheat.


What is the pressure in a 19.1 L cylinder filled with 0.684 mol of nitrogen gas at a temperature of 326 K ?

Answers

Answer:

The hydrogen sample has a pressure of 0.957 atmospheres.

Explanation:

Let consider that the hydrogen sample behaves ideally, the equation of state for ideal gases is:

[tex]P\cdot V = n\cdot R_{u}\cdot T[/tex] (1)

Where:

[tex]P[/tex] - Pressure, in atmospheres.

[tex]V[/tex] - Volume, in liters.

[tex]n[/tex] - Molar quantity, in moles.

[tex]T[/tex] - Temperature, in Kelvin.

[tex]R_{u}[/tex] - Ideal gas constant, in atmosphere-liters per mole-Kelvin.

If we know that [tex]V = 19.1\,L[/tex], [tex]n = 0.684\,mol[/tex], [tex]T = 326\,K[/tex] and [tex]R_{u} = 0.082\,\frac{atm\cdot L}{mol\cdot K}[/tex], then the pressure of the hydrogen sample is:

[tex]P = \frac{n\cdot R_{u}\cdot T}{V}[/tex]

[tex]P = \frac{(0.684\,mol)\cdot \left(0.082\,\frac{atm\cdot L}{mol\cdot K} \right)\cdot (326\,K)}{19.1\,L}[/tex]

[tex]P = 0.957\,atm[/tex]

The hydrogen sample has a pressure of 0.957 atmospheres.

Are the components of a solution fixed?

Answers

Answer:

yes

Explanation:

the components of solutions fixed

During the course of your experiment you have obtained the following data: mass of the hydrate: 1.973 g mass of the anhydrate: 1.196 g The formula of the anhydrous salt: CaCl2 Calculate the following: (round to correct the number of significant figures and include units as required). mass of water loss in . number of moles of anhydrous salt after heating, in moles number of moles of water lost, in moles • number of moles of water per mole of hydrate, in moles (round to the whole number) provide the formula of a hydrate Note: you will not be able to add the bscript and leave one space between ionic compound and water.

Answers

Answer:

See explanation

Explanation:

Mass of water lost = mass of hydrated salt - mass of anhydrous salt

Mass of water lost = 1.973 g - 1.196 g = 0.777g

Number of moles of water lost = 0.777g/18g/mol = 0.043 moles

Number of moles of anhydrous salt = 1.196 g /111g/mol = 0.011 moles

To obtain the number of moles of water of crystalization per hydrate molecule;

Number of moles of anhydrous salt = number of moles of hydrated salt

0.011 = 1.973 /111 + 18x

0.011(111 + 18x) = 1.973

1.221 + 0.198x = 1.973

0.198x = 1.973 - 1.221

x= 4

Hence, there are 4 moles of water per hydrate molecule. The formula of the hydrate is CaCl2.4H2O

A reaction vessel for synthesizing ammonia by reacting nitrogen and hydrogen is charged with 6.54 kg of H2 and excess N2. A total of 30.4 kg of NH3 are produced. What is the percent yield of the reaction

Answers

Explanation:

The given data is:

The mass of hydrogen is 6.54 kg.

The actual yield is 30.4 kg.

The balanced chemical equation of the reaction is:

[tex]N_2(g)+3H_2(g)<=>2NH_3(g)[/tex]

At first the theoretical yield should be calculated by using the balanced chemical equation:

3 mol. of hydrogen forms ---- 2 mol. of ammonia.

The molar mass of hydrogen is 2.0 g/mol.

The molar mass of ammonia is 17.0 g/mol.

Hence, the above statement can be rewritten as:

6g of hydrogen forms --- 34g of ammonia.

Then,

6.54g of hydrogen forms :

[tex]6.54 kg x 34 g / 6 g\\=37.1 kg[/tex]

% yield = (actual yield /theoretical yield )x 100

=(30.4 kg /37.1 kg )x100

=81.9

Hence, % yield is 81.9.

1)Consider the reactions observed when NaOH(aq) and NH3(aq) were added to the solutions containing Zn2 (aq): a)What is the identity of the precipitate formed when the NaOH(aq) and NH3(aq) were added dropwise (limited amounts added)

Answers

Answer:

A white gelatinous precipitate is observed in each case.

Explanation:

Qualitative analysis in chemistry is mostly used to identify the ions present in a sample by adding certain reagents. The observation after adding the reagent often leads to an inference.

When NaOH is added to a solution containing Zn^2+ in drops, a white gelatinous precipitate is observed.

When NH3(aq) is added in drops to a solution containing Zn^2+, a white gelatinous precipitate is also observed.

3 why does soldium produce blue colour when dissolve in ammonia?​

Answers

Answer:

Because it is dissolving and has pigment.  

Explanation:

Answer:

The solvated electron is responsible for a great deal of radiation chemistry. Alkali metals dissolve in liquid ammonia giving deep blue solutions which conduct electricity . The blue colour of the solution is due to ammoniated electrons which absorb energy in the visible region of light.

Identify the element for each of these electron configurations. Then determine whether this configuration is the ground state or an excited state.
a. 1s2 2s2 2p6 3s2 3p6 4s2 3d 9
b. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f 14 5d7

Answers

Answer:

a. 1s2 2s2 2p6 3s2 3p6 4s2 3d 9 - the element is zinc and this is an excited state configuration

b. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f 14 5d7 -the element is iridium and this is a ground state configuration

Explanation:

The ground state is the lowest energy state of an atom while excite states of Zn atom are higher energy states.

The configuration, 1s2 2s2 2p6 3s2 3p6 4s2 3d 9 applies to zinc atom in excited state while the configuration 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f 14 5d7 applies to iridium atom in ground state.

Carboxylic acids and alcohols react via dehydration and condensation to produce a/an _______ and water.

Question options:



amine




ether




polymer




ester

Answers

Answer:

ester

Explanation:

Carboxylic acids and alcohols react in the presence of strong acid to produce an ester and water. The two carbon chains come together, which is the condensation, and then water is generated, which is dehydration. The resulting compound is an ester.

A functional group introduces heteroatoms into a carbon chain to increase





polarity.




chain length.




molecular mass.




reactivity.

Answers

Answer:

reactivaty

Explanation:

here you go for the answer

Aqueous hydrochloric acid HCl will react with solid sodium hydroxide NaOH to produce aqueous sodium chloride NaCl and liquid water H2O. Suppose 20. g of hydrochloric acid is mixed with 7.56 g of sodium hydroxide. Calculate the minimum mass of hydrochloric acid that could be left over by the chemical reaction. Round your answer to 2 significant digits.

Answers

here's the answer to your question

Prepare a flow sheet for the preparation of triphenylmethanol. Using your knowledge of the physical properties of the solvents, reactants, and products, show how the products can be purified. Indicate which layer should contain the product in the liquid/liquid extraction steps.

Answers

Answer:

See explanation and Image attached

Explanation:

The preparation of triphenylmethanol occurs as shown in the image attached to this answer.

The first step is the nucleophillic reaction of the phenyl magnesium bromide with the carbonyl group.

Reaction of the second molecule of phenyl magnesium bromide with the product yields triphenyl methoxide ion. Reaction with acid yields the triphenylmethanol product which is extracted into the organic phase.

The triphenylmethanol product can be purified by recrystallization.

Standard hydrogen electrode acts as both anode and cathode.Explain.​

Answers

Answer:

A Standard Hydrogen Electrode is an electrode that scientists use for reference on all half-cell potential reactions. The value of the standard electrode potential is zero, which forms the basis one needs to calculate cell potentials using different electrodes or different concentrations. It is important to have this common reference electrode, just as it is important for the International Bureau of Weights and Measures to keep a sealed piece of metal that is used to reference the S.I. Kilogram.

Answer:

The role of an electrode as cathode or anode depends on the nature and electrode potential of the other electrode with which it forms the complete electrochemical cell.

When a cell is to be made with zinc electrode and hydrogen electrode, the hydrogen electrode will behave as a cathode and the zinc electrode will behave as anode because zinc is present above hydrogen in the activity series. That is zinc is more electropositive than hydrogen.

If the cell is made with a copper electrode and hydrogen electrode, the hydrogen electrode will behave as anode and the copper electrode as a cathode. This is due to the fact that Cooper is present below hydrogen in the activity series. Copper is less electropositive than hydrogen.

Explanation:

Determine the rate of reaction based on the data below:
75-
rate of reaction = y
hydrogen produced (cm)
х
y
25
50
75
100
125
time (seconds)

Answers

Answer:

75

Explanation:

is the answer for your question

4. A sample of ammonia, NH3, contains 3.3 x 1021 hydrogen atoms. How many NH; molecules are in this sample?​

Answers

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

Question 4
18 g of carbon dioxide contains how many oxygen atoms?

Answers

Answer:

4.92×10²³ atoms of oxygen.

Explanation:

We'll begin by calculating the number of mole of oxygen in 1 mole of CO₂. This can be obtained as follow:

1 mole of CO₂ contains 2 mole of oxygen.

1 mole of CO₂ = 12 + (2×16)

= 12 + 32

= 44 g

Thus,

44 g of CO₂ contains 2 moles of oxygen.

Next, we shall determine the number of mole of oxygen in 18 g of CO₂. This can be obtained as follow:

44 g of CO₂ contains 2 moles of oxygen.

Therefore, 18 g of CO₂ will contain

= (18 × 2)/ 44 = 0.818 mole of oxygen.

Finally, we shall determine the number of atoms in 0.818 mole of oxygen. This can be obtained as follow:

From Avogadro's hypothesis,

1 mole = 6.02×10²³ atoms.

Therefore,

0.818 mole = 0.818 × 6.02×10²³ atoms.

0.818 mole of oxygen = 4.92×10²³ atoms.

Thus, 18 g of CO₂ contains 4.92×10²³ atoms of oxygen.

If the balance were not tared prior to weighing out the KHP.... how would you expect this to affect the molarity of NaOH calculated? What type of error is this?

Answers

Answer:

Following are the response to the given question:

Explanation:

In the given scenario, When the balance has never been tainted before the KHP is weighted, which can affect the molar concentration of NaOH because its molarity is directly proportional to the weight including its substance. In this question it is the mistake is systemic because it may be corrected by modifying balancing parameters.

A sample of gas occupies 12 L under a pressure of 1.2 atm. What
would its volume be if the pressure were increased to 3.6 atm?
(assume temp is constant)

Answers

Explanation:

here's the answer to your question

WHAT WOULD THE RIGHT OPTION??

how many resonance structures of benzene are known?
A) 3
B) 4
C) 5
D) 6 ​

Answers

Answer:

C) 5

Step-by-step explaination:

Benzene has 5 resonance structures.

Decide which of the following statements are true and which are false.
True False: Real gas molecules behave most ideally at low temperature and high pressure.
True False: Ideal gas molecules have small volumes and exert weak attractive forces on one another.
True False: At constant temperature, the heavier the gas molecules, the smaller the average velocity.
True False: In order for two separate 1.0 L samples of O2(g) and H2(g) to have the same average velocity, the O2(g) sample must be at a lower temperature than the H
2(g) sample.
True False: At constant temperature, the heavier the gas molecules, the larger the average kinetic energy.
True False: As temperature decreases, the average kinetic energy of a sample of gas molecules decreases.

Answers

Answer:

False

True

True

False

False

True

Explanation:

Ideal behavior of gases is observed at high temperature and low pressure when the gas molecules are isolated from each other.

According to the kinetic theory of gases, gases occupy negligible volume and do not exert significant attractive forces on each other.

The average velocity of gases at constant temperature depends on molecular mass. Heavier molecules possess smaller average velocity than lighter molecules at constant temperature.

At constant temperature, molecules of different gases have the same average kinetic energy but different average velocities since they have different molecular masses. So, the average kinetic energy of gas molecules only depends on temperature.

12.39 HBr can be added to alkenes in either the absence or presence of peroxides (producing either the Markovnikov or the anti-Markovnikov addition product). What intermediates leading to the formation of the major product are observed when 1-butene is treated with 1) HBr or 2) HBr/peroxides

Answers

Answer:

See explanation and image attached

Explanation:

The reaction of HBr with 1-butene is an addition reaction. The HBr adds across the double bond to yield a saturated halogenoalkane.

In the absence of peroxides, the reaction proceeds in accordance with Markovnikov rule which states that;''the negative part of the addendum, is attached to the carbon atom with the least number of hydrogen atoms attached.'' This occurs in the first reaction shown in the image.

In the presence of peroxides, the reaction proceeds in an anti-Markovnikov manner to yield the product shown in the second reaction.

What is the formula for manganese (IV) oxide?
A. MnO4
B. Mn40
C. MNO2
D. Mn20

Answers

The formula of manganese (IV) oxide is MNO2

The formula for manganese (IV) oxide is [tex]MnO_4[/tex]. Therefore, the correct option is A.

A manganese atom is bonded to four oxygen atoms to produce an inorganic compound known as manganese(IV) oxide with the chemical formula [tex]MnO_4[/tex]. It is often referred to as manganese dioxide. The +4 oxidation state of a manganese compound is indicated by the Roman numeral "IV" in the name.

Pyrolusite, a naturally occurring mineral, is a dark brown or black solid consisting of manganese(IV) oxide. Due to its favorable properties, it is often employed in a wide variety of applications. It acts as a catalyst, especially when breaking down hydrogen peroxide. Additionally, it is used to make batteries, ceramics, glass and pigments.

Therefore, the correct option is A.

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