Which of the following is evidence of a physical change?
A) burning
B) melting
C) decomposing
D) rusting
need helpp asapp please
Answer:
B. None of these
Explanation:
Sulfur has less ionization energy than phosphorus because sulfur has a pair of electron in its 3p subshell that increases electron repulsion in sulfur and sulfur electrons can easily remove from its sub-level.
While, there are no electron pairs in 3p subshell of phosphorus, therefore it requires more energy to remove an electron from 3p subshell.
Hence, the reason is electron repulsion and the correct answer is B.
This ether can, in principle, be synthesized by two different combinations of haloalkane and metal alkoxide. Draw the combination of alkyl chloride and potassium alkoxide that forms the higher yield of ether. You do not have to consider stereochemistry. You do not have to explicitly draw H atoms. Include counter-ions, e.g., Na , I-, in your submission, but draw them in their own separate sketcher. Separate multiple reactants using the sign from the drop-down menu.
Answer:
The 2 different combinations are given in the attached figure. The 2nd combination has a higher yield due to less hindrance by the alkyl halide.
Explanation:
The first reaction is between an alkyl halide and metal alkoxide. In this case, the alkyl chloride would be a secondary component and thus will cause greater hindrance to the yield. The reaction is as given in the attached figure
The second reaction is between a benzene ring containing halide and metal alkoxide. Now as the reaction is via alkyl chloride being the primary agent, there is less hindrance and thus greater yield in this case.
A sample of gas occupies a volume of 67.5 mL . As it expands, it does 131.0 J of work on its surroundings at a constant pressure of 783 Torr . What is the final volume of the gas g
Answer:
The final volume [tex]V2=1.3175L[/tex]
Explanation:
between work ( w), pressure ( P ) and volume ( V ) is the following:
w=−PΔV
where,
ΔV=V2−V1
It was stated that the gas is expanding, then the work is done by the system and it is of a negative value .
Note that work, should be expressed in 1L⋅atm=101.3J
CHECK THE ATTACHMENT FOR DETAILED EXPLATION
408 J of energy is transferred to a system consisting of 2.0 moles of an ideal gas. If the volume of this gas stays at a constant 4.4 L, calculate the change in internal energy of the gas.
Answer: The change in internal energy of the gas is +408 J
Explanation:
According to first law of thermodynamics:
[tex]\Delta E=q+w[/tex]
[tex]\Delta E[/tex] =Change in internal energy
q = heat absorbed or released
w = work done or by the system
w = work done on the system= [tex]-P\Delta V[/tex]
As volume is constant , [tex]\Delta V[/tex] = 0 and w = 0.
q = +408J {Heat absorbed by the system is positive}
[tex]\Delta E=+408J+(0J)=+408J[/tex]
Thus the change in internal energy of the gas is +408 J
The water in a pressure cooker boils at a temperature greater than 100°C because it is under pressure. At this higher temperature, the chemical reactions associated with the cooking of food take place at a greater rate. (a) Some food cooks fully in 7.00 min in a pressure cooker at 113.0°C and in 49.0 minutes in an open pot at 100.0°C. Calculate the average activation energy for the reactions associated with the cooking of this food. kJ mol-1 (b) How long will the same food take to cook in an open pot of boiling water at an altitude of 10000 feet, where the boiling point of water is 89.8 °C? min
Answer:
the activation energy Ea = 179.176 kJ/mol
it will take 7.0245 mins for the same food to cook in an open pot of boiling water at an altitude of 10000 feet.
Explanation:
From the given information
[tex]T_1 = 100^0 C = 100+273 = 373 \ K \\ \\ T_2 = 113^0 C = 113 + 273 = 386 \ K[/tex]
[tex]R_1 = \dfrac{1}{7}[/tex]
[tex]R_2 = \dfrac{1}{49}[/tex]
Thus; [tex]\dfrac{R_2}{R_1} = 7[/tex]
Because at 113.0°C; the rate is 7 time higher than at 100°C
Hence:
[tex]In (7) = \dfrac{Ea}{8.314}( \dfrac{1}{373}- \dfrac{1}{386})[/tex]
1.9459 = [tex]\dfrac{Ea}{8.314}* 9.0292 *10^{-5}[/tex]
[tex]1.9459*8.314 = Ea * 9.0292*10^{-5}[/tex]
[tex]16.1782126= Ea * 9.0292*10^{-5}[/tex]
[tex]Ea = \dfrac{16.1782126}{ 9.0292*10^{-5}}[/tex]
Ea = 179.176 kJ/mol
Thus; the activation energy Ea = 179.176 kJ/mol
b)
here;
[tex]T_2 = 386 \ K \\ \\T_1 = (89.8 + 273)K = 362.8 \ K[/tex]
[tex]In(\dfrac{R_2}{R_1})= \dfrac{Ea}{R}(\dfrac{1}{T_1}- \dfrac{1}{T_2})[/tex]
[tex]In(\dfrac{R_2}{R_1})= \dfrac{179.176}{8.314}(\dfrac{1}{362.8}- \dfrac{1}{386})[/tex]
[tex]In (\dfrac{R_2}{R_1}) = 0.00357[/tex]
[tex]\dfrac{R_2}{R_1}= e^{0.00357}[/tex]
[tex]\dfrac{R_2}{R_1}= 1.0035[/tex]
where ;
[tex]R_2 = \dfrac{1}7{}[/tex]
[tex]R_1 = \dfrac{1}{t}[/tex]
Now;
[tex]\dfrac{t}{7}= 1.0035[/tex]
t = 7.0245 mins
Therefore; it will take 7.0245 mins for the same food to cook in an open pot of boiling water at an altitude of 10000 feet.
a). The activation energy given by the reactions related to the cooking of food in the pressure cooker would be:
[tex]Ea = 179.176 kJ/mol[/tex]
b). The time duration that is taken by the same food to cook in an open vessel would be:
[tex]7.0245 mins[/tex]
Activation Energya). Given that,
Temperature [tex]1[/tex] [tex]= 100[/tex]° C
Temperature [tex]2[/tex] [tex]= 113[/tex]° C
In Kelvin,
Temperature [tex]1[/tex] [tex]= 100 + 273[/tex]
[tex]= 373 K[/tex]
Temperature [tex]2[/tex] [tex]= 113 + 273[/tex]
[tex]= 386 K[/tex]
[tex]R_{1} = 1/7\\R_{2} = 1/49[/tex]
∵ [tex]R_{2}/R_{1} = 49/7 = 7[/tex]
It is given that at [tex]113[/tex] rate [tex]=[/tex] [tex]7[/tex] × [tex]100[/tex]°C
Therefore,
[tex]Ea/8.314 (1/373 - 1/386) =[/tex] [tex]In(7)[/tex]
so,
[tex]Ea[/tex] [tex]= 16.1782126/(9.0292 * 10^{-5})[/tex]
∵ Activation energy [tex]= 179.176 kJ/mol[/tex]
b). As we know,
[tex]T_{2}[/tex] [tex]= 386 K[/tex]
[tex]T_{1}[/tex] [tex]= (89. 8 + 273)[/tex]
[tex]= 362.8 K[/tex]
by employing the formulae,
[tex]In(\frac{R_{2} }{R_{1} }) = \frac{Ea}{R} (1/T_{1} - 1/T_{2})[/tex]
[tex]In(\frac{R_{2} }{R_{1} }) = 179.176/8.314 (1/362.8 - 1/386)[/tex]
By solving this, we get
[tex]R_{2}/R_{1} = 1.0035[/tex]
Thus,
[tex]R_{2} = 1/7[/tex]
[tex]R_{1} = 1/t[/tex]
∵ t [tex]= 7.0245 min[/tex]
Thus, the time duration would be [tex]7.0245 minutes[/tex].
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Do you think there is a limit to the size of Atoms scientist can make? prove with evidence.
Answer:
Yes, there is a limit to the size of atoms that scientists can make.
Explanation:
In the nucleus, atoms contain protons and neutrons. It is known that as the number of protons in the nucleus increases, the atom becomes unstable due to the repulsion of positively charged protons clumped together in the small space of the nucleus.
However, an attractive force exists between neutrons and protons which binds the nucleus together and minimizes repulsion between protons. Even neutrons have recently been found to slightly repel each other.
Several attempts made at synthesizing many very heavy elements lately have proved abortive because the elements only exist for a few fractions of a second owing to large repulsion between the particles in the nucleus.
This goes a long way to show that there is a limit to the number of protons and neutrons that can be assembled together to form a new nucleus. We cannot bring an unlimited number of nucleons together to form new atoms due to inter particle repulsive forces.
Choose the correct option for the redox reaction below : 8H+(aq) + MnO4-(aq) + 5Fe2+(aq) → Mn2+(aq) + 5Fe3+(aq) 4H2O(l) H+ (oxidized or reduced) Answer 1 Choose... MnO4- (oxidizing or reducing agent) Answer 2 Choose... Fe2+ (oxidizing or reducing agent) Answer 3 Choose... Fe2+ (oxidized or reduced) Answer 4 Choose... O in MnO4- (oxidized or reduced) Answer 5 Choose... Mn in MnO4- (oxidized or reduced) Answer 6 Choose...
Explanation:
8H+(aq) + MnO4-(aq) + 5Fe2+(aq) → Mn2+(aq) + 5Fe3+(aq) + 4H2O(l)
To determine if a substance was reduced or oxidized, the oxidation number at the reactant and product side is compared.
When oxidation occurs, an element loses electrons and its oxidation number increases (becomes more positive). When reduction occurs, an element gains electrons and its oxidation number decreases or is reduced (becomes more negative).
H+ (oxidized or reduced) Answer 1 Choose...
There is an increase in oxidation number from 0 to 1. This means H+ was oxidized.
MnO4- (oxidizing or reducing agent) Answer 2 Choose...
In chemistry, an oxidizing agent is a substance that has the ability to oxidize other substances — in other words to accept their electrons
MnO4- is a strong oxidizing agent.
Fe2+ (oxidizing or reducing agent) Answer 3 Choose...
A reducing agent means it will itself get oxidized. In this reaction, Fe2+ is the reducing agent.
Fe2+ (oxidized or reduced) Answer 4 Choose...
Oxidized
O in MnO4- (oxidized or reduced) Answer 5 Choose...
There is no change in oxidation number of , so it was neither reduced nor was it oxidized.
Mn in MnO4- (oxidized or reduced) Answer 6 Choose...
There is a decreaase in oxidation number from +7 to +2. This means reduction.
A weather balloon is inflated to a volume of 27.6 L at a pressure of 755 mmHg and a temperature of 29.9 ∘C. The balloon rises in the atmosphere to an altitude where the pressure is 385 mmHg and the temperature is -14.1 ∘C. Assuming the balloon can freely expand, calculate the volume of the balloon at this altitude.
Answer: The volume of the balloon at this altitude is 46.3 L
Explanation:
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 755 mm Hg
[tex]P_2[/tex] = final pressure of gas (at STP) = 385 mm Hg
[tex]V_1[/tex] = initial volume of gas = 27.6 L
[tex]V_2[/tex] = final volume of gas = ?
[tex]T_1[/tex] = initial temperature of gas = [tex]29.9^0C=(29.9+273)K=302.9K[/tex]
[tex]T_2[/tex] = final temperature of gas = [tex]-14.1^0C=((-14.1)+273)K=258.9K[/tex]
Putting all the values we get:
[tex]\frac{755\times 27.6}{302.9}=\frac{385\times V_2}{258.9}[/tex]
[tex]V_2=46.3L[/tex]
Thus the volume of the balloon at this altitude is 46.3 L
A certain mass of carbon reacts with 9.53 g of oxygen to form carbon monoxide. ________ grams of oxygen would react with that same mass of carbon to form carbon dioxide, according to the law of multiple proportions.
Answer: 9.53 *2= 19.06
Explanation:
The law of multiple proportions states that if two elements combines to form more than one compound the ratio of masses of the second element which combines to the fixed mass of the first element will always be the ratios of the small whole numbers.
in case of carbon monoxide, mass of carbon will be the same of mass of oxygen.
But in case of carbon dioxide, if carbon is 9.53 units then oxygen will be twice as that of carbon.
CO2, so 9.53*2= 19.06 grams of oxygen will combine with 9.53 grams of carbon to form carbon dioxide.
A glass flask has a volume of 500 mL at a temperature of 20° C. The flask contains 492 mL of mercury at an equilibrium temperature of 20°C. The temperature is raised until the mercury reaches the 500 mL reference mark. At what temperature does this occur? The coefficients of volume expansion of mercury and glass are 18 ×10-5 K-1 (mercury) and 2.0 ×10-5 K-1 (glass).
Answer:
101.63° C
Explanation:
Volume expansivity γa = γr - γ g = 18 × 10⁻⁵ - 2.0 × 10⁻⁵ = 16 × 10⁻⁵ /K
v₂ - v₁ / v₁θ = 16 × 10⁻⁵ /K
(500 - 492 ) mL / (492 × 16 × 10⁻⁵) = θ
θ = 101.63° C
Which phrase describes one characteristic of radioactive elements?
are produced in a laboratory
O decay at a constant rate
O have a consistent number of particles
release energy and particles to maintain radioactivity
Answer:
B) decay at a constant rate
Explanation:
Over their lifetime, the radioactive elements tend to have constant rate of decay. This is seen in chemistry in Kinetics, where we see that radioactive elements follow first order kinetics where the rate at which they decay is constant (no matter what concentration we have)
Answer:
B) decay at a constant rate
Explanation:
just took the test
In the first 15.0 s of the reaction, 1.7×10−2 mol of O2 is produced in a reaction vessel with a volume of 0.440 L . What is the average rate of the reaction over this time interval?
Answer:
[tex]Rate=2.57x10^{-3}\frac{M}{s}[/tex]
Explanation:
Hello,
In this case, for the reaction:
[tex]2N_2O(g) \rightarrow 2N_2(g)+O_2(g)[/tex]
We can easily compute the average rate by firstly computing the final concentration of oxygen:
[tex][O_2]=\frac{0.017mol}{0.440L}=0.0386M[/tex]
Then, we compute it by using the given interval of time: from 0 seconds to 15.0 seconds and concentration: from 0 M to 0.0386M as oxygen is being formed:
[tex]Rate=\frac{0.0386M-0M}{15.0s-0s}\\ \\Rate=2.57x10^{-3}\frac{M}{s}[/tex]
Regards.
According to the question,
Volume = 0.440 LTime = 15.0 sMol of O₂ = 1.7×10⁻²The reaction will be:
[tex]2 N_2 O (g) \rightarrow 2 N_2 (g) +O_2 (g)[/tex]Now,
The final concentration of O₂ will be:
→ [tex][O_2] = \frac{0.017}{0.440}[/tex]
[tex]= 0.0386 \ M[/tex]
hence,
The rate of reaction will be:
= [tex]\frac{0.0386-0}{15.0-0}[/tex]
= [tex]2.57\times 10^{-3} \ M/s[/tex]
Thus the above approach is right.
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In the diagram below, particles of the substance are moving from the liquid phase to the gas phase at the same rate as they move from the gas phase to the liquid phase. A number of balls are loosely packed in the bottom of a container, beneath a line across the middle of the container, and a few balls above the line. 2 balls below the line have arrows pointing upward through the centerline; a few of the balls above the line have arrows pointing down through the centerline. The gas and liquid are at equilibrium. a high vapor pressure. a low vapor pressure. zero vapor pressure.
Answer:
The gas and liquid is in equilibrium.
Explanation:
liquids within a container undergoes state change, changing into gas. If this container is left open, these gases will escape into the external environment. In a situation in which the container is closed, the molecules that leave the liquid surface as gas will eventually condense on contact with the cover wall and change back into the liquid state. Some of these gases will reenter the liquid surface. At first, more of the liquid is transformed into gas and escape into the space above the liquid surface. Eventually, the available space becomes saturated with vapor, and then some of the gases start entering the liquid phase at the same rate as the liquid enters the gas phase. At this stage, the gas and liquid phase now exists in equilibrium.
Benny Beaver wants to determine what dyesare present in his favorite sports drink. He analyzesa sample witha UV-visiblespectrophotometer and sees absorbance peaks at 415.2nm and 519.6nm. What colordyesare present in his drink
Answer:
At 415.2nm and 519.6nm, the dyes observed by the instrument are violet and green respectively.
Explanation:
In the electromagentic spectrum, visible wavelengths cover a range from approximately 400 to 800 nm. The colours of the spectrum range from red to violet (Red, Orange, Yellow, Green, Blue, Indigo and violet: a.k.a ROGBIV), in order of decreasing wavelength.
I hope this explanation would suffice.
When the following molecular equation is balanced using the smallest possible integer coefficients, the values of these coefficients are:
sulfur dioxide (g) + water (l) __________sulfurous acid (H2SO3) (g) + water (I)
Answer:
Sulfur dioxide + 2 ( water ) -----> sulfurous acid + water /
SO2 + 2 ( H2O ) -----> H2SO3 + H2O
Explanation:
This formula may not be right. Sulfur dioxide tends to react with water to produce sulfurous acid as per it's formula, but then again that chemical reaction need not be balanced. However, I will solve for either case here -
Sulfur dioxide + water -----> sulfurous acid,
Sulfur dioxide + water -----> sulfurous acid + water
_______________________________________________________
As I mentioned before, Sulfur dioxide + water -----> sulfurous acid is a chemical reaction that need not balancing as the number of each element present on the reactant and product side are the same. To help, let me rewrite this reaction -
SO2 + H2O -----> H2SO3,
Reactant | Product
Sulfur = 1, Sulfur = 1,
Oxygen = 3, Oxygen = 3,
Hydrogen = 2 Hydrogen = 2
And hence the equation is already balanced. Now let us consider the case we supposedly have at hand - Sulfur dioxide + water -----> sulfurous acid + water. Take a look at the attachment below;
A theater director reinterprets a play by replacing its classical score with
current pop hits. Which statement describes the most likely effect of this
change on audience members?
O A. The main characters will appear more conservative.
B. The play will be more appealing to a younger audience.
C. The audience will think more about themes of patriotism.
O D. The tone will be more negative and depressing.
Answer:
The play will be more appealing to a younger audience.
Explanation:
A younger audience will more likely appreciate current pop hits rather than classical score.
Answer:
B. The play will be more appealing to a younger audience.
Explanation:
If the audience is younger, then this would be more appealing to them because pop has always been one of the fan-favorties of younger generations
The proposed mechanism for a reaction is: Step 1: A + B X (fast) Step 2: X + C Y (slow) Step 3: Y D (fast) What is the overall reaction? A. A + B + C D B. A + X Y + D C. A + B Y D. A + Y D
Answer:
A. A + B + C --> D
Explanation:
Step 1: A + B --> X (fast)
Step 2: X + C --> Y (slow)
Step 3: Y --> D (fast)
To obtain the overall reaction, we have to sum up the reactants and products of all step and eliminate the intermediates.
Reactants:
A + B + X + C + Y
Products:
X + Y + D
So we have;
A + B + X + C + Y --> X + Y + D
Upon elimination of intermediates, we have;
A + B + C --> D
The correct option is A.
all compounds are neutral true or false
Answer:
Even all compounds are neutral.
Explanation:
Some of them exhibit polarity. Because of the difference in electron affinity of the constituent atoms, the shared electrons are pulled towards the atom with high affinity to electrons.
can a kind human being help me with this table at least only with the first burning fire wood someone please
Answer:
See below
Explanation:
* Burning fire wood is given to be our first option. Now burning tends to be a property of wood, and it does effect the chemical compositions of it. Wood, in the presence of fire / oxygen, turns into ash and carbon dioxide.
* Decomposition is recognized as a chemical change, and heating copper carbonate is a perfect example of decomposition. When energy is added to this chemical process, the copper carbonate decomposes into copper oxide.
* Mixing sodium chloride solution and silver nitrate solution. When this reaction takes place, a white precipitate of AgCl is formed. And of course, this is a chemical reaction.
* When acids or bases come in contact with citric acid, the pH degree changes much. Due to this, carbon dioxide bubbles are formed.
* When eggs are fried they absorb the heat in the pan. Doing so the egg starts to curl a bit, resulting in the formation of new particles.
_______________________________________________________
I hope this gave you a start!
Given a gas whose temperature is 418 K at a pressure of 56.0 kPa. What is the pressure of the gas if its Temperature changes to 64°C?
Answer: P₂=0.44 atm
Explanation:
For this problem, we are dealing with temperature and pressure. We will need to use Gay-Lussac's Law.
Gay-Lussac's Law: [tex]\frac{P_{1} }{T_{1} } =\frac{P_{2} }{T_{2} }[/tex]
First, let's do some conversions. Anytime we deal with the Ideal Gas Law and the different laws, we need to make sure our temperature is in Kelvins. Since T₂ is 64°C, we must change it to K.
64+273K=337K
Now, it may be uncomfortable to use kPa instead of atm, so let's convert kPa to atm.
[tex]56.0kPa*\frac{1000Pa}{1kPa} *\frac{atm}{101325Pa} =0.55atm[/tex]
Since our units are in atm and K, we can use Gay-Lussac's Law to find P₂.
[tex]P_{2} =\frac{T_{2} P_{1} }{T_{1} }[/tex]
[tex]P_{2}=\frac{(337K)(0.55atm)}{418K}[/tex]
P₂=0.44 atm
What type of chemical reaction occurs between AgNO3 (sliver nitrate) and Cu (Copper)?
Answer:
The answer is option c.
I hope this helps you.
Oxygen gas is most soluble in water under which set of conditions?
High pressure and low temperature.
When 1-iodo-1-methylcyclohexane is treated with NaOCH2CH3 as the base, the more highly substituted alkene product predominates. When KOC(CH3)3 is used as the base, the less highly substituted alkene predominates. Give the structures of the two products and offer an explanation.
Answer:
See explanation
Explanation:
In this case, we have 2 types of reactions. [tex]CH_3CH_2ONa[/tex] is a strong base but only has 2 carbons therefore we will have less steric hindrance in this base. So, the base can remove hydrogens that are bonded on carbons 1 or 6, therefore, we will have a more substituted alkene (1-methylcyclohex-1-ene).
For the [tex]KOC(CH_3)_3[/tex] we have more steric hindrance. So, we can remove only the hydrogens from carbon 7 and we will produce a less substituted alkene (methylenecyclohexane).
See figure 1
I hope it helps!
3. The Kp for the reaction below is 1.49 × 108 at 100.0 °C:CO (g) + Cl2 (g) → COCl2 (g)In an equilibrium mixture of the three gases, PCO = PCl2 = 1.76 × 10-4 atm. The partial pressure of the product, phosgene (COCl2), is ________ atm.
Answer:
In an equilibrium mixture of the three gases, PCO = PCl2 = 2.22 × 10-4 atm. The partial pressure of the product, phosgene (COCl2), is kp=(COCl2)/(CO)(Cl2) which is . So, the correct answer is 7.34.
artaric acid, H2C4H4O6, has two acidic hydrogens. The acid is often present in wines and precipitates from solution as the wine ages. A solution containing an unknown concentration of the acid is titrated with NaOH. It requires 21.65 mL of 0.3500 M NaOH solution to titrate both acidic protons in 50.00 mL of the tartaric acid solution. You may want to reference (Pages 149 - 153) Section 4.6 while completing this problem. Part A Write a balanced net ionic equation for the neutralization reaction. Express your answer as a chemical equation including phases.
Answer:
2H⁺(aq) + + 2OH⁻(aq) → 2H₂O(l)
Explanation:
A acid that has two acidic hydrogens requires to moles of NaOH per mole of acid producing the salt of the acid and water.
If the acid is tartaric acid, H₂C₄H₄O₆, the reaction with NaOH is:
H₂C₄H₄O₆(aq) + 2NaOH(aq) → 2H₂O(l) + 2NaC₄H₄O₆(aq)
Now, ions in solution in the reaction are:
2H⁺(aq) + C₄H₄O₆²⁻(aq) + 2Na⁺(aq) + 2OH⁻(aq) → 2H₂O(l) + 2Na⁺(aq) +C₄H₄O₆²⁻(aq)
Thus, net ionic equation (Lisiting only the ions involved in the reaction) is:
2H⁺(aq) + + 2OH⁻(aq) → 2H₂O(l)ii)
An organic liquid having carbon, hydrogen, nitrogen and oxygen was found to
contain C = 41.37%; H = 5.75% ; N= 16.09 % and the rest oxygen. Calculate
the Empirical formula
(6 marks)
Answer:
C3H5NO2
Explanation:
C = 41.37%;
H = 5.75% ;
N= 16.09 %;
O= (100 - 41.37 - 5.75 - 16.09)% = 36.79 %.
In 100 g of substance we have
C = 41.37 g;
H = 5.75 g ;
N= 16.09 g;
O = 36.79 g.
Molar mass (C) = 12 g/mol;
Molar mass(H) =1 g/mol;
Molar mass(N)= 14 g/mol;
Molar mass(O) = 16 g/mol.
C = 41.37 g* 1 mol/12g = 3.4475 mol;
H = 5.75 g *1 mol/1g = 5.75 mol;
N= 16.09 g*1mol/14g = 1.1493 mol;
O = 36.79 g* 1mol/16g = 2.2994 mol.
The Empirical formula shows ratio of moles of elements in the substance , so
C : H : N : O = 3.4475 mol : 5.75 mol : 1.1493 mol : 2.2994 mol =
= (3.4475 mol /1.1493 mol) : (5.75 mol/1.1493 mol) : (1.1493 mol /1.1493 mol) : :( 2.2994 mol/1.1493 mol) = 3 : 5 : 1 : 2
C : H : N : O = 3 : 5 : 1 : 2
C3H5NO2
Combustion analysis of a 13.42-g sample of estriol (which contains only carbon, hydrogen, and oxygen) produced 36.86 g CO2 and 10.06 g H2O. The molar mass of estriol is 288.38 g/mol . Find the molecular formula for estriol. Express your answer as a chemical formula.
Answer:
C18H24O3
Explanation:
Step 1:
Data obtained from the question. This include the following:
Mass of estriol = 13.42g
Mass of CO2 = 36.86g
Mass of H2O = 10.06g
Molar mass of estriol = 288.38g/mol
Step 2:
Determination of the mass of Carbon (C), Hydrogen (H) and Oxygen (O) present in the compound. This is illustrated below:
For Carbon, C:
Molar mass of CO2 = 12 + (2x16) = 44g/mol
Mass of C in CO2 = 12/44 x 36.86 = 10.05g
For Hydrogen, H:
Molar Mass of H2O = (2x1) + 16 = 18g/mol
Mass of H in H2O = 2/18 x 10.06 = 1.12g
For Oxygen, O:
Mass of O = 13.42 – (10.05 + 1.12) = 2.25g
Step 3:
Determination of the empirical formula for estriol. This is illustrated below:
C = 10.05g
H = 1.12g
O = 2.25g
Divide by their molar mass
C = 10.05/12 = 0.8375
H = 1.12/1 = 1.12
O = 2.25/16 = 0.1406
Divide by the smallest i.e 0.1406
C = 0.8375/0.1406 = 6
H = 1.12/0.1406 = 8
O = 0.1406/0.1406 = 1
Therefore, the empirical formula for estriol is C6H8O
Step 4:
Determination of the molecular formula for estriol. This is illustrated below:
Molecular formula is simply a multiple of the empirical formula i.e
Molecular formula => [C6H8O]n
[C6H8O]n = 288.38g/mol
[(12x6) + (8x1) + 16]n = 288.38
[72 + 8 + 16]n = 288.38
96n = 288.38
Divide both side by 96
n = 288.38/96 = 3
Molecular formula => [C6H8O]n
=> [C6H8O]n
=> [C6H8O]3
=> C18H24O3
Therefore, the molecular formula for estriol is C18H24O3
The compound is C18H24O3.
From the information in the question;
Mass of C = 36.86 g/44 g/mol × 12 g/mol = 10.1 g
Number of moles of carbon = 10.1 g/12 g/mol = 0.84 moles
Mass of hydrogen = 10.06 g/18 g/mol × 2 g/mol = 1.11 g
Number of moles of hydrogen = 1.11 g/1g/mol = 1.11 moles
Mass of oxygen = 13.42 - (10.1 g + 1.11 g) = 2.21 g
Number of moles of oxygen = 2.21g/16 g/mol = 0.14 moles
Dividing through by the lowest number of moles;
C - 0.84 moles/0.14 moles H - 1.11 moles/0.14 moles O - 0.14 moles/0.14 moles
C - 6 H - 8 O -1
The empirical formula is C6H8O
The molecular formula of the compound is;
[6(12) + 8(1) + 16]n = 288.38
n = 288.38/86 =3
The compound is C18H24O3
Learn more about molecular formula:https://brainly.com/question/8073802
What is the net ionic equation of the reaction of MgSO4 with Ba(NO3)2 ?
Answer:
Ba(+2)(aq) + SO4(-2)(aq) -----> BaSO4(s)
Explanation:
Take a look at the attachment below;
Which group of diamagnetic transition metals exhibits trends in density and melting points that don't match the same trends seen in other groups?
A. Group 12
B. Group 3
C. Group 11
D. Group 7
Answer:
Group 12
Explanation:
Group 12 transition metals include; zinc cadmium, mercury and copernicium. Because of their striking difference in property when compared to other transition elements, they are sometimes called post-transition elements.
These elements possess completely filled ns and nd orbitals hence they are diamagnetic. They have the lowest melting points and densities among all transition metals. Their densities in gcm^-3 are; Zn (7.14), Cd(8.65) and Hg (13.5). We can see that unlike other transition metal groups, their densities vary only within a narrow margin hence they have properties slightly different from other transition elements.