Answer:
[tex][OH^-]=3.33x10^{-7}M[/tex]
Explanation:
Hello,
In this case, for the given concentration of hydronium, we can compute the pH as shown below:
[tex]pH=-log([H^+])=-log(3.0x10^{-8})=7.52[/tex]
Now, given the relationship between pH and pOH we can compute the pOH which is directly related with the concentration of hydroxyl in the solution:
[tex]pOH=14-pH=14-7.52=6.48[/tex]
Then, the concentration of hydroxyl turns out:
[tex][OH^-]=10^{-pOH}=10^{-6.48}[/tex]
[tex][OH^-]=3.33x10^{-7}M[/tex]
Best regards.
Which sample is most likely to experience the smallest temperature change upon observing 55KJ of heat? 
Answer:
100 g of water: specific heat of water 4.18 J/g°C
Explanation:
To know the correct answer to the question, we shall determine the temperature change in each case.
For 100 g of water:
Mass (M) = 100 g
Specific heat capacity (C) = 4.18 J/g°C
Heat absorbed (Q) = 55 KJ = 55000 J
Change in temperature (ΔT) =..?
Q = MCΔT
55000 = 100 x 4.18 x ΔT
Divide both side by 100 x 4.18
ΔT = 55000/ (100 x 4.18)
ΔT = 131.6 °C
Therefore the temperature change is 131.6 °C
For 50 g of water:
Mass (M) = 50 g
Specific heat capacity (C) = 4.18 J/g°C
Heat absorbed (Q) = 55 KJ = 55000 J
Change in temperature (ΔT) =..?
Q = MCΔT
55000 = 50 x 4.18 x ΔT
Divide both side by 50 x 4.18
ΔT = 55000/ (50 x 4.18)
ΔT = 263.2 °C
Therefore the temperature change is 263.2 °C
For 50 g of lead:
Mass (M) = 50 g
Specific heat capacity (C) = 0.128 J/g°C
Heat absorbed (Q) = 55 KJ = 55000 J
Change in temperature (ΔT) =..?
Q = MCΔT
55000 = 50 x 0.128 x ΔT
Divide both side by 50 x 0.128
ΔT = 55000/ (50 x 0.128)
ΔT = 8593.8 °C
Therefore the temperature change is 8593.8 °C.
For 100 g of iron:
Mass (M) = 100 g
Specific heat capacity (C) = 0.449 J/g°C
Heat absorbed (Q) = 55 KJ = 55000 J
Change in temperature (ΔT) =..?
Q = MCΔT
55000 = 100 x 0.449 x ΔT
Divide both side by 100 x 0.449
ΔT = 55000/ (100 x 0.449)
ΔT = 1224.9 °C
Therefore the temperature change is 1224.9 °C.
The table below gives the summary of the temperature change of each substance:
Mass >>> Substance >> Temp. Change
100 g >>> Water >>>>>> 131.6 °C
50 g >>>> Water >>>>>> 263.2 °C
50 g >>>> Lead >>>>>>> 8593.8 °C
100 g >>> Iron >>>>>>>> 1224.9 °C
From the table given above we can see that 100 g of water has the smallest temperature change.
A vehicle travels 2345 meter in 35 second toward the evening sun in the West. What is its speed? A. 47 m/s West
Explanation:
Speed = 2345 ÷ 35 = 67m/s
What word or two-word phrase best describes the shape of the water ( H2O ) molecule?
Answer:
Water (H2O) is an inorganic chemical compound formed by two hydrogen (H) and one oxygen (O) atoms. 3 This molecule is essential in the life of living beings, serving as a medium for the metabolism of biomolecules, is found in nature in its three states and was key to its formation. It is necessary to distinguish between drinking water and pure water, since the first is a mixture that also contains salts in solution; this is why in the laboratory and in other areas distilled water is used.
Explanation:
I hope I've helped
According to the molecular geometry, the V-shape or bent structure best describes the shape of water molecule.
What is molecular geometry?Molecular geometry can be defined as a three -dimensional arrangement of atoms which constitute the molecule.It includes parameters like bond length,bond angle and torsional angles.
It influences many properties of molecules like reactivity,polarity color,magnetism .The molecular geometry can be determined by various spectroscopic methods and diffraction methods , some of which are infrared,microwave and Raman spectroscopy.
They provide information about geometry by taking into considerations the vibrational and rotational absorbance of a substance.Neutron and electron diffraction techniques provide information about the distance between nuclei and electron density.
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Arrange the following elements in order of decreasing first ionization energy: S, Ca, F, Rb, and Si.
Rank from largest to smallest. To rank items as equivalent, overlap them.
Answer:
The concentration of energy needed to withdraw an electron from an atom’s mole in the gas phase is known as the ionization energy of an atom. It is more accurately termed as the first ionization energy. The ionization energy upsurges from left to right through a period and from top to bottom in the groups.
Of the given elements S, Ca, F, Rb, and Si, the S, and Si belong to the third period, and the atomic radius of S is less in comparison to Si, F belongs to the second period, Rb belongs to the fifth period, and Ca belongs to the fourth period. Thus, the decreasing order of first ionization energy, that is, from largest to smallest is F > S > S > Ca > Rb.
Considering the definition of ionization energy,
Ionization energy, also called ionization potential, is the necessary energy that must be supplied to a neutral, gaseous, ground-state atom to remove an electron from an atom. When an electron is removed from a neutral atom, a cation with a charge equal to +1 is formed.
You should keep in mind that the electrons of the last layer are always lost, because they are the weakest attracted to the nucleus.
In a group, the ionization energy increases upwards because when passing from one element to the bottom, it contains one more layer of electrons. Therefore, the valence layer electrons, being further away from the nucleus, will be less attracted to it and it will cost less energy to pluck them.
In the same period, in general, it increases as you shift to the right. This is because the elements in this way have a tendency to gain electrons and therefore it will cost much more to tear them off than those on the left which, having few electrons in the last layer will cost them much less to lose them.
Taking into account the above, the decreasing order of first ionization energy, that is, from largest to smallest is F > S > S > Ca > Rb.
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https://brainly.com/question/24409114https://brainly.com/question/14158485?referrer=searchResultshttps://brainly.com/question/14454446?referrer=searchResultsPhosphorus pentafluoride, PF5, acts as a __________ during the formation of the anion PF−6. Select the correct answer below: A. Lewis acid B. Lewis base C. catalyst D. drying agent
Answer:
Lewis acid
Explanation:
In chemistry, a Lewis acid is any chemical specie that accepts a lone pair of electrons while a Lewis base is any chemical specie that donates a lone pair of electrons.
If we look at the formation of PF6^-, the process is as follows;
PF5 + F^- -----> PF6^-
We can see that PF5 accepted a lone pair of electrons from F^- making PF5 a lewis acid according to our definition above.
Hence in the formation of PF6^-, PF5 acts a Lewis acid.
If a radioactive isotope of thorium (atomic number 90, mass number 232) emits 6 alpha particles and 4 beta particles during the course of radioactive decay, what is the mass number of the stable daughter product?
Answer:
The mass number of the stable daughter product is 208
Explanation:
First thing's first, we have to write out the equation of the reaction. This is given as;
²³²₉₀Th → 6 ⁴₂α + 4 ⁰₋₁ β + X
In order to obtain the identity of X, we have to obtain it's mass numbers and atomic number.
There is conservation of matter so we expect the mass number to remain the same in both the reactant and products.
Mass Number
Reactant = 232
Product = (6* 4 = 24) + (4 * 0 = 0) + x = 24 + x
since reactant = product
232 = 24 + x
x = 232 - 24 = 208
Atomic Number
Reactant = 90
Product = (6* 2 = 12) + (4 * -1 = -4) + x = 8 + x
since reactant = product
90 = 8 + x
x = 90 - 8 = 82
What are the concentrations of [K+], [OH-], [CO32-] and [H+], in a 1.2 M solution of K2CO3 ? (Note: Question is asking for concentrations and not pH) g
Answer:
The concentrations are: [K⁺] = 1.2 M, [OH⁻] = 0.016 M, [CO₃²⁻] = 1.18 M and [H⁺] = 6.25x10⁻¹³ M.
Explanation:
The dissociation equation of K₂CO₃ in water is:
K₂CO₃(aq) ⇄ K⁺(aq) + CO₃²⁻(aq) (1)
Also, the CO₃²⁻ will react with water as follows:
CO₃²⁻(aq) + H₂O(l) ⇄ HCO₃⁻(aq) + OH⁻(aq) (2)
The constant of the reaction (2) is:
[tex] Kb = \frac{[OH^{-}][HCO_{3}^{-}]}{[CO_{3}^{-2}]} = 2.08 \cdot 10^{-4} [/tex]
The solution of K₂CO₃ is 1.2 M, and since the mole ratio of K₂CO₃ with K⁺ and CO₃²⁻ is 1:1, then we have:
[tex] [K_{2}CO_{3}] = [K^{+}] = [CO_{3}^{-2}] = 1.2 M [/tex]
Now, from equation (2) we have:
CO₃²⁻(aq) + H₂O(l) ⇄ HCO₃⁻(aq) + OH⁻(aq) (3)
1.2 - x x x
[tex] 2.08 \cdot 10^{-4} = \frac{[OH^{-}][HCO_{3}^{-}]}{[CO_{3}^{-2}]} [/tex]
[tex] 2.08 \cdot 10^{-4} = \frac{x^{2}}{1.2 - x} [/tex]
[tex] 2.08 \cdot 10^{-4}*(1.2 - x) - x^{2} = 0 [/tex] (4)
By solving equation (4) for x we have:
x = 0.016 M = [HCO₃⁻] = [OH⁻]
Hence, the CO₃²⁻ concentration is:
[CO₃²⁻] = 1.2 M - 0.016 M = 1.18 M
Finally, the concentration of [H⁺] is:
[tex] [H^{+}][OH^{-}] = 10^{-14} [/tex]
[tex][H^{+}] = \frac{10^{-14}}{[OH^{-}]} = \frac{10^{-14}}{0.016} = 6.25 \cdot 10^{-13} M[/tex]
Therefore, the concentrations are: [K⁺] = 1.2 M, [OH⁻] = 0.016 M, [CO₃²⁻] = 1.18 M and [H⁺] = 6.25x10⁻¹³ M.
I hope it helps you!
For each reaction, write the chemical formulae of the oxidized reactants in the space provided. Write the chemical formulae of the reduced reactants.
reactants oxidized _____
reactants reduced _____
a. 2Fe(s)+3Pb(NO3)2(aq)→3Pb(s)+2Fe(NO3)3(aq)
b. AgNO3(aq)+Cu(s)→2Ag(s)+CuNO)2(a)
c. 3AgNO(aq)+Al()→3Ags)+Al(NO3)3(aq)
Answer:
a. Oxidized: Fe(s)
Reduced: Pb(NO3)2
b.Oxidized: Cu(s)
Reduced: AgNO3
c. Oxidized: Al(s)
Reduced: AgNO3
Explanation:
In a redox reaction, one reactant is been oxidized whereas the other is reduced.. The reduced reactant is the one that is gaining electrons and the oxidized one is loosing electrons.
In the reactions:
a. 2Fe(s)+3Pb(NO3)2(aq)→3Pb(s)+2Fe(NO3)3(aq)
The Fe is as reactant as Fe(s) (Oxidation state 0) and the product is +3 (Because NO3, nitrate ion, is always -1). That means Fe is oxidized. The Pb as reactant is +2 and as product 0 (Gaining 2 electrons). Pb(NO3)2 is reduced
b. 2AgNO3(aq)+Cu(s)→2Ag(s)+Cu(NO3)2(a)
AgNO3 is +1 and Ag(s) is 0. AgNO3 is reduced. Cu(s) is 0 as reactant and +2 as product. Cu(s) is been oxidized
c. 3AgNO3(aq)+Al(s)→3Ag(s)+Al(NO3)3(aq)
Here, in the same way, AgNO3 is +1 as reactant and 0 as product. AgNO3 is reduced. And Al(s) is 0 as reactant but + 3 as product. Al(s) is oxidized.
g Increasing the number of unsaturations in a fatty acid ____________ the melting temperature of the fatty acid.
Answer:
Decreases
Explanation:
Fatty acid which have the double bond or triple bond are called unsaturated fatty acids. Because of the double or triple bond, unsaturated fatty acids are loosely packed and form some distance among molecules which lowers the melting point of unsaturated fatty acids.
So, if the unsaturation of fatty acid will increase, it leads to more branched and loosely packed molecules and decreases the melting temperature accordingly.
A certain radioactive nuclide has a half life of 1.00 hour(s). Calculate the rate constant for this nuclide. s-1 Calculate the decay rate for 1.000 mole of this nuclide. decays s-1
Answer:
k= 1.925×10^-4 s^-1
1.2 ×10^20 atoms/s
Explanation:
From the information provided;
t1/2=Half life= 1.00 hour or 3600 seconds
Then;
t1/2= 0.693/k
Where k= rate constant
k= 0.693/t1/2 = 0.693/3600
k= 1.925×10^-4 s^-1
Since 1 mole of the nuclide contains 6.02×10^23 atoms
Rate of decay= rate constant × number of atoms
Rate of decay = 1.925×10^-4 s^-1 ×6.02×10^23 atoms
Rate of decay= 1.2 ×10^20 atoms/s
1. In the addition of HBr to conjugated dienes, is the product which results from 1,2-addition or that which results from 1,4-addition the product of kinetic control?
A. From 1,2-addition
B. From 1,4-addition
2. Which of the following is the strongest acid?
A. CH3CH20H
B. CHзOCH3
C. CH3CH
D. CH3COCH3
E. CH3COH
Answer:
The answer to this question can be defined as follows:
In question 1, the answer is "Option A".
In question 2, the answer is "[tex]\bold{CH_3COOH}[/tex]".
Explanation:
In the second question, there is mistype error in the choices so the correct answer to this question can be defined as follows:
The product From 1,2-addition as its consequence of 1,4-addition is the result of kinetic regulation by HBr in conjugated dienes.The chemical name of the [tex]CH_3COOH[/tex] is the acetic acid, it is one of the carboxylic acids quite basic. It is a major chemical production factor for use as disposable soft drinks, movies or wood glue, polyethylene terephthalate, and many plastics, fibers, and fabrics. It is also used in the storage of the water and soft drinks in the bottles.Citra is using the basic permanent wrap method to perm Holly's hair. As Citra divides Holly's hair into panels, how wide should she make them?
Answer:
Citra should make it equal to the length of the rod.
Explanation:
A basic permanent wrap method is a 9 section wrap method in which all the base sections are horizontal, having same length and width of the rod
Basic permanent wrap method causes a uniform curl from the scalp to the end of the hair.
In permanent wrap method, paneling the hair equal to the length will make the will give the same size as the rod.
The length of the rod determines the size of the curl.
Once Holly's hair is divided into panel and make it as wide as the length of the rod, it will curl in the same size as the rod lengths and the hair will perm well.
Calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. Round your answer to the nearest .
Answer:
-471 Kj/mole acrylic acid
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. In the first step, calcium carbide and water react to form acetylene and calcium hydroxide: CaC (s) + 2 H2O(g) - CH (9) + Ca(OH),(s) AH -414. kJ In the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6 C H (9) + 3 CO2(9) + 4H2O(g) - SCH,CHCO,H) AH-132. kJ Calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. Round your answer to the nearest kJ. x 5 ?
The two equations from the reaction can be written as;
a)CaC₂(s) + 2H₂O(l) ------->C₂H₂(g) + CaOH₂(s)
Δ H= -414Kj ........................ equation (a)
b)6C₂H₂(g) +3CO₂(g)+4H₂O(g) -------> 5CH₂CHCO₂H(g) Δ H= 132Kj ...................... equation (b)
In equation (b)acrylic acid was produced by the reaction between Acetylene carbon dioxide and water
Then we can multiply equation(a) by factor of 6 and the ΔH Then we have (6× -414Kj)= ΔH= -2484Kj.
6CaC₂(s) + 12H₂O(l) ------->6C₂H₂(g) + 6CaOH₂(s)
Δ H= -2484Kj.................. equation (c)
6C₂H₂(g) +3CO₂(g)+4H₂O(g) -------> 5CH₂CHCO₂H(g) Δ H= 132Kj
Then add equation (c) and equation(b) then we have
6CaC₂(s) + 16H₂O(l)+3CO₂(g)------> 5CH₂CHCO₂H(g) + 6CaOH₂(s) ΔH= -2352Kj
ΔH(net)= -2352Kj/5moles
=-471Kj/mole
therefore, net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. Round your answer to the nearest kJ. x 5 ? is -471Kj/mole acrylic acid
Determine the volumes of 0.10 M CH3COOH and 0.10 M CH3COONa required to prepare 10 mL of the following pH buffers: pH 4.7, pH 5.7. (Note: the pKa of CH3COOH
Answer:
pH 4.7: 5mL of 0.10 M CH3COOH and 5mL 0.10 M CH3COONa
pH 5.7: 0.91mL of 0.10 M CH3COOH and 9.09mL 0.10 M CH3COONa
Explanation:
pKa acetic acid, CH3COOH = 4.7
It is possible to determine pH of a buffer using H-H equation:
pH = pka + log [A⁻] / [HA]
For the acetic buffer,
pH = 4.7 + log [CH3COONa] / [CH3COOH]
As you want a pH 4.7 buffer:
4.7 = 4.7 + log [CH3COONa] / [CH3COOH]
1 = [CH3COONa] / [CH3COOH]
That means you need the same amount of both species of the buffer to make the pH 4.7 buffer. That is:
5mL of 0.10 M CH3COOH and 5mL 0.10 M CH3COONaFor pH 5.7:
5.7 = 4.7 + log [CH3COONa] / [CH3COOH]
1 = log [CH3COONa] / [CH3COOH]
10 = [CH3COONa] / [CH3COOH] (1)
That means you need 10 times [CH3COONa] over [CH3COOH]
And as you know:
10mL= [CH3COONa] + [CH3COOH] (2)
Replacing (1) in (2):
10 = 10mL + [CH3COOH] / [CH3COOH]
10[CH3COOH] = 10mL + [CH3COOH]
11[CH3COOH] = 10mL
[CH3COOH] = 0.91mL
And [CH3COONa] = 10mL - 0.91mL =
[CH3COONa] = 9.09mL
That is:
0.91mL of 0.10 M CH3COOH and 9.09mL 0.10 M CH3COONaThe volumes according to the pH are as follows:
(i) 5mL of 0.10 M CH₃COOH and 5mL 0.10 M CH₃COONa for pH 4.7
(ii) 0.91mL of 0.10 M CH₃COOH and 9.09mL 0.10 M CH₃COONa pH 5.7
Calculating the volume of chemicals needed:Given that pKa of acetic acid, CH₃COOH = 4.7
The pH of a buffer using the H-H equation is given by:
pH = pKa + log [A⁻] / [HA]
For the acetic buffer,
pH = 4.7 + log [CH₃COONa] / [ CH₃COOH]
4.7 = 4.7 + log [CH₃COONa] / [ CH₃COOH]
0 = log [CH₃COONa] / [ CH₃COOH]
takin antilog on both sides of the equation we get:
1 = [CH₃COONa] / [CH₃COOH]
It implies that the same amount of both species is needed to make the pH 4.7 buffer.
So,
5mL of 0.10 M CH₃COOH and 5mL 0.10 M CH₃COONa makes a buffer of pH 4.7
Similarly:
5.7 = 4.7 + log [CH₃COONa] / [CH₃COOH]
1 = log [CH₃COONa] / [CH₃COOH]
takin antilog on both sides of the equation we get:
10 = [CH₃COONa] / [CH₃COOH]
10[CH₃COOH] = [CH₃COONa]
It implies that we need 10 times [CH₃COONa] as much of [CH₃COOH]
We have to prepare 10 mL of buffer, so:
10mL= [CH₃COONa] + [CH₃COOH]
10mL = 11[CH₃COOH]
[CH₃COOH] = 0.91mL
So, [CH₃COONa] = 10mL - 0.91mL
[CH₃COONa] = 9.09mL
Therefore,
0.91mL of 0.10 M CH3COOH and 9.09mL 0.10 M CH3COONa is required to make a buffer of pH 5.7
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Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. It is used to make cosmetics, ointments, soaps, and candles and is found in animal tissue as part of many saturated fats. In fact, when you eat meat, you are ingesting some fats containing stearic acid. ( of C18H36O2 = –948 kJ/mol, CO2=-393.5kJ/mol, H2O=-241.826kJ/mol).
Calculate the heat (q) released in kcal when 2.831 g of stearic acid is burned completely.
The molar mass of stearic acid is 18*AC+36*AH+2*AO=18*12+36*1+16*2=284g/mol.
n=m/M=2.831/284=0.01 moles
C18H36O2+27O2-->18CO2+18H2O
we have 18*0.01=0.18 moles of CO2
18*0.01=0.18 moles of H2O
0.01*948=9.48kJ from stearic acid
0.18*393.5=70.83kJ from CO2
0.18*241.826=43.52kJ from H2O
9.48+70.83+43.52=123.83kJ
123.83*4.184=518.10kcal
14. Based on your previous observations, predict the impact of changing the number of moles of a gas sample on the volume of the gas sample (if pressure and temperature are held constant). What effect would changing the number of moles of a gas sample have on the temperature of a gas sample (if pressure and volume are held constant)? Explain
Answer:
Number of moles of gas is directly proportional to the volume of the gas
Number of moles of the gas is directly proportional to the temperature of the gas
Explanation:
According to Avogadro's law, changing the number of moles of a gas changing the volume of the gas also since the volume of a gas is directly proportional to the number of moles of the gas.
Hence from Avogadro's law; V= kn where k is a proportionality constant, V is the volume of the gas and n is the number of moles of the gas.
Changing the number of moles will also lead to a change in the temperature of the gas, since volume is directly proportional to the number of moles of the gas and volume is also directly proportional to temperature (Charles law), it the follows that number of moles of the gas is directly proportional to its temperature.
The cell potential for an electrochemical cell with a Zn, Zn2 half-cell and an Al, Al3 half-cell is _____ V. Enter your answer to the hundredths place and do not leave out a leading zero, if it is needed.
Answer:
0.900 V
Explanation:
Oxidation half cell;
2Al(s) -----> 2Al^3+(aq) + 6e
Reduction half equation;
3Zn^2+(aq) + 6e ----> 3Zn(s)
E°anode = -1.66V
E°cathode= -0.76 V
E°cell= E°cathode - E°anode
E°cell= -0.76-(-1.66)
E°cell= 0.900 V
Which of these groups of elements show the least electronegativity?
Explanation:
On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group. As a result, the most electronegative elements are found on the top right of the periodic table, while the least electronegative elements are found on the bottom left. The answer is alkali metals.D-Fructose is the sweetest monosaccharide. How does the Fischer projection of D-fructose differ from that of D-glucose? Match the words in the left column to the appropriate blanks in the sentences on the right. Fill in the blanks.
a ketone
carbon 3
carbon 2
carbon 1
an aldehyde
carbon 4
In D-glucose, there is__________ functional group, and the carbonyl group is at___________ when looking at the Fischer projection.
In D-tructose. there is functional group, and the carbonyl group is at when looking at______ the Fischer projection.
Answer:
aldehyde
carbon-1
ketone
carbon-2
Explanation:
Monosaccharides are colorless crystalline solids that are very soluble in water. Moat have a swwet taste. D-Fructose is the sweetest monosaccharide.
In the open chain form, monosaaccharides have a carbonuyl group in one of their chains. If the carbonyl group is in the form of an aldehyde group, the monosaccharide is an aldose; if the carbonyl group is in the form of a ketone group, the monosaccharide is known as a ketose. glucose is an aldose while fructose is a ketose.
In D-glucose, there is an aldehyde functional group, and the carbonyl group is at carbon-1 when looking at the Fischer projection.
In D-fructose, there is a ketone functional group, and the carbonyl group is at carbon-2 when looking at the Fischer projection.
What mass of aluminum metal can be produced per hour in the electrolysis of a molten aluminum salt by a current of 21 A? Express your answer using two significant figures.
Answer
mass of aluminum metal= 7 .0497g of Al
Explanation:
current = 21 A
time = 1 hour = 60 X 60 = 3600 s
quantity of electricity passed = current X time = 21X 3600 = 75600 C
Following the electrolysis the below reaction will occur :
Al3+ + 3e- --------> Al
therefore, 3F i.e. 3 X 96500 C = 289500 C gives 1 mole of Al
so 1 C will produce 1/289500 moles of Al
so 108000 C will produce 1/289500 X 75600 = 0.2611 moles of Al
now 1 mole of aluminium weighs = 27 g/mole
so 0.2611 moles of Al = 0.2611 X 27 = 7 .0497 g
mass of aluminum metal= 7 .0497 g of Al
The mass of aluminum metal can be produced per hour in the electrolysis of a molten aluminum salt by a current of 21 A is 7.05 g
We'll begin by calculating the the quantity of electricity used. This can be obtained as follow:
Current (I) = 21 A
Time(t) = 1 h = 60 × 60 = 3600 s
Quantity of electricity (Q) =?Q = it
Q = 21 × 3600
Q = 75600 CFinally, we shall determine the mass of the aluminum metal produced. Al³⁺ + 3e —> AlRecall:
1 mole of Al = 27 g
1 electron (e) = 96500 C
Thus,
3 electrons = 3 × 96500 = 289500 C
From the balanced equation above,
289500 C of electricity produced 27 g of Al.
Therefore,
75600 C of electricity will produce = (75600 × 27) / 289500 = 7.05 g of Al
Thus, the mass of the aluminum metal obtained is 7.05 g
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Which compound is composed of oppositely charged ions? A. SCl2 B. OF2 C. PH3 D. Li2O
Answer:
D.
Explanation:
If a compound is composed of oppositely charged ions, it has to be formed by metal and non-metal.
Li2O
Li - metal
O - non-metal
a certain compound was found to contain 54.0 g of carbon and 10.5 grams of hydrogen. its relative molecular mass is 86.0. find the empirical and molecular formulas
Answer:
empirical formula = C3H7
molecular formula = C6H14
What is titration? Question 1 options: The process of quickly adding one solution to another until a solid is formed. The process of slowly adding one solution to another until the reaction between the two is complete. The process of mixing equal volumes of two solutions to observe the reaction between the two. The process of combining two solids until the reaction between the two is complete.
Answer:
The process of slowly adding one solution to another until the reaction between the two is complete.
Explanation:
When you perform a titration, you are slowly adding one solution of a known concentration called a titrant to a known volume of another solution of an unknown concentration until the reaction reaches neutralization, in which the reaction is no longer taking place. This is often indicated by a color change.
Hope that helps.
1. Unas de las formas de producir nitrógeno gaseoso (N2) es mediante la oxidación de metilamina (CH3NH2), tal como se muestra en la siguiente reacción: CH3NH2 + O2 → CO2 + H2O + N2 Si reaccionan 0,5 mol de metil amina (CH3NH2) con 25,6 g de O2. Determine: a) Balancee la ecuación. (2 ptos) b) ¿Cuántos gramos de nitrógeno (N2) se pueden producir? (4 ptos) c) Si experimentalmente se obtuvieron 3,5 gramos de N2. Determine el porcentaje de rendimiento de la reacción. (4 ptos) Por favor es urgente!!!
Answer:
a) 4CH₃NH₂ + 9O₂ ⇄ 4CO₂ + 10H₂O + 2N₂
b) m = 5,043 g
c) % = 69,4 %
Explanation:
a) La ecuación balanceada es la siguiente:
4CH₃NH₂ + 9O₂ ⇄ 4CO₂ + 10H₂O + 2N₂
En el balanceo, se tiene en la relación estequiométrica que 4 moles de metilamina reacciona con 9 moles de oxígeno para producir 4 moles de dióxido de carbono, 10 moles de agua y 2 moles de nitrógeno.
b) Para determinar la masa de nitrógeno se debe calcular primero el reactivo limitante:
[tex]n_{O_{2}} = \frac{m}{M} = \frac{25,6 g}{31,99 g/mol} = 0,800 moles[/tex]
[tex]n_{CH_{3}NH_{2}} = \frac{4}{9}*0,800 moles = 0,356 moles[/tex]
De la ecuación anterior se tiene que la cantidad de moles de metilamina necesaria para reaccionar con 0,800 moles de oxígeno es 0,356 moles, y la cantidad de moles iniciales de metilamina es 0,5 moles, por lo tanto el reactivo limitante es el oxígeno.
Ahora, podemos calcular la masa de nitrógeno producida:
[tex]n_{N_{2}} = \frac{2}{9}*n_{O_{2}} = \frac{2}{9}*0,8 moles = 0,18 moles[/tex]
[tex]m_{N_{2}} = n_{N_{2}}*M = 0,18 moles*28,014 g/mol = 5,043 g[/tex]
Por lo tanto, se pueden producir 5,043 g de nitrógeno.
c) El redimiento de la reacción se puede calcular usando la siguiente fórmula:
[tex] \% = \frac{R_{r}}{R_{T}}*100 [/tex]
Donde:
[tex]R_{r}[/tex]: es el rendimiento real
[tex]R_{T}[/tex]: es el rendimiento teórico
[tex]\% = \frac{3,5}{5,043}*100 = 69,4[/tex]
Entonces, el procentaje de rendimiento de la reacción es 69,4%.
Espero que te sea de utilidad!
The overall process that uptakes energy-poor molecules (CO2 and H2O) from their reservoirs in nature and converts them into energy-rich molecules is
Answer:
Photosynthesis
Explanation:
Photosynthesis is a process by which photosynthetic organisms use the energy of captured sunlight to convert energy-poor molecules such as carbon (iv), CO₂ and water (H₂O) into energy-rich organic molecules sch as carbohydrates e.g. glucose.
Photosynthesis occurs in a variety of bacteria and algae as well in vascular plants. The overall equation for the reaction of photosynthesis is as follows:
CO₂ + H₂O + light-------> (CH₂O) + O₂
It is a redox reaction in which water donates electrons (as hydrogen) for the reduction of CO₂ to carbohydrate, (CH₂O).
Carbohydrates are energy-rich molecules which serves as energy sources for many living organisms.
What amounts of sodium benzoate would be required to prepare 2.5L of 0.35M benzoic buffer solution with a pH of 6.10? Ka of benzoic acid = 6.5 x 10-5 MW benzoic acid, HC7H5O2, is 122.01 MW sodium benzoate, NaC7H5O2, is 144.01
Answer:
Benzoic acid: 1.288g
Sodium benzoate: 124.48g
Explanation:
Benzoic acid, HC7H5O2 is in equilibrium with its conjugate base, C7H5O2⁻ producing a buffer. The pH of the buffer can be determined following H-H equation:
pH = pKa + log [C7H5O2⁻] / [HC7H5O2] (1)
Where pH is desire pH = 6.10 pKa is -log Ka = 4.187 and [] are molar concentrations of the buffer.
As you want to prepare 2.5L of a 0.35M of buffer, moles of buffer are:
2.5L ₓ (0.35mol / L) = 0.875moles of buffer.
And you can write:
0.875 moles = [C7H5O2⁻] + [HC7H5O2] (2)
Replacing (2) in (1)
pH = pKa + log [C7H5O2⁻] / [HC7H5O2]
6.10 = 4.187 + log [C7H5O2⁻] / [HC7H5O2]
1.913 = log [C7H5O2⁻] / [HC7H5O2]
81.846 = 0.875mol - [HC7H5O2] / [HC7H5O2]
81.846 [HC7H5O2] = 0.875mol - [HC7H5O2]
82.846 [HC7H5O2] = 0.875mol
[HC7H5O2] = 0.01056 molesAnd moles of the benzoate, [C7H5O2⁻]:
[C7H5O2⁻] = 0.875mol - 0.01056mol =
[C7H5O2⁻] = 0.8644molUsing molar mass of benzoic acid and sodium benzoate, amount of each compound you must add to prepare 2.5L of the buffer are:
Benzoic acid: 0.01056mol ₓ (122.01g/mol) = 1.288g
Sodium benzoate: 0.8644mol ₓ (144.01g/mol) = 124.482g
Determine the volume occupied by 10 mol of helium at 27 ° C and 82 atm
please.
Answer:
3.00 L
Explanation:
Convert the pressure to Pascals.
P = 82 atm × (101325 Pa/atm)
P = 8,308,650 Pa
Convert temperature to Kelvins.
T = 27°C + 273
T = 300 K
Use ideal gas law:
PV = nRT
(8,308,650 Pa) V = (10 mol) (8.314 J/mol/K) (300 K)
V = 0.00300 m³
If desired, convert to liters.
V = (0.00300 m³) (1000 L/m³)
V = 3.00 L
Answer:
[tex]\large \boxed{\text{3.0 L}}[/tex]
Explanation:
[tex]\begin{array}{rcl}pV &=& nRT\\\text{82 atm} \times V & = & \text{10 mol} \times \text{0.082 06 L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times \text{300.15 K}\\82V & = & \text{246 L}\\V & = & \textbf{3.0 L} \\\end{array}\\\text{The volume of the balloon is $\large \boxed{\textbf{3.0 L}}$}[/tex]
Which of the choices is not a statement or direct application of the second law of thermodynamics? There are no 100% efficient heat engines. The change in internal energy of a system can be found by combining the heat energy added to a system minus the work done by the system. Heat energy naturally transfers from a high temperature substance to a low temperature substance. All natural processes tend toward states of increased entropy.
Answer:
The change in internal energy of a system can be found by combining the heat energy added to a system minus the work done by the system is not a direct application of second law of thermodynamics.
Explanation:
Second law of thermodynamics states that heat can be transfer spontaneously from high temperature to low temperature only.
The change in internal energy of a system can be found by combining the heat energy added to a system minus the work done by the system is not a direct application of second law of thermodynamics because according to the second law of thermodynamics it is impossible in any system for heat transfer from a source to completely convert to work done in a cyclical process( bring the system to its original stage after each cycle) in which the system then return to it's original stage.
what are the similarities between amorphous solid and crystalline solid
Answer:
solid dont know
Explanation:
so sorry ask another
A solution of malonic acid, H2C3H2O4, was standardized by titration with 0.0990 M NaOH solution. If 20.52 mL mL of the NaOH solution is required to neutralize completely 11.13 mL of the malonic acid solution, what is the molarity of the malonic acid solution
Answer:
0.0913 M
Explanation:
We'll begin by writing the balanced equation for the reaction.
This is given below:
H2C3H2O4 + 2NaOH —> C3H2Na2O4 + 2H2O
From the balanced equation above, we obtained the following:
The mole ratio of the acid (nA) = 1
The mole ratio of the base (nB) = 2
Data obtained from the question include:
Molarity of base, NaOH (Mb) = 0.0990 M
Volume of base, NaOH (Vb) = 20.52 mL
Volume of acid, H2C3H2O4 (Va) = 11.13 mL
Molarity of acid, H2C3H2O4 (Ma) =..?
The molarity of the acid, H2C3H2O4 can be obtained as follow:
MaVa/MbVb = nA/nB
Ma x 11.13 / 0.0990 x 20.52 = 1/2
Cross multiply
Ma x 11.13 x 2 = 0.0990 x 20.52 x 1
Divide both side by 11.13 x 2
Ma = (0.0990 x 20.52)/ (11.13 x 2)
Ma = 0.0913 M
Therefore, the molarity of malonic acid, H2C3H2O4 solution is 0.0913 M