Answer:
135 KJ.
Explanation:
The following data were obtained from the question:
Mass of ethanol, C₂H₅OH = 143.45 g
Heat of vaporisation, ∆Hvap = 43.3 kJ/mol
Heat required (Q) =.?
Next, we shall determine the number of mole in 143.45 g of ethanol (C₂H₅OH). This is can be obtained as follow:
Mass of ethanol, C₂H₅OH = 143.45 g
Molar mass of ethanol, C₂H₅OH = (12×2) + (1×5) + 16 + 1
= 24 + 5 + 16 + 1
= 46 g/mol
Mole of ethanol, C₂H₅OH =?
Mole = mass /Molar mass
Mole of ethanol, C₂H₅OH = 143.45/46
Mole of ethanol, C₂H₅OH = 3.118 moles
Finally, we shall determine the heat required to vaporize the ethanol, C₂H₅OH as follow:
Heat of vaporisation, ∆Hvap = 43.3 kJ/mol
Mole of ethanol, C₂H₅OH (n) = 3.118 moles
Heat required (Q) =.?
Q = n•∆Hvap
Q = 3.118 × 43.3
Q = 135 KJ
Therefore, the heat required is 135 KJ
Iron(III) oxide gets mixed with elemental carbon and heated to make elemental iron and carbon dioxide.
a) If they want to convert 1.00kg of iron (III) oxide to elemental iron, how much carbon needs to be added to the mix?
b) That 1.00kg of iron (III) oxide, with an excess of carbon, produces how much elemental iron.
Answer:
Explanation:
Iron(III) oxide gets mixed with elemental carbon and heated to make elemental iron and carbon dioxide.
2Fe₂O₃ + 3C = 4 Fe + 3 CO₂
2 x 160 3 x 12 4 x 56
320 gram of iron ( iii ) oxide requires 36 g of carbon for reduction
1 kg of iron will require 36 / 320 g of carbon
carbon required = 36 / 320 g
= .1125 g
= .113 g rounding off to 3 significant fig .
b )
320 gram of iron ( iii ) oxide produces 224 g of iron after reduction
1 g of iron will produce 224 / 320 g of iron
iron produced = 224 / 320 g
= 0.700 g .
what do you mean by saying that the molality of a solution is 2?
Answer:
2 molal solution means that 2 moles of solute is dissolved in 1 kg of solvent.
A stack of ten 3.5 in diskettes is 34 mm high. How many diskettes does it take to make a stack 100 yards high?
Answer:
3.5 divided by 34 then divide again 100
Explanation:
math
Suggest what the effect of using growth hormone on meat cattle might be
It might affect the health of consumer of that meat. Hope it helps
If object A and object B have the same density, but object A has greater mass, then object A must have:
object A has a larger volume than object B
1.How did the electrolyte properties of the NaCl solution compare as you added more salt to the water
Explanation:
The dissociation of NaCl increases. This happens because of the Le Chatalier's principle which says that, the rate of reaction shift to product side when more product is added to the reaction. Therefore, its electrolytic properties are enhanced.
Which of the following statements is true concerning the reaction given below?2H2S(g) + O2(g) → 2S(s) + 2H2O(g)a. The reaction is second-order in H2S(g) and first-order in O2(g).b. The reaction is first-order in H2S(g) and second-order in O2(g).c. The rate law is Rate = k[H2S]2[O2].d. The rate law is Rate = k[H2S][O2].e. The rate law may be determined only by experiment.
Answer:
The rate law may be determined only by experiment.
Explanation:
For a reaction, A + B ---> C, the rate law can only be determined from experimental data. Chemists determine the rate of reaction by carefully observing the changes in the concentration of species as the reaction progresses.
Hence, the rate law is not determined by inspection of the chemical reaction equation, it must be obtained from the experimental data, hence the answer given.
The radius of a nickel atom is 125 pm. How many nickel atoms would have to be laid side by side to span a distance of 1.74 mm
Answer:
6960000 Nickel atoms
Explanation:
radius = 125 pm = 125 x 10^-12 m
diameter of each atom = 125 pm x 2 = 250 pm = 250 x 10^-12 m
span of distance to be achieved = 1.74 mm = 1.74 x 10^-3 m
number of nickel atoms = (1.74 x 10^-3 m)/(250 x 10^-12 m) = 6960000 Nickel atoms
Write the empirical formula of at least four binary ionic compounds that could be formed from the following ions:
Ca^2+, Cr^4+, Cl^-, S^2-
Answer:
[tex]$ CaCl_2$[/tex], CaS, [tex]$ Cr Cl_4$[/tex], [tex]$ CrS_2$[/tex]
Explanation:
The reaction can be done by adding the cations and the anions.
The binary compounds are always formed by the two different elements.
When one calcium ion, [tex]$ Ca ^{2+} $[/tex] combines with the two calcium ions, [tex]$ Cl^-$[/tex], they formed a binary compound of [tex]$ CaCl_2$[/tex].
When one [tex]$ Ca ^{2+} $[/tex] combines with one [tex]$S^{2-}$[/tex] ion, they formed CaS binary compound.
When one chromium ion [tex]$ Cr^{4+}$[/tex] combines with four ions of chlorine, [tex]$ Cl ^- $[/tex], the compound formed is [tex]$ Cr Cl_4$[/tex].
When 1 ion of [tex]$ Cr^{4+}$[/tex] combines with 2 ions of sulphur, [tex]$S^2$[/tex], the binary compound formed is [tex]$ CrS_2$[/tex].
i need to know the measurements of this to the appropriate amount of significant figures
Answer:
[See Below]
Explanation:
140 ml.
(5.391 ´ 10-7) + (2.5531 ´ 10-6) =
Answer:
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6}) = 3.0922 * 10^{-6}[/tex]
Explanation:
Given
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6})[/tex]
Required
Solve
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6})[/tex]
Remove the brackets
[tex]5.391 * 10^{-7} + 2.5531 * 10^{-6}[/tex]
Express [tex]10^{-7}[/tex] as [tex]10^{-1-6}[/tex]
[tex]5.391 * 10^{-1-6} + 2.5531 * 10^{-6}[/tex]
Apply law of indices
[tex]5.391 * 10^{-1} * 10^{-6} + 2.5531 * 10^{-6}[/tex]
[tex]0.5391 * 10^{-6} + 2.5531 * 10^{-6}[/tex]
Factorize:
[tex](0.5391 + 2.5531)10^{-6}[/tex]
[tex](3.0922)10^{-6}[/tex]
Remove bracket
[tex]3.0922 * 10^{-6}[/tex]
Hence:
[tex](5.391 * 10^{-7}) + (2.5531 * 10^{-6}) = 3.0922 * 10^{-6}[/tex]
what are the molecular formula of 20 elements
Explanation:
Hydrogen (H)
Helium (He)
Lithium (Li)
Beryllium (Be)
Boron (B)
Carbon (C)
Nitrogen (N)
Oxygen (O)
Fluorine (F)
Neon (Ne)
Sodium (Na)
Magnesium (Mg)
Aluminum (Al)
Silicon (Si)
Phosphorus (P)
Sulfur (S)
Chlorine (Cl)
Argon (Ar)
Potassium (K)
Calcium (Ca)
Hope this is correct and helpful
HAVE A GOOD DAY!
suggest what the effect of using growth hormone on meat cattle might be
Answer:
Natural BGH and rBGH both increase the level of another hormone called insulin-like growth factor (IGF-1) in the cow.
Beef cattle are often given steroids to increase and speed growth. Common steroids include:
Natural steroids like estradiol, testosterone, and progesterone Man-made steroids from compoundsMajor groups such as FDA and Food and Agricultural Organization state track level of hormones in food. They state that the levels of hormones in food are safe to eat. Not everyone agrees.
Explanation:
Hormones are present in all animal products. Some are natural, others may be added through supplements. Hormones and steroids are given to livestock. It can increase the number of dairy products and beef.
FDA establishes the acceptable safe limits for hormones in meat. A safe level for human consumption is a level of drug in the meat that would be expected to have no harmful effect in humans based on extensive scientific study and review.
how potassium iodide aids the titration of the cyclohexane layer.
Answer:
to avoid iodine vapor from escaping.
Explanation:
This question is all about an experimental work on the determination of the distribution of iodine between waters and cyclohexane. To understand this question one has to understand the topic "Equilibrium" very well.
One important thing that must be noted in this question is for us to remember that water and cyclohexane are two immiscible liquids. So, when Iodine is added to the two solvents, the iodine dissolves in both water and cyclohexane to certain rate ands then to an equilibrium which is;
Kd = I₂[Cyclohexane]/ I₂[water]. ----------------------------------------[**].
There is a release of I⁻¹ From the added potassium iodide which helps in making sure that the iodine vapor does not escape. Thus, forming a tri-iodide ion.
If you have 24 grams of an unstable atom with a half life of 5,000 years, how many grams would be left after 15,000 years
Answer:
3 g.
Explanation:
The following data were obtained from the question:
Original amount (N₀) = 24 g
Half life (t½) = 5000 years
Time (t) = 15000 years
Amount remaining (N) =?
Next, we shall determine the rate constant K. This can be obtained as follow:
Half life (t½) = 5000 years
Rate constant (K) =.?
K = 0.693 / t½
K = 0.693 / 5000
K = 1.386×10¯⁴ / years
Finally, we shall determine the amount remaining (N) after 15000 years as follow:
Original amount (N₀) = 24 g
Time (t) = 15000 years
Rate constant (K) = 1.386×10¯⁴ / years
Amount remaining (N) =?
Log (N₀/N) = kt/2.3
Log (24/N) = 1.386×10¯⁴ × 15000/2.3
Log (24/N) = 2.079/2.3
Log (24/N) = 0.9039
24/N = antilog (0.9039)
24/N = 8.01
Cross multiply
24 = N × 8.01
Divide both side by 8.01
N = 24/8.01
N = 3 g
Therefore, the amount remaining after 15000 years is 3 g.
Look at this picture and please help
Answer : The kinetic energy will be 24 J.
Explanation : Given,
Mass of marble = 3 kg
Velocity of a marble = 4 m/s
Formula used to calculate the kinetic energy is:
[tex]K.E=\frac{mv^2}{2}[/tex]
where,
K.E = kinetic energy
m = mass
v = velocity
Now putting all the given values in this formula, we get:
[tex]K.E=\frac{3kg\times (4m/s)^2}{2}[/tex]
[tex]K.E=24kg.m^2/s^2=24J[/tex] [tex](1J=1kg.m^2/s^2)[/tex]
Therefore, the kinetic energy will be 24 J.
Rank the following compounds in order of reactivity toward nitration with HNO3:_______. thiophene, benzene, 3-methylthiophene, and 2-methylfuran.
Answer:
3-methylthiophene > thiophene > benzene > 2-methylfuran
Explanation:
Primarily, five membered heterocyclic aromatic rings undergo nitration at carbon-2. This is because, nitration at carbon-2 leads to the formation of three resonance structures while attack at carbon-3 yields only two resonance structures, hence it is less stabilized.
The presence of a methyl group which donates electrons promotes the stabilization of the cation formed in the nitration of 3-methylthiophene.
2-methylfuran is the least reactive towards nitration because the 2-position has been blocked by a methyl group.
C-12 has 6 protons.
How many neutrons does C-13 have?
A. 6
B. 7
C. 13
D. 19
Answer:
B-7
Explanation:
13-6=7
How do biotic factors impact ecological organization?
Answer:
plz mark as BRAINLIEST plz
Explanation:
The biotic factors in an ecosystem are the living organisms, such as animals. Biotic factors in an ecosystem are the participants in the food web, and they rely on each other for survival. ... These living organisms affect each other and influence the health of the ecosystem.
What color would the cyanidin indicator turn in an acidic solution?
Answer:
It would change to a strong Red color
Explanation:
Cyanidin indicators turn strong red in acidic solutions and blue or green in a basic environment
Which solvent caused the ink from the dots to move the most? Question 4 options: A) vegetable oil B) water C) alcohol D) half water, half alcohol
Answer:
half water, half alcohol
Explanation:
Some inks are water soluble while some are alcohol soluble. Inks that do not dissolve in water usually dissolve in alcohol.
If inks are to be separated by chromatography, we have to make the mobile phase a mixture of alcohol and water in order for the dots to move the most.
Answer:
alcohol
Explanation:
Three different samples were weighed using a different type of balance for each sample. The three were found to have masses of 0.6160959 kg, 3.225 mg, and 5480.7 g. The total mass of the samples should be reported as?
Answer:
6.096799125kg
Explanation:
According to the question, three different samples weighed using different types of balance had masses: 0.6160959 kg, 3.225 mg, and 5480.7 g.
Based on observation, the mass units in the three measurements are different but must be uniform in order to find the total mass. Hence, we need to convert to the standard unit (S.I unit of mass), which is kilograms (kg)
Since 1kg equals 1,000,000mg
Hence, 3.225mg will be 3.225/1000000
= 0.000003225kg
Also, 1kg equals 1000g
Hence, 5480.7g will be 5480.7/1000
= 5.4087kg
Hence, the total mass of the three samples (now in the same unit) are:
5.4807kg + 0.000003225kg + 0.6160959 kg
= 6.096799125kg
Which of the following reactions is NOT a redox reaction? Question 25 options: SO3(g) + H2O(l) H2SO4(aq) Al(s) + 3Ag+(aq) Al3+(aq) + 3Ag(s) Ba(s) + Cl2(g) BaCl2(s) H2(g) + O2(g) H2O(g) Al(s) + Fe2O3(s) Fe(s) + Al2O3(s)
Answer:
SO3(g) + H2O(l) ------> H2SO4(aq)
Explanation:
'Redox' is a term used to describe reduction and oxidation since the both are complementary processes, one can not occur without the other.
A redox reaction is one in which there is a change in the oxidation number of the reactants from left to right of the reaction equation.
If we looks at the reaction;
SO3(g) + H2O(l) ------> H2SO4(aq)
There was no change in the oxidation numbers of species from left to right of the reaction equation. For instance, the oxidation state of sulphur is +6 on both sides of the reaction equation hence it is not a redox reaction.
The distance between the nuclei of two iron atoms is about 4 angstroms.a. Trueb. False
Answer:
The correct option is b. false
Explanation:
The distance between the nucleus of an atom and it's outermost shell is called is atomic radius. The atomic radius of an Iron atom (Fe) is 0.126 nm or 1.26 angstrom. The distance between the nuclei of two Iron atoms will be 1.26 × 2 = 2.52 angstroms.
Since 2.52 angstroms is lower than 4 angstroms, the correct option is false
HF:______
a) dispersion force
b) dipole-dipole force
c) hydrogen bond
Answer:
HF: hydrogen bond
Explanation:
The hydrogen bond is a type of interaction that is established between a molecule that presents hydrogen with another that presents an atom with a high electronegativity, such as oxygen, fluorine or nitrogen (O, F, N), joining covalently due to their opposite charges.
The hydrogen atom has a positive charge and is known as a donor atom. The oxygen, fluorine or nitrogen atom is the bond acceptor atom.
So:
HF: hydrogen bond
In terms of atomic structure, explain why the first ionization energy K is less than that of Ca ?
What is the Ksp of Al(OH)3 if the concentration of OH– in a saturated solution of Al(OH)3 is 1.6 × 10–8 M?
Answer:
[tex]Ksp=2.2x10^{-32}[/tex]
Explanation:
Hello,
In this case, since the dissociation of aluminum hydroxide is:
[tex]Al(OH)_3(s)\rightleftharpoons Al^{3+}+3OH^-[/tex]
The equilibrium expression is:
[tex]Ksp=[Al^{3+}][OH^-]^3[/tex]
Thus, given the concentration of hydroxyl ions in the solution, and the 3:1 mole ratio with the aluminum ions, the concentration of those turn out:
[tex][Al^{3+}]=1.6x10^{-8}\frac{molOH^-}{L}*\frac{1molAl^{3+}}{3molOH^-} =5.3x10^{-9}M[/tex]
Therefore, the solubility product, Ksp turns out:
[tex]Ksp=(5.3x10^{-9}M)[1.6x10^{-8}M]^3\\\\Ksp=2.2x10^{-32}[/tex]
Regards.
how do you make it so that 43200 ml have only 3 significant figures? I will give brainiest pls help
Answer:
3 sig figs
Explanation:
one of the rules for sig figs is a when a whole number has zeros if they are sandwiched between whole number for ex. 34007 they would all be sig figs. hope this helps!
btw all the zeros behind the decimal are significant for ex. 0.4800
Answer:
you could make it 43.2 x 10^2
Explanation:
Assume a healthy hearts beats exactly 70 times per minute. If individual lives to age 85 years, estimate the number of heartbeats in their lifespan using scientific notation and the correct number of sig figs.
Given :
Number of heart beat in 1 minute , n = 70 .
The individual lives for 85 years .
To Find :
The number of heartbeats in their lifespan .
Solution :
Now , number of minutes in one hour is 60 .
One day contains 24 hours .
Therefore , minutes in one whole day :
[tex]24\times 60 = 1440\ sec[/tex]
Now , 1 year contains 365 days .
( Note : We are not considering any leap years )
Minutes in one year are :
[tex]365\times 1440=525600=5.25\times 10^5\ sec[/tex]
So ,total minutes in 85 years is :
[tex]=5.25\times 10^5\times 85\\\\=4.46\times 10^7\ sec[/tex]
Hence , this is the required solution .
Give one example of how studying chemistry could be
useful in everyday life
Answer:
Chemistry is used almost everywhere you go. from the car you use to get to work (gasoline burning) to the nuclear reactors that power many homes ( uranium becoming unstable to product electricity.