Answer:
When the substance is cooled, its temperature will fall below 78 °C after 100% of the vapor has changed to liquid.
Explanation:
Boiling point is the temperature at which a liquid changes state from liquid form to gaseous form without change in temperature. It may defined as the temperature at which the vapor pressure is equal to the pressure of the gas above the liquid.A liquid with a boiling point of 78°C, it means that, when the liquid is heated, its temperature will start rising above 78 °C after 100% of the liquid has changed to vapors. Additionally, when the liquid is cooled, its temperature will fall below 78 °C after 100% of the vapor has changed to liquid.The accurate statement is that the temperature of a substance with a boiling point of 78 0C will fall below this temperature once all the vapor has condensed into liquid, as the phase change maintains the boiling point until the transition is complete.
The statement about a substance with a boiling point of 78 0C that is true is: When the substance is cooled, its temperature will fall below 78 0C after 100% of the vapor has changed to liquid. At the boiling point, a substance undergoes a phase change from liquid to vapor, and it remains at this temperature until the liquid has fully transitioned into vapor. Therefore, the temperature won't rise above the boiling point until all the liquid has become vapor. Conversely, when cooling, the temperature will not drop below the boiling point until all vapor has condensed back to liquid.
This is due to the energy being used to facilitate the change of state rather than altering temperature. Similarly, when a substance is melting or freezing, the temperature remains constant at the melting point until the transition between solid and liquid is complete.
If aluminum is the limiting reactant, SOME/NONE/ALL of it will still be visible after the reaction completes. If CuCl2 is the limiting reactant,SOME/NONE/ALL of the aluminum will still be visible.
Answer:
If aluminum is the limiting reactant, NONE of it will still be visible after the reaction completes.
If CuCl2 is the limiting reactant, SOME of the aluminum will still be visible.
Explanation:
Any chemical reaction, if the reactants are not in equimolar ratios, contains limiting reactant and leftover reactant.The limiting reactant in a chemical reaction is the reactant that is totally consumed when the chemical reaction is complete. The amount of product formed is limited by this reagent, since the reaction cannot continue without it.The leftover reactant is the reactant that is in excess and not consumed completely and some of it remains in the reaction mixture.So,
If aluminum is the limiting reactant, NONE of it will still be visible after the reaction completes.
and,
If CuCl2 is the limiting reactant, SOME of the aluminum will still be visible.
Answer:
If aluminum is the limiting reactant, none of it will still be visible after the reaction completes.
If CuCl2 is the limiting reactant, some of the aluminum will still be visible.
Any reaction that absorbs 150 kcal of energy can be classified as ________.
a. endothermic
b. exothermic
c. activated
d. reduction
e. oxidation
Answer:
a. endothermic
Explanation:
Endothermic reaction: is a chemical reaction that absorbs heat or energy through the reaction.While, exothermic reaction: is a chemical reaction that releases energy through light or heat. It is the opposite of an endothermic reaction.So, Any reaction that absorbs 150 kcal of energy can be classified as a. endothermic.
how does carbon dioxide malfunction
Answer:
if in excess the carbon dioxide is harmful to both the humen and other living things.
Explanation:
in our daily life we exhale carbon dioxide after inhaling oxygen.
but if carbon dioxide is in excess in atmosphere which is caused by burning fossils may cause changes in weather and climate at large due to aerosol particle emittion which inturn cause damage to o-zone layer causing global warming.which are effect to aquatic life and also to human.
How many valence electrons does an iodine atom have
Answer:
An iodine atom has 7 valence electrons.Explanation:
Iodine is a halogen so it is the group (column number) 17 of the periodic table. It is a representative element.
The number of valence electrons for the representative elements is equal to the second digit of the group number. So, group 17 means that iodince has 7 valence electrons.
Now, more formally, the valence electrons are the electrons in the outermost shell of the atom and you can determine how many of them an atom has by doing the electron configuration.
These are the steps:
Atomic number, of iodine, Z = 53Number of electrons of the neutral atom = number of protons = 53Distribute the electrons in ascending order of orbital energies, following Aufbau's rules:1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁵If you count the electrons you must obtain 53: 2 + 2 +6 + 2 + 6 + 2 + 10 + 6 + 2 + 10 + 5 = 53.The valence electrons are those in the highest principal energy level: 5s² 5p⁵, i.e 2 + 5 = 7.An iodine atom has seven valence electrons and generally gains one electron to become a negatively charged iodide ion (I-). Iodine is in the 17th group of the periodic table and prefers to achieve a full octet by accepting an additional electron rather than losing seven electrons.
An iodine atom has seven valence electrons. When looking to achieve a stable electronic configuration, iodine typically gains one electron to complete its octet because it is more energetically favorable than losing seven electrons. When an iodine atom gains an electron, it forms a negatively charged ion known as an iodide ion (I-). The formula of the resulting ion is I-.
The atomic number of iodine (53) reveals that a neutral atom of iodine consists of 53 protons and an equal number of electrons. Iodine is a halogen and is part of the 17th group in the periodic table which is characteristic of elements with seven valence electrons. According to the octet rule, atoms tend to bond in such a way that they each end up with eight valence electrons; gaining one electron is the preferred pathway for iodine.
The concept of a hypervalent structure involves molecules that contain more than eight electrons in their valence shell. However, in the case of the triiodide ion, resonance structures without violating the octet rule offer a more accurate representation of the bonding. As iodine tends to form weak bonds, the I2 molecule can dissociate into atomic iodine at a relatively lower energy compared to lighter halogens.
Which of the following is an example of inertia?
An asteroid flying through the vacuum of space
A bullet striking a hard surface
A plane taking off from the runway
Catching a softball in a catcher's mitt
An asteroid flying through the vacuum of space is an example of inertia where it maintains its motion due to the absence of external forces except gravity. Other examples involving bullets, planes, and softballs are influenced by external forces and hence do not demonstrate inertia in its pure form.
Inertia and Its Examples
Inertia is the resistance of any physical object to a change in its velocity. This includes changes to the object's speed, or direction of motion. An object that isn't influenced by anything other than gravity is considered to be in an inertial frame of reference.
An example of inertia is an asteroid flying through the vacuum of space. This is because the asteroid will maintain its state of motion - traveling at a constant velocity - until acted upon by an outside force, such as another object's gravity. It fits the definition of an inertial frame as it is not being affected by any external forces except gravity, which doesn't change its velocity (considering the incredibly vast distances in space where gravitational influences are relatively minor).
In contrast, a bullet striking a hard surface, a plane taking off from the runway, and catching a softball in a catcher's mitt are all examples where external forces act on the objects, thereby affecting their motions and not illustrating a pure state of inertia.
A bullet striking a hard surface is an example of an object encountering a force that rapidly decelerates it.
A plane taking off is being propelled by the force generated by its engines.
Catching a softball involves an external force applied by the catcher's mitt to stop the ball.
Which combination is the best choice to prepare a buffer with a ph of 9.0? which combination is the best choice to prepare a buffer with a of 9.0? nh3; nh4cl (pkb for nh3 is 4.75) hcho2; nacho2 (pka for hcho2 is 3.74) c5h5n; c5h5nhcl (pkb for c5h5n is 8.76) hno2;nano2 (pka for hno2 is 3.33)?
Answer:
[tex]\boxed{\text{NH$_{3}$; NH$_{4}$Cl}}[/tex]
Explanation:
The best choice to prepare a buffer of pH 9.0 is a conjugate acid/base pair in which the acid has pKₐ = 9.0 ± 1.
Let's examine each of the choices.
A. NH₃/NH₄Cl
For NH₃, = pK_b = 4.75
For NH₄⁺, pKₐ 14.00 - 4.75 = 9.25
B. HCHO₂/NaCHO₂
For HCHO₂, pKₐ = 3.74
C. C₅H₅N/ C₅H₅NHCl
For C₅H₅N, = pK_b = 8.76
For C₅H₅N⁺, pKₐ 14.00 – 8.76 = 5.21
D. HNO₂/NaNO₂
For HNO₂, pKₐ = 3.33
The only acid with a pKₐ close to 9.0 is the ammonium ion.
The best buffer to prepare a buffer with pH 9.0 is [tex]\boxed{\text{NH$_{3}$; NH$_{4}$Cl}}[/tex]
From the given options, the best combination to prepare a buffer with a PH of 9.0 is given by;
Option 1; NH₃;NH₄Cl
A buffer solution is defined as an aqueous solution that consists of a mixture of a weak acid and its conjugate base or mixture of a weak base and its' conjugate acid.Now, we want to find the best choice to prepare a buffer of pH 9.0. Thus, let us look at each option;
Option 1; NH₃;NH₄Cl
We are given that pK_b for NH₃ is 4.75
Thus pKₐ for NH₄ is;
NH₄; pKₐ = 14.00 - 4.75
NH₄; pKₐ = 9.25
Option 2; HCHO₂; NaCHO₂
We are given that pK_a for HCHO₂ is 3.74
HCHO₂; pKₐ = 3.74
Option 3; C₅H₅N; C₅H₅NHCl
We are given that pK_b for C₅H₅N is 8.76
Thus
For C₅H₅N, = pK_b = 8.76
Thus, pKₐ for C₅H₅N is;
C₅H₅N; pKₐ = 14.00 – 8.76
C₅H₅N; pKₐ = 5.21
Option 4; HNO₂;NaNO₂
We are given pKₐ for HNO₂ as 3.33
HNO₂; pKₐ = 3.33
Looking at all the pKₐ values, the only acid that has a pKₐ close to 9.0 is NH₄ with a pKₐ of 9.25.
In conclusion, the best combination to prepare a buffer with pH of 9.0 is
NH₃;NH₄Cl
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Diamonds are mostly composed of what element?
Answer:
Diamonds are composed almost entirely of the element carbon, often with some other impurities in them, such as nitrogen (i.e., pure diamonds are entirely carbon). The element carbon comes in three different natural forms, or allotropes: diamond, graphite, and amorphous.
Explanation:
What is the basic building block of matter
Answer:
Atoms
Explanation:
Atoms are widely believed to be the most fundamental particle of matter and their basic building blocks. When atoms combines together, they form compounds. Molecules are another units of matter that are made up of tiny particles of atoms.
Which of the following conditions remain constant in Gay-Lussac's law? Temperature and number of moles Volume and number of moles Density and temperature Volume and pressure
Answer:
Volume and number of moles.
Explanation:
Gay-Lussac's law was found by Joseph Louis Gay-Lussac in 1808. It states that, for a given mass (no. of moles) and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature.So, no. of moles and V are constant.
P ∝ T,
∴ P1/T1 = P2/T2.
So, the right choice is: Volume and number of moles.Answer:
Volume and Number of Moles
Explanation:
I hope this helps !! :)
The reaction depicted in the figure would take place in which of the following?
Answer: Option (a) is the correct answer.
Explanation:
Nuclear fission is defined as a reaction in which a heavy nucleus splits into two or more small nuclei along with emission of energy.
For example, [tex]^{235}_{92}U + ^{1}_{0}n \rightarrow ^{139}_{56}Ba + ^{95}_{36}Kr + 3^{1}_{0}n[/tex]
So, the given diagram shows a large nucleus is splitting into two small nuclei. Therefore, it is a nuclear fission reaction.
Whereas a nuclear reaction in which two small nuclei combine together to result into the formation of a large nucleus is known as a nuclear fusion reaction.
Thus, we can conclude that the reaction depicted in the figure would take place in fission reactor.
The chart shows the path reactants take to become products. Which statement best describes the chart? A. Heat was removed from the activation energy to create the product. B. Heat was added to create the product. C. The products have less energy than the reactants. D. The products have the same energy as the reactants.
Answer:
B
Explanation:
The final position of the curve is higher than the original height of the curve, meaning the products have more energy than the reactants.
Hence energy was added for the reactants to become the products. This is why the reaction is endothermic, because the products retained some of the supplied energy.
Part of the energy supplied was used to overcome the activation energy (the peak of the curve). However, this extra energy is recuperated as heat once the product is formed.
Answer:
B-
Heat was added to create the product
Explanation:
Just did the quiz on edg
The health of bones depends upon a good supply of calcium. If a person consumes 0.06 g of calcium, how many moles of calcium did he consume? A. 6.6 x 102 mol B. 7.5 x 10-2 mol C. 2.4x 101 mol D. 1.5 x 10-3 mol
Answer:
[tex]\boxed{\text{D. }1.5 \times 10^{-3}\text{ mol}}[/tex]
Explanation:
1 mol of Ca = 40.08 g
[tex]\text{Moles of Ca = 0.06 g Ca} \times \dfrac{\text{1 mol Ca}}{\text{40.08 g Ca}} = 1.5 \times 10^{-3}\text{ mol Ca}\\\\\text{The person consumed }\boxed{1.5 \times 10^{-3}\text{ mol Ca}}[/tex]
Final answer:
By dividing the mass of calcium consumed (0.06 g) by its molar mass (40.08 g/mol), we calculate that the individual consumed 1.5 x 10⁻³ moles of calcium, corresponding to option D.
Explanation:
The health of bones is strongly tied to adequate calcium intake, which is crucial during periods of bone growth and density increase, such as adolescence. To calculate the number of moles of calcium consumed when a person ingests 0.06 g, we need to use the molar mass of calcium. The molar mass of calcium is approximately 40.08 g/mol.
To find the number of moles (n), we use the formula:
n = mass (g) / Molar mass (g/mol)
For calcium:
n = 0.06 g / 40.08 g/mol = 1.5 x 10⁻³ moles
Therefore, the person consumed 1.5 x 10⁻³ moles of calcium, which corresponds to option D.
Consider the titration curve below
If an Erlenmeyer flask that is used in this titration contains 40.0 mL of 0.10 M HCl, how many moles of hydrogen ions are present at the point that is labeled A on the graph?
OPTION A) 0.0025
OPTION B) 0.0040
OPTION C) 40.0
OPTION D) 4000
i think A because .10 divided by 40 would be .0025
Answer:
0.0040
Explanation:
What happens to a reaction at equilibrium when more reactant is added to the system?
Answer:
When more reactant is added to a system at equllibrium more product is produced.Explanation:
Provided all other conditons remain constant (e.g. volume and temperature), the addition of more reactant means the increase of the concentration of the reactant, and so, at constant temperature, more product must be produced to compensate such addition of more reactant.
An equlibrium reaction may be represented by the general expression:
aA + bB ⇄ cC + dDAnd the equilibrium constant is given by:
[tex]Keq=\frac{[C]^c.[D]^d}{[A]^a.[B]^b}[/tex]Thus, since at constant temperature Kea is constant, the increase of a reactant concentration (A or B are in the denominator) means that the concentration of the products (C and D in the numerator) must increase.
Since, the molecular point of view what happens is that the increase of the concentration of reactions increase the rate of the direct (forward) reaction yielding to the production of more products.
Final answer:
Adding more reactant to a reaction at equilibrium causes the system to shift right, increasing the rate of the forward reaction and leading to the formation of more products until a new equilibrium is established, with the equilibrium constant (Kc) remaining unchanged.
Explanation:
When a chemical reaction has reached equilibrium, adding more reactant to the system causes the equilibrium to shift. The concepts behind this phenomenon are encapsulated by Le Châtelier's Principle, which states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change.
In the case where more reactant is added, the equilibrium will shift to the right, meaning that the reaction system will respond by forming more products to relieve the stress caused by the added reactant. This increase in reactant concentration results in a temporary increase in the rate of the forward reaction compared to the reverse reaction, leading to a consumption of the added reactant and an increase in product concentration until a new equilibrium is established.
After the system readjusts, the reaction quotient (Qc) will once again equal the equilibrium constant (Kc), which remains unchanged as it is only affected by temperature. This adjustment process continues until the rate of the forward reaction and the rate of the reverse reaction are equal again. In essence, by adding more of a reactant, one can temporarily push the reaction to produce more products, a strategy often used in industrial processes to increase yield.
What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction?
Answer: oxidized
Explanation:
When a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes
oxidized.
Good luck! and sorry if is not the answer ur looking 4!
Answer:
The glucose molecule is oxidized
Explanation:
When glucose loses a hydrogen atom it is losing 1 proton and 1 electron. As it is losing an electron, the glucose is oxidized.
The combustion of ________ has added great quantities of carbon dioxide to the atmosphere.
Answer:
fossil fuel combustion
Explanation:
Fossil fuel is the source of energy that drives almost all industrial processes on the surface of earth. Burning of these fuels releases energy for use in automobiles, industries, homes e.t.c. The complete combustion of these fuels in the presence of oxygen liberates carbon-dioxide and water with heat energy.
Fossil fuels are to a large extent hydrocarbon compounds and their derivatives. They form from organisms million of years ago. When organic matter is prevented from decay in an oxic or oxygen rich environment, they are able to conserve and preserve the energy in them for a vast duration in geologic time. This preserved energy is what becomes available during combustion.
Some of the fossil fuels are oil, natural gas, coal, e.t.c.
How is the equilibrium constant of a reaction determined
Answer:
It is given by the concentration of the products divided by the concentration of the reactants
What kind of weather would an occluded front likely bring?
a.
sunny and warm
c.
thunderstorms
b.
much precipitation
d.
cold and dry
Answer:
The answer is b. much precipitation
Explanation:
A front is a strip in which two air masses of different temperatures are separated. An occluded front occurs when a cold front that generally moves more quickly reaches a hot front and merges. The cold air mass, being heavier, stays below, forcing the warmer to rise. When this happens it cools and condenses, causing heavy precipitation.
The occluded fronts cause weak and continuous rains at first with stratiform-type clouds, and later the rains intensify with the arrival of vertically developing clouds, which cause storms.
Answer:
The answer is B.
Explanation:
Which best describes nuclear fission?
Are there choices to pick from?
A solute crystal is dropped into a solution containing dissolved solute. It falls to the bottom of the beaker and does not dissolve after vigorous stirring. What does this indicate about the solution?
It is probably super saturated.
In the electrolysis of brine, the substances produced at the cathode are _____.
oxygen gas and hydroxide ions
sodium metal and hydrogen gas
chlorine gas and hydrogen gas
hydrogen gas and hydroxide ions
Answer:
In the electrolysis of brine, the substances produced at the cathode are sodium metal and hydrogen gas.
Explanation:
In the electrolysis of brine (Sodium chloride solution) using carbon as electrode, Chlorine gas is produced in the positive electrode (anode), while hydrogen gas is produced in the negative electrode (cathode).
Again, in the electrolysis of molten sodium chloride, chlorine gas is produced in anode, while sodium metal is produced in the cathode.
Nacl ⇄ Na⁺ + Cl⁻
Case 1: Molten Nacl
Anode(+ve) Product | Cathode (-ve) product
Cl⁻ -----> Cl + e⁻ | Na⁺ + e⁻ ---------> Na
Cl + Cl ------> Cl₂
Case 2: Nacl solution
Anode(+ve) Product | Cathode (-ve) Product
Cl⁻ -----> Cl + e⁻ | H⁺ + e⁻ ---------> H
Cl + Cl ------> Cl₂ | H + H ------------> H₂
Thus, cathodic products of electrolysis of brine are sodium metal and hydrogen gas
You are running a lemonade stand with your friend. You prepared 10 liters of 0.7 molarity lemonade, but your friend did online research and found that people prefer 0.4 Molarity lemonade. How can you fix the lemonade you made so that it is 0.4 Molarity without starting over?
Answer:
add 7.5L of water
Explanation:
M1×V1=M2×V2
M is molarity, V is volume
0.7 × 10 = 0.4 × V2
V2= 17.5L
vol. of water to add= 17.5 - 10 = 7.5L
The volume which is required to prepare 0.4M lemonade is 17.5L.
How do we calculate the required volume?Required volume of the solution will be calculated by using the below equation as:
M₁V₁ = M₂V₂, where
M₁ & V₁ are the molarity and volume of initial lemonade.
M₂ & V₂ are the molarity and volume of final prepared lemonade.
On putting all values from the question, we get
V₂ = (0.7)(10) / (0.4) = 17.5 L
Hence required volume of final lemonade is 17.5 L.
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There are 3 beakers each of which contains saline solution.
Beaker A initially contains 3 liters of 10\% salt solution.
Beaker B initially contains 2 liters of 20\% salt solution.
Beaker C initially contains 4 liters of 0\% salt solution.
Two liters are transferred from A to B and the result is thoroughly mixed. Then one liter is transferred from B to C and the result mixed. Finally two liters are transferred from C back to A. What is the percentage concetration of salt in A after all this?
Percentage concentration of salt in A=____ \%
Answer:
Percentage concentration of salt in A = 5.3%Explanation:
Assume all the concentrations are expressed in volumetric terms, i.e 10% = 10 liter salt / 100 liter solution, 20% = 20 liter salt / 100 liter soluton, 0% = 0 liters salt.
1) First transformation: 2 liters are from A to B
Solution A:
Concentration: 10 % salt ⇒ 10 liter salt / 100 liter solutionVolume of solution: 3 litersVolume of salt: 3 liters × 10 liter / 100 liters = 0.300 liter saltVolume of water: 3 liters - 0.300 liters = 2.700 liters solventSolution B:
Concentraion: 20%Volume of solution: 2 literVolume of salt: 2 liter × 0.20 = 0.4 liter saltVolume of water: 2 liter - 0.4 liter = 1.6 liter waterResultant mixture in beaker B: 2 liters of solution A plus 2 liters of solution B
Salt: 2 liter × 0.10 + 2 liter × 0.20 = 0.20 + 0.4 = 0.6 liter saltWater: 2 liter × 0.90 + 2 liter × 0.80 = 3.40 liter waterSolution: 2 liter + 2 liter = 4 liter solutionConcentration: 0.6 liter salt / 4 liter solution = 0.15 = 15%
2) Second transformation: 1 liter transferred from B to C
Salt: 1 liter × 0.15 + 0 = 0.15 liter salt↑ ↑
(from B) ( in C)
Solution: 1 liter + 4 liter = 5 liter solutionConcentration: 0.15 liter salt / 5 liter solution = 0.03 = 3.0%
3) Third transformation: 2 liters are from C to A.
Salt: 0.03 liter salt × 2 liter solution + 1 liter × 0.10 = 0.16 liter salt↑ ↑
(from C) (in A)
Solution: 2 liter + 1 liter = 3 liter solution% of salt in A = (0.16 liter salt / 3 liter solution) × 100 =5.3 %A solution is made by mixing equal masses of methanol,
CH4O, and ethanol, C2H6O. How would you determine the mole fraction of each component to at least three significant figures?
Answer:
Mole fraction of methanol: 0.590 Mole fraction of ethanol: 0.410Explanation:
1) Definition of mole fraction: number of moles of a component / number of moles total number of moles.
2) The number of moles of each component is determined from the respective molar mass. Using the letter n for the number of moles of a component:
n = mass in grams / molar mass.3) CH₄O
n₁ = mass CH₄O / molar mass CH₄OMolar mass CH₄O = 32.04 g/mol
n₁ = mass CH₄O / 32.04 g/mol
4) C₂H₆O
n₂ = mass of C₂H₆O / molar mass of C₂H₆OMolar mass C₂H₆O = 46.07 g/mol
n₂ = C₂H₆O = mass of C₂H₆O / 46.07 g/mol
5) Both masses are equal; call them m.
n₁ = m / 32.04 n₂ = m / 46.07 n₁ + n₂ = m / 32.04 + m / 46.076) Mole fraction of CH₄O:
Use the letter X for mole fraction.
X₁ = n₁ / [n₁ + n₂] = [ m / 32.04 ] / [ m / 32.04 + m / 46.07]Cancel the common factor m:
X₁ = [ 1 / 32.04] / [1 / 32.04 + 1 /46.07] = 0.590
7) Mole fraction of C₂H₆O
X₁ + X₂ = 1 ⇒ X₂ = 1 - X₁= 1 - 0.590 = 0.410The mole fractions are rounded to three significant figures.
if you have 10 grams of a substance that decays with a half life of 14 days then how much will you have after 70 days?
Answer: If it has a 1/2 life of 14 days, after 14 days there will be half of it left correct?
Explanation:So, how many half-lifes are in 42 days?
42 / 14 = 3
This means it will divide 3 times.
1st half life period: 10 / 2 = 5g
2nd period: 5 / 2 = 2.5g
3rd period: 2.5 / 2 = 1.25g
10 g at start, 5 g at 14 days, 2.5 g at 28 days, 1.25 g at 42 days.
Answer: The amount of substance left will be 0.316 grams.
Explanation:
All the decay processes follow first order kinetics.
The equation used to calculate half life for first order kinetics:
[tex]t_{1/2}=\frac{0.693}{k}[/tex]
where,
[tex]t_{1/2}[/tex] = half life of the reaction = 14 days
k = ?
Putting values in above equation, we get:
[tex]k=\frac{0.693}{14days}=0.0495days^{-1}[/tex]
Rate law expression for first order kinetics is given by the equation:
[tex]t=\frac{2.303}{k}\log\frac{a}{y}[/tex]
where,
k = rate constant = [tex]0.0495days^{-1}[/tex]
t = time taken for decay process = 70 days
a = initial amount of the reactant = 10 grams
y = amount left after decay process = ? grams
Putting values in above equation, we get:
[tex]70days=\frac{2.303}{0.0495days^{-1}}\log\frac{10g}{y}\\\\y=0.316g[/tex]
Hence, the amount of substance left will be 0.316 grams.
In a nonpolar covalent bond,
protons are shared equally by two atoms.
electrons are shared equally by two atoms.
electrons are shared unequally by two atoms.
protons are transferred from one atom to another.
Which molecule below has a triple covalent bond?
Diatomic Fluorine
Diatomic Nitrogen
Diatomic Oxygen
Diatomic Hydrogen
Answer:
#11: In a nonpolar covalent bond, electrons are shared equally between two atoms.
#12: Only the diatomic nitrogen molecule [tex]\rm N_2[/tex] contains a triple covalent bond among the four molecules.
Explanation:
#11Consider: what is a covalent bond?
Two atoms share a pair of electrons (called a bonding pair as opposed to a lone pair) between them.
Nonpolar covalent bonds exist only between atoms with similar electronegativity values. The two bonding atoms attract the bonding pair with similar strength, such that the bonding pair is shared mostly equally between the two atoms.
In case the two atoms differ in their electronegativity, the bonding pair will be closer to the more electronegative atom. That will make a polar covalent bond.
#12Atoms share electrons with each other to achieve an octet of eight valence electrons (two for hydrogen.) Atoms form a covalent bond for every two valence electrons that they need.
Consider: how many electrons do atoms in each molecule need to gain before achieving an octet?
Fluorine is in group 17 of the new IUPAC periodic table. Each fluorine atom needs 18 - 17 = 1 valence electron to achieve an octet. There are two fluorine atoms in an [tex]\rm F_2[/tex] molecule. These two atoms will need two electrons in total to achieve an octet. They will thus need to form [tex]2/2 = 1[/tex] covalent bond.
Similarly:
Nitrogen is in group 15.Each Nitrogen atom is 18 - 15 = 3 electrons away from an octet.There are two nitrogen atoms in each [tex]\rm N_2[/tex] molecule. The two nitrogen atoms need six more electrons in total and will form [tex]6/2 =3[/tex] covalent bonds.Oxygen is in group 16.Each oxygen atom is 18 - 16 = 2 electrons away from an octet.There are two oxygen atoms in each [tex]\rm O_2[/tex] molecule. The two oxygen atoms need four more electrons in total and will form [tex]4/2 =2[/tex] covalent bonds.Hydrogen is a special case in the "octet" rule.Each hydrogen atom needs one valence electron to attain the electron configuration of the next noble gas element, He. There are two hydrogen atoms in each [tex]\rm H_2[/tex] molecule. The two hydrogen atoms need two more electrons in total and will form [tex]2/2 =1[/tex] covalent bonds.Answer:
11. Electrons are shared equally by two atoms.
12. Diatomic nitrogen
Explanation:
An example of the the first bond is the diatomic hydrogen.
There are 5 electrons in the nitrogen atom's outer shell. The 2 nitrogen atoms will each share 3 electrons to form 3 covalent bonds.
Base your answer to this question on the information below.During a bread-making process, glucose is converted to ethanol and carbon dioxide, causing the bread dough to rise. Zymase, an enzyme produced by yeast, is a catalyst needed for this reaction.Choose the correct structural formula for the alcohol formed in this reaction.
Answer: 1 C6H12O6===> 2 C2H5OH + 2 CO2
75 In the space in your answer booklet, draw a structural formula for the alcohol formed in this reaction. [1]
Explanation:
The correct structural formula for the alcohol formed in this reaction [tex]CH_3-CH_2-OH[/tex] is also called ethanol.
What is alcohol?Alcohol is any of a class of organic compounds characterized by one or more hydroxyl (―OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain).
Ethanol is simple alcohol produced via the fermentation of sugars (such as glucose, fructose, and sucrose) by yeasts because yeasts do this conversion in the absence of oxygen.
The correct structural formula for the alcohol formed in this reaction [tex]CH_3-CH_2-OH[/tex] is also called ethanol.
Learn more about the alcohol here:
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Hydrochloric acid is a strong acid that is diprotic. True or false?
Answer:
False.
Correction: Hydrochloric acid is a strong acid that is monoprotic.
Explanation:
Hydrochloric acid is a strong acid because it is completely dissociated to its ions in the solution.But it is a monoprotic acid because it produces 1 mol of H⁺ when it is dissociated. according to the reaction:HCl → H⁺ + Cl⁻.
So, the answer is: False.
And the correction is:
Hydrochloric acid is a strong acid that is monoprotic.
What causes an electric current in a wire
An electrical phenomenon is caused by flow of free electrons from one atom to another. The characteristics of current electricity are opposite to those of static electricity. Wires are made up of conductors such as copper or aluminum. ... Current flows from positive to negative and electron flows from negative to positive.
Which of the following equations is balanced correctly and has the correct products for the reactants RbNO3 and BeF2?3RbNO3 + 3BeF2 → Be(NO3)3 + 3RbF, because Be increases in charge from 2+ to 3+ when it is replaced2RbNO3 + BeF2 → Be(NO3)2 + 2RbF, because Be keeps a 2+ charge throughout the reactionRbNO3 + BeF2 → BeNO3 + RbF2, because Be keeps a 1+ charge throughout the reaction2RbNO3 + BeF2 → Be(NO3)2 + 2RbF, because Be increases in charge from 1+ to 2+ when it is replaced
Answer:
2RbNO₃ + BeF₂ → Be(NO₃)₂ + 2RbF, because Be keeps a 2+ charge throughout the reaction.
Explanation:
It is a double replacement reaction.A double replacement reaction is a type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products.In this reaction, there is no change in the oxidation state of different atoms.It is just a replacement reaction.So, the right choice is:2RbNO₃ + BeF₂ → Be(NO₃)₂ + 2RbF, because Be keeps a 2+ charge throughout the reaction.
Answer:
b
Explanation: