Answer:
H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq)
HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq)
Explanation:
Carbonic acid (H₂CO₃) has 2 acidic protons. When is dissolved in water, it loses the protons (H⁺) in two sequential steps:
- First, it loses 1 proton to form the hydrogen carbonate ion (HCO₃⁻)
H₂CO₃(aq) ⇄ H⁺(aq) + HCO₃⁻(aq)
- Then, the acid carbonate anion loses its proton to form carbonate ion (CO₃²⁻):
HCO₃⁻(aq) ⇄ H⁺(aq) + CO₃²⁻(aq)
4. Look at the equation below and determine what fitsI in the empty box.
14 C --> 4 N+
?
re
c. en TH
What belongs in the empty box?
A.
В.
e
D.
Answer:
Beta particles
Explanation:
A beta emission is said to occur when a neutron is converted into a proton. When a beta emission takes place, the daughter nucleus increases it's atomic number by 1. A neutrino is also produced.
Since the mass number remain the same but the daughter nucleus has it's atomic number increased by 1, then the particle is a beta particle.
A molecule has a molar mass of 22.45 g/mol. What is the mass of 4.12*10^24 of the molecules?
Answer:
153.56g
Explanation:
Number of moles = mass/molar mass
To get the number of moles of the molecule, we divide the number of molecules contained by Avagadro's number, which is 6.02 × 10^23 molecules.
moles = 4.12 × 10^24 ÷ 6.02 × 10^23
number of moles = 0.684 × 10^(24-23)
number of moles = 0.684 × 10^(1)
number of moles = 6.84mol
If the molar mass of the molecule is 22.45 g/mol, the mass of the molecule can be calculated thus:
mass = moles × molar mass (MM)
mass = 6.84 × 22.45
mass = 153.558
mass = 153.56g
If 27.3% of a sample of silver-112 decays in 1.52 hours, what is the half-life (in hours to 3 decimal places)?
Answer: The half life of the sample of silver-112 is 3.303 hours.
Explanation:
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
[tex]k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}[/tex]
where,
k = rate constant = ?
t = time taken = 1.52 hrs
[tex][A_o][/tex] = Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:
[tex]k=\frac{2.303}{1.52hrs}\log \frac{100}{72.7}\\\\k= 0.2098hr^{-1}[/tex]
To calculate the half life period of first order reaction, we use the equation:
[tex]t_{1/2}=\frac{0.693}{k}[/tex]
where,
[tex]t_{1/2}[/tex] = half life period of first order reaction = ?
k = rate constant = [tex]0.2098hr^{-1}[/tex]
Putting values in above equation, we get:
[tex]t_{1/2}=\frac{0.693}{0.2098hr^{-1}}\\\\t_{1/2}=3.303hrs[/tex]
Hence, the half life of the sample of silver-112 is 3.303 hours.
Conservation of Energy is the principle stating…
A.
that energy can not be destroyed nor created.
B.
that thermal energy always equals kinetic energy.
C.
that an object’s energy is always the same.
D.
that no two objects can have exactly the same amount of energy.
Select an answer
Answer:
A
Explanation:
because The law of conservation of energy, also known as the first law of thermodynamics, states that the energy of a closed system must remain constant—it can neither increase nor decrease without interference from outside
Percent yield is very important in terms of money. The higher the percent yield, the more of a product you can make. If you are working for a drug company and your theoretical yield is 120 kg, but you actually made 105 kg, what is your percent yield?
A. 8.75%
B. 114%
C. 87.50%
D. 15.00%
Answer:
87.5 %
Explanation:
Step 1: Given data
Theoretical yield: 120 kgReal yield: 105 kgStep 2: Calculate the percent yield
When working with chemical reactions, we can determine the efficience in obtaining a product measuring the percent yield. The theoretical yield is the maximum amount of product that we could obtain according to the stoichiometry, whereas the real yield is the amount of product that we actually obtain when we carry out the process. We can calculate the percent yield usign the following expression.
%yield = real yield / theoretical yield × 100%
%yield = 105 kg / 120 kg × 100%
%yield = 87.5 %
In the artice, "As Sticky as a Gecko...but Ten
Times Stronger, scientists applied knowledge of
gecko feet to produce an adhesive, How did
scientists explain this application of knowledge?
Check all that apply.
The researchers created an adhesive made
from nitrogen nanotubes.
The adhesive is made up of two different
layers.
The lower layer is made up of vertically
aligned nanotubes
The upper layer is made up of curly.
spaghetti-ike, nanotubes.
Answer:
The adhesive is made up of two different layers.
The lower layer is made up of vertically aligned nanotubes.
The upper layer is made up of curly, spaghetti-like, nanotubes.
Answer:
B,C,D
Explanation:
Can someone answer 4 for me please?
An aqueous solution of calcium hydroxide is standardized by titration with a 0.112 M solution of hydrobromic acid. If 15.2 mL of base are required to neutralize 12.4 mL of the acid, what is the molarity of the calcium hydroxide solution?
Answer:
0.0457 M
Explanation:
The reaction that takes place is:
2HBr + Ca(OH)₂ → CaBr₂ + 2H₂OFirst we calculate how many moles of acid reacted, using the HBr solution's concentration and volume:
Molarity = Moles / VolumeMolarity * Volume = Moles0.112 M * 12.4 mL = 1.389 mmol HBrNow we convert HBr moles to Ca(OH)₂ moles, using the stoichiometric ratio:
1.389 mmol HBr * [tex]\frac{1mmolCa(OH)_{2}}{2mmolHBr}[/tex] = 0.6944 mmol Ca(OH)₂Finally we calculate the molarity of the Ca(OH)₂ solution, using the given volume and calculated moles:
0.6944 mmol Ca(OH)₂ / 15.2 mL = 0.0457 MWhat is the molarity of a NaOH solution if 28.2 mL of a 0.355 M H2SO4 solution is required to neutralize a 25.0-mL sample of the NaOH solution?A) 0.801B) 0.315C) 0.629D) 125E) 0.400
Answer:
A) 0.801
Explanation:
The reaction that takes place is:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂OFirst we calculate the H₂SO₄ moles that reacted:
0.355 M * 28.2 mL = 10.011 mmol H₂SO₄Now we convert H₂SO₄ moles to NaOH moles:
10.011 mmol H₂SO₄ * [tex]\frac{2mmolNaOH}{1mmolH_2SO_4}[/tex] = 20.022 mmol NaOHFinally we calculate the molarity of the NaOH solution:
20.022 mmol NaOH / 25.0 mL = 0.801 MSo the answer is option A.
The molarity of the NaOH solution used in the neutralization reaction has been 0.801 [tex]\rm \times\;10^-^3[/tex] M. Thus, option A is correct.
The neutralization reaction has resulted in the formation of the salt and water on reacting an acid with a base. In the neutralization reaction, the strength of acid and base can be given as:
[tex]\rm 2\;NaOH\;+\;H_2SO_4\;\rightarrow\;Na_2SO_4\;+\;H_2O[/tex]
For the neutralization of 1 mole of sulfuric acid, 2 moles of NaOH has been required.
The moles of sulfuric acid can be given as:
Moles = Molarity × Volume
Given, the molarity of acid ([tex]\rm H_2SO_4[/tex]) = 0.355 M
Volume of acid = 28.2 ml = 0.0282 L
Volume of base (NaOH) = 25 ml = 0.025 L
Moles of [tex]\rm H_2SO_4[/tex] = 0.355 × 0.0282 mol
Moles of [tex]\rm H_2SO_4[/tex] = 10.011 mol.
Since, 1 mole [tex]\rm H_2SO_4[/tex] = 2 moles NaOH
10.011 moles [tex]\rm H_2SO_4[/tex] = 10.011 × 2 moles NaOH
10.011 moles [tex]\rm H_2SO_4[/tex] = 20.022 moles NaOH.
The neutralization of 0.355 M [tex]\rm H_2SO_4[/tex] requires 20.022 moles NaOH. The strength of the NaOH solution will be:
Molarity = [tex]\rm \dfrac{Moles}{Volume\;(L)}[/tex]
Molarity of NaOH = [tex]\rm \dfrac{20.022}{0.025}[/tex]
Molarity of NaOH = 0.801 [tex]\rm \times\;10^-^3[/tex] M.
The molarity of the NaOH solution used in the neutralization reaction has been 0.801 [tex]\rm \times\;10^-^3[/tex] M. Thus, option A is correct.
For more information about the neutralization reaction, refer to the link:
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Balanced or Unbalanced
CH4+4CI2=CCI4+4HCI
Answer:
Balanced Chemical Equation
CH4 + 4Cl2 → CCl4 + 4HCl
Explanation:
Brainliest please?
why tha homolytic dissociantion of H-H is lower than the heterolytic dissociation
Answer:
Bond cleavage, or bond fission, is the splitting of chemical bonds. This can be generally referred to as dissociation when a molecule is cleaved into two or more fragments. In general, there are two classifications for bond cleavage: homolytic and heterolytic, depending on the nature of the process. ... The singlet excitation energy of a silicon–silicon sigma bond is lower than.
Latitude plays a major role in determining the climate, or long-term weather patterns, of an area. Because of
differences in the intensity of solar energy, climates in higher latitudes are generally colder than climates in lower
latitudes. What causes some areas of Earth to receive less intense solar energy than others?
A) the mass of the Earth
B) the curve of the Earth
the density of the Earth
D the elevation of the Earth
Answer: D
Explanation: because the earth is slanted and at the north and south pole do not get that much sunlight so that makes it colder than most places on earth
What is electron affinity?
Answer:
The ability of an atom to accept an electron.
Explanation:
Electron affinity is measured by observing the energy change of a substance when an electron is added to it in its neutral gas form. For example, elements that are on the far right of the periodic table (excluding noble gases) are more likely to accept electrons rather than give them up. This is why Fluorine has the highest electron affinity of all atoms on the periodic table.
A student makes observations of a tree in a nearby forest. Which of the following observations of the
tree's characteristics would be useful in determining its identity with a dichotomous key?
A
It contains the nests of several birds.
B
Its leaves are long and narrow.
с
Its branches were recently cut.
D
It provides shade for ground brush.
The observations of the tree's characteristics would be useful in determining its identity with a dichotomous key is its leaves are long and narrow. The correct option is B.
What is an observation?Observation is a process of recognizing and recording an event or fact that frequently involves measuring it with tools. Recognizing and recording an event, or fact frequently involves measuring with tools. Field notes are written observations made while participating in field observations or immediately afterward.
They are crucial for understanding phenomena that have been seen in the field. Field notes frequently take the form of scratch notes, diaries, and notebooks. In the scientific field, observation is a crucial step.
Therefore, the correct option is B. Its leaves are long and narrow.
To learn more about observation, refer to the link:
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The red outlined elements have what major characteristics in common?
1 point
Metals, Nonmetals, and Metalloids
One major characteristic they have in common is they are metals.
You want to calculate the average atomic mass of a sample of Nickle. There are 32 atoms of Nickle-60 and 89 atoms of Nickle-57.
What is the percent distribution of Nickle-60?
What is the percent distribution of Nickle-57?
What is the average atomic mass of the sample? Round to the correct number of decimals and include units?
Answer:
Average atomic mass = 57.79 amu
Percent contribution of Ni-60 = 26.45%
Percent contribution of Ni-5 = 73.55%
Explanation:
Given data:
Number of atoms of Ni-60 = 32
Number of atoms of Ni-57 = 89
Percent distribution of both isotopes = ?
Average atomic mass of sample = ?
Solution:
Percent contribution:
Total number of atoms = Ni-60 + Ni-57
Total number of atoms = 32 +89 = 121
Percent contribution of Ni-60 = 32/121×100
= 26.45%
Percent contribution of Ni-57 = 89/121×100
= 73.55%
Average atomic mass:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (26.45×60)+(73.55×57) /100
Average atomic mass = 1587 + 4192.35 / 100
Average atomic mass = 5779.35 / 100
Average atomic mass = 57.79 amu.
At what temperature is water a gas
Answer:
212 degrees Fahrenheit
Explanation:
When liquid water reaches a low enough temperature, it freezes and becomes a solid—ice. When solid water is exposed to enough heat, it will melt and return to a liquid. As that liquid water is further heated, it evaporates and becomes a gas—water vapor.
what form of energy causes an ice cube to melt
A.mechanial
B.magnetic
C.sound
B.thermal
Answer:
Thermal
Explanation:
When something heats up its atoms become further apart making it melt when something heats up or gets heat or loses heat that's thermal energy
A metal is found that has a mass of 27g and will displace 6mL of water. Calculate its density and identify the metal.
The density of metal = 4.5 g/ml, and the metal = Titanium
Further explanationDensity is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
ρ = density
m = mass
v = volume
mass of metal=27 g
volume = 6 ml
The density :
[tex]\tt \rho=\dfrac{27}{6}\\\\\rho=4.5~g/ml[/tex]
The metal with a density of 4.5 g/ml is Titanium
Based on the activity series provided, which reactants will form products? F > Cl > Br > I CuI2 + Br2 Right arrow. Cl2 + AlF3 Right arrow. Br2 + NaCl Right arrow. CuF2 + I2 Right arrow.
Answer: Cul2 + Br2 ->
Explanation:
Answer:
i believe the answer is a
Explanation:
The combustion of ethyne, shown below unbalance, produces heat which can be used to weld metals:
C2H2 (g) +502 (g) →2CO: (g) +H20 (g) AH reaction= -1544kJ
How much ethyne gas (in g) would you need to react with excess oxygen according to this reaction in order to raise the temperature of 325 g of high carbon steel from 165'C to its melting point, 1540 C? The heat capacity of high carbon steel is 0.490 J/g'C. (Assume a complete reaction and that all heat is transferred from the reaction to the metal with no loss.)
a. 7.37g
b. 1.84 g
c. 4.13 g
d 3.69 g
Answer:
3.69 g
Explanation:
Given that:
The mass m = 325 g
The change in temperature ΔT = ( 1540 - 165)° C
= 1375 ° C
Heat capacity [tex]c_p[/tex] = 0.490 J/g°C
The amount of heat required:
q = mcΔT
q = 325 × 0.490 × 1375
q = 218968.75 J
q = 218.97 kJ
The equation for the reaction is expressed as:
[tex]C_2H_{2(g)} + 5O_{2(g)} \to 2CO_{2(g)} + H_2O_{(g)} \ \ \ \ \ \Delta H^o_{reaction} = -1544 \ kJ[/tex]
Then,
1 mole of the ethyne is equal to 26 g of ethyne required for 1544 kJ heat.
Thus, for 218.97 kJ, the amount of ethyne gas required will be:
[tex]= \dfrac{26 \ g}{1544 \ kJ} \times 218.97 \ kJ[/tex]
= 3.69 g
Which is stronger, the strong force (SF) or the electromagnetic force (EMF)? Describe how they battle each other in the nucleus. What would happen if their strengths were reversed?
Answer:uclear Force that holds together the nucleus of an atom. electromagnetic force. ... They are unstable because the Strong Force that would hold them together if the protons and neutrons were closer is weakened because the protons and neutrons get too far apart.
Explanation:
A student is looking for an element to react with lithium to create the most vigorous reaction possible. To which direction on the periodic table should the student look?
A. Lower left
B. Upper left
C. Lower right
D. Upper right
Answer:
D. Upper right
Explanation:
The position the student should look for such element is in the upper right corner before the noble gases.
Specifically, the group of halogens will react vigorously with lithium.
Lithium is an electropositive metal. To attain stability, it must lose an electron. The group of halogens are a series of highly electronegative elements. They have 7 electrons in their outer shell and requires just one more to complete their octet. Therefore, they combine violently with halogensHalogens are found in the upper right corner on the periodic table.Answer:
D. Upper right
Explanation:
I had the exact same question
Electron transfer between redox centers in proteins is controlled by quantum tunneling. We can model the region between two redox centers as an energy barrier which the electron must cross. If the distance between the redox centers is 0.681 nm and the energy of the electron is 0.5540.554eV lower than the height of the barrier, what is the probability that the electron will successfully cross to the next redox center
Answer:
5.61 e⁻³
Explanation:
Given that:
The barrier length = 0.681 nm = 6.81 × 10⁻¹⁰
The difference between the height of the barrier & the energy of the electron is;
[tex]V - E = 0.554 \ eV (1.6 \times 10^{-19} )[/tex]
= 8.864 × 10⁻²⁰ V
where;
m = 9.1 × 10⁻³¹ kg
The probability[tex]P = e^{-2 \ kd}[/tex]
[tex]k = 2 \pi \sqrt{\dfrac{2m (V-E)}{h^2} }[/tex]
[tex]k = 2 \pi \times \dfrac{\sqrt{2 \times 9.1 \times 10^{-31} \times 8.864 \times 10^{-20}}}{6.63 \times 10^{-34}}[/tex]
k = 3.806 × 10⁹
[tex]P = e^{-2 \ kd}[/tex]
[tex]P = e^{2 \times 3.806 \times 10^9 \times 6.81 \times 10^{-10}}[/tex]
P = 0.005606
P = 5.61 × 10⁻³
P = 5.61 e⁻³
WILL BE MARKED BRAINLIEST IF U ANSWER CORRECT
PLUS 30 PT
Why does DNA dissolve in water?
Why is salt added to solution of DNA and water?
How does ethanol help the precipitate form?
After a pellet is formed, is the DNA in the pellet or the supernate?
Explanation:
Because of this, DNA and RNA can easily dissolve in water. ... Adding ethanol helps the Na+ and PO3- ions come together, because ions travel easier in ethanol than water. The supernate is removed and new ethanol is added in the second washing. This removes any residual salt that remained on the pelleted DNA.
Answer:
DNA is polar due to its highly charged phosphate backbone. Its polarity makes it water-soluble (water is polar) according to the principle "like dissolves like". ... This fact makes water a very good solvent for charged compounds like salts.
Your DNA's sugar phosphate backbone is charged. By adding salt, we help neutralize the DNA charge and make the molecule less hydrophilic, meaning it becomes less soluble in water. The salt also helps to remove proteins that are bound to the DNA and to keep the proteins dissolved in the water.
It is well known that Ethanol has a lower dielectric constant than water, making it to promote ionic bond formations between the Na+ (from the salt) and the PO3- (from the DNA backbone), further, causing the DNA to precipitate.
Explanation:
Ideally DNA needs to be precipitated with pellet and should not remain in supernatant. DNA is acidic in nature and therefore, needs optimum salt concentration in the buffer to be pelleted from a solution. At very low salt concentration or without salt DNA would remain in supernatant.
All solutions
are mixtures; but
all mixtures are
not solutions.
why?
All solutions are mixtures of two or more substances, but unless the mixture has a homogeneous distribution of solutes in the solvent, then the mixture is not a solution. Therefore, all mixtures are not solutions.
Balance the following equation and determine the coefficients in order
from left to right. Co + O2 - C0203
A 1,3,2
B 2,3,1
C 1,1,2
D 4, 3, 2
Answer:
D 4,3,2
Explanation:
4 Co + 3 O2 ----> 2 Co2O3
How many mL of solution are required to make a 0.270M solution of sodium chloride if you have 2.18g of sodium chloride?
Answer:
138mL are required to make the solution
Explanation:
A solution of 0.270M contains 0.270 moles of solute (NaCl in this case), per liter of solution.
To solve this problem we need to determine the moles of NaCl in 2.18g. With these moles and molarity we can find the volume required to prepare the solution:
Moles NaCl -Molar mass: 58.44g/mol-:
2.18g * (1mol / 58.44g) = 0.0373moles NaCl
Volume of solution:
0.0373moles NaCl * (1L / 0.270moles) = 0.138L
138mL are required to make the solutionHow high of a Frequency would a photon have to be for it to have an energy of 4 joules
The frequency of photon=6.03 x 10³³ /s
Further explanationRadiation energy is absorbed by photons
The energy in one photon can be formulated as
[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
Energy of photon = 4 J
So the frequency :
[tex]\tt f=\dfrac{E}{h}\\\\f=\dfrac{4}{6.626.10^{-34}}\\\\f=6.03.10^{33}/s[/tex]
What type of particles would be in a sample of carbon dioxide?
Nuetrons, Electrons, and Protons.