Answer:
[A] = 8.69x10⁻⁵g
Explanation:
Kinetics law of a radioactive atom, A, is:
Ln[A] = -kt + ln[A]₀
Where [A] could be taken as mass of A after time t (In seconds),
k is rate constant = ln2 / Half-Life
[A]₀ is intial mass of A
k = ln2 / 14.9s = 0.04652s⁻¹
Time in seconds:
5min * (60s / 1min) = 300s
Replacing each value:
ln[A] = -0.04652s⁻¹*300s + ln[100.0g]
ln[A] = -9.35
[A] = 8.69x10⁻⁵gSomeone took the last cookie from the cookie jar last night. The last person to leave the scene is the culprit. Who was it? Highlight the guilty culprit based on the clues provided.
A system performed 145 kJ of work on the surroundings and absorbed 105 kJ of heat from the surroundings. What is the change in energy of the system?
Answer:
250 kJ
Explanation:
Step 1: Given data
Work performed by the system (w): 145 kJ (By convention, when the system performs work on the surroundings, w > 0)Heat absorbed by the system (q): 105 kJ (By convention, when the system absorbs heat from the surroundings, q > 0)Step 2: Calculate the change in the internal energy of the system
The internal energy of a thermodynamic system is the energy contained within it. We can calculate the change in the internal energy (ΔE°) using the following expression.
ΔE° = q + w
ΔE° = 105 kJ + 145 kJ = 250 kJ
Which set of terms best defines what affects kinetic energy and potential energy, respecrively
Why are a molecule's atoms as far away from each other as they can get?
A) Electronegativity differences force the atoms apart
B) The protons in the nuclei push the atoms apart
C) Forces between electron pairs push the atoms apart
D) Induced dipoles push the atoms away from each other
Answer:
the answer is a
Explanation:
an electron contains a negative charge and like charges repel each other. Hence, in a atom the force of repulsion between the atoms away from each other. As a result a molecules atoms are as far away from each others as they can get .
A molecule's atoms as far away from each other as they can get because "Forces between electron pairs push the atoms apart".
So, option C is correct one.
Why electrons repel each other?Since, an electron is negative charge species revolve around the nucleus of an atom. So, when two atoms come close to each other in molecules there is repulsion occurs between negative charge electron .
To learn more about electrons here.
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What is the hydrogen ion molarity of a solution with a pH of 10.16
The hydrogen ion molarity : 6.918 x 10⁻¹¹ M
Further explanationpH is the degree of acidity of a solution that depends on the concentration of H⁺ ions. The greater the value the more acidic the solution and the smaller the pH.
pH = - log [H⁺]
So that the two quantities between pH and [H⁺] are inversely proportional because they are associated with negative values.
A solution whose value is different by n has a difference in the concentration of H⁺ ion of 10ⁿ.
pH of solution = 10.16
the [H₃0⁺] of the solution :
[tex]\tt pH=-log[H_3O^+]\\\\10.16=-log[H_3O^+]\\\\(H_3O^+]=10^{-10.16}=6.918\times 10^{-11}[/tex]
Which reaction takes place in a nuclear fission reactor?
C+HN
2 Put He → Cm
OCO+ He-Cot 'n
o U+ nKr+Ba+3'n
Answer:
The reaction that takes place in a nuclear fission reactor is answer D.
Explanation:
Step-by-step explanation:
Nuclear fission reactions involves the process by which large atomic nuclei are bombarded with energetic particles and release of an enormous amount of nuclear energy, which mainly ends up as heat energy.
So now, consider the nuclear reaction from D, after the uranium nucleus absorbs the neutron its split into two smaller nuclei (often radioactive themselves), Krypton and Barium and releases more neutrons (or energy).
Find the pH of the solution obtained when 0.027 L of 0.063 M benzylamine, C7H7NH2, is titrated to the equivalence point with 0.048 M hydrochloric acid. Kb for benzylamine is 4.7×10-10.
Answer:
pH = 3.12
Explanation:
C7H7NH2 + HCl ---> C7H7NH3+Cl-
moles of C7H7NH2 = 0.027 x 0.063 = 1.7 x 10^-3 mol
moles of C7H7NH2 = moles of HCl at equivalence point
1.7 x 10^-3 = 0.048 x V
V = 0.035 L
volume of HCl = 0.035 L
so C7H7NH3+Cl- salt formed = 1.7 x 10^-3 moles
salt concentration = moles / total volume
= 1.7 x 10^-3 / (0.027 + 0.035) = 0.027M
this salt formed from weak base strong acid . so pH <7
pH = 7 - 1/2 [pKb + logC]
pH = 7 -1/2 [9.33 + logC]
pH = 3.12
19.
Caustic soda is 20 M NaOH and is olluted for household use. What is the household concentration of 10
mL of the concentrated solution is diluted to 500 ml?
(A) 0.4 M N OH
(B) 400 M NaOH
(C) 4 M NaOH
(D) 20M NaO
Answer:
(A) 0.4M NaOH
Explanation:
The 20M NaOH caustic soda is diluted from 10mL to 500mL, that is:
500mL / 10mL = Is diluted 50 times.
That means we can solve the new concentration of the diluted solution dividing the stock concentration (20M) 50 times:
20M / 50 = 0.4M NaOH is the concentration of the diluted NaOH solution.
Right answer is:
(A) 0.4M NaOHIn a laboratory experiment, students synthesized a new compound and found that when 11.01 grams of the compound were dissolved to make 158.1 mL of a ethanol solution, the osmotic pressure generated was 1.91 atm at 298 K. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound?
Answer:
892 g/mol
Explanation:
Step 1: Given and required data
Mass of the nonvolatile and a non-electrolyte solute: 11.01 gVolume of solution: 158.1 mL = 0.1581 LOsmotic pressure (π): 1.91 atmIdeal gas constant (R): 0.0821 atm.L/mol.KAbsolute temperature (T): 298 KStep 2: Calculate the molarity (M) of the solution
The osmotic pressure is a colligative property that can be calculated using the following expression.
π = M × R × T
M = π / R × T
M = 1.91 atm / (0.0821 atm.L/mol.K) × 298 K
M = 0.0781 M
Step 3: Calculate the molecular weight of the solute
We will use the following expression for molarity.
M = mass of solute / molecular weight of solute × liters of solution
molecular weight of solute = mass of solute / M × liters of solution
molecular weight of solute = 11.01 g / (0.0781 mol/L) × 0.1581 L
molecular weight of solute = 892 g/mol
DO IT PLS
6. A helium laser emits light with a wavelength of 363 nm. What is the frequency of the light?
What mass of dinitrogen monoxide, N2O, contains the same number of molecules as 3.00 g of trichlorofluoromethane, CCl3F?
Answer:
0.9612 g
Explanation:
First we calculate how many moles are there in 3.00 g of CCl₃F, using its molar mass:
3.00 g CCl₃F ÷ 137.37 g/mol = 0.0218 mol CCl₃FNow, we need to calculate how many grams of N₂O would have that same number of molecules, or in other words, the same amount of moles.
Thus we calculate how many grams would 0.0218 moles of N₂O weigh, using the molar mass of N₂O :
0.0218 mol N₂O * 44.013 g/mol = 0.9612 g N₂OThe mass of dinitrogen monoxide is 0.9612 g
The calculation is as follows:The number of moles are there in 3.00 g of CCl₃F, using its molar mass:
= 3.00 g CCl₃F ÷ 137.37 g/mol
= 0.0218 mol CCl₃F
Now the mass should be
=[ 0.0218 mol N₂O × 44.013 g/mol
= 0.9612 g N₂O
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Phosphorus trichloride, PCl3, is commonly used in the chemical industry as a source of phosphorus in various reactions. Indicate the electron pair geometry and the molecular geometry of the PCl3 molecule. Electron pair geometry: T-shaped tetrahedral trigonal planar trigonal pyramidal trigonal bipyramidal Molecular geometry: tetrahedral trigonal pyramidal trigonal bipyramidal trigonal planar T-shaped
Answer:
Electron pair geometry - tetrahedral
molecular geometry- trigonal pyramidal
Explanation:
According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule is determined by the number of electron pairs around the central atom in the molecule. Lone pairs distort a molecule away from its expected geometry based on VSEPR. This is why the electron pair geometry differs from the actual molecular geometry.
PCl3 has four regions of electron density, three substituents and one lone pair hence its electron pair geometry is tetrahedral. However, the three substituents are arranged in a trigonal pyramidal geometry(its molecular geometry).
What is a solute?
A material that is dissolved in another material.
O A material in which another material is dissolved.
An area of space surrounding the nucleus.
O Chemical formulas on the left side of an equation.
You take a balloon with fixed volume and submerge it in a hot tub for a few minutes. What would you expect to happen to the pressure of the balloon after you take it out? Explain.
Answer:
pressure will be high because the temp is high, the gas is gonna expand
Explanation:
when temp increases it causes gas to expand which causes high pressure. this is because pv=nrt, p=pressure in atmosphere, v is volume in liters, n is number of particles in moles, t is temp in kelvin is r is ideal gas constant
The impact on the pressure should be high since the temperature should be high due to which the gas should be expanded.
What is pressure?Pressure refer to the force applied that should be perpendicular to the surface of an object per unit area so that the force is distributed. In the case when the temperature should be increased so here gas should be expanded that resulted into the high temperature.
Here the following formula should be applied
pv = nrt
Here p = pressure
v means the volume
n means no of particles in moles
r means the ideal gas constant
learn more about pressure here: https://brainly.com/question/4417455
What happens after condensation to cause precipitation?
A
The sun heats water on the Earth's surface.
B
Water is absorbed into the ground.
C
Clouds fill with moisture and get too heavy.
D
Excess water runs downhill.
Answer:
The answer is c, Clouds fill with moisture and get too hravy
What is the frequency of this wave?
1
2
3
4
Help! I dont know how to do this lol
the order is :
- Aufbau principle
- Hund's Rule
- Pauli's Exclusion Principle
1 carbon atom mixed with 1 oxygen atom what is the formula
Answer:
carbon mono oxide CO
Explanation:
as both are in 1:1 ratio so CO is formed
What is the structural formula of CF2Br2
Answer:
Dibromodifluoromethane
Explanation:
What is the average Mw for a fatty acid mixture whose fats (1 gram) required 0.0034 equivalents of NaOH to titrate. Remember: 1 Fatty acid has 1 equivalent.
1. Ew = Mw (#H+)
2. Ew = mass/eq
a.) 294.12 g/mol
b.) 145.04 g/mol
c.) 345.56 g/mol
d.) 132.04 g/mol
Answer:
a.) 294.12 g/mol
Explanation:
1 equivalent of fatty acid reacts with 1 equivalent of NaOH.
As in the titration are required 0.0034 equivalents of NaOH, the equivalents of fatty acids = moles of fatty acids are:
0.0034 moles of fatty acids
Molar mass is defined as the ratio between mass of substance in a determined amount of moles. The mass of the fats was 1 gram, that means the molar mass is:
1g / 0.0034moles =
294.12g/mol
Right option is:
a.) 294.12 g/molWhich terms describe a substance that has a low melting point and poor electrical conductivity?
(1) Metallic and lustrous
(2) Dull and brittle
(3) Brittle and lustrous
(4) Metallic and dull
which of the following is an isotope of hydrogen
Please I have a D in chem and grades close tomorrow ;-;
Which of the following polyatomic lons will form an lonic compound with a single sodium lon?
co₂2-
нсо3^1-
S04^2-
S03^2-
HELP ASAPPPP BRAINLIEST
Answer:
2nd option
Explanation:
15 points! Answer only if you can please!
1. Have you ever grabbed the handle of a hot metal pan? Why did it feel hot to you?
2. What would happen if a person who is wearing a heavy winter jacket were to place a thermometer inside the jacket next to his or her skin? What would happen if we took the same jacket, after it had been hanging in a closet, and placed a thermometer inside?
3. How do you think the transfer of thermal energy causes unpopped popcorn kernels to pop?
Answer:
1. Yes
2. it would be the same i guess
3. because it travels to popcorn kernels with its heat and makes it pop'
did i get it right?
Explanation:
Which graph shows the pressure-volume relationship expected for an ideal gas? (This is an illustration of Boyle's law.)
Question 11 options:
A)
Graph B
B)
Graph C
C)
Graph D
D)
Graph A
Answer:
D
Explanation:
The graph of Boyle's law is known as pressure-volume graph or PV curve. It is as follows:
As observed from the graph above, pressure increases with a decrease in volume, and vice versa. Thus, pressure is inversely proportional to volume. Other parameters (temperature and amount of gas) are constant in the graph above.
Volume is on the x-axis and pressure, on the y-axis. The equation of the curve is PV = k, which is the equation of Boyle's law. The curve is hyperbolic in nature having two asymptotes: P = 0 (horizontal) and V = 0 (vertical).
As volume tends to positive infinity, pressure tends to zero, and we get the horizontal asymptote, P = 0.
Horizontal asymptote, P=0
When volume approaches zero, pressure approaches infinity, and it results in the vertical asymptote, V = 0.
The graph which shows the pressure-volume relationship expected for an ideal gas is: C) Graph D.
Boyle's states that when the temperature of an ideal gas is kept constant, the pressure of the gas is inversely proportional to the volume occupied by the gas.
Mathematically, Boyle's law is given by the formula:
[tex]PV = k[/tex]
Where;
P is the pressure of an ideal gas.V is the volume of an ideal gas.For the illustration of Boyle's law using a graph, volume is represented on the x-axis while pressure is represented on the y-axis.
Generally, the graph of Boyle's law is a hyperbolic curve with two asymptotes:
P = 0 (horizontal axis).V = 0 (vertical axis).Find more information: https://brainly.com/question/1437490
what is protein denaturation
Answer:
Denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some
Explanation:
Need help please? Thanks youu
Answer:
A
B
E
Explanation:
"Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei
and fusion is the process where two light nuclei combine together releasing vast amounts of energy"
a process that releases energy is respiration
ASAP I WILL GIVE BRAINLIEST!Which arrow represents the change of state described above? The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance lose energy during a change of state. After the change, the atoms are close together but are able to slide past one another.
0 L
0 N
0 O
0 P
Answer:
O
Explanation:
The atoms lose energy during a change of state, but can still slide past each other; gas to a liquid.
Answer:
i think the answer is C: O
Explanation:
correct me if im wrong
which two changes of state can be caused by removing thermal energy from a substace A. deposition B. condencation C. vaporization D.sublimation
Answer:
maybe is b but wait to other people answer
Answer:A. deposition B. condencation
Explanation: