Answer:
Maintenance of homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them.
You want to clean a 500-ml flask that has been used to store a 0.9M solution. Each time the flask is emptied, 1.00 ml of solution adheres to the walls, and thus remains in the flask. For each rinse cycle, you pour 9.00 ml of solvent into the flask (to make 10.00 ml total), swirl to mix uniformly, and then empty it. What is the minimum number of such rinses necessary to reduce the residual concentration of 0.00001 M or below
Answer:
In the 5th cycle rinse, the residual concentration of the solution is < 0.00001M
Explanation:
In each rinse cycle, the dilution that you are doing of the solution is from 1.00mL to 10.00mL, that is a dilution of 10
In the first rinse the concentration must be of 0.9M 10 = 0.09M
2nd = 0.009M
3rd = 0.0009M
4th = 0.00009M
5th = 0.000009M →
In the 5th cycle rinse, the residual concentration of the solution is < 0.00001MAmmonium phosphate is an important ingredient in many solid fertilizers. it can be made by reacting aqueous phosphoric acid with liquid ammonia. calculate the moles of ammonium phosphate produced by the reaction of 0.085 mol of ammonia. be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
0.028 mole of ammonium phosphate, (NH₄)₃PO₄.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
H₃PO₄ + 3NH₃ —> (NH₄)₃PO₄
From the balanced equation above,
3 moles of NH₃ reacted to produce 1 mole of (NH₄)₃PO₄.
Finally, we shall determine the number of mole of (NH₄)₃PO₄ produced by the reaction of 0.085 mole of ammonia, NH₃. This can be obtained as follow:
From the balanced equation above,
3 moles of NH₃ reacted to produce 1 mole of (NH₄)₃PO₄.
Therefore, 0.085 mole of NH₃ will react to produce = (0.085 × 1)/3 = 0.028 mole of (NH₄)₃PO₄.
Thus, 0.028 mole of ammonium phosphate, (NH₄)₃PO₄ were obtained from the reaction.
Suppose a chemical engineer studying a new catalyst for the Haber reaction finds that liters per second of dinitrogen are consumed when the reaction is run at and the dinitrogen is supplied at . Calculate the rate at which ammonia is being produced. Give your answer in kilograms per second. Be sure your answer has the correct number of significant digits.
The question is incomplete. Here is the complete question.
In the Haber reaction, patented by German chemist Fritz Haber in 1908, dinitrogen gas combines with dihydrogen gas to produce gaseous ammonia. This reaction is now the first step taken to make most of the world's fertilizer. Suppose a chemical engineer studying a new catalyst for the Haber reaction finds that 505. liters per second of dinitrogen are consumed when the reaction is run at 172.°C and 0.88 atm. Calculate the rate at which ammonia is being produced. Give your answer in kilogram per second. Be sure your answer has the correct number of significant digits.
Answer: Rate = 0.41 kg/s
Explanation: The balanced Haber reaction is
[tex]N_{2}+3H_{2}\rightarrow2NH_{3}[/tex]
As all the components are gases, we can use Ideal Gas Law, which relates Pressure (P), Volume (V), Temperature (T) and Moles (n) in the following formula:
PV = nRT
where
R is gas constant and, in this case, is R = 0.082 L.atm.K⁻¹mol⁻¹
T is in Kelvin
Converting Celsius in Kelvin:
T = 273 + 172
T = 445 K
Calculating moles
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{0.88(505)}{0.082(445)}[/tex]
n = 12.18 moles
According to the balanced equation, for 1 mol of dinitrogen gas consumed, 2 moles of ammonia is produced.
With 12.18 moles of dinitrogen, the reaction will result in
2(12.18) = 24.36 moles of ammonia
Molar mass of ammonia is M = 17.031 g/mol.
In 24.36 moles, there are
[tex]m=n.M[/tex]
m = 24.36.17.031
m = 414.87 grams
Since it's asking in kilograms: m = 0.41 kg.
In the beginning, it is said that dinitrogen gas is consumed at a rate of liters per second. So, the production rate of ammonia will be 0.41 kg/s.
How many orbitals in an atom can have each of the following designations:
(a) 1s;
(b) 4d;
(c) 3p;
(d) n=3?
Answer:
(a) 1s; has one orbital
(b) 4d; has five orbitals
(c) 3p; has three orbitals
(d) n=3 has nine orbitals
Explanation:
Electrons in an atom are always in constant motion, making it hard to predict there exact position. However, the most probable locations electrons can be be found are described with the terms shells, subshells and orbitals. A shell contains subshells and orbitals are found within subshells. The shells are given names such as K, L, M, N, which correspond to the principal quantum numbers, n = 1, 2, 3, and 4 respectively. There are 4 major types of subshells that can be found in a shell. They are named as s, p, d, f. Each subshell is composed of several orbitals.
a. 1s; the s subshell has only one orbital. Therefore, the 1s subshell has one orbital
b. 4d; the d subshell has five orbitals. Therefore, the 4d subshell has five orbitals
c. 3p; the p subshell has three orbitals. Therefore, the 3d subshell has three orbitals
d. n = 3; the shell with n = 3 has the following subshells, 3s, 3p, 3d.the number of orbitals will be 1 + 3 + 5 = 9 orbitals. Therefore, the number of orbitals in n = 3 is nine orbitals
Which element is oxidized in the following reaction Mn²⁺ + 2 K → Mn(s) + 2 K⁺ ?
1. Radiation with a frequency of 1.85 MHz, falls in the radio wave region. What is the wavelength (in nm) of this electromagnetic radiation?
(HINT: Hz is "cycles per second" and should be replaced by 1/s as a unit in the calculation. First convert MHz to Hz (106) also the final answer convert to nm. (10-9)
2. What is the frequency of visible light, which has a wavelength of 625 nm? What color is the wave?
(HINT: Notice for final answer that nm must be converted to m in order for the units to cancel properly)
Answer:
1. 1.62×10¹¹ nm
2. 4.8×10¹⁴ Hz
Explanation:
1. Determination of the wavelength.
We'll begin by converting 1.85 MHz to Hz. This can be obtained as follow:
1 MHz = 10⁶ Hz
Therefore,
1.85 MHz = 1.85 MHz × 10⁶ Hz / 1 MHz
1.85 MHz = 1.85×10⁶ Hz
Next, we shall determine the wavelength of the electromagnetic radiation. This can be obtained as follow:
Frequency (f) = 1.85×10⁶ Hz
Velocity of electromagnetic radiation (v) = 3×10⁸ m/s
Wavelength (λ) =?
v = λf
3×10⁸ = λ × 1.85×10⁶
Divide both side by 1.85×10⁶
λ = 3×10⁸ / 1.85×10⁶
λ = 162.16 m
Finally, we shall convert 162.16 m to nm. This can be obtained as follow:
1 m = 10⁹ nm
Therefore,
162.16 m = 162.16 m × 10⁹ nm / 1 m
162.16 m = 1.62×10¹¹ nm
Thus, the wavelength of the electromagnetic radiation is 1.62×10¹¹ nm
2. Determination of the frequency.
We'll begin by converting 625 nm to m. This can be obtained as follow:
1 nm = 10¯⁹ m
Therefore,
625 nm = 625 nm × 10¯⁹ m / 1 nm
625 nm = 6.25×10¯⁷ m
Finally, we shall determine the frequency the visible light as follow:
Wavelength (λ) = 6.25×10¯⁷ m
Velocity of light (v) = 3×10⁸ m/s
Frequency (f) =?
v = λf
3×10⁸ = 6.25×10¯⁷ × f
Divide both side by 6.25×10¯⁷
f = 3×10⁸ / 6.25× 10¯⁷
f = 4.8×10¹⁴ Hz
Therefore, the frequency of the visible light is 4.8×10¹⁴ Hz
Cameron connects a battery, a lightbulb, and electrical wires to make a simple circuit. Which choice correctly lists the forms of energy found in the circuit?
chemical only
chemical and electrical
chemical, electrical, light
chemical electrical, light, heat
Answer:
Chemical,electrical,light,heat
Answer:
chemical electrical, light, heatExplanation:
After running, Ollie’s blood pressure was high. His nervous system sensed this and sent a message to decrease heart rate and blood flow.
Answer:
Circulatory
Explanation:
What is the structure formula of c10h18
Answer: I'm not 100% sure this is the formula but I hope it still helps! :)
Explanation:
Bornane; Cyclodecene; Decalin; Decynes. 1-Decyne; 2-Decyne; 3-Decyne; 4-Decyne; 5-Decyne, also known as dibutylethyne; Spirodecane
Benzophenone has a normal freezing point of +48.1 oC, with freezing point depression constant Kfpt = − 9.78 oC/m. A 0.1500 molal solution of ionizing salt had a freezing point of +44.0 oC. What is the van't Hoff (ion dissociation) constant i for this salt? (i.e., the average number of ions produced in the solution.) Report 3 significant digits.
Answer:
i = 2.79
Explanation:
The excersise talks about the colligative property, freezing point depression.
Formula to calculate the freezing point of a solution is:
Freezing point of pure solvent - Freezing point of solution = m . Kf . i
Let's replace data given. (i = Van't Hoff factor, numbers of ions dissolved in solution)
48.1°C - 44°C = 0.15 m . 9.78°C/m . i
4.1°C / (0.15 m . 9.78°C/m) = i
i = 2.79
In this case, numbers of ions dissolved can decrease the freezing point of a solution, which is always lower than pure solvent.
Showing little or no charge is called
Which is a gas at room temperature A.aluminum B.nitrogen C.potassium D.sodium
Answer:
B.nitrogen
Explanation:
Nitrogen is a gas at room temperature.
How many moles of hydrogen gas are present in 65.0 liters at STP?
1456 moles
1.45 moles
3.00 moles
2.90 moles
Answer:
2.9moles of hydrogen gas
Explanation:
convert liters to dm³
since 1liter= 1dm³
thus, 65.0liters = 65.0dm³
number of moles = volume given/22.4dm³
= 65.0/22.4
=2.9moles
which two substances are among the four major types of organic compounds made by living things
A.lipids
B.water
C.carbon dioxide
D.Nucleic acids
will give brainliest
Identify three farming practices that contribute to desertification. Discuss how each practice can be avoided and how changing the practice will affect the soil.
Answer:
See explanation
Explanation:
Poor irrigation: When too much water is used during irrigation or water is inefficiently used for irrigation purposes, there could be an overall decrease in the availability of water resources leading to vegetation loss and desertification. Therefore, water resources should be properly managed to avoid desertification.
Overgrazing: Overgrazing refers to excessive grazing of a grassland. When livestock are allowed to overgraze on a particular area, there is vegetation loss and consequent desertification. Grazing practices should be organized in such a way that grasslands are not subjected to overgrazing.
Poor tillage practices: Poor tillage practices such as continuous cropping makes the soil more porous and exposes the soil to erosion. There may be vegetation loss and finally desertification. Sustainable tillage practices such as shifting cultivation and bush fallowing should be adopted.
The history of atomic theory
Answer:
Atomic theory originated as a philosophical concept in ancient India and Greece. ... In the fifth century BCE, Democritus proposed that matter consists of indestructible, indivisible units called atoms. The Roman poet Lucretius recorded the idea, so it survived through the Dark Ages for later consideration.
Hope this is fine for youA compound with molecular formula C5H10Br2 displays the following 13C NMR along with the DEPT-90 and DEPT-135 13CNMR spectra. What is the structure for this compound?
Answer:
Explanation:
The correct structure for the compound C5H10Br2 is:
Br -- CH₂ -- CH₂ -- CH₂ -- CH₂ -- CH₂ -- Br
1 2 3 4 5
The name of the required compound is 1,5-dibromopentane.
The DEPT spectroscopy is applied to differentiate between CH₃, CH₂, and CH groups.
Assuming the DEPT is up, this shows a positive peak which illustrates CH₃ group
Assuming the DEPT is down, this shows a negative peak which illustrates CH₂ or CH group
C-13 NMR with DEPT-135
The negative peak in DEPT at 26.77 ppm illustrates CH₂ or CHThe negative peak at 31.85 ppm illustrate CH₂ or CHThe negative peak at 33.24 ppm illustrate CH₂ or CHThe carbon analysis is:
Assign ppm
1 33.24
2 31.85
3 26.77
4 31.85
5 33.24
When a substance undergoes a chemical change, its identity does not change.
O True
O False
Answer:
False
Explanation:
Chemists make a distinction between two different types of changes that they study—physical changes and chemical changes. Physical changes are changes that do not alter the identity of a substance. Chemical changes are frequently harder to reverse than physical changes.
Two volumes of nitric oxide react with one volume of oxygen gas to form two volumes of a reddish-brown gas. Deduce the formula of this gas and sketch particle representations of its molecules.
Answer:
Explanation:
Nitric oxide is the gas NO, it reacts with oxygen as shown below;
2NO(g) + O2(g) -----> 2NO2(g)
Now the gas formed is the gas NO2 which is known to be reddish brown in colour.
A diagrammatic representation of this reaction is shown in the image attached to this answer.
Image credit: Chemlibretext
What is the atomic number of an element that has six protons and eight neutrons?
A. 6 B. 2 C. 8 D. 14
Answer:
D. 14
Explanation:
This is a Carbon Atom which has an atomic number of 14. 6+8=14
WHY IS IT IMPORTANT FOR A POPULATION TO NOT ALL BE IDENTICAL?
Answer:
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Explanation:
P4+O2=P2O3
What’s the balance of this equation?
Explanation:
P₄+O₂=P₂O₃; non-balanced
P₄+O₂=2P₂O₃; to add '2' on the right side; non-balanced
P₄+3O₂=2P₂O₃. to add '3' before O₂ in the left side; balanced
Name the energy store that two electrical
charges have when they attract or repel each
other.
Answer:
In contrast to the attractive force between two objects with opposite charges, two objects that are of like charge will repel each other. That is, a positively charged object will exert a repulsive force upon a second positively charged object.
Explanation:
Hope it has answered your questionif LiCl and MgBr2 were to enter into a chemical reaction which member of MgBr2 will chlorine replace?
Answer:
It replaces Br in MgBr2.
Explanation:
Hello!
In this case, when carrying out double displacement reactions, we need to take into account that cations and anions are switched; thus, when LiCl and MgBr2 react, since Li and Mg are the cations, Br and Cl switch as shown below:
[tex]2LiCl+MgBr_2\rightarrow 2LiBr+MgCl_2[/tex]
Thus, chlorine replace Br in MgBr2 to form MgCl2.
Best regards!
Do you think crystals formed in conditions that were stable or did they change often?
Answer:
They were made in unstable conditions
Explanation: Im smarty pants
Draw the kinetic and thermodynamic addition products formed when one equivalent of HBr reacts with the diene .
Answer:
See explanation and images attached
Explanation:
The addition of HBr to the diene could yield either a kinetic or thermodynamic product. The kinetic product is formed faster while the thermodynamic product is more stable and formed at equilibrium.
Recall that the alkene that is surrounded by more alkyl groups is more stable. Also, the carbocation undergoes rearrangement to form a more stable carbocation intermediate that ultimately leads to the formation of the thermodynamic (1,4) product which predominates.
The structures of the two products are shown in the image attached to this answer.
What is the atomic number?
pls help.
Answer:
8
Explanation:
Describe a method of Municipal treatment of water with neat diagram?
a pressure of 10Nm -2 is equal to ?
Answer:
a pressure of 10 Nm -2 is equal to ?
1 atmosphere
Explanation:
A pressure of 10 N/m² is equal to 10 Pa and 9.86x10⁻⁵ atm.
Pressure (P) is the measure of the perpendicular force (F) applied to an object's surface area (A):
[tex] P = \frac{F}{A} [/tex]
Hence, the unit of the pressure is Newton per square meter (N/m²), which is defined as Pascal (Pa).
[tex] 1 Pa = 1 N/m^{2} [/tex]
Also, we have that 1 atm is equal to 101325 Pa, so:
[tex] P = 1 Pa*\frac{1 atm}{101325 Pa} =9.86 \cdot 10^{-6} atm [/tex]
So, in a pressure of 10 N/m² we have:
[tex] P = 10 N/m^{2} = 10 Pa = 9.86 \cdot 10^{-5} atm [/tex]
Therefore, a pressure of 10 N/m² is equal to 10 Pa and 9.86x10⁻⁵ atm.
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As a part of a clinical study, a pharmacist is asked to prepare a modification of a standard 22g package of a 2% mupirocin ointment by adding the needed quantity of mupirocin powder to prepare a 3% w/w mupirocin ointment. How many mg of mupirocin powder are required?
Answer:
226.8 mg of mupirocin powder are required
Explanation:
Given that;
weight of standard pack = 22 g
mupirocin by weight = 2%
so weight of mupirocin = 2% × 22 = 2/100 × 22 = 0.44 g
so by adding the needed quantity of mupirocin powder to prepare a 3% w/w mupirocin ointment
mg of mupirocin powder are required = ?, lets rep this with x
Total weight of ointment = 22 + x g
Amount of mupirocin = 0.44 + x g
percentage of mupirocin in ointment is 3?
so
3/100 = 0.44 + x g / 22 + x g
3( 22 + x g ) = 100( 0.44 + x g )
66 + 3x g = 44 + 100x g
66 - 44 = 100x g - 3x g
97 x g = 22
x g = 22 / 97
x g = 0.2268 g
we know that; 1 gram = 1000 Milligram
so 0.2268 g = x mg
x mg = 0.2268 × 1000
x mg = 226.8 mg
Therefore, 226.8 mg of mupirocin powder are required
We have that for the Question "How many mg of mupirocin powder are required? "
It can be said that
[tex]0.2268g[/tex] of mupirocin powder is required
From the question we are told
a pharmacist is asked to prepare a modification of a standard 22g package of a 2% mupirocin ointment by adding the needed quantity of mupirocin powder to prepare a 3% w/w mupirocin ointment
Weight of standard package = 22g
mupirocin = 2%
Therefore,
Weight of mupirocin = [tex]\frac{2}{100}*22[/tex]
[tex]=0.44g[/tex]
Let amount of mupirocin to be added to prepare 3% w/w mupirocin ointment = X
Therefore,
Total weight of ointment = [tex](22 + X)g[/tex]
amount of mupirocin = [tex](0.44+X)g[/tex]
% of mupirocin in ointment = [tex]3\%[/tex]
therefore,
[tex]\frac{3}{100} = \frac{0.44+X}{22+X}\\\\66+3X = 44+100X\\\\X = 0.2268g[/tex]
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