Answer:false
Explanation:
An incompressible Newtonian fluid is brought to flow in a pipe by pulling a wire in the center at a velocity of 18 cm/s. The wire has a diameter of 5 cm, while the stationary pipe has a diameter of 10 cm. Calculate the shear stress(tre) in the fluid using Newtonian's law of viscosity. The flow is isothermal at °25 and the fluid has a viscosity of 3.0 cp. Provide the sketch of the velocity profile.
Answer:
The shear stress is 2.16 Pa
Explanation:
Newton's law of viscosity can be expressed as follows;
[tex]\tau =\mu \times \dfrac{dv}{dy}[/tex]
Where:
τ = Shear stress in the fluid
Given that the diameter of the wire = 5 cm
The velocity of the wire = 18 cm/s
The diameter of the pipe = 10 cm
The fluid viscosity, μ = 3.0 cp = 1×10⁻³· Pa·s
The change in velocity from the surface of the wire to the internal surface of the pipe = dv = 18 cm/s
The change in the y (perpendicular) direction of motion of the fluid from the surface of the wire to the interior surface of the tube = dy = 10/2 - 5/2 = 2.5 cm
By putting in the values, we have;
[tex]\tau =0.3 \times \dfrac{18}{2.5} = 2.16 \ Pa[/tex]
The shear stress = 2.16 Pa
Which of the following questions can be answered by science? What is the composition of air? Should the driving age be reduced? What is the purpose of our existence on Earth? Should students be allowed to bring toys to school?
Your answer is A. What is the composition of air?
The question that can be answered by science is What is the composition of air? The correct option is A.
What is science?Science is a subject that deals with the components of the earth. It has a wide variety of components of earth. Like planets and meteorites. Plants, animals, and other creatures. Nature, trees, and other abiotic factors.
Science gives answers to the secrets of the earth, and they unravel the mysteries of nature and the earth. They solve the mysteries of air, water, and other natural processes.
So the composition of air can be told by science. The air is made up of a mixture of gases. Air is present in the atmosphere. It is needed for breathing, and it is an important component of life because it provides oxygen to the body.
The correct option is A. What is the composition of air?
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when a substance goes directly from a solid state to a gas state as dry ice
Answer:
Sublimation
Explanation:
Sublimation refers to the process by which the change of matter takes place directly from solid to liquid state. The matter from the solid-state directly changes into the gaseous state without changing into the liquid state. More energy is required in this process. This is an endothermic reaction. Dry ice is the solid carbon dioxide sublimes in the air.
DNA Mutations
Pre-Test
Active
1
A mutation causes a dog to be born with a tail thatis shorter than normal.
Which best describes this mutation
Answer:
Explanation:
A
Why was Niels Bohr atomic model superior to all the earlier models
Answer:
because it showed how the electron could orbit the nucleus without falling into it.
What are the percent compositions of hydrogen and oxygen in water
Answer:
H % = 11.11%
O % = 88.89%
Explanation:
atomic weight of H = 1
atomic weight of O = 16
each molecule of water contains 2 atoms of H and one atom of O
hence molecular weight of water = 18
H % = 2 x 100/18 = 11.11%
O % = 16 x 100/18 = 88.89%
Answer:
-H= 11.19%
-O= 88.81%
Explanation: the answer above mine is incorrect!, i just did it and i got it right, the answer is h= 11.19% and O= 88.81% hope it helps!
1. The diameter of an atom is in the order of
A. 0.2m
B. 0.2mm
C. 0.2nm
D. 0.2pm
Answer:
0.2 nm
Explanation:
Explain why only the lone pairs on the central atom are taken into consideration when predicting molecular shape. What substances from the lab activity have more than one central atom?
Answer:
VSEPR molecular shapes are the substances from the laboratory operation that have more than one central atom.
Explanation:
Molecular shapes from VSEPR
Party breaches think that the largest aspect of a poisonous substance is the gravitational waves that makeup it. Its lone pair of electrons with that kind of a transition metal around this one, in either covalent bond, higher value, or lone pairs, has always been as close to a primary commitment as far as practicable to one another and. The shape of the molecule is defined by the most linear direction, i.e. layout in which minimal electrostatic repulsion is present. The degree of the repulsive force between pairs of electrons is as follows: bond pair-bond pair < bond pair-lone pair < lone pair-lone pair <. Because repulsive force among covalent bonds is strong, the molecules take a shape in which the lone pairs on the nitrogen carbon are at a given range from it to obtain the most reliable outcome.Explanation:
The reason is VSEPR theory, it considers electrons, involved in bond formation as the key part. The pairs of electrons around a central atom, they may be in sigma bonds, pi bonds, or lone pairs, are always in proximity with the positive nucleus and as far as possible from each other. Therefore, only the lone pairs on the central atom are taken into consideration when predicting molecular shape.
H2O2 , C2O4, CH3OH, CH3NH2
substances from the lab activity have more than one central atom
25cm3 of 0.2mol/dm3 barium hydroxide solution reacted with 22.8cm3 hydrochloric acid. Calculate the concentration of the hydrochloric acid in mol/dm3. Ba(OH)2 + 2HCl BaCl2 + 2H2O
Explanation:
1 mol of Ba(OH)2 = 2 moles of HCl
Earth's gravitational potential energy: GPE = mgh = Gravity (9.81m/s2) *
Mass (kg) x Height (m)
Kinetic energy: KE= Imov?
How do the mass and speed of an object affect the kinetic energy?
Answer:
as mass and the square of speed is directly proportional to the the kinetic enegry so, more there will be mass and speed there will be more kinetic enegry.
Which form of energy does a battery-powered flashlight receive as an input?
Answer:
chemical energy
Explanation:
A battery stores energy in the form of chemical energy. Chemical energy is stored in the bond of atoms and molecules. These bonds break and convert to other forms of energy. In the given case, the chemical energy is converted to electric energy which powers the flashlight. Thus, flashlight receives energy input in the form of chemical energy.
We have air (21% O2 and 79% N2) at 23 bar and 30 C. 4. What is the ideal molar volume (m^3/kmol)? a. b. What is the Z factor? What is the real molar volume?
Answer:
The ideal molar volume is [tex]\frac{V}{n} =V_z= 0.001095 \ m^3/mol[/tex]
The Z factor is [tex]Z = 0.09997[/tex]
The real molar volume is [tex]\frac{V_r}{n} = V_k= 0.0001095\ \frac{m^3}{mol}[/tex]
Explanation:
From the question we are told that
The pressure is [tex]P = 23 \ bar = 23 *10^5 Pa[/tex]
The temperature is [tex]T = 30 ^ oC = 303 \ K[/tex]
According to the ideal gas equation we have that
[tex]PV = nRT[/tex]
=> [tex]\frac{V}{n}=V_z= \frac{RT}{P}[/tex]
Where [tex]\frac{V}{n }[/tex] is the molar volume and R is the gas constant with value
[tex]R = 8.314 \ m^3 \cdot Pa \cdot K^{-1}\cdot mol^{-1}[/tex]
substituting values
[tex]\frac{V}{n} =V_z= \frac{ 8.314 * 303}{23 *10^{5}}[/tex]
[tex]\frac{V}{n} =V_z= 0.001095 \ m^3/mol[/tex]
The compressibility factor of the gas is mathematically represented as
[tex]Z = \frac{P * V_z}{RT}[/tex]
substituting values
[tex]Z = \frac{23 *10^{5} * 0.001095}{8.314 * 303}[/tex]
[tex]Z = 0.09997[/tex]
Now the real molar volume is evaluated as
[tex]\frac{V_r}{n} = V_k= \frac{Z * RT }{P}[/tex]
substituting values
[tex]\frac{V_r}{n} = V_k= \frac{0.09997 * 8.314 * 303}{23 *10^{5}}[/tex]
[tex]\frac{V_r}{n} = V_k= 0.0001095\ \frac{m^3}{mol}[/tex]
What is the number of molecules of 140 g of CO?
Answer:
3.01
[tex] \times [/tex]
10-22
moles=mass/RMM
moles=140/28
=5moles
1mole=6.02*10-23
5moles=?
=3.01*10-22
hope this is helpful
Study the reactions for the formation of compounds from their elements. I. C(s) + O2(g) → CO2(g) ΔHf = −394 kJ II. H2(g) + 12O2(g) → H2O(l) ΔHf = −242 kJ III. 2C(s) + 3H2(g) → C2H6(g) ΔH =−84 kJ The combustion of C2H6 is shown by the following equation: C2H6(g) + 72O2(g) → 2CO2(g) + 3H2O(l) Which option correctly gives the enthalpy of combustion of 0.2 moles of C2H6(g)? −1,430 kJ 286 kJ −286 kJ 1,430 kJ Exam 3 Click on the numbers to jump from one question to another. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Answer:
The correct option is -286 kJ
Explanation:
The given parameters are
C(s) + O₂(g) → CO₂(g) ΔHf = -394 kJ
H₂(g) + 12O₂(g)→H₂O ΔHf = -242 kJ
2C(s) + 3H₂(g)→C₂H₆(g) ΔH = -84 kJ
Te given equation is C₂H₆(g) + 7/2O₂(g) →2CO₂(g) + 3H₂O(l)
The heat of formation or enthalpy of combustion = Heat of formation of the products - Heat of formation of the reactants
The enthalpy of combustion of the reaction = 2*(-394) + 3*(-242)- ((-84)+7/2*0)) = -1,430 kJ
Given that the reaction consists of one mole of C₂H₆(g), we have;
The enthalpy of combustion of one mole of C₂H₆(g) = -1,430 kJ
Therefore, the enthalpy of combustion of 0.2 mole of C₂H₆(g) = -1,430 kJ × 0.2 = -286 kJ
The correct option = -286 kJ.
Answer:
Positive 1,430
Explanation:
A cesium sulfate solution reacts with barium bromide solution to produce a precipitate of barium sulfate and a solution of cesium bromide. Write the molecular equation for this reaction. part 1 - (Use the lowest possible coefficients. Use the pull-down boxes to specify states such as (aq) or (s). If a box is not needed, leave it blank.) part 2-Write the corresponding net ionic equation. (Use the lowest possible coefficients. Use the pull-down boxes to specify states such as (aq) or (s). If a box is not needed, leave it blank.)
Answer:
molecular eq.
Cs2SO4 (aq) + BaBr2(aq) → BaSO4(s) + 2CsBr(aq)
ionic eq.
SO₄²-(aq) + Ba^+2 (aq) → BaSO4 (s)
explanation
separate the ions
Cs₂^+1(aq) + SO₄^+2(aq) + Ba^+2(aq) + Br₂^-1(aq) → BaSO₄(s) + 2Cs(aq) + Br(aq)
than simplify it
SO₄²-(aq) + Ba^+2 (aq) → BaSO4 (s)
Which of the following reactants can oxidize sodium?
lithium
barium
aluminum
potassium
Answer:
The answer is Aluminum
Hope this helps you
What are the masses of subatomic particles in their atomic mass unit
Answer:
Subatomic particles are the proton (1 amu), neutron (1 amu), and electron (0 amu)
Explanation:
Atomic mass unit (amu; dalton): A unit of mass equal to exactly 1/12 the mass of one 12C atom, or 1.660538921 x 10−27 kg. This is the approximate mass of one proton or one neutron. It is the basis of atomic weights.
Answer:
[tex]\boxed{\mathrm{see \: below}}[/tex]
Explanation:
Protons have a mass of 1 amu (atomic mass unit).
Electrons have a mass of [tex]\frac{1}{1840}[/tex] amu (atomic mass unit).
Neutrons have a mass of 1 amu (atomic mass unit).
a compound X is formed by an element y which is in the form of pellet. The compound X is also the product of chlor - alkali process. Identify X and Y
Answer:
X is sodium hydroxide (caustic soda, NaOH)
y is sodium (Na)
Explanation:
The process of industrial electrolysis of sodium chloride solution by which chlorine and sodium hydroxide (caustic soda) can be produced is known as the chlor-alkali process as follows;
2NaCl + 2H₂O → Cl₂ + H₂ + 2NaOH
Given that the compound X is formed from a element y which is in the form of a pellet, we have;
The element in the above reaction that can exist as pellet is the silver white metallic sodium pellet
Therefore, the compound X is NaOH and the element y is sodium, Na.
Sodium azide nan3 is dissolved in water. Acidified silver nitrate is added to the solution and a white precipitate forms. Aqueous ammonia is then added to the solution and a white precipitate forms. Aqueous ammonia is then added to the white precipitate. The azide ion n3- has similar chemical properties to the cl- ion. What is the formula of the ppt formed and what is the observation on adding aqueous ammonia?
Answer:
The formula of the precipitate formed is AgN₃ (Silver azide).
On adding aqueous ammonia to the precipitate formed, the precipitate dissolves due to the formation of a soluble complex compound with aqueous ammonia.
Explanation:
Sodium azide is NaN₃
Silver Nitrate is AgNO₃
The two of them react and theres a double displacement where the ions exchange radicals.
NaN₃(aq) + AgNO₃(aq) → NaNO₃(aq) + AgN₃(s)
The azide ion (N₃⁻), which has very similar chemical properties as the chloride ion (Cl⁻), also forms an insoluble compound with Silver.
And just like AgCl, the precipitate (AgN₃) also dissolves when ammonia is added by forming a soluble complex.
AgN₃(s) + 2NH₃(aq) → [Ag(NH₃)₂]N₃(aq)
Hope this Helps!!!
When sound molecules stack up" in front of high-speed flights, what could
happen?
Answer: The added pressure could cause pilots to become disorinated
Explanation:
Answer:
When sound molecules stack up in front of high-speed flights, loud noises are produced that can damage the ears.
expalin how electron flows in chemical reaction
state the use of multimeters
Answer:
a use of mesurements
Explanation:
please help pls help 20 points Which of the following is a myth about water conservation? An important part of water conservation is preventing water pollution. Using an electric clothes dryer conserves more water than air-drying clothes. Buying bottled water does not conserve more water than drinking from the tap. A front-loading washing machine uses less water than a top-loading washing machine.
Answer:
Air-drying clothes conserves more water than using an electric clothes dryer.
help me with this
hurricans are most likely to hit the gulf of Mexico and the Caribbean is this classified as weather or climate please answer
Answer
Climate, because this describes what the weather is like over a long period of time.
What does it mean if something is insoluble?
A. It releases a gas upon reacting.
B. It will not dissolve in water.
C. It exists in a liquid state.
D. It is not reactive,
Answer:
It will not dissolve in water.
Explanation:
You're welcome
If something is insoluble it means that it will not dissolve in water. Therefore, option B is correct.
What is solubility?Solubility can be defined as the maximum amount of Solute that can dissolve in a known solvent at a particular temperature. By changing the temperature of the solution, we can increase the solubility of a substance. Sparingly soluble solids or liquids can be fully liquified by increasing the temperature.
Solubility depends on the nature of the given solute and the solvent. Substances such as sugar, NaCl, etc dissolve in water while substances such as naphthalene can not dissolve in water.
An insoluble substance can be defined as a substance or solid that will not dissolve in a solvent even after mixing such as sand. For example, Sand, Stones, Oil, Flour, and wax. Examples, of soluble things, are Salt, Sugar, Vinegar, Coffee, and Lemon Juice.
Learn more about solubility, here:
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(image attached)
what type of model is shown?
A) a structural formula
B) a chemical formula
C) a space-filling model
D) a ball-and-stick model
Answer:
Option (A).
Explanation:
A). Structural formula
Structural formula of a chemical compound represents a graphic structure of a molecule.
B). Chemical formula
Chemical formula shows the chemical proportions of the atoms which constitute a molecule of the compound.
C). Space filling model
Space filling model is a 3-D molecular model in which atoms are represented by the spheres whose radii are proportional to the radii of the atoms and distances between the atoms are proportional to the distances between the atomic nuclei.
D). A ball and stick model
This model shows the 3-D positions of the atoms and the bonds between them.
In this model atoms are represented by the spheres and bonds connected by the sticks.
Therefore, model shown is STRUCTURAL FORMULA.
Option (A) is the answer.
Answer:
A
Explanation:
write these numbers rounded to the three nearest significant figures
Answer:
(a) 52.2 mL helium
(b) 18.0 g nitrogen
(c) 78.5 mg MSG
(d) 23,600,000 mm wavelength
(e) 0.00420 kg lead
Rounded the numbers to three nearest significant figures.
give an example of process you notice or use each day that obeys the law of conservation of mass. and explain how this process works
Answer:
Cellular respiration:
[tex]C_6H_{12}O_6+6O_2\rightarrow 6CO_2+6H_2O[/tex]
Explanation:
Hello,
In this case, the law of conservation of mass states that matter cannot be created nor destroyed but modified, therefore, typical examples are the raft chemical reactions in nature or carried out in a laboratory. Thus, a typical one that could be daily found is in the cellular respiration wherein glucose and oxygen are converted into carbon dioxide, water and energy for us to use it in our daily activities. It is chemically represented by:
[tex]C_6H_{12}O_6+6O_2\rightarrow 6CO_2+6H_2O[/tex]
Law of conservation of mass is verified as six carbon atoms are before and after the chemical reaction, twelve hydrogen atoms are before and after it and eighteen oxygen atoms as well.
Best regards.
Which compounds give one singlet in the 1H NMR spectrum? CH3CH3 1461113dichloro22dibromo 1461123dimethyl2butene CH3―C≡C―CH3 CH2═CHCH═CH2 14611cyclohexadione 14611cyclopentane 14611123tribromopropane 14611ketone 14611ester
Answer:
CH3CH3, 1,3- dichloro-2,2- dibromo, 2-butyne, cyclopentane, 2,3- dimethylbut-2-ene, 2,2,4,4- tetramethlpenta-3-one.
Explanation:
This problem or question has to do with spectroscopy. Spectroscopy is one of the Important aspect of physical Chemistry. It is important because it helps in the identification of chemical samples or compounds. The Nuclear Magnetic field work generally on the principle of absorption of energy.
The following compounds as given in the question above shows singlet in the 1H NMR spectrum.
(1). CH3CH3: shows singlet in the 1H NMR spectrum at 0.86 ppm.
(2). 1,3- dichloro-2,2- dibromo; shows singlet.
(3). 2- butyne shows singlet
(4). Cyclopentane shows singlet.
(5). 2,3 - dimethylbut-2-ene shows singlet.
(6). 2,2,4,4- tetramethlpenta-3-one shows singlet.
Kindly note that I have used the IUPAC naming system to name the Compounds in the question above.
Two students are given different samples of a substance and are instructed to determine the properties of the substance.Which statement describes a property that will be the same for both students
Answer:
The boiling point of the substances
Explanation:
Because Boiling point is an intensive property.