Answer:
B. H2CO3 and KHCO3
Explanation:
The buffer system is a system in which the solution deny for change in the ph level i.e. at the time when the acid is added to it. It can be made either in a weak acid and salt or can be a weak base and its salt. Now when the acid is added to a buffer so the ratio is not impacted due to which it does not change sufficient for pH level
As per the given options, the third one is correct as the H2CO3 denotes a weak acid and the KHCO3 represents the salt. And these two solution does not create any change in the level of pH
Therefore the option B is correct
How do the key results indicate
A liquid containing 55.0 wt% methanol (M), 5.00 wt% polyacrylate (P), and 40.0 wt% water (W) is distilled at steady-state into a top steam and a bottom stream. The total mass flow rates of the top and bottom streams are the same. The top stream has 85.0 wt% M and 0% P. a. Can you set a basis of calculation in this problem? Why or why not? b. Calculate the composition (mass fractions) in the bottom stream.
Answer:
a) YES ( Basis : F=100kg/h)
b) composition mass fraction in the bottom stream
(Xm)B = 0.25
(Xp)B = 0.1
(Xw)B = 0.65
Explanation:
a)
Can you set a basis of calculation in this problem? Why or why not?
Yes we can set a basis if calculation in this problem.
A good basis makes the calculation more easier. the problem are given in weight basis so we can choose basis of feed rate of 100kg/h
BASIS : 100kg/h
b)
given that;
mass flow rate of M in the feeds Mf = 0.55*F = 0.55*100 = 55kg/h
mass flow rate of p in the feeds Pf = 0.05*F = 0.05*100 = 5kg/h
mass flow rate of W in the feeds Pf = 0.40*F = 0.40*100 = 40kg/h
Now Balance
F = T + B
( but T=B)
so F = T + T = 2T
B = T = 50kg/h
TOP
mass flow rate of M in the top Mt = 0.85*T = 0.85*50 = 42.5 KG/H
mass flow rate of P in the top Pt = 0kg/h
mass flow rate of W in the top Wt = 0.15*T = 0.15*50 = 7.5kg/h
balance on M
Mf = Mt + Mb
Mb = Mf - Mt = 55kg/h - 42.5kg/h = 12.5kg/h
Balance on P
Pf = Pb + Pt
Pb = Pf - Pt = 5kg/h - 0kg/h = 5kg/h
Balance on W
Wf = Wt + Wb
Wb = Wf - Wt = 40kg/h - 7.5kg/h = 32.5kg/h
So bottom composition
mass fraction of M in Bottom XmB = Mb/B = (12.5kg/g) / (50kg/h) = 0.25
mass fraction of P in Bottom XpB = Pb/B = (5kg/g) / (50kg/h) = 0.1
mass fraction of W in Bottom XwB = Wb/B = (32.5kg/g) / (50kg/h) = 0.65
The transfer of thermal energy by particles moving through a fluid (either a
gas or a liquid) is called?
Answer:
Convection
Explanation:
Convection is the transfer of thermal energy by particles moving through a fluid.
Answer:
convection
Explanation:
trust
What is the mass of a block that measures 6.7cm x 6.8cm x4.3cm and has a density of 22.29g/cm³
Answer:
4366.8 grams or 4.4 kg
Explanation:
Density = Mass / Volume
Mass = Density x Volume
M = 6.7 x 6.8 x 4.3 x 22.29
M = 4366.8 g
Best Regards!
Select the answer from the drop-down, ranging from true or false.
Mixtures have components that are always in fixed ratios.
[ true or false ]
Compounds can only be separated physically.
[ true or false ]
The components of a mixture keep their unique properties.
[ true or false ]
Mixtures can be physically separated
[ true or false ]
Mixtures are pure substances
[ true or false ]
Compounds are pure substances
[ true or false ]
Answer:
False, False, True, True, False, True
Explanation:
Mixtures have components that are always in fixed ratios. FALSE. The ratio of components in a mixture is variableCompounds can only be separated physically. FALSE. Compounds can only be separated chemically.The components of a mixture keep their unique properties. TRUE. Mixtures can be physically separated. TRUE. Mixtures are pure substances. FALSE. Mixtures are formed by a mixture of 2 or more pure substances, not bonded chemically.Compounds are pure substances. TRUE.true? no false. ... no its true uhhhhh no gotta be false true. false. true. fase. gotta be tru false or maybe its true? nah its false
pls brainliest?
An example of an extensive physical property is
Group of answer choices
mass
density
boiling point
melting point
Answer:
boiling point
In the following atomic model, where does the strong nuclear force happen?
Answer:
the strong nuclear force happens in the neuclus
Which ocean zone lies inside V-shaped ocean trenches? O A. Bathypelagic O B. Abyssopelagic Ο Ο Ο Ο O C. Mesopelagic O D. Hadalpelagic
Answer:
O D. Hadalpelagic is the answer.
Solve: (6.825 x 10-3) (1.2 x 10-8)
Choose the answer with the correct number of significant figures.
a 8.2 x 10-11
b 0.081 x 10-8
C 8.01 x 1011
d None of the above
Answer: a.) 8.2 x 10^-11
Explanation:
Convert 542 nanograms to grams.
g.
Answer:
542 nanograms to grams = 5.42E-7g
Explanation:
HELPPP ANSWERS ????
A: 3
B: 2
C: 1
D: 4
Answer:
B. 2
Explanation:
We see from the reaction side of the equation that we have 2 Li. That means we need the same number of Li on the products side. Therefore, our only option is 2.
Answer:
b
Explanation:
Give the name of HI as an acid and as a binary compound
Answer:
HI is a diatomic molecular compound known as hydrogen iodide or hydroiodic acid. It is a strong acid.
Which of the reactions are spontaneous (favorable)?
A. 2Mg(s) + O2(g) rightarrow 2MgO (s) delta G = - 1137 kJ / mol
B. NH3(g) + HCl(g ) rightarrow NH4Cl(s) delta G = - 91.1 kJ / mol
C. AgCl(s) rightarrow Ag+ (aq) + Cl-[aq) delta G = 55.6 kJ / mol
D. 2H2(g) + O2(g) rightarrow 2H2O(g) delta G= 456 kJ / mol
E. C(s) + H2O(t) rightarrow CO(g) + H2(g) delta G = 90.8 kJ / mol
F. CH4(g) + 2O2(g) rightarrow CO2(g) + 2H2O(t) delta G = -820 kJ / mol
A. Reaction A.
B. Reaction B.
C. Reaction C.
D. Reaction D.
E. Reaction E.
F. Reaction F.
Answer: Reactions: A, B and F
Explanation: Gibbs Free Energy, symbol G, combines Enthalpy (sum of internal energy) and Entropy (measure of how much the energy of atoms and molecules become spread out in a process).
The change in free energy (ΔG) is the sum of enthalpy and the product of temperature and entropy of the system.
With free energy, it is possible to determine if a reaction is spontaneous, i.e., happens wthout external energy, or non-spontaneous.
If ΔG is negative, reaction is spontaneous. If ΔG is positive, reaction is non-spontaneous.
Analysing each ΔG of the reactions above, reactions A, B and F's Gibbs Free energy are negative, so these 3 are spontaneous.
Use the drop-down menus to identify the career that matches each description Helos employees and management negotiate: Oversees payment of employees Maintains employee records, such as contact information: Oversees the Human Resources department of a company.
Answer:
✔ Labor Relations Specialist
✔ Compensation and Benefits Manager
✔ Human Resources Assistant
✔ Human Resources Manager
B
D
A
C
Answer:
Helps employees and management negotiate:
✔ Labor Relations Specialist or B.)
Oversees payment of employees:
✔ Compensation and Benefits Manager or D.)
Maintains employee records, such as contact information:
✔ Human Resources Assistant or A.)
Oversees the Human Resources department of a company:
✔ Human Resources Manager or C.)
2. The four parts, or blocks, on the
periodic table are _d, and f.
s, P
a, b
Answer:
s, p
Explanation:
The four parts, or orbitals, on the periodic table are s, p, d, and f.
Which of these statements is supported by the results of Thomson’s experiment? Check all of the boxes that apply.
Atoms are indivisible.
Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
Answer: Cathode rays are made up of negatively charged particles.
Atoms contain negatively charged particles.
Aqueous hydrochloric acid HCl will react with solid sodium hydroxide NaOH to produce aqueous sodium chloride NaCl and liquid water H2O. Suppose 9.84 g of hydrochloric acid is mixed with 3.1 g of sodium hydroxide. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to 2 significant digits.
Answer:
1.4 g H₂O
Explanation:
In a reaction, the reactants are usually not present in exact stoichiometric amounts, that is, in the proportions indicated by the balanced equation. Frequently a large excess of one reactant is supplied to ensure that the more expensive reactant is completely converted to the desired product. Consequently, some reactant will be left over at the end of the reaction. The reactant used up first in a reaction is called the limiting reagent, because the maximum amount of product formed depends on how much of this reactant was originally present. When this reactant is used up, no more product can be formed.
What is the answer? Please
Answer:
To instill a high degree of personal honor, self-reliance, and confidence in each cadet by presenting a military environment in which cadets will be forced to rely upon themselves and their shipmates to study, work, and learn.
HELP 100 POINTS WILL MARK BRAINLIEST In ancient times, early astronomers watched stars travel across the sky in one direction for several months, then over the course of a few weeks the stars would reverse course and move in the opposite direction. After these few weeks, the stars would reverse direction again and resume their original course. The ancient astronomers called these “wanderer stars”. After more research was done, it was found that these “wanderer stars” were actually other planets. As more data was collected, it was shown that all planets move at different speeds as they travel in their orbits around the Sun. As the Earth moves in its orbit, it moves faster than some planets and slower than others. This causes the Earth to “pass” some planets as it travels, which results in the appearance that the other planets move backwards. Is this a description of a scientific law or scientific theory? 100 points PLEASE HELP
Which of the following isotopes are NMR inactive?
a. 1H
b. 12C
c. 15N
d. 16o
e. 19F
f. 31P
Answer:
12C and 16O
Explanation:
Here, we want to select which of the options are NMR inactive. For an isotope to be NMR inactive, then the net nuclear spin is zero.
What this means is that the number of proton present coupled with the number of neutrons are an even number pair.
What we are saying here is that the number of protons is an even number while the number of neutrons too is an even number. So the net nuclear spin in this case is zero.
in the case of oxygen, we have 8 protons and 8 neutrons. This makes the nuclear spin zero and consequently makes the isotope NMR inactive.
Same is in the case of carbon. There are 6 protons and 6 neutrons and this also makes nuclear spin zero .
In all the other isotopes in the question, we have odd number even number or even number odd number pairs of protons and neutrons.
What is the purpose of keeping a running list of new vocabulary words?
A. To make it easier to decode the word when you see it again
B. To provide an easy-to-remember picture associated with the word
C. To make it easier to remember and use new words
D. To allow you to critically evaluate every new word you come
across
Shjajfbcjahaixhfjwnzhsbsjxjdbxbsjzjfbwnznsnwnnsndndnwnbwjshsbdbdndnndndndbxbxnsnsn
Answer:
C
Explanation:
As C would be the wisest choice as being able to remember and use more words than the average human not only opens up your vocabulary but also your chances of writing a better essay using said words.
Answer:
C
Explanation:
Makes it easier to remember and use new words
How many sig figs are there
5.00000008
Answer:
2 sig figs.
Explanation:
Sig Fig Rules:
Any non-zero digit is a significant figure.
Any zeros between 2 non-zero digits are significant figures.
Trailing zeros after the decimal are significant figures.
The measurement 3.8 x 10^3 g could also be written as
Right now it's written in scientific notation, so you can just move the decimal place in 3.8 to the right 3 times (as it is times 10 to the third power) to get 3,800g.
The measurement 3.8 x 10³ grams could also be written as 3.8 kilograms.
What is a unit of measurement?A unit of measurement is a specified magnitude of a quantity that is established and used as a standard for measuring other quantities of the same kind. It is determined by convention or regulation.
As given in the problem we have to convert the measurement of 3.8 x 10³ grams into some different units,
1000 grams = 1 kilograms
1 gram = 1 /1000 kilograms
3.8 x 10³ grams = 3.8 x 10³ ×1 /1000 kilograms
=3.8 kilograms
Thus, the measurement 3.8 x 10³ grams could also be written as 3.8 kilograms.
To learn more about the unit of measurement from here, refer to the link;
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how do you tell if an chemical eqaution is unbalanced
What does green design refer to?
A. Using materials and design techniques that reduce the negative
environmental impact of a structure
B. Using innovative steel production, modern safety elevators, and
other engineering technologies
C. Using natural colors when designing building so that they don't
seem harsh against the natural landscape
D. Incorporating various materials' strengths and weaknesses in the
design process
SUBMIT
Answer:
A. Using materials and design techniques that reduce the negative
environmental impact of a structure
Explanation:
A P E X
Using materials and design techniques that reduce the negative
environmental impact of a structure. Hence, option A is correct.
What is green design?Green design is the 'creation of buildings which are energy-efficient healthy, comfortable, flexible in use and designed for long life.
The word ‘Green’ represents designs which are eco-friendly and less harmful to humans and other organisms. It helps in the protection of natural resources such as water, air etc.
Green designs are also referred to as techniques and materials that reduce the negative environmental impact of a structure.
Hence, option A is correct.
Learn more about green design here:
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Making a Lis changing something to improve your work. A) scenario
B) revision
C) entry event
D) wish list
Identify the reagents
Is gasoline evaporated, gasoline, burned water frozen and water heated up a chemical change
Answer:
as gasoline is evaporated, this gasoline still remains as gasoline but in gaseous form when gas is being burned .
PLEASE HELP(DUE IN 10 Minuets)
14. Which of the following will result in a chemical change?
A. Melting ice to obtain water
B. Evaporating alcohol into vapor
C. Burning coal in a furnace
D. Drying wood in a shed
Help ASAP
Answer:
C
Explanation:
a chemical change is when a substance changes into another.
wood burning turns into heat which would be considered a chemical change