To prepare 500 mL of a 2.75 molar solution of NaCl, measure 80.44 g of NaCl, place it in a 500 mL volumetric flask and fill it with water to the mark.
We'll begin by calculating the number of mole of NaCl in the solution
Volume = 500 mL = 500 / 1000 = 0.5 L Molarity = 2.75 MMole of NaCl =?Mole = Molarity x Volume
Mole of NaCl = 2.75 × 0.5
Mole of NaCl = 1.375 mole
Next, we shall determine the mass of 1.375 mole of NaCl.
Mole of NaCl = 1.375 mole Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol Mass of NaCl =?Mass = mole × molar mass
Mass of NaCl = 1.375 × 58.5
Mass of NaCl = 80.44 g
Therefore, to prepare 500 mL of a 2.75 molar solution of NaCl, measure 80.44 g of NaCl, place it in a 500 mL volumetric flask and fill it with water to the mark.
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List the four quantum numbers
Answer: In atoms, there are a total of four quantum numbers: the principal quantum number (n), the orbital angular momentum quantum number (l), the magnetic quantum number (ml), and the electron spin quantum number (ms).
Answer:
(n)
(i)
(mı)
(ms) s is suppose to be smaller than the m
Explanation:
the principal quantum number (n)
the orbital angular momentum quantum number (I)
the magnetic quantum number (ml)
the electronic spin quantum number (ms)
Would you expect a Boron (B) atom with atomic mass = 9.999 to be stable?
The balance of forces allows to find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 uma is unstable because the repulsive force increases.The stability of atomic nuclei depends on the balance the force is electrostatic repulsion between the protons and the strong interaction of attraction.
One way to achieve this balance is to increase the separation of the protons with uncharged particles between them, the neutral ones, the strong interaction is of the same magnitude for protons and neutrons, therefore the repulsion is decreased and the strong attraction interaction is maintained. .
In the case of Boron, which has 5 protons, the stable structures have more atomistic 10 and 11 una, which is why it has 5 and 6 neutrons each. Therefore each proton has a neutrons next to it and in the other case a proton at the end has two neutrons, this causes the distance between the protons to increase, decreasing the electrostatic repulsion.
It indicates that we have a Boron nucleus of mass 9.999. The number of protons must remain fixed, therefore there are only 4 neutrons.
Consequently, some of the protons does not have a neutron next to it and can approach the other proton, therefore the electrostatic repulsion increases and the stability of the atom decreases.
In conclusion, using the balance of Forces we can find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 amu is unstable because the repulsive force increases.Learn more about nuclear stability here: https://brainly.com/question/897383
Which statement best explains the purpose of using a mole in the measurement of matter? It is commonly used as another unit of mass. It allows chemists to deal with a large number of atoms. It is used only for studying the properties of gases. It explains that substances with the same moles have the same mass.
Answer:
B) It allows chemists to deal with a large number of atoms.
Explanation:
On Edge 2022
The statement which best explains the purpose of using a mole in the measurement of matter is that it allows chemists to deal with a large number of atoms.
What is a mole?Mole is defined as the unit of amount of substance . It is the quantity measure of amount of substance of how many elementary particles are present in a given substance.
It is defined as exactly 6.022×10²³ elementary entities. The elementary entity can be a molecule, atom ion depending on the type of substance. Amount of elementary entities in a mole is called as Avogadro's number.
It is widely used in chemistry as a suitable way for expressing amounts of reactants and products.For the practical purposes, mass of one mole of compound in grams is approximately equal to mass of one molecule of compound measured in Daltons .Molar mass has units of gram per mole . In case of molecules, where molar mass in grams present in one mole of atoms is its atomic mass.
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Which of the following is a challenge of prosthetic engineering that has been met through tissue engineering?
- Predicting failure
- Biocompatibility
- Strength
- Power
Answer:
Biocompatibility
Explanation:
I’m a genius and it’s the answer :D
Biocompatibility is a challenge of prosthetic engineering that has been met through tissue engineering. Hence, option B is correct.
What is Biocompatibility?Biocompatible materials are used in medical devices, such as menstrual cups, stents, or ventilators.
A biocompatibility problem might happen when some of the materials are trapped in the patient's gingival sulcus.
Tissue engineering is an important field of regenerative medicine for tissue repair (after damaged caused by a disease or an accident, for example).
To offer this possibility, stem cells are important tools owing to their capacity to differentiate into a large number of cells according to the stimuli provided.
Hence, option B is correct.
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An ammonia solution has a pH of 8.25. What is its [OH-]?
pH + pOH = 14
If pH=8.25, then:
pOH = 14 - 8.25 = 5.75
pOH = -log[OH-]
5.75 = -log[OH-]
-5.75 = log[OH-]
10^(-5.75) = [OH-]
[OH-] = 0,0000017783
[OH-] = 1,78×10^(-6) mol/dm³
please help me!! DUE TOMORROW :(
Answer:
It’s in the photo, sorry if it’s really messy!
Explanation:
Please ask if you have any questions!
convert 8.4 • 10^16 molecules of CO2 to moles
Answer:
0.00000000000000084
Explanation:
what are the solar home lighting
Answer:
Sunlight
Explanation:
Home lighting System is powered by solar energy using solar cells that convert solar energy (sunlight) directly to electricity. The electricity is stored in batteries and used for the purpose of lighting whenever required
If 2.5 moles of PA react completely, how many
moles of P203 are formed?
Answer:
For every 2 moles of Na used, 2 moles of NaCl are produced.
Explanation:
A substance has a molar heat of combustion of -810.4 kj/mol. when 0.285 mol of the substance is burned in a calorimeter containing 8.60 kg of water, the increase in water temperature is:
Answer:
6.42 °C
Explanation:
Q = mcΔT
Q = energy gain/release (J)
m = mass (kg)
c = specific heat capacity (J/°C/kg)
ΔT = change in temperature (°C)
Qs = n(ΔH°c)
Qs = energy gained/released from substance (kJ)
n = moles (mol)
ΔH°c = molar heat of combustion (kJ/mol)
m = 8.60
n = 0.285
ΔH°c = -810.4
c (of water) = 4184
Qs = 0.285(-810.4)
Qs = -230.964 (or -230964 J)
Q = 230964
230964 = (8.60)(4184)ΔT
230964 = 35982.4(ΔT)
ΔT = 6.4188... °C → 6.42 °C
Which pair of elements form an ionic bond with
each other?
A. KCL
B. ICL
C. PCL
D. HCL
I think it’s A and D but if it’s not both can you please explain why it’s one and not the other?
Answer:
Yes Both A) KCL and D) HCL are correct...
Answer:
It's only A
Explanation:
Potassium (K) is a metal and Chlorine (Cl) is a nonmetal, and ionic compounds are formed between metals and nonmetals. So KCl forms ionic bonds.
Hydrogen (H) and Chlorine (Cl) are both nonmetals, and only covalent bonds form between nonmetals. (Only exception is when its an acid, then it's ionic)
Also, the question indicated which "pair" and not "pairs" meaning that there is only one answer, and I'm more likely to go with A rather than D.
what is wrong with the statement? "because there are no common factors in the molecular formula, k2co3 is also the empirical formula of potassium carbonate"
The empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound.
The empirical formula of a compound shows the ratio of atoms of each element in the compound while the molecular formula shows the number of atoms of each element in the compound.
For the compound, K2CO3, the empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound. It has nothing to do with common factors.
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Name three sources of atmospheric carbon dioxide.
Answer:
Natural sources include decomposition, ocean release and respiration. Human sources come from activities like cement production, deforestation as well as the burning of fossil fuels like coal, oil and natural gas.
Which of the following ideas did Greek philosopher Democritus contribute to the atomic theory?
A. Matter is composed of only one kind of particle, which can be easily destroyed.
B. Every element has a specific type of atom, which remains the same size in all forms of matter.
C. All matter is composed of small particles, which combine to make larger objects.
D. Each object is made up of one atom, which varies in size from very small to very large.
I will mark the correct answer the brainliest
Answer:
c. all matter is composed of small particles,which combine to make larger objects
which planet is closests to the moon
Answer:
Earth
Explanation:
Answer:
Earth
Explanation:
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how many compounds can I make with sodium, hydrogen, oxygen?
will give brainliest and 100 points to the correct answer
Answer:
маны
Explanation:
Answer:
2H2 + O2 → 2H2O
Explanation:
Diazene, N2H2 (also known as diimine), is commonly used as a reagent for organic syntheses. Label each image with the type of
bond in diazene that it shows.
The first image shown at the left hand side is a pi bond. The other two images show sigma bonds.
In chemistry, a bond results from the overlap of atomic orbitals. This overlap may be end to end (sigma bond) or side by side (pi bond). Having said this, it is easier to decide whether the bonds in the image shown are sigma or bi bonds.
If we label the images; 1,2,3 from left to right, we can see that the overlap in image 1 is side by side. The electron density lies above and below the plane of the bond. This is a pi bond. In images 2 and 3, the overlap occurs in an end to end manner. This is a sigma bond.
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Can someone please help. I have no idea how to do this
Explanation:
c-o number if electrons shared: 4. doubke bond. non polar
c-cl 2 electrons sharde single bond non polar
I know this cause one dash equals 2 electrons chemistry teachers use them when two compounds are sharing electrons rather then using two dots so people know the difference
What is the total pressure exerted by a mixture containing two gases if the partial pressure of one gas is 70 kPa and the partial pressure of the other gas is 30 kPa?
Answer:
The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas: Ptotal=P1+P2+… +Pn. + P n . The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.
Explanation:
hope this helps have a wonderfull day!
C= ( F - 32) / 1.8
86 F = ?
Answer:
C = 30
Explanation:
C = (86 - 32)/1.8
C = (54)/1.8
C = 30
I have a problem with solving this type of chemistry problem. Please Help!
Which of the following is not part of an amino acid?
A. ammonium group
B. carboxylate group
C. ether group
D. unique "R" group
Answer:
C
Explanation:
Ether group does not exist in amino acids
Ammonium group is on one side
the carboxylate group is opposite to the ammonium group
the R group defines what amino acid it is.
What is the wavelength, in nanometers, of light with a frequency of 1.97x10^15 Hz?
a) 1.52 nm
b) 1.52x10^-7 nm
c) 152 nm
d) 15.2 nm
1. List the ketose carbon(s) that is(are) reduced with NaBH4.
Answer:
ehh im nit sure but here!
Explanation:
Explain in your own words:
i. Sublimation
ii. Condensation
iii. Melting
increasing temperature increases:
1:Enthalpy
2:Free Energy
3:Entropy
4:Specific heat
Answer:
2 :free energy
Explanation:
I hope it is fine answer for you ☺️☺️☺️
is the effect of hot and cold water on acid different?
Answer:
When the acid is mixed with the water, an immediate chemical reaction takes place. The formation of carbon dioxide causes breakdown of the sample into finer particles.
The heat in the Stomach rises up, causing esophageal reflux, chronic sinusitis, headaches, eye disorders and problems with the teeth. Furthermore, ingesting cold water creates moisture or “dampness.” Bacteria, candida, and parasites thrive in damp areas, especially in your stomach and uterus.
Why does the Hubble Space Telescope take clearer pictures than other telescopes?
Answer:
Space-based telescopes like Hubble get a much clearer view of the universe than most of their ground-based counterparts. ... Ground-based telescopes can't do the same, because the Earth's atmosphere absorbs a lot of the infrared and ultraviolet light that passes through it.
Define Endothermic reaction in terms of Deta H
I didn't learn about that topic in school,but I found this :
I hope it helps<3
Polyvalent ions are
1) Anions with variable charges
2) Cations from columns 3 to 12
3) Ions that can be positive or negative