Answer:
sry i don't know answer of This question
why atoms of magnet differ from normal atoms?
Answer:
ones in magnets r close together while others can be spread apart
How many molecules are in 35.5 grams of carbon dioxide?
Answer:
you have to use the avogadro's constant of 6.023×10^23 to calculate the number of molecules of carbon dioxide.and you also have to use the molecular mass which is 44.
35.5/44×6.023×10^23
=4.85×10^23
I hope this helps and sorry if it's wrong
Which atom is abundant on earth
Answer:
Oxygen
Explanation:
Oxygen is abundant on earth
Name three metals on the periodic table and their uses
PLS HELP
Explain which intermolecular force is primarily responsible for the unusually high boiling point of H2OH2O. Compare the strengths of intermolecular forces of attraction present in a sample of liquid water to the strengths of intermolecular forces of attraction present in liquid samples of H2SH2S, H2SeH2Se, and H2TeH2Te. Justify your answer using the information presented in both tables, and complete the statements below.
Answer:
See explanation
Explanation:
Intermolecular forces are forces of attraction that exist between molecules of a substance in a particular state of matter.
The dominant intermolecular force of attraction in H2O is the hydrogen bond. The hydrogen bond exists between molecules of a substance when the substance is made of hydrogen atoms bonded to atoms of a highly electronegative element. Hence, strong hydrogen bonding accounts for the high boiling point of water.
The magnitude of hydrogen bonding between molecules depends on the electro negativity of the atoms to which hydrogen is bonded.
The more the electro negativity of the atoms to which hydrogen is bonded, the greater the magnitude of intermolecular hydrogen bonding.
Since the electro negativity of elements decrease down the group, the strength of intermolecular hydrogen bonding between the molecules decreases as follows;
H2O> H2S> H2Se> H2Te
A certain volume of gas S takes 180 secs to diffuse through a porous plug. An equal amount of gas Q takes 240 secs to diffuse the same plug. Calculate the molar mass of gas Q if the molar mass of gas S is 18.
Answer:
31.98g/mol
Explanation:
Using Graham's law of diffusion, which states that the rate of diffusion of a gas is inversely proportional to the square root of its molecular mass (M). Rate of diffusion = volume/time.
Since both gas S and Q have equal volumes, we can calculate molecular mass of gas Q as follows:
tQ/tS = √mQ /√mS
Where:
tQ = time of diffusion of gas Q
tS = time of diffusion for gas S
mQ = molar mass of gas Q
mS = molar mass of gas S
According to the information provided in this question;
tQ = 240s
tS = 180s
mQ = ?
mS = 18g/mol
Using tQ/tS = √mQ /√mS
240/180 = √mQ / √18
1.333 = √mQ / √18
Square both sides
1.333² = mQ/18
1.78 = mQ/18
mQ = 18 × 1.78
mQ = 31.98g/mol
Molar mass of Q = 31.98g/mol
Formation of HCl from H₂and Cl₂ is example of
photochemical
electrochemical
displacement
Answer:
Combination reaction.
Explanation:
The reaction depicted in the question is;
H2 (g) + Cl2 (g) ⟶ 2HCl (l)
Now, this reaction shows that two reactants namely hydrogen and chlorine react to form a single product named Hydrogen chloride. This process is called combination reaction.
What is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water?
The mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water is 29.7%.
What is mass percent ?Mass percent is a means to describe a component in a specific combination or to convey a concentration. The mass percentage used to describe the solution composition indicates the mass of solute contained in a given mass of solution.
To determine the mass percent of an element in a compound, we divide the mass of the element in one mole of the compound by the compound's molar mass and multiply the result by 100.
Given:
Number of moles = 0.64 moles
Moles of sodium fluoride = Given mass/molar mass
0.64 moles = Mass / 42
Mass = 26.88gram
Mass % = Mass of solute/ mass of solution × 100
= 26.88/90.48 × 100
= 29.7 %
Thus, 29.7 % is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water
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Calculate the amount of solute excess out when the 60 gm of saturated solution of
NH4Cl having solubility of 57 at 60 ℃ is cooled to 20 ℃ , the solubility being 35.
Answer:
weight of salt = 90 gram,
solubility = 50
sing formula
solubility of solute =
weightofsolventinsaturatedsolution
weightofsoluteinsaturatedsolution
×100
or 50=
weightofsolventinsaturatedsolutio
90gm
×100
so weight of solvent in saturated solution =
50
90gm
×100=180gm
Hence 180 gm of water is required to prepare a saturated solution.
What does the reducing agent do in a redox reaction? (A.P.E.X)
Answer:
The reducing agent donates electron to the oxidizing agent and gets oxidized itself
Explanation:
In an oxidation-reduction reaction, also known as REDOX reaction, one of the reactants is called OXIDIZING AGENT while the other is called REDUCING AGENT. The reducing agent is called so because it reduces another substance in the reaction.
It reduces another atom/ion by donating electrons to that atom, hence, getting oxidized itself in the process. For example, in the following reaction:
H2 + F2 → 2HF
Fluorine is getting oxidized from -2 to 0 by donating electrons to H and reducing it from +2 to 0.
Answer:
Reduces another atom
Explanation:
:)
Question 3: Functional Groups
Identify the type of molecule from the name of the molecule.
Answer:
1. Organic Alcohol
2. Ester (specifically acetate ester)
3. Organic Alcohol
4. Carboxylic acid
5. Ketone
6. Ether
7. Amine
Explanation:
You can tell what type it is both from the nomenclature and looking at the functional group on the molecular structure. Hope this helps!
2.
In photosynthesis, which substances are used up, which are produced and which are necessary
but remain unchanged after the reaction?
used up
produced
remain
A
carbon dioxide
water
oxygen
A
8
chlorophylt
carbon dioxide
water
с
oxygen
starch
cellulose
D
water
oxygen
chlorophyll
D. Water is used up, Oxygen is produced and Chlorophyll is necessary, but remains unchanged.
Currently, nuclear energy provides only a small fraction (~10%) of energy used in the United States. In some other places, like France, it is close to 80%. Do you think nuclear energy will ever be a more widely used source of energy in the United States? Why or why not?
PLEASE HELP ASAP PLEASEEE
Nuclear energy is currently within almost every country becoming a growing source of energy use since it can provide a lot of energy within a short amount of time with little resources used to create it. It is quite possible that within the next few generations that nuclear energy could become a much larger source of energy within the United States. Although, many countries after the leak have resorted to other means of energy sources learning from the mistakes of Japan.
Hope this helps :)
PLZ HELP ME WITH MY WORK
What is a compound?
A substance that is made from two different metals
B. A substance that cannot be broken into simpler substances
C. A substance that is made using a chemical reaction
D. A substance that can be separated by physical means
Answer:
C.
Explanation:
Answer A is incorrect because a compound doesn't have to be made with only metals.
Answer B is incorrect because that is actually the definition of a pure element.
Answer C is correct because to make a compound, there has to be a chemical reaction where bonds are formed and an entirely new substance is created.
Answer D is incorrect because compounds cannot be separated by physical means.
Hope this helps :D
A block of dry ice (-40°C) is placed in contact with an ice cube (-10°C).
What will happen, assuming no chemical reactions occur?
O Heat will flow from the ice cube to the dry ice.
O Heat will flow from the dry ice to the ice cube.
O There is no way to tell without a thermometer
O No heat will flow.
Explanation:
Answer is that : no heat will flow
Answer:
Heat will flow from the ice cube to the dry ice
Explanation:
Vitamin C is a water-soluble vitamin, so your body doesn't store it. You have to get the required amount from your diet (citrus fruits are a great source!), or you could take a daily vitamin C supplement pill. Vitamin C is ascorbic acid, so to determine how much vitamin C (acid) has been placed in each pill, you could do an acid-base titration. One vitamin C pill was dissolved in water and titrated to an endpoint by 16.00 mL of a 0.447 M solution of NaOH. How many grams of ascorbic acid were there in the pill? (MW of ascorbic acid is 176.1 /mol). Explain and show your work.
Answer:
Mass of ascorbic acid in the pill = 7.152 x 176.1/1000 = 1.26 g
Explanation:
The mass of ascorbic acid in the pill would be,
1.26 g
Now,
Moles of ascorbic acid = Moles of NaOH = 0.447 M x 16 ml = 7.152 mmol
Mass of ascorbic acid in the pill = 7.152 x 176.1/1000 = 1.26 g
Calculate the amount (in moles) of gas which occupies 250cm³ at STP
Answer:
0.01
Explanation:
volume of 22.4 L (22,400 ml) at s.t.p. 250 ml out of 22,400 ml is 0.01 rounded, therefore I assume that is the answer. About 0.01 mole occupies 250 cm3 at s.t.p.
According to the kinetic molecular theory, what happens to a liquid when it is transferred from one container to another?
ОООО
O The volume and the shape stay the same.
The volume increases to fill the new container, but the shape stays the same.
The volume stays the same, but the shape changes to fit the new container.
The volume and the shape change to fill the new container.
Answer:
C. The volume stays the same, but the shape changes to fit the new container.
Explanation:
It changes shape to fit the container since it's a liquid.
9. a) Name salt that can be prepared by precipitation
I think its the substances that sublimes
PLZ HELP ME WITH MY WORK
Answer:
c. H2 andO2
I think this is the answer not sure ok
Fe + HNO₃ -> Fe(NO₃)2 + H₂
I need help getting this done
Answer:
I put the right structures in the pictures for you
Although tom was a poor student, he studied very well
My theoretical yield is 14 grams of water. I actually produced 6 grams of water. What is my percent yield?
Answer:
Pertaining to the interrogate, the answer to such is acknowledged and henceforth disseminated as 43.0%
Explanation:
To evaluate such, the following must be comprehended:
Percent Yield Calculator:
% Yield = (What You Actually Got / What You Should Theoretically Get) * 100
The following variables may be denoted, as stated within the interrogate:
Yielded/Produced: 6 grams.
Theoretical Yield: 14 grams.
(6 g/14 g) * 100 = 42.8571428571
*Grams measurement cancels*
42.8 ==> 43.0%
Thus, if rounded to the nearest tenth, the percent yield is equivalent to 43.0%.
balance the equation:2Na+3H2O-2NaOH+H2
Answer:
2Na + 2H2O → 2NaOH + H2
Explanation:
A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge are the same for both the reactants and the products.
How does knowing the reactants and
help you classify a chemical reaction?
if you know what kind of chemical a reactant is, it can help you to quickly distinguish the chemical reaction.
Ex:
HCl + KOH <---> KCl + H2O
We can look at the reactants and identify that this reaction is an acid-base reaction because HCl is an acid (it gave a proton) and KOH is a base (it accepted the proton)
Answer:
Products
Explanation:
I just got it right.
Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 0.4 Hg/mL, what is the total mass in kilograms of mercury in the lake
Answer:
The total mass of mercury in the lake is 631,542.7 kg
Explanation:
Question: The given dimensions of the lake as obtained from a similar question posted online are;
The surface area of the lake, A = 100 mi²
The lake's average depth, d = 20 ft.
The concentration of the mercury, C = 0.4 μg Hg/mL = 0.4 × 10⁻⁶ kg Hg/L
Therefore, we have;
The volume of water mixture in the lake, V = A × d
∴ V = 100 mi² × 20 ft. = 2,787,840,000 ft.² × 20 ft. = 55,756,800,000 ft.³
1 ft³ = 28.31685 L
∴ 55,756,800,000 ft.³ = 55,756,800,000 ft.³ × 28.31685 L/ft.³ = 1.57885675 × 10¹² L
The total mass of mercury in the lake, m = C × V
∴ m = 0.4 × 10⁻⁶ kg Hg/L × 1.57885675 × 10¹² L = 631,542.7 kg
The total mass of mercury in the lake, m = 631,542.7 kg.
The addition of solute particles into a solution causes:
A. the solvent particles to be attracted to the solute particles and to have less kinetic energy.
B. the solute particles to bump the solvent particles out of the solution, making it easier to boil.
C. the solute particles to form seed crystals and make the solution freeze more easily.
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Answer:
D. the solvent particles to be spread further out and have more to move, increasing their kinetic energy.
Explanation:
The addition of solute particles results in an increased boiling point. As the solutes increases so does the energy inside as the solutes add and occupies more space near the surface of the liquid.A molecular orbital is a region of space in a covalent species where electrons are likely to be found. The combination of two atomic orbitals always forms two molecular orbitals; the bonding molecular orbital, which is _____ in energy, and the antibonding molecular orbital, which is _____ in energy, than the original atomic orbitals.
Answer:
bonding molecular orbital is lower in energy
antibonding molecular orbital is higher in energy
Explanation:
Electrons in bonding molecular orbitals help to hold the positively charged nuclei together, and they are always lower in energy than the original atomic orbitals.
Electrons in antibonding molecular orbitals are primarily located outside the internuclear region, leading to increased repulsions between the positively charged nuclei. They are always higher in energy than the parent atomic orbitals.
What is the energy of a photon emitted with a wavelength of 448 nm?
O A. 2.97 x 10-22 J
O B. 4.44 x 10-19 J
O C. 8.91 x
10-23 J
O D. 1.48 x 10-27 J
Answer: B is the correct answer
Explanation:
The energy of a photon is 4.44×[tex]10^{-19}[/tex]J for the wavelength of 448 nm.
So, option (B) is correct. This can be calculated by using the energy formula.
The energy of a photon:The energy of a photon is said to be photon energy. It is directly proportional to the photon's electromagnetic frequency and inversely proportional to the wavelength. If the frequency of the photon is high then its energy is also high.
The energy of a photon, E=hc/λ
Given data:Given that,
λ = 448nm
h= 6.63×[tex]10^{-34}[/tex]J/s
Calculating the energy:E = 6.63×[tex]10^{-34}[/tex]×3×[tex]10^8[/tex]/448×[tex]10^-^9[/tex]
E = 4.44×[tex]10^{-19}[/tex] J
Hence option (B) is correct.
Therefore, the energy of a photon emitted with a wavelength of 448nm is 4.44×[tex]10^{-19}[/tex] J.
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