Which of the following statements best explains the trends in boiling points?
A. The atomic size increases down the group, and this decreases the strength of the intermolecular forces.
A is incorrect
B. The total number of electrons decreases down the group, and this decreases the strength of the intermolecular forces.
B is incorrect
C. The total number of electrons increases down the group, and this increases the strength of the intermolecular forces.
C is correct
D. The chances of forming a permanent dipole increases down the group, and this increases the strength of the intermolecular forces.
D is incorrect
The boiling point increase down a group because the total number of electrons increases down the group, and this increases the strength of the intermolecular forces. Hence option C is correct.
What is boiling point?Boiling point of a substance is the temperature at which the substance changes from its liquid state to vapour state. Boiling point of a molecule or compounds depends on the bond type, molecular weight, temperature and pressure.
For ionic compounds, boiling point will be higher since ionic bonds are stronger than covalent compounds. There is a periodic trend for the physical properties such as boiling point for elements in periodic table.
Down a group, the number of electrons increases and the atomic size also as well as the ionic character increases down a group . These two facts leads to higher intermolecular attraction, thus more temperature have to applied to weaken the bonds.
Higher temperature to be applied means the boiling point of the substance is higher. Therefore, boiling point down a group increases because of the higher intermolecular attraction as said in option C.
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If an atom of chlorine (CI) were to ionize, it would
electron(s).
Answer:
Explanation:
As per being a Group 7 element, it would gain one electron, which changes it's charge to 1-. It is therefore negatively charged, having a full outer shell of 8, having its electronic structure to be at 2,8,8.
how is electrovalent bond formed ? Describe with an example .
Answer:
For example, the bond between the sodium and chlorine atoms in sodium chloride (NaCl) is formed by the transfer of an electron from sodium to chlorine, creating Na + and Cl – ions. ... The electrostatic attraction between these ions provides the bonding in NaCl.
Which atom is abundant in the universe
Answer:
hydrogen is abundant in nature
which statement is generally true about CaCaI2 ?
Explanation:
"Its bonds are formed by large differences in electronegativity" is the statement among the choices given in the question that is generally true about CaCl2.
how can you separate mixture of suphur, nacl and nh4cl
Answer:
Ammonium chloride, iron ,Sulphur and salt mixed together... they can be separated in the following methods.
1. Ammonium chloride is separated by sublimination... NC4CI is sublimable. Heat the mixture in a china dish and collect the funds of NC4CI (sublimable substance)
2. Bring a magnet close to the remaining mixture. Iron is magnetic substance and thus, it will be attracted towards the magnet. Iron is separated.
3. Sulphur is insoluble in water and salt is soluble. Add water to the remaining mixture and then wait for sedimentation. Separate the sulphur by decantation.
4. Heat the filtered salt solution to obtain salt.
100cm³ of ethane gas diffuses through a porous plug in 100 seconds.What is the molecular mass of the gas Q if 100cm³ of the gas diffuses through the same plug in 121 secknds under the same condition?(C=12.0,H=1.0)
Answer:
The molar mass of gas Q is 43.923 g/mol
Explanation:
The given volume of ethane gas that diffuses through a porous plug in 100 seconds = 100 cm³
Therefore;
The rate of diffusion of ethane gas through the porous plug, [tex]v_{ethane}[/tex], is given as follows;
[tex]v_{ethane}[/tex] = (100 cm³/100 s) = 1 cm³/s
The molar mass of ethane, C₂H₆ = 2×12 g/mol + 6×1 g/mol = 30 g/mol
The given volume of gas, Q, that diffuses through a porous plug in 121 seconds = 100 cm³
∴ The rate of diffusion of the gas, Q, [tex]v_Q[/tex] = 100/121 cm³/s
Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of the molecular mass of the gas
Mathematically, we have;
[tex]\dfrac{v_A}{v_B} =\sqrt{\dfrac{m_B}{m_A} }[/tex]
Where;
[tex]v_A[/tex] = The rate of diffusion of gas A
[tex]v_B[/tex] = The rate of diffusion of gas B
[tex]m_A[/tex] = The molar mass of the gas A
[tex]m_B[/tex] = The molar mass of the gas B
Therefore, for ethane and gas Q, measured under the same condition, we have;
[tex]\dfrac{v_{ethane}}{v_Q} =\sqrt{\dfrac{m_Q}{m_{ethane}} }[/tex]
[tex]\dfrac{1 \ cm^3/s}{\dfrac{100}{121} \ cm^3/s} =\sqrt{\dfrac{m_Q}{30 \ g/mol} }[/tex]
[tex]m_Q = \left ({\dfrac{121}{100} } \right) ^2 \times 30 \ g/mol = 43.923 \ g/mol[/tex]
The molar mass of gas Q, [tex]m_Q[/tex] = 43.923 g/mol.
PLZ HELP ME WITH MY WORK
Which is an example of using a physical model to represent an earthquake?
O A. Using a computer to measure what happens during an earthquake
O B. Thinking of an earthquake as someone jumping on the bed next to YOU
C. Calculating the movement of the ground during an earthquake
O D. Shaking a cake that has models of buildings on it SUBMIT
Answer:
D. Shaking a cake [...]
Explanation:
None of the rest are actual physical models representing earthquakes.
Hope that's right! :D
convert the following into Kelvin scale 253°c
Explanation:
253°C + 273.15 = 526.15K
526.15 kelvins
Please help I have been stuck on this problem for a couple hours and can't figure it out
Answer:
11.92 Liters O₂(g) at STP
Explanation:
For most stoichiometry problems, if one will convert all given data into moles, solve by rxn ratios, then finish by converting to needed dimensions to complete problem.
2Pb(NO₃)₂ => 2PbO + 4NO₂ + O₂
Given 237.5 grams PbO formed in reaction = 237.5 g/223.2 g/mole = 1.064 mole PbO
From equation ratios, moles O₂ formed = 1/2(moles PbO) = 1/2(1.064 moles O₂) = 0.532 mole O₂
0.532 mole O₂ = 0.532 mole x 22.4 liters/mole at STP = 11.91756272 liters (calculator answer) ≅ 11.92 liters O₂ at STP (4 sig.figs. based on given 237.5g PbO)
H3C6H507 + H2O + H3O+ + H2C6H507
acid
base
Explanation:
an acid will give away a proton and become a conjugate base.
A base will accept a proton and become a conjugate acid.
as the balloon rises what happens to the external pressure
Answer:
As the ballon rises higher the atmospheric pressure will drop if the ballon is made of an elastic material,it will stretch to allow the gas inside it to expand
There is 25.3 mL of the sulfuric acid solution; the sulfuric acid concentration is 2.30 M. Your base solution is 1.00 M. What is the volume in mL of base that is required to complete the neutralization of the acid
Answer:
The volume of the base is 0.05819·x L, where x is the number of moles of base that combines with one mole of sulfuric acid
Explanation:
The volume of the sulfuric acid, V = 25.3 mL = 25.3 × 10⁻³ L
The concentration of the sulfuric acid, c = 2.30 M
The concentration of the base, [tex]c_{base}[/tex] = 1.00 M
Let the mole ratio of the acid to base be 1 : x
The number of moles of sulfuric acid present, n = c × V
∴ n = 2.30 M/L × 25.3 × 10⁻³ L = 0.05819 moles
The number of moles of sulfuric acid present, n = 0.05819 moles
1 mole of sulfuric acid combines with x moles of base
Therefore, 0.05819 moles of sulfuric acid will combine with 0.05819·x moles of base
The number of moles of base, [tex]n_{base}[/tex] = 0.05819·x moles
Therefore, the volume of base, [tex]V_{base}[/tex] = [tex]n_{base}[/tex]/[tex]c_{base}[/tex]
∴ [tex]V_{base}[/tex] = 0.05819·x/1 ≈ 0.05819·x L
The volume of base, [tex]V_{base}[/tex] ≈ 0.05819·x L.
What are you most likely to observe when an endothermic reaction is taking place?
Answer:
An endothermic reaction is when heat is needed by the reaction, so it draws heat from its surroundings, making them feel cold. Just like a ice pack.
Emission and abpsorption spectra from a given atom or molecule can tell us: Group of answer choices the composition of substances, even at great distances away, by identifying its uniques spectral fingerprint. The motion toward or away from us based on the doppler effect and corresponding red shift or blue shift The temperature of an object by using Wien's Law. All of the above.
Answer:
The motion towards or away from us based on the Doppler effect and corresponding red shift or blue shift.
Explanation:
The emission and absorption spectra demonstrates the lines where light has been absorbed by the atoms. The spikes can be observed due to atoms releasing photons at those wavelengths. Infrared and ultra violet waves can be observed during spectroscopy.
Calculate the amount of mole(s) of CoF2 required to react with 12.8 moles of HCI.
CoCl2 + 2HF --> CoF2 + 2HCI
Explanation:
here's the answer to your question
burning sugar is a chemical change give reason?
Burning a sugar cube is a chemical change. Fire activates a chemical reaction between sugar and oxygen. The oxygen in the air reacts with the sugar and the chemical bonds are broken. Burning sugar leads to reaction of sugar with oxygen in air and leads to formation of carbon dioxide and water. The change is irreversible and is thus a chemical change
which elements total number of electrons is equal to the number of core electrons in barium(Ba)?
Answer:
Xenon
Explanation:
The core electrons of an element are the electrons that do not take part in the chemical reactions of the element
The electronic configuration of barium Ba is presented as follows;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s²
2+2+6+2+6+2+10+6+2+10+6
The valence electrons of boron are the 6s² electrons
The core electrons of boron are the; 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶
The electronic configuration of xenon, Xe, which is the previous noble element before barium, is presented as follows;
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ which is the same as the core electrons of barium
Therefore, the total number of electrons in xenon is equal to the number of core electrons in barium
What is the density of ammonia (NH3) at 273 K and 1.00 atm?
A - 0.7601 g/L
B - 0.982 g/L
C - 1.23 g/L
D - 2.43 g/L
Answer:
0.7602 g/L
Explanation:
We'll begin by calculating the molar mass of NH₃. This can be obtained as follow:
Molar mass of NH₃ = 14.01 + (3×1.01)
= 14.01 + 3.03
= 17.04 g/mol
Finally, we shall determine the density of ammonia, NH₃. This can be obtained as follow:
Temperature (T) = 273 K
Pressure (P) = 1 atm
Molar mass of NH₃ (M) = 17.04 g/mol
Gas constant (R) = 0.0821 atm.L/Kmol
Density (D) =?
D = PM / RT
D = (1 × 17.04) / (0.0821 × 273)
D = 17.04 / 22.4133
D = 0.7602 g/L
Answer:
It is A
Explanation:
What is the concentration of a solution formed by diluting 25.0 ml of a 3.8M glucose solution to 250ml
Explanation : số mol glucose 3.8M là :
n = Cm . V = 3.8 . 25 =95
=> Cm khi pha loãng = [tex]\frac{n}{V}[/tex] = [tex]\frac{95}{250}[/tex] = 0.38M
According to molar concentration, the concentration of a solution formed by diluting 25.0 ml of a 3.8 M glucose solution to 250 ml is 0.38 M.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.In case of 2 solutions given it is calculated as M₁V₁=M₂V₂,on substitution, M₂=3.8×25/250=0.38 M.
Thus, the concentration of a solution formed by diluting 25.0 ml of a 3.8 M glucose solution to 250 ml is 0.38 M.
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what is precipitating ???
anyone please tell me how to delete an I'd
Explanation:
Desposition of solid matter in a solution
Which of the following oxides is amphoteric oxide?
A)Na2O
B)Al2O3
C)MgO
D)SO2
Answer:
absolutely B because Al2O3 could react with axit and bazo
Explanation:
Answer:
"Aluminum oxide, beryllium oxide, tin oxide, zinc oxide all are amphoteric. They have reactions as both a base and an acid."
Explanation:
What information does the percent composition of an atom in a molecule
give?
A. The relative number of atoms one element contributes to a
molecule
B. The relative amount of mass an atom contributes to a molecule
C. The total mass that element contributes to a molecule
D. The total number of atoms of that element in a molecule
C.
This is basically the definition of percent composition which is how much mass a element contributes to a specific molecule.
Answer: B.
Explanation:
the relative amount of mass an atom contributes to a molecule
which of the following has more atoms 3.14 g Cu or 1.10 g of H? Explain
25.Which of the following reaction will not take place?
A. Zn+ FeSO4 → ZnSO4 + Fe
C. Fe + NiSO4 → FeSO4 + Ni
B. 2Al + 3MgSO4→ Al2(SO4)3 + 3Mg D.
Cu + 2AgNO3 → Cu(NO3)2 + 2Ag
Answer:
B
Explanation:
because Mg is stronger than Al
Write a balanced molecular equation describing each of the following chemical reactions.
(a) Solid calcium carbonate is heated and decomposes to solid calcium oxide and carbon
dioxide gas.
(b) Water vapor
Answer:
don't know..............
I need help with question 2
Answer:
here's the answer to your question
describe two ways in which gases are similar to liquids in properties
Answer:
they have weak intermolecular forces
How many moles are in 68 liters of H2S gas at STP? :}
Answe:
Explanation:
số mol của H2S là : 68/22.4=3.03 nha
Can someone do these? Brainliest included
Answer:
Explanation:
6. p⁺ e⁻
Ca²⁺ 20 18
F⁻ 9 10
O²⁻ 8 10
Na⁺ 11 10
7. Physical properties of matter are properties that can be measured or observed without matter changing to an entirely different substance. These include odor, boiling point, melting point, density, electrical conductivity and heat conductivity.
Separation of mixture:
Chromatography involves solvent separation on a solid medium.
Distillation takes advantage of differences in boiling points.
Evaporation removes a liquid from a solution to leave a solid material.
Filtration separates solids of different sizes.
Funnel partitioning with solvents. Solvent dissolves one component but not the other.
8.Bulk Elements => Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur & Phosphouous
Microminerals are those minerals needed in less than 100 mg quantities. Trace minerals or trace elements are usually needed in microgram quantities. Microminerals include iron, zinc, copper, iodine, fluoride, chromium, cobalt, selenium, manganese, and molybdenum.
Diatomic Molecules => H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂
9. Electron Configurations
Na: 1s²2s²2p⁶3s¹ => valence = 3s¹
N: 1s²2s²2p³ => valence = 2s²2p³
Al: 1s²2s²2p⁶3s²3p¹ => valence = 3s²3p¹
Valence is the highest principle quantum number (or, principle energy level ~ ring) in the electron configurations.
10.moles of glucose = 450g/180.16 g/mol =2.50 moles
C₂H₆O₂ = 2(12) + 6(1) + 2(16) = 24 + 6 + 32 = 62 g/mole
what’s the name of the organic molecule
Answer:
hexane
Explanation:
This is a 6- carbon hydrocarbon with no multiple bonds or any functional groups (such as -OH). Thus, the prefix 'hex' refers to the 6 carbons and 'ane' refers to the molecule being an alkane.
Naming molecules:
Number of carbons
• pentane: 5 carbons
• hexane: 6 carbons
• heptane: 7 carbons
• octane: 8 carbons
• nonane: 9 carbons
Functional groups (for 6- carbons molecules)
• Alkene (C=C): hexene
• Alcohol (-OH): hexanol
• Alkyne (C≡C): hexyne
