Answer:
Use the Rydberg Equation 1/λ = R(1/n²(final) - 1/n²(initial) where R = 109,678 cm⁻¹. Substitute initial orbital number and final orbital number and solve for wavelength (λ).
Explanation:
Example:
Assume an electron transition from n = 5 to n = 2.
1/λ = 109,678cm⁻¹(1/2² - 1/5²) = 109,678(0.25 - 0.04)cm⁻¹ = 23,032cm⁻¹
λ = 1/23,032cm⁻¹ = 4.34 x 10⁻⁵cm x 10⁻²m/cm x 10⁹nm/m = 434nm
Calculate the pH at the equivalence point for the following titration: 0.25 M HCOOH versus 0.25 M NaOH.
The pH at the equivalence point for the titration of 0.25 M HCOOH versus 0.25 M NaOH is 8.5.
Let's consider the following neutralization reaction.
HCOOH + NaOH ⇒ HCOONa + H₂O
At the equivalence point, 0.25 M HCOOH completely reacted with 0.25 M NaOH to form 0.25 M HCOONa.
HCOONa undergoes hydrolysis. The net ionic equation is:
HCOO⁻(aq) + H₂O(l) ⇄ HCOOH(aq) + OH⁻(aq)
Given the concentration of HCOO⁻ is 0.25 M (Cb) and the basic dissociation constant of HCOO⁻ is 4.8 × 10⁻¹¹ (Kb), we can calculate the concentration of OH⁻ using the following expression.
[tex][OH^{-} ] = \sqrt{Kb \times Cb } = \sqrt{(4.8 \times 10^{-11} ) \times 0.25 } = 3.5 \times 10^{-6} M[/tex]
The pOH of the solution is:
[tex]pOH = -log [OH^{-} ] = -log (3.5 \times 10^{-6} ) = 5.5[/tex]
The pH of the solution is:
[tex]pH = 14 -pOH = 14 -5.5 = 8.5[/tex]
The pH at the equivalence point for the titration of 0.25 M HCOOH versus 0.25 M NaOH is 8.5.
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what is the best way to learn and understand high school chemstry?
Answer:
Firstly, try to Go through your chapter and pay attention to main keywords.
secondly try to watch 'Uube' videos related to specific topic instead of chapter and pay attention to it closely and watch it with a keen interest.
Discuss topics that you find harder with your friends or peer group members, Because you learn faster when you study with the people of your age.
Answer:
i think the best way to learn chemistry is study over things that involve it
Explanation:
Do you think sugar would be soluble in hexane based on its structure
Answer:
The dipole forces (particularly H-bonds) that keep polar solute molecules together can be replaced by polar solute-solvent interactions, so substances that are predominantly polar (like glucose) dissolve in polar solvents like water but not in nonpolar solvents like hexane (H-bonds).
Explanation:
Calculate the pH when the following quantities of 0.100 M NaOH solution have been added to 50.0 mL of 0.100 M HCl solution
Answer:
see explanation
Explanation:
Given 0.100M NaOH + 50ml 0.100M HCl
If 50ml of 0.100M NaOH is added to 50ml 0.100M HCl => pH = 7
if less than 50ml of 0.100M NaOH => pH < 7
if more than 50ml of 0.100M NaOH => pH > 7.
Example:
50ml(0.100M NaOH) + 50ml(0.100MHCl) =>
0.500mole NaCl + 0.500mole H₂O
In this mix, both NaOH and HCl are converted to NaCl and H₂O and NaOH or HCl are no longer present giving a neutral solution. Since neither Na⁺ nor Cl⁻ undergo hydrolysis, the pH is dependent upon H₂O ⇄ H⁺ + OH⁻ and [H⁺] = [OH⁻] = 10⁻⁷M => pH = -log[H⁺] = -log(10⁻⁷) = -(-7) = 7
If less than 50ml of 0.100M NaOH is added, the mix will have an excess of HCl and the pH will be acidic; i.e., less than 7.
If more than 50ml of 0.100M NaOH is added, the mix will have an excess of NaOH and the pH will be alkaline (basic); i.e., greater than 7.
identify each of the following changes of states as melting ,freezing,sublimation or deposition
a: ice sculpture start breaking down as temperature rise above 0 degree
Answer:
Melting
Explanation:
Ice begins to melt at 0 degrees celsius
Melting is from solid to liquid
Freezing is from liquid to solid
Sublimation is from solid to gas
Deposition is from gas to solid
What is the name of the branched alkane shown below?
لہ
A. 3-methyloctane
B. 4-methylheptane
C. 3-methylheptane
D. 4-methyloctane
Answer:
4-methyloctane
Explanation:
other guy got it wrong, this one's right
The name of the branched alkane is 4-methyloctane as it has 8 carbon atoms.
What is an atom?An atom is defined as the smallest pa of matter which makes a basis of an element. Every form of matter whether it be a solid,liquid , gas consists of atoms . Each atom has a nucleus which is contains protons and neutrons and shells in which the electrons revolve.
The protons are positively charged particles and neutrons are neutral particles and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged particles and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not change the chemical properties of the substances.
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HELP
How can you tell if mass is being conserved
How many aluminum ions are present in 65.5 mL of 0.210 M All3solution?
Answer:
Aluminium ions present's in 65.5mL of 0.210
M All 3solution is Given below-:
Answer and Explanation: 1
The first step is to determine the moles of aluminum ions. This utilizes the volume, molar concentration, and subscripts from the chemical formula of aluminum (III) fluoride as shown.
65.5 mL×1 L1000 mL×0.210 mol AlF31 L×1 mol Al3+1 mol AlF3=0.013755 mol Al3+65.5 mL×1 L1000 mL×0.210 mol AlF31 L×1 mol Al3+1 mol AlF3=0.013755 mol Al3+
To calculate for the number of aluminum ions, we use Avogadro's number as shown.
0.013755 mol Al3+×6.022×1023 ions1 mol Al3+=8.28×1021 ions Al3+.
Itz the ans. of collage ok man.
Answer:
m0.013755
m
o
l
A
l
3
+
×
6.022
×
10
23
i
o
n
s
1
m
o
l
A
l
3
+
=
8.28
×
10
21
i
o
n
s
A
l
3
+
L
×
1
L
1000
m
L
×
0.210
m
o
l
A
l
F
3
1
L
×
1
m
o
l
A
l
3
+
1
Explanation:
The first step is to determine the moles of aluminum ions. This utilizes the volume, molar concentration, and subscripts from the chemical formula of aluminum (III) fluoride as shown.
65.5. To calculate for the number of aluminum ions, we use Avogadro's number as shown.
10. Based on their valence electrons, how many
atoms of chlorine are expected to bond
with each of the following elements?
a. carbon
b. nitrogen
c. aluminum
d. sulfur
will share 2 elctrons with 2 Cl to form
S in column 16 WILL SHARE 2 ELECTRONS WITH 2 /Cl to form
SCl2
,
Answer:
a. carbon CCl4
b. nitrogen NCl3
c. aluminum AlCl3
d. sulfur SCl2
Explanation:
10. Based on their valence electrons, how many
atoms of chlorine are expected to bond
with each of the following elements?
a. carbon CCl4
b. nitrogen NCl3
c. aluminum AlCl3
d. sulfur SCl2
Cl is in Periodic Table column 17, so it has 7 valence and needs 1 more to have an electronic structure like its nearest noble gas, Ar.
It then has an oxidation state 0f -1.
Carbon in column has +/-4 charge, so 4 Cl will bond with 1 C to make
covalent CCl4
Nitrogen in column 15 is -3. It will share 3 electrons with 3 Cl to form
covalent NCl3
Al in column 13 give away 3 electrons to 3 Cl to form
ionic AlCl3
S in column 16 will share 2 electrons with 2 Cl and frorm
SCl2
Will give Brainliest
Use the image to answer the question.
An illustration shows the process that takes place in a cold pack. The warm cold pack has ammonium nitrate on one side and water on the other. The water is kept separate in a thin plastic bag. The pack is squeezed and the inner bag bursts. The mixture cools as ammonium nitrate dissolves.
Which kind of reaction is shown in this image?
(1 point)
It is an endothermic reaction because the system takes energy from the surroundings.
It is an exothermic reaction because the surroundings take energy from the system.
It is an endothermic reaction because the surroundings take energy from the system.
It is an exothermic reaction because the system takes energy from the surroundings.
Answer:
it is an endothermic reaction because the system takes energy from the surrounding.
Answer:
It is an endothermic reaction because the system takes energy from the surroundings.
Explanation:
I did the test.
Which one of the following salts has the highest molar solubility in water?
Answer:
Correct option is
C
Ag
2
CO
3
; K
sp
=6.2×10
−12
(A) For CaCO
3
,S=
Ksp
=
8.7×10
−9
=9.3×10
−5
M
(B) For CuS,S=
Ksp
=
8.5×10
−45
=9.2×10
−23
M
(C) For Ag
2
CO
3
,S=(Ksp/4)
1/3
=(6.2×10
−12
/4)
1/3
=1.15×10
−4
M
(D) For Pb(IO
3
)
2
,S=(Ksp/4)
1/3
=(2.6×10
−13
/4)
1/3
=4×10
−5
M
Hence, Ag
2
CO
3
has the greatest molar solubility in pure water.
The
is the wind system responsible for the movement of weather from west to east across most of the continental United States
A
polar easterlies
B
prevailing westerlies
C
trade winds
Answer:
Westerlies are prevailing winds that blow from the west at midlatitudes. They are fed by polar easterlies and winds from the high-pressure horse latitudes, which sandwich them on either side.Nov 15, C answer
How many molecules are present in 4.61x10-2 mol of O2
Answer:
6.02 × 1023
The molar mass from the periodic table is 32.00 g O2 = 1 mol O2, and by definition, 1 mol O2 = 6.02 × 1023 molecules O2.
How are metals, metalloids, nonmetals grouped
no I will not please put you because that's the god of the Bible
Metals are good conductors of heat and electricity, and are malleable (they can be hammered into sheets) and ductile (they can be drawn into wire).
Nonmetals are (usually) poor conductors of heat and electricity, and are not malleable or ductile; many of the elemental nonmetals are gases at room temperature, while others are liquids and others are solids.
The metalloids are intermediate in their properties. In their physical properties, they are more like the nonmetals, but under certain circumstances, several of them can be made to conduct electricity.
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Which scientific law describes the observation that energy cannot be created or destroyed?
Law of universal gravitation
Law of conservation of energy
Newton's first law of motion
Newton's third law of motion
Answer:
law of conservation of energy
What is the mass of sulphate ions 96.06 in 25.0ml of a 0.125 solution
Answer:
12.34
Explanation:
because this is how we do this
What type of mixture is this illustration?
Answer:
Suspension
Explanation:
It's a suspension because it is not mixed at all, and has distinctly separate layers.
How do weak intermolecular bond strengths affect the melting and boiling point of a substance? (Picture is of answers I can choose from)
For a weak intermolecular bond, both the melting point and boiling point are lower.
A lesser energy is required to break bond of weak intermolecular forces while a greater energy is required to break bond of strong intermolecular forces.
E ∝ T
where;
E is the energy required to break the bondT is the temperatureA lesser energy means a lower temperature and a lower temperature will result in lower boiling point and melting point.
Thus, we can conclude that for a weak intermolecular bond, both the melting point and boiling point are lower.
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how much heat will we use when 30 grams of ice turns into water at 30 degrees Celsius?
Answer:
more heat
Explanation:
more heat bro , more heat
Explanation:
The answer is given in the question
Which statement about petroleum fractions is correct?
A. All petroleum fractions are used as fuels.
B. Gas oil is used to make bottled gas for heating.
C. Hydrocarbons in diesel have higher boiling points than hydrocarbons in
gasoline.
D. Molecules in kerosene are larger than molecules in fuel oil.
Answer: It is either C. or D.
Explanation: I did some reading about it and it talks about fuel but I know that it didn’t say all of them are used as fuels. maybe I’m wrong
Petroleum is composed of hydrocarbons of various chain length. Different products can be extracted from petroleum but all products cannot be used as fuel.
Hydrocarbons in diesel have higher boiling point than that of gasoline.
What is petroleum?Petroleum is a naturally occurring crude liquid mixture of hydrocarbons. Petroleum can be fractionated to different components such as gasoline, kerosene, diesel etc.
Each fraction vary in the number of carbons and hydrogens in it or called the difference in chain length. Kerosene contains 8-16 carbons where as gasoline and diesel have more carbons.
Not all products of petroleum fractionation can be used as fuel. Some of them with effective quality is taken as fuels.
The boiling point of hydrocarbons in diesel is greater (about 130-380 degree Celsius) than the hydrocarbons in gasoline which is having boiling point in he range 30-225 degree Celsius.
Therefore, the statement C is correct.
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Identify the movements of the glenohumeral joint that occur with contraction of the infraspinatus and teres minor.
Answer: adduction of the arm
lateral rotation of the arm
Explanation:
Calculate the mass of 5.3 moles of chloric acid (HClO3). Explain the process or show your work by including all values used to determine the answer.
Answer:
447.64 grams
Explanation:
To find the mass when given moles, it is a pretty simple process.
I start by finding the molar mass of chloric acid, which comes out to 84.46 grams/mol. To find the MM (molar mass), you just take the mass of each element in the molecule from the periodic table and add them all together.
After this, you set up the equation by taking the moles given and multiplying it by the molar mass. This gives you the new value in grams (since we cancelled out the moles). I have attached my work below.
I hope this helps! :^)
The mass of 5.3 moles chloric acid has been 447.85 g.
The mass of 1 mole of a compound has been equivalent to the molar mass of the compound. The molar mass of a compound has been the sum of the constituent atoms in a formula unit.
The molar mass (mwt) of chloric acid has been given as:
[tex]mwt=m_H\;+\;m_C_l\;+\;(m_O\;\times\;3)[/tex]
By substituting the values for the mass of constituent atoms, the molar mass has been given as:
[tex]mwt=1\;+\;35.5\;+\;16\;\times\;3\\mwt=36.5\;+\;48\\mwt=84.5[/tex]
The molar mass of chloric acid has been 84.5 g/mol.
The mass of 1 mole of chloric acid has been 84.5 g/mol. The mass of 5.3 moles chloric acid has been:
[tex]\rm 1\;mol=84.5\;g\\5.3\;mol=5.3\;\times\;84.5\;g\\5.3\;mol=447.85\;g[/tex]
The mass of 5.3 moles chloric acid has been 447.85 g.
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A small, rocky object directly orbits the sun. If this object is not large enough to be a planet, it most likely is what?
Answer:
It is most likely to be an asteroid
What is the molality of sodium chloride in solution that is 13.0% by mass sodium chloride and that
the solution has a density of 1.10 g/mL?
Answer:
2.4 M
Explanation:
1. Suppose you have 100 mL solution:
Use density to find grams of solution:
100 mL solution x (1.10 g / 1 mL) = 110 g solution
2. FInd the amount of sodium chloride pure:
110 g solution x(13 g NaCl / 100 g solution) = 14.3 g NaCl
3. Change grams to mol:
14.3 g NaCl x ( 1 mol NaCl/ 58.44 g NaCl) = 0.24 mol NaCl
4. Molarity:
M = mol NaCl / L solution
M = 0.24 mol NaCl / 0.1 L = 2.4 M
WILL MARK BRAINLIEST IF YOU ANSWER EVERY QUESTION!!!!
Answer:
The answer for number one is .A
The answer for number two is heat rises
Explanation:
If aqueous solutions of Na2CO3 and BaCl2 are mixed, which insoluble precipitate is formed?
Answer:
barium chloride (BaCl2) is added to sodium carbonate (Na2CO3). The result is a white precipitate.
Explanation:
How many moles of lithium hydroxide would be required to produce 38.5 g of Li₂CO₃ in the following chemical reaction?
2 LiOH(s) + CO₂(g) → Li₂CO₃(s) + H₂O(l)
Numer of moles of Li₂CO₃:
[tex]\longrightarrow\: n_{(Li_2 CO_3)} = \dfrac{38.5}{(6 \times 2) + 12 + (16 \times 3)}[/tex]
[tex]\longrightarrow\: n_{(Li_2 CO_3)} = \dfrac{38.5}{12+ 12 +48}[/tex]
[tex]\longrightarrow\: n_{(Li_2 CO_3)} = \dfrac{38.5}{72}[/tex]
[tex]\longrightarrow\: n_{(Li_2 CO_3)} = 0.53473 \: mol[/tex]
Chemical Reaction:
2 LiOH(s) + CO₂(g) → Li₂CO₃(s) + H₂O(l)
1 mole of Li₂CO₃ is formed from 2 moles of LiOH.Therefore, applying unitary method:
0.53473 mole of Li₂CO₃ is formed from 2 × 0.53473 = 1.06946 moles of LiOH.No. of moles of lithium hydroxide would be required to produce 38.5 g of Li₂CO₃ in the following chemical reaction are 1.03.
What is mole concept?Avogadro's number is the number of units in one mole of any substance and equals to 6.02214076 × 10²³. The units can be electrons, atoms, ions, or molecules.
No. of moles is defined as a particular no. of particles that we can calculate with the help of Avogadro’s number.
Mass of a particular product is also find out by stoichiometry of a reaction as per the no. of mole given in the reaction.
Given,
2LiOH(s) + CO₂(g) → Li₂CO₃(s) + H₂O(l)
2 moles of LiOH are required to produce 73.8g Li₂CO₃
0.027 moles of LiOH are required to produce 1g Li₂CO₃
1.03 moles of LiOH are required to produce 38.5 Li₂CO₃
Therefore, No. of moles of lithium hydroxide would be required to produce 38.5 g of Li₂CO₃ in the following chemical reaction are 1.03.
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A 1.8 mole sample of a compound weighs 195 g and is found to be 11.18% H and 88.82% C. What is the molecular formula for the compound?
Answer:
C8H12
Explanation:
First find the molar mass
195/1.8 × 1 = 108.3 gmol-1
Then the molecular formula
Mass of C in 1 mole of compound = 88.82×108.3/100
= 96.2 g
Mass of H in 1 mol of.the compound = 108.3×11.18/100 = 12.11 g
Divide the mass by their molar masses to get no. of moles in 108.3 g of compound or 1 mole of compound
Moles of C in one Mole of compound = 96.2g/12 gmol-1 = 8 mol
Moles of H in 1 mole of compound = 12.11g/1 gmol-1 =12 mol
Since we need the molecular formula it's C8H12
How many grams of oxygen will react with 2.0 grams of iron II sulfide?
Answer:
How many grams Iron(II) Sulfide in 1 mol? The answer is 87.91. We assume you are converting between grams Iron(II) Sulfide and mole. You can view more details on each measurement unit: molecular weight of Iron(II) Sulfide or mol The molecular formula for Iron(II) Sulfide is FeS. The SI base unit for amount of substance is the mole.
Explanation:
Bio fuel is a mixture of petrol and 20%——————
Answer:
methane and petrol okkkkkkkkkkkkkkkkkkk