Answer:
photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.
How is a light bulb related to radiation?
A. Light bulbs do not have anything to do with radiation.
B. A light bulb emits radiation when its filament is burned out and can longer emit light. This makes it important to remove dead lightbulbs as soon as they wear out.
C. As light is emitted from the filament, the energy in the metal is replaced as lightbulbs absorb background radiation. This prevents the filament from burning out quickly but the radiation cannot be used as power so electricity is still required for the lightbulb to work.
D. The light emitted by a light bulb is a form of radiation that occurs when the filament heats up and its thermal emission gains enough energy to move into the visible spectrum.
Answer:
As light is emitted from the filament, the energy in the metal is replaced as lightbulbs absorb background radiation. This prevents the filament from burning out quickly but the radiation cannot be used as power so electricity is still required for the lightbulb to work.
The chemical formula for strontium sulfide is SrS . A chemist measured the amount of strontium sulfide produced during an experiment. She finds that 199.g of strontium sulfide is produced. Calculate the number of moles of strontium sulfide produced. Be sure your answer has the correct number of significant digits.
Answer:
The number of moles of strontium sulfide produced is:
= 1.663.
Explanation:
Chemical formula for strontium sulfide = SrS
Production of strontium sulfide = 199g
1 mole = 1 moles Strontium Sulfide, which is equal to 119.685 grams
The number of moles of strontium sulfide produced = 1.663 (199/119.685)
The number of moles of strontium sulfide produced is the dividend of the amount of strontium sulfide produced during the experiment divided by the mass of 1 mole.
The enthalpy of formation for CO2 (s) and CO2 (g) is: -427.4 KJ/mole and -393.5 KJ/mole, respectively. The sublimation of dry ice is described by CO2 (s) → CO2 (g).
The enthalpy needed to sublime 986 grams of CO2 is:
(a) 181.5 Kcal
(b) 611.7 Kcal
(c) 248.3 Kcal
(d) 146.2 Kcal
Answer:
a. 181.5 kcal
Explanation:
Step 1: Calculate the enthalpy of the process (ΔH°).
Let's consider the following process.
CO₂(s) → CO₂(g)
We can calculate the enthalpy of the process using the following expression.
ΔH° = ∑ np × ΔH°f(p) - ∑ nr × ΔH°f(r)
ΔH° = 1 mol × ΔH°f(CO₂(g)) - 1 mol × ΔH°f(CO₂(s))
ΔH° = 1 mol × (-393.5 kJ/mol) - 1 mol × (-427.4 kJ/mol) = 33.9 kJ
According to the balanced equation, 33.9 kJ are required to sublime 1 mole of CO₂.
Step 2: Convert 986 g of CO₂ to moles
The molar mass of CO₂ is 44.01 g/mol.
986 g × 1 mol/44.01 g = 22.4 mol
Step 3: Calculate the enthalpy needed to sublime 22.4 moles of CO₂
22.4 mol × 33.9 kJ/1 mol = 759 kJ
We can convert it to Kcal using the conversion factor 1 kcal = 4.184 kJ.
759 kJ × 1 kcal/4.184 kJ = 181.5 kcal
what is calcium anyone tell plz
Answer:
Calcium is a chemical element with the symbol Ca and atomic number 20.
Calcium is a mineral that is necessary for life. In addition to building bones and keeping them healthy, calcium enables our blood to clot, our muscles to contract, and our heart to beat. About 99% of the calcium in our bodies is in our bones and teeth.
A tank contains oxygen gas at 2.551 atm. What is the pressure in mmHg?
The force exerted on the container by the particles of the matter is called pressure. The tank containing oxygen gas at 2.551 atm will have a pressure of 1939 mm Hg.
What is pressure?Pressure is the property used to estimate the force experienced by the system due to the liquid or the gas held in it. The pressure of the gas can be calculated by the ideal gas and force and area.
The pressure is created due to the collision of the particles of the gases and liquids on the wall perpendicularly. It is estimated in Pascal (Pa) as the standard unit along with atm and mmHg.
It is known that 1 atm = 760 mm Hg
Given,
The pressure of oxygen gas = 2.551 atm
Using the conversion factor the pressure from atm to mm Hg is calculated as,
1 atm = 760 mm Hg
2.551 atm = (2.551 atm × 760 mm Hg) ÷ 1 atm
= 1938.76 mmHg
Therefore, 1939 mm Hg is the pressure of the oxygen gas.
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What are fires classified by?
Answer:
A fire class is a system of categorising fire with regard to the type of material and fuel for combustion. Class letters are often assigned to the different types of fire, but these differ between territories. There are separate standards for the United States, Europe, and Australia
The color cyan has a frequency of 5.902x10^14 What is the wavelength in nm ? Record your answer with 2
decimals.
The wavelength of the color cyan is 508 nm.
To solve the problem, we use the following equation that relates the frequency (ν) and the wavelength (λ) of a wave:
c = λ x ν
Given:
c = speed of light = 3.00 x 10⁸ m/s (is a constant)
ν = 5.902 x 10¹⁴ Hz = 5.902 s⁻¹
We introduce the data to calculate the wavelength in m:
λ = c/ν = (3.00 x 10⁸ m/s)/(5.902 s⁻¹) = 5.08 x 10⁻⁷ m
We know that 10⁻⁹m = 1 nm, so we convert λ to nm:
λ = 5.08 x 10⁻⁷ m x 1 nm/10⁻⁹m = 508 nm
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Please help me fast! Pleaseee
I think 2 answer is write
the ability for carbon to form long chain or rings is
A sample of gas contains 0.1200 mol of H2(g) and 0.1200 mol of O2(g) and occupies a volume of 11.5 L. The following reaction
takes place:
H2(g) + O2(g)>H2O2(g)
Calculate the volume of the sample after the reaction takes place, assuming that the temperature and the pressure remain constant.
L
Answer:
5.75L is the volume of the sample after the reaction
Explanation:
Based on the reaction, 1 mole of H2 reacts with 1 mole of O2 to produce 1 mole of H2O2.
As in the reaction, 0.1200 moles of H2 and 0.1200 moles of O2 are added, 0.1200 moles of H2O2 are produced.
Before the reaction, the moles of gas are 0.2400 moles and after the reaction the moles are 0.1200 moles of gas.
Based on Avogadro's law, the moles of a gas are directly proportional to the volume under temperatura and pressure constant. The equation is:
V1/n1 = V2/n2
Where V is volume and n are moles of 1, initial state and 2, final state.
Replacing:
V1 = 11.5L
n1 = 0.2400 moles
V2 = ?
n2 = 0.1200 moles
11.5L*0.1200 moles / 0.2400 moles = V2
V2 = 5.75L is the volume of the sample after the reaction
what is the difference between Absorption and adsorption
what type of forces either interatomic or intermolecular forces prevents ice cubes from adopting the shape of their container
There are two types of electrostatic forces: interatomic or intermolecular.
In this case the type of force that prevents ice cubes from adopting the shape of their container is intermolecular.
Interatomic forcesWithin a molecule, the atoms are held together by interatomic forces. These forces are what determine the chemical properties of substances because it is these forces that must be overcome for a chemical change to occur.
In summary, intermolecular forces are characterized by holding more than one molecule together.
Intermolecular forcesOn the other side, intermolecular forces act on different molecules or ions and cause them to attract or repel each other, causing different physical states in chemical compounds.
Therefore, the intermolecular forces are responsible for the existence of the liquid and solid state (between the molecules of a gas do not exist intermolecular forces.).
Case of ice cubesThen ice cubes do not ocuppy the shape of thir container because it is in solid state, existing intermolecular force between molecules to maintain said physical state.
In summary, the type of force that prevents ice cubes from adopting the shape of their container is intermolecular.
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https://brainly.com/question/14220340?referrer=searchResultshttps://brainly.com/question/13136165?referrer=searchResultsConsider the reaction below. How much heat is absorbed if 5.00 moles of nitrogen react
with excess oxygen?
2 N2 (8) + O2(g) → 2 N20 (8) AHrxn- +163.2 kJ
Explanation:
The given chemical reaction is:
[tex]2 N_2 (g) + O_2(g) -> 2 N_20 (g) delta Hrxn= +163.2 kJ[/tex]
When two moles of nitrogen reacts with oxygen, it requires 163.2kJ of energy.
When 5.00 mol of nitrogen requires how much energy?
[tex]5.00 mol x \frac{163.2 kJ }{2 mol} \\=408 kJ[/tex]
Hence, the answer is 408 kJ of heat energy is required.
In an ELISA, the compound 4-chloro-1-naphthol is used because:_______
a. it turns color in the presence of an enzyme that is bound to the secondary antibody
b. it helps the primary antibody bind to the protein
c. it helps the secondary antibody to bind to the protein
d. all of the choices
Answer:
a. It turns color in the presence of an enzyme that us bound to the secondary antibody.
Explanation:
The compound chloronapthenel is used in the reaction because it changes the color in the presence of an enzyme. It is strong organic compound which is used in biochemical processes.
what is food nutrients
Answer:
Nutrients arw compounds in foods essential to life and heath
Answer: In simple terms nutrients are the energy that you get from food certain foods give more nutrients and others give close to none. That is what nutrients in your food is
Explanation:
Which of the following substances can be used to neutralize HF?
A: HF
B: SO2
C: HCI
D: NaOH
Answer:
option (D) NaOH is right answer
A neutralization reaction is "a reaction in which an acid and a base react to form water and a salt and involves H+ ions and OH- ions to produce water.
What is an acid?An acid is "any hydrogen-containing substance that is capable of donating a proton or hydrogen ion to another substance".
What is base?Base is "a substance that gets dissociated in an aqueous solution to form hydroxide ions OH-".
Hence, NaOH can be used to neutralize HF.
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If 7 mol of copper reacts with 4 mol of oxygen, what amount of copper (II) oxide is produced? What amount of the excess reactant remains?
Answer:
7 mol CuO
0.5 mol O₂
Explanation:
Step 1: Write the balanced equation
2 Cu + O₂ ⇒ 2 CuO
Step 2: Identify the limiting reactant
The theoretical molar ratio (TMR) of Cu to O₂ is 2:1.
The experimental molar ratio (EMR) of Cu to O₂ is 7:4 = 1.75:1.
Since TMR > EMR, Cu is the limiting reactant
Step 3: Calculate the amount of CuO produced
7 mol Cu × 2 mol CuO/2 mol Cu = 7 mol CuO
Step 4: Calculate the excess of O₂ that remains
The amount of O₂ that reacts is:
7 mol Cu × 1 mol O₂/2 mol Cu = 3.5 mol O₂
The excess of O₂ that remains is:
4 mol - 3.5 mol = 0.5 mol
2. The reaction of a triglyceride with methanol in the presence of a strong base to form
methyl esters and glycerol is called
O A. transesterification.
O B. saponification.
O C. ester formation.
O D. dehydration condensation.
Answer:
The answer it's A. transesterification
A sample of neon gas occupies 105 L at 27°C under a pressure of
985 torr. What volume would it occupy at standard condition
Answer: Volume occupied by given neon sample at standard condition is 123.84 L.
Explanation:
Given: [tex]V_{1}[/tex] = 105 L, [tex]T_{1} = 27^{o}C = (27 + 273) K = 300 K[/tex], [tex]P_{1}[/tex] = 985 torr
At standard conditions,
[tex]T_{2}[/tex] = 273 K, [tex]P_{2}[/tex] = 760 K, [tex]V_{2}[/tex] = ?
Formula used to calculate the volume is as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{985 torr \times 105 L}{300 K} = \frac{760 torr \times V_{2}}{273 K}\\V_{2} = \frac{94116.75}{760} L\\= 123.84 L[/tex]
Thus, we can conclude that volume occupied by given neon sample at standard condition is 123.84 L.
Calculate the molality of each of the following solutions: (a) 36.2 g of sucrose (C12H22O11) in 323 g of water, m (b) 8.63 moles of ethylene glycol (C2H6O2) in 1889 g of water.
Answer:
(a) m = 0.327 m.
(b) m = 4.57 m.
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to solve this problem by firstly considering the fact that the molality is computed by dividing the moles of solute by the kilograms of solvent, in this case water; in such a way, we proceed as follows:
(a) We firstly calculate the moles of 36.2 grams of sucrose as its molar mass is 342.3 g/mol:
[tex]\frac{36.2g}{342.3g/mol} =0.106mol[/tex]
Next, the kilograms of water in this case are 0.323 kg so that the molality will be:
[tex]m=\frac{0.106mol}{0.323kg}\\\\m=0.327m[/tex]
(b) In this case, we directly realize that the kilograms of water are now 1.889 kg so that the molality will be:
[tex]m=\frac{8.63mol}{1.889kg}=4.57m[/tex]
Clearly, the both of them in molal, m, units.
Regards!
Calculate the enthalpy change for the reaction of hydrogen and chlorine using the bond energies below.
"BOND." " BOND ENERGY "
H-H. 436
CL-CL. 242
H-CL. 431
Answer:
final-intial temperature= enthalpy change
What volume (in liters) of a solution contains 0.14 mol of KCl?
1.8 M KCl
Express your answer using two significant figures.
Answer:
[tex]\boxed {\boxed {\sf 0.078 \ L }}[/tex]
Explanation:
We are asked to find the volume of a solution given the moles of solute and molarity.
Molarity is a measure of concentration in moles per liter. It is calculated using the following formula:
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}[/tex]
We know there are 0.14 moles of potassium chloride (KCl), which is the solute. The molarity of the solution is 1.8 molar or 1.8 moles of potassium chloride per liter.
moles of solute = 0.14 mol KCl molarity= 1.8 mol KCl/ Lliters of solution=xSubstitute these values/variables into the formula.
[tex]1.8 \ mol \ KCl/ L = \frac { 0.14 \ mol \ KCl}{x}[/tex]
We are solving for x, so we must isolate the variable. First, cross multiply. Multiply the first numerator and second denominator, then the first denominator and second numerator.
[tex]\frac {1.8 \ mol \ KCl/L}{1} = \frac{0.14 \ mol \ KCl}{x}[/tex]
[tex]1.8 \ mol \ KCl/ L *x = 1*0.14 \ mol \ KCl[/tex]
[tex]1.8 \ mol \ KCl/ L *x = 0.14 \ mol \ KCl[/tex]
Now x is being multiplied by 1.8 moles of potassium chloride per liter. The inverse operation of multiplication is division, so we divide both sides by 1.8 mol KCl/L.
[tex]\frac {1.8 \ mol \ KCl/ L *x}{1.8 \ mol \ KCl/L} = \frac{0.14 \ mol \ KCl}{1.8 \ mol \ KCl/L}[/tex]
[tex]x= \frac{0.14 \ mol \ KCl}{1.8 \ mol \ KCl/L}[/tex]
The units of moles of potassium chloride cancel.
[tex]x= \frac{0.14 }{1.8 L}[/tex]
[tex]x=0.07777777778 \ L[/tex]
The original measurements of moles and molarity have 2 significant figures, so our answer must have the same. For the number we found, that is the thousandth place. The 7 in the ten-thousandth place tells us to round the 7 up to a 8.
[tex]x \approx 0.078 \ L[/tex]
There are approximately 0.078 liters of solution.
Hydrogengasand oxygengas react to form water vapor. Suppose you have of and of in a reactor. Calculate the largest amount of that could be produced. Round your answer to the nearest .
The question is incomplete. The complete question is :
Hydrogen [tex](H_2)[/tex] gas and oxygen [tex](O_2)[/tex] gas react to form water vapor [tex](H_2O)[/tex]. Suppose you have 11.0 mol of [tex]H_2[/tex] and 13.0 mol of [tex]O_2[/tex] in a reactor. Calculate the largest amount of [tex]H_2O[/tex] that could be produced. Round your answer to the nearest 0.1 mol .
Solution :
The balanced reaction for reaction is :
[tex]$2H_2(g) \ \ \ \ + \ \ \ \ \ O_2(g)\ \ \ \rightarrow \ \ \ \ 2H_2O(g)$[/tex]
11.0 13.0
11/2 13/1 (dividing by the co-efficient)
6.5 mol 13 mol (minimum is limiting reagent as it is completely consumed during the reaction)
Therefore, [tex]H_2[/tex] is limiting reagent. It's stoichiometry decides the product formation amount from equation above it is clear that number of moles for [tex]H_2O[/tex] will be produced = number of moles of [tex]H_2[/tex]
= 11.0 mol
8) Determine whether mixing each pair of the following results in a buffera. 100.0 mL of 0.10 M NH3 with 100.0 mL of 0.15 MNH4Cl b. 50.0 mL of 0.10 M HCL with 35.0 mL of 0.150 M NaOHc. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOHd. 175.0 mL of 0.10 M NH3 with 150.0 mL of 0.12 M NaOH
Answer:
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
Explanation:
A buffer system is formed in 1 of 2 ways:
A weak acid and its conjugate base.A weak base and its conjugate acid.Determine whether mixing each pair of the following results in a buffer.
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
YES. NH₃ is a weak base and NH₄⁺ (from NH₄Cl ) is its conjugate base.
b. 50.0 mL of 0.10 M HCl with 35.0 mL of 0.150 M NaOH.
NO. HCl is a strong acid and NaOH is a strong base.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
YES. HF is a weak acid and it reacts with NaOH to form NaF, which contains F⁻ (its conjugate base).
d. 175.0 mL of 0.10 M NH₃ with 150.0 mL of 0.12 M NaOH.
NO. Both are bases.
If you add a solution of NaOH to a solution of H₂CO₃, two reactions occur, one after the other. Write the chemical equations for these two reactions. (Hint: NaOH dissociate into Na+ and OH-, and the hydroxide ion is the actual base).
We have a solution of NaOH and H₂CO₃
First, NaOH will dissociate into Na⁺ and OH⁻ ions
The Na⁺ ion will substitute one of the Hydrogen atoms on H₂CO₃ to form NaHCO₃
The H⁺ released from the substitution will bond with the OH⁻ ion to form a water molecule
If there were to be another NaOH molecule, a similar substitution will take place, substituting the second hydrogen from H₂CO₃ as well to form Na₂CO₃
Select the structure of a compound C6H14 with a base peak at m/z 43.
A) CH3CH2CH2CH2CH2CH3
B) (CH3CH2)2CHCH3
C) (CH3)3CCH2CH3
D) (CH3)2CHCH(CH3)2
E) None of these choices.
The structure of a compound C₆H₁₄ with a base peak at m/z 43 is none of these .
What is a compound?Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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Consider an equilibrium (K1) that is established after 10 mL of compound A and 10 mL of compound B are mixed. Now, imagine the equilibrium (K2) where 1 mL of compound A is added to 100 mL of compound B. How are K1 and K2 related algebraically (read this question VERY carefully, at least one more time)?
K1 and K2 are related algebraically because once the values are inserted into the equilibrium equation, both equations will yield a denominator of 100.
Give the amino acid sequence in the following tetrapeptide using both 3-letter and 1-letter abbreviations for the amino acids. (Capitalize amino acid abbreviations appropriately.) ball
Answer:
ggggggggggggg
Explanation:
gggggggggggthyjum
A chlorine (CI) atom has 7 valence electrons. Which of the following would be the most likely way for a chlorine atom to become stable?
A. Lose 5 electrons
B. Gain 2 electrons
C. Gain 1 electron
D. Lose 7 electrons
Answer:
Option C. Gain 1 electron
Explanation:
Valence electron(s) are the electron(s) located on the outermost shell of an atom. Valency is simply defined as the combining power of an atom.
Chlorine (Cl) atom has 7 valence electron. This implies that Cl needs just one electron to complete it's octet configuration. It will be difficult for Cl to lose any of it's valence electron(s). Cl can either gain or share 1 electron to become stable.
Thus, considering the options given in the question above, option C gives the correct answer to the question.
crassify the given quantities into scalar quantity and vetor quantity
Answer:
where is the quantities?
