The time needed to decrease reactant concentration based on its half-life is 68.47 seconds.
We need to know about the half-life of the radioactive elements to solve this problem. The radioactive element will decay over time and follow the equation
N = No(1/2)^(t/t'')
where N is the final quantity, No is the initial quantity, λ is the decaying constant, t is time and t'' is the half-life of a radioactive element.
From the question above, we know that
t'' = 41.3 s
No = 6.5 m
N = 2.06 m
By substituting the given parameters, we can calculate the time taken
N = No(1/2)^(t / t'')
2.06 = 6.5 . (1/2)^(t / 41.3)
0.32 = (1/2)^(t / 41.3)
⁰'⁵log(0.32) = t / 41.3
1.66 = t / 41.3
t = 68.47 seconds
Find more on half-life at: https://brainly.com/question/25750315
#SPJ4
suppose you did not want to calculate the precise atomic mass for one of the elements, such as nitrogen or oxygen. how could you approximate the value of the atomic mass?
The atomic mass of every element may be simply calculated using the number of protons and neutrons in the nucleus.
The atomic mass can be approximated by summing the number of protons and neutrons in the atom. The average mass of an element's atoms that are meaningfully measured in the atomic mass unit (amu) is defined as its atomic mass. It should be noted that the atomic mass is calculated by adding the masses of all the element's isotopes. This is the most precise method for calculating the relative atomic mass.
However, if we do not wish to compute the precise atomic mass of one of the elements, we may simply sum the number of protons and neutrons in the atom. This provides us a ballpark estimation of the atom's mass. Another way for estimating the atomic mass of any element is to simply double the value of the atomic number that is known for each individual element.
Learn more about Atomic mass here:
https://brainly.com/question/17067547
#SPJ4
What is the atomic mass of hafnium if, out of every 100 atoms, 5 have a mass of 176, 19 have a mass of 177, 27 have a mass of 178, 14 have a mass of 179, and 35 have a mass of 180. 0?.
The average atomic mass of the given isotopes of Halfnium is 178.55 amu
The average atomic mass of an element is equal to the sum of its isotope masses multiplied by it's own natural abundance (the decimal associated with the percent of atoms of that element for a given isotope).
In order to determine the weighted average, we must consider the % natural abundances of each isotope. The atomic mass of an element is the weighted average of the atomic masses of the element's naturally occurring isotopes. Determine the average atomic mass by using atomic masses and percentage abundances of each isotope. To convert each percentage abundance to decimal form, divide it by 100. Multiply this figure by the atomic mass of the isotope. To get the average atomic mass, add the atomic masses of each isotope together.
To determine the average atomic mass of Halfnium, the mass fractions of the isotopes multiplied by their respected atomic masses must all be added.
Using 100 atoms as the basis, calculate the mass fractions (m1, m2,...m5):
m1 = 5/100 = 0.05
m2 = 19/100 = 0.19
m3 = 27/100 = 0.27
m4 = 14/100 = 0.14
m5 = 35/100 = 0.35
Multiplying the mass fractions with the atomic masses of the respective isotopes.
Average atomic mass of Halfnium is:
Avg = (m1 x 176) + (m2 x 177) + (m3 x 178) + (m4 x 179) + (m5 x 180)
Avg = (0.05 x 176) + (0.19 x 177) + (0.27 x 178) + (0.14 x 179) + (0.35 x 180)
Avg = 178.55 amu
Therefore, the average atomic mass of Halfnium based on the data for its given isotopes is 178.55 amu.
Learn more about Average atomic mass of isotopes here:
https://brainly.com/question/13292428
#SPJ4
how many milliliters of 3.0m naoh are required to react with 0.5g of cu 2 to form cu(oh)2? ( hint: write the net ionic equation for reaction 2, to get correct mole ratio) ( answer should be written in decimal form)
The number of milliliters of 3.0m NaOH required to react with 0.5g of Cu2+ to form Cu(OH)2 is 5.249 ml
The reaction is as follows;
2NaOH + Cu2+ ------------> Cu(OH)2 + 2Na+
From the balanced chemical reaction, 0.5 g of Cu2+ = 0.5/63.5 = 7.874x10-3 moles (molar mass of Cu2+ = 63.5 g)
Thus, moles of NaOH required = 2*moles of Cu2+ = 0.01575
Now, moles of NaOH = molarityxvolume in litres
or, 3*volume in litres = 0.01575
or, volume in litres = 5.249*10-3 litres = 5.249 ml
A balanced chemical equation is one that contains the same number of atoms on either side of the equation.It follows the law of conservation of mass.To learn more about balanced chemical equation visit:
brainly.com/question/28294176
#SPJ4
The chemical formula for glucose, a simple sugar, is c6h12o6. When a glucose molecule is assembled during photosynthesis, the process takes up 12 hydrogen ions from the stroma of the chloroplast. What process adds 12 hydrogen ions to the chloroplast?.
Light energy is used in photosynthesis to convert carbon dioxide and water into glucose and oxygen. 1 glucose molecule and 6 oxygen molecules are produced for every 6 carbon dioxide and 6 water molecules.
C₆H₁₂O₆ is the chemical formula for glucose, a simple sugar. When a glucose molecule is assembled during photosynthesis, it absorbs 12 hydrogen ions from the chloroplast stroma. Reactants in photosynthesis include oxygen, carbon dioxide, ATP, and NADPH. Water and GA3P are both products. Chlorophyll, water, and carbon dioxide are reactants in photosynthesis. When the process is finished, photosynthesis produces oxygen and carbohydrate molecules, most commonly glucose. These sugar molecules contain the energy required by living things to survive.
Learn more about Photosynthesis here-
https://brainly.com/question/26494694
#SPJ4
calculate the number of joules given off when 32.0 grams of steam cools from 110.0 C to ice at -40.0 C
Answer:0.74
Explanation:0.74
14.67KJ is the number of joules given off when 32.0 grams of steam cools from 110.0 C to ice at -40.0 C.
What is heat?The vibrations of molecules or atoms increase when a body's temperature rises. From one area of the body to another, these vibrations are then transmitted. The amount of energy that a system's molecules vibrate with is referred to as its stored heat.
According to the definition of heat, it is the movement of energy from a warm item to a cooler one. The flow of heat energy is in the direction of moving from a substance with a higher temperature to one with a lower temperature.
q =mcΔT
=32.0×4.18×(110-40)
= 14.67KJ
Therefore, 14.67KJ is the number of joules given off when 32.0 grams of steam cools from 110.0 C to ice at -40.0 C.
To know more about heat, here:
https://brainly.com/question/30603212
#SPJ2
If soil erosion is happening at a greater rate than new soil can form, what will eventually happen to the soil in that region? Find a real-life example of this by googling "areas of extreme soil degradation."
Likely the foremost recognizable impact of soil disintegration is land degradation.
Asia-Pacific region is an area of extreme soil degradation.
Likely the foremost recognizable impact of soil disintegration is land debasement. As disintegration wears down the soil and its arrival, its capacity to bolster plant life diminishes.
Around the globe, soil disintegration is happening at a speedier rate than it can regenerate. When arrival corrupts, it annihilates territories and diminishes the sum of arrival accessible for agricultural needs or the requirements of natural life.
Since of land degradation, the soil cannot back plant life. Plants require solid, nutrient-filled soil to develop and deliver. In case the ground isn’t able to back vegetation, you won’t be able to develop nourishment.
Other than that, with fewer plants accessible to sequester carbon dioxide from the environment, the rate of climate alters increments. Increasingly carbon dioxide is cleared out within the climate, which is causing harm to the environment.
It increments the earth’s normal temperature and modifies precipitation, both of which can advance the progress of desertification.
Learn more about soil erosion at
https://brainly.com/question/28343872
#SPJ1
4. which parts of the amino acids x and y are involved in the formation of a peptide bond between them? assume that w is the first amino acid in the polypeptide chain, x is the second, and y is the third.
In a polypeptide chain, to generate an amide, the peptide bond connects the carboxyl group of one amino acid (x) to the amino group of the subsequent amino acid (y).
A polypeptide chain is defined as a series of amino acids linked together by peptide bonds. Poly stands for numerous, while peptide stands for protein. A polypeptide chain is therefore a chain of protein or amino acid building components. Polypeptide chains are crucial because they are the building blocks of proteins.
The carboxyl group of the first amino acid, w binds with the amino group of the next amino acid, x. The carboxyl group of x binds with the amino group of the y amino acid. Thus, peptide bonds are formed between the w-x-y amino acids making them a polypeptide chain.
Learn more about Polypeptide chains here:
https://brainly.com/question/14694121
#SPJ4
the lead-acid storage battery is the oldest rechargeable battery in existence. it was invented in by french physician gaston plante and still retains application today, more than years later. there are two reactions that take place during discharge of the lead-acid storage battery. in one step, sulfuric acid decomposes to form sulfur trioxide and water: (l) (g) (l) in another step, lead, lead(iv) oxide, and sulfur trioxide react to form lead(ii) sulfate: (s) (s) (g) (s) calculate the net change in enthalpy for the formation of one mole of lead(ii) sulfate from lead, lead(iv) oxide, and sulfuric acid from these reactions. round your answer to the nearest .
The net change in enthalpy for the formation of one mole of lead(ii) sulfate from lead, lead(iv) oxide, and sulfuric acid is -274.5 KJ,
Calculation
Reaction 1: [tex]H_{2} SO_{4(aq)}--- > SO_{3(g)} +H_{2} O_{(l)}[/tex] , Δ[tex]H^{Q} = +113 KJ[/tex]
Reaction 2: [tex]Pb_{(s)} +PbO_{2(s)} +2SO_{3(s)} --- > 2PbSO_{4(aq)}[/tex] Δ[tex]H^{Q} =-775 KJ[/tex]
To calculate the net change in enthalpy for the formation of 1 mole of [tex]PbSO_{4(aq)}[/tex]
Divide reaction 2 by 2
⇒[tex]\frac{Pb_{(s)}}{2} +\frac{PbO_{2(s)}}{2} +\frac{2SO_{3(s)}}{2} --- > \frac{2PbSO_{4(aq)}}{2}[/tex], Δ[tex]H^{Q} =\frac{-775}{2} KJ[/tex]
⇒[tex]\frac{Pb_{(s)}}{2} +\frac{PbO_{2(s)}}{2} +SO_{3(s) --- > PbSO_{4(aq)[/tex] , Δ[tex]H^{Q} =-387.5 KJ[/tex]
Subtract reaction 1 with the above reaction
[tex]H_{2} SO_{4(aq)}--- > SO_{3(g)} +H_{2} O_{(l)}-\frac{Pb_{(s)}}{2} +\frac{PbO_{2(s)}}{2} +SO_{3(s) --- > PbSO_{4(aq)[/tex]
⇒[tex]H_{2} SO_{4(aq)}+\frac{Pb_{(s)}}{2}+\frac{PbO_{2(s)}}{2} --- > PbSO_{4(aq)}+H_{2} O_{(l)}[/tex]
Δ[tex]H^{Q}[/tex]=Δ[tex]H^{Q} Product[/tex]+Δ[tex]H^{Q} Rreactant= -387.5 KJ+113 KJ[/tex]
Δ[tex]H_{formation} =-274.5 KJ[/tex]
What is the enthalpy change?An enthalpy change is roughly equivalent to the energy gained through the production of new chemical bonds in a reaction minus the energy required to break existing chemical bonds. It describes how a system changes in terms of energy while pressure is constant. The symbol H stands for enthalpy change. At constant pressure, H is equal to the sum of the system's internal energy and the pressure-volume work it performs on its surroundings.To learn more about enthalpy change, refer to https://brainly.com/question/16387742
#SPJ4
Question 9What pressure will be exerted by 15 g of carbon dioxide gas in a 20 L container at 0 °C?
In this question, we need to find the value of pressure of a 15 grams sample of CO2 gas, and in order to find this value, we will be using the Ideal gas law formula, which is the following:
PV = nRT
Where:
P = pressure in atm
V = volume in liters, 20 Liters
n = number of moles
R = gas constant, 0.082
T = temperature in kelvin, 0°C = 273 K
The number of moles we need to find based on the mass in the question and based on the molar mass of CO2, 44g/mol:
44g = 1 mol
15g = x moles
44x = 15
x = 15/44
x = 0.34 moles of CO2 in 15 grams
Now we have the values to add to the formula:
P * 20 = 0.34 * 0.082 * 273
20P = 7.61
P = 7.61/20
P = 0.38 atm of pressure
The pressure will be 0.38 atm
can someone help me with balancing this chemical equation?
( ^ means subscript )
NH^3+0^2= NO+H^2O
This chemical equation is balanced.
What is chemical equation?
chemical equation are symbolic representation of chemical reactions in which the reactants and the product are expressed in term of their respective chemical formula.
Reactants are converted to products and the process is symbolise by a chemical equation.
Sol-
NH^3+O^2------>NO+H^2O
2NH^3+O^2----->2NO+3H^2O
2NH^3+O^2------>2NO+3H^2O
2NH^3+5/2 O^2------2NO+3H^2O
2NH^3+5/2 O^2------->2NO+3H^2O
To know more about chemical equation click-
https://brainly.com/question/26694427
#SPJ9
When metals bond with other elements to create new compounds, which type of element do they mainly react with?.
Chemical compounds are created when elements combine and are frequently separated into two groups. Ionic compounds are frequently created when metals and nonmetals react.
These substances are made of neutral atoms and molecules that have had their electrons added to or taken away to generate positive and negative ions.
The mantle and the solid inner core are separated by this layer of the planet. It is the sole liquid layer, a 1,400 mile sea made largely of iron and nickel. Iron and nickel make up the majority of the lava. The magnetic field of the Earth is produced by the outer core. The inner core, which is the last layer, is 900 miles deep. According to scientists, the inner core is a solid ball of minerals and iron.
To know more about the ionic compound visit here :
https://brainly.com/question/10005144
#SPJ4
An atom of Iodine contains 75 neutrons. What is its mass number?
Answer:
128
Explanation:
Iron has atomic number of 53
so mass number is 53 + 75 = 128
A student with long hair (or loose clothing) is heating a solution over a Bunsen burner. As the student leans over the burner to reach for something, their hair (or clothing) catches fire.
Get the fire blanket and notify the teacher.
If your clothing catches fire do not run or do anything else to fan the flames. Immediately drop it on the ground and roll it to extinguish the flames. The laboratory is also equipped with fire blankets to extinguish clothing fires. Used by instructors as needed to completely extinguish flames.
Long hair should be tied up and long sleeves should not be worn. Always keep hair clothing, and hands at a safe distance from flames. Never touch the open flame with your hands. Use tongs when holding objects in flames. Long hair can fall on lab benches or come into contact with chemical or biological agents.
Learn more about Catches fire here:-https://brainly.com/question/23854054
#SPJ1
find values of the intrinsic carrier concentration n. for silicon at -55°c, 0°c, 20°c, 75°c, and 125°c. at each temperature, what fraction of the atoms is ionized? recall that a s
The intrinsic carrier concentration and the fraction of ionized atoms of silicon at -55℃, 0℃, 20℃, 75℃, 125℃ is calculated below.
The intrinsic carrier concentration in intrinsic material is the number of electrons found in the conduction band or holes in the valence band. This quantity of carriers is determined by the material's band gap as well as its temperature.
Because the number of holes equals the number of electrons, the concentration of each is equal to some amount, ni, and this quantity is known as the intrinsic carrier concentration, and the pure semiconductor material is referred to as intrinsic material.
Given:
B = 5.4 x [tex]10^{31}[/tex]
[tex]E_G[/tex] = 1.12 ev for silicon
K = 8.62 x [tex]10^{-5}[/tex]
Silicon crystal = 5 x [tex]10^{22}[/tex] atoms/[tex]cm^3[/tex]
To find:
Intrinsic carrier concentration, ni = ?
Fraction of ionized atom = ?
Formula:
[tex]ni^2 = BT^3 e^{\frac{-E_G}{KT}[/tex]
Fraction of ionized atom = ni / 5 x [tex]10^{22}[/tex]
Calculations:
(a) For -55℃:
T = -55 + 273 = 218K
ni = [tex]5.4 * 10^{31} * 218^3 * e^{(\frac{-1.12}{8.62 * 10^{-5} * 218})}[/tex]
ni = 2.7018 x [tex]10^6[/tex] carriers/[tex]cm^3[/tex]
Fraction of ionized atom = 2.7018 x [tex]10^6[/tex] / 5 x [tex]10^{22}[/tex]
Fraction of ionized atom = 5.403 x [tex]10^{-17}[/tex] atoms/[tex]cm^3[/tex]
(b) For 0℃:
T = 0 + 273 = 273K
ni = [tex]5.4 * 10^{31} * 273^3 * e^{(\frac{-1.12}{8.62 * 10^{-5} * 273})}[/tex]
ni = 1.53 x [tex]10^9[/tex] carriers/[tex]cm^3[/tex]
Fraction of ionized atom = 1.53 x [tex]10^9[/tex] / 5 x [tex]10^{22}[/tex]
Fraction of ionized atom = 3.07 x [tex]10^{-14}[/tex] atoms/[tex]cm^3[/tex]
(c) For 20℃:
T = 20 + 273 = 293K
ni = [tex]5.4 * 10^{31} * 293^3 * e^{(\frac{-1.12}{8.62 * 10^{-5} * 293})}[/tex]
ni = 8.65 x [tex]10^9[/tex] carriers/[tex]cm^3[/tex]
Fraction of ionized atom = 8.65 x [tex]10^9[/tex] / 5 x [tex]10^{22}[/tex]
Fraction of ionized atom = 1.73 x [tex]10^{-13}[/tex] atoms/[tex]cm^3[/tex]
(d) For 75℃:
T = 75 + 273 = 348K
ni = [tex]5.4 * 10^{31} * 348^3 * e^{(\frac{-1.12}{8.62 * 10^{-5} * 348})}[/tex]
ni = 3.724 x [tex]10^{11}[/tex] carriers/[tex]cm^3[/tex]
Fraction of ionized atom = 3.724 x [tex]10^{11}[/tex] / 5 x [tex]10^{22}[/tex]
Fraction of ionized atom = 7.449 x [tex]10^{-12}[/tex] atoms/[tex]cm^3[/tex]
(e) For 125℃:
T = 125 + 273 = 398K
ni = [tex]5.4 * 10^{31} * 398^3 * e^{(\frac{-1.12}{8.62 * 10^{-5} * 398})}[/tex]
ni = 4.75 x [tex]10^{12}[/tex] carriers/[tex]cm^3[/tex]
Fraction of ionized atom = 4.75 x [tex]10^{12}[/tex] / 5 x [tex]10^{22}[/tex]
Fraction of ionized atom = 9.51 x [tex]10^{-11}[/tex] atoms/[tex]cm^3[/tex]
The complete question is in the image given below.
Learn more about Intrinsic carrier concentrations of silicon here:
https://brainly.com/question/15078086
#SPJ4
determine the molarity of a solution formed by dissolving 50.54 g libr (86.84 g/mol) in enough water to yield 750.0 ml of solution. your answer should have three decimal places and no units.
The molarity of a solution is 3.743M.
Molarity of a solution:
Molar concentration is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of the amount of substance per unit volume of solution.
The formula for the molarity of a solution:
M = [tex]w_{B}[/tex] × 1000 / [tex]M_{B}[/tex] × V(ml)
[tex]w_{B}[/tex] = 50.54g
[tex]M_{B}[/tex] = molecular mass of water(H2O) = 2 + 16 = 18
V = Volume = 750ml
Putting the value in the equation, we get
M = 50.54 ×1000 / 18 × 750
= 50540 / 13500
= 3.743M
Therefore the molarity of a solution is 3.743M
To know more about the molarity of a solution refer to the link given below:
https://brainly.com/question/26528084
#SPJ4
group 1 got 113.8-115.4°c and group 2 got 108.3-116.3°c. which group had the better data and why? list 3 ways that the groups could improve their results in terms of the crystallization experiment and the melting point investigation.
The group with a better result is group 1
Three ways that the groups could improve their results in terms of the crystallization experiment and the melting point investigation are: recrystallisation, elimination of impurity, and heating the solvent.
Group 1's result is better, it is so because they have got the melting point range in a close proximity, that means they do not have a broad range. Smaller the range of melting point, more accurate the compound is synthesized.
3 ways that the groups could improve their results:
Recrystallisation again and again by using any volatile solvent such as ethanol, petroleum ether By eliminating the impurity. If eliminating the impurity will not work well then heat the solvent along with the compound and place it for recrystallisation. This will surely work out.Learn more about crystallization experiment here:
https://brainly.com/question/24180366
#SPJ4
In a constant-pressure calorimeter of negligible heat capacity, 25 ml of 1. 00 m cacl2 is mixed with 25 ml of 2. 00 m kf, resulting in solid caf2 precipitating out of the solution. During this process, the temperature of the water rises from 25. 0°c to 26. 7°c. Assume the specific heat capacity of the solution is 4. 184 j/°c•g and the density of the solution is 1. 00 g/ml. Calculate the enthalpy of precipitation in kj per mole of caf2 precipitated.
The enthalpy of precipitation of calcium fluoride is -13.974 kJ/mol.
In order to solve this, first we need to write the balanced chemical reaction equation of the reaction in question:
CaCl₂(aq) + 2KF(aq) → CaF₂(s) + 2KCl(aq)
In order to calculate the enthalpy of precipitation (ΔH), we need the amount of heat released (Q) and the number of moles of CaF₂ (n):
ΔH = Q/n
To calculate the number of moles, we can use the molarity (c = 1.00 M) of the calcium chloride solution and its volume (V = 25 mL = 0.025 L):
c = n/V ⇒ n = c*V
n = 1.00 M * 0.025 L = 0.025 mol
We calculate the amount of heat released (Q) using the following equation:
Q = (t₁ - t₂) * C * m
t₁ - initial temperature (25.0 ⁰C)
t₂ - final temperature (26.7 ⁰C)
C - specific heat capacity (4.184 J/⁰Cg)
m - the mass of the solution
We need the mass of the solution, which we can calculate using the density (d = 1.00 g/mL) and the volume (V = 25 mL + 25 mL = 50 mL) of the solution:
d = m/V ⇒ m = d*V
m = 1.00 g/mL * 50 mL = 50 g
Q = (25.0 ⁰C - 26.7 ⁰C) * 4.184 J/°Cg * 50 g
Q = -349.4 J
ΔH = -349.4 J / 0.025 mol
ΔH = -13974 J/mol = -13.974 kJ/mol
You can learn more about enthalpy here:
brainly.com/question/7827769
#SPJ4
In two to three sentences, explain the trend for atomic size. Why does this trend occur?
Answer:
Atomic Size Trend Across the Period
This is caused by the increase in the number of protons and electrons across a period. One proton has a greater effect than one electron cause of the coulombic law. Thus, electrons are pulled towards the nucleus, resulting in a smaller radius.
Explanation:
The only transition metal that is a liquid at room temperature
(21 °C) is named
Answer:
mercury
Explanation:
mercury is a metal on the periodic table which is liquid at room temperature
1. What are hormones
Answer: Hormones are are the body's chemical messengers, sending signals into the bloodstream and tissues. Hormones work slowly, over time, and affect many different processes, including growth and development, metabolism – how your body gets energy from the foods you eat- sexual function, reproduction, and mood
What formed a channel on mars?
Continental drift is a geologic process that forms channel on Mars.
Continental drift, the same process that creates contemporary channels like the mid-Atlantic channel or the African Rift Valley, is the geologic process that is most likely to have created the channel on Mars. Massive troughs that are visible from orbit are being exposed when Mars' tectonic plates separate. Similar to Earth, Mars too experiences gradual continental drift, which moves by less than an inch per year and is much too slow for any person to notice. However, this can lead to significant geological and geographic changes over millions of years that modify the planet's surface.
To know more about the planet channels, refer to the following link:
https://brainly.com/question/20307993
#SPJ9
Identify the hybridization of the N atoms in N2H4
All of the nitrogen in the N2H4 molecule hybridizes to Sp3.
How does hybridization work?The combining of two atomic orbitals to create a whole new class of hybridized orbitals is the notion of hybridization in chemistry. Hybrid orbitals with completely distinct energies are often the outcome of this mixing. In hybridization, the same-energy level atomic orbitals are crucial. However, as long as they have an equivalent amount of energy, both fully and partially filled orbitals can participate in this process.
All of the nitrogen in the N2H4 molecule hybridizes to Sp3. N2H4 has a dipole moment of 1.85 D and is polar in nature. The nitrogen atoms in N2H4 have no formal charge. The N2H4 molecule has a trigonal molecular geometry (shape).
To know more about hybridization, go to link
https://brainly.com/question/22765530
#SPJ9
Heat can bring about chemical reactions and chemical reactions can produce heat. is this also true for light and heat? give an example to illustarte each case.
Yes, there are chemical reactions that are brought about through the use of light (such as free radical halogenation) and there are chemical reactions that produce light (chemiluminescence).
Numerous reactions use light as an initiator. For example, in various examples of free radical halogenation (a reaction between a hydrocarbon and a halogen molecule, where alkyl halides are formed), light is needed to break the bond between the bromine atoms in order to form bromine radicals that then initiate the chain reaction leading to the formation of the product.
The phenomenon of producing light through a chemical reaction is called chemiluminescence. It is relatively rare, but not unheard of. One example is the reaction between luminol and hydrogen peroxide, which forms 3-aminophthalate and releases light.
You can learn free radical halogenation here:
brainly.com/question/13046867
#SPJ4
A 24.20 g sample of a metal displaces 1.26 mL of water. Calculate the density of the metal.
19.2g/cm³
D = m / V
24.20g / 1.92ml = 19.2g/cm³
If an Oreo cookie is 0.69 cm thick (1 cookie = 0.69 cm), how many Oreos does it take to reach the moon if the moon is 3.84 x 10^8 m away from earth?
It takes 5.89 x 10¹⁰ Oreos to reach the moon.
The average distance from the Earth to the moon is 385 000.6 km.
Metres = 385 000.6 km × (1000 m/1 km ) = 385 000 600 m
Centimetres = 38 500 060 000 m × (100 cm/1 m) = 38 500 060 000 cm
Oreos = 38 500 060 000 cm × (1 Oreo/0.654 cm) = 58 900 000 000 Oreos
= 5.89 x 10¹⁰ Oreos
Its diameter is around one-quarter that of the Earth (comparable to the width of Australia). The Moon is the Solar System's fifth-largest satellite. It is the largest (and most massive) satellite relative to its home planet and is larger than any other known dwarf planet. [f] According to geophysical criteria, the Moon is a planetary-mass object that became a differentiated rocky body, making it a satellite planet. There is no atmosphere, hydrosphere, or magnetic field. Its surface gravity is around one-sixth that of Earth (0.1654 g). Io, Jupiter's moon, has the highest surface gravity and density of any satellite in the Solar System.
To learn more about the moon the given link:
brainly.com/question/13538936
#SPJ10
some ammonia is sealed in a container and allowed to equilibrate at a particular temperature. the reaction is endothermic. 2nh3(g) ↔ n2(g) 3h2(g) in which direction will the reaction occur if ammonia is added to the system?
If ammonia is added to the system, the reaction will shift to the right, in favour of the forward direction.
A reaction is said to be at equilibrium when the concentration of reactants is equal to the concentration of the products. This means that the rate at which reactants are forming products is equal to the rate at which products are changed back to reactants.
All reactions at equilibrium follow Le Chatelier's principle, which states that if a chemical system in equilibrium is disturbed by changing the conditions (such as concentration, temperature and pressure changes), the position of equilibrium shifts to the left or to the right in order to counteract the change and to re-establish an equilibrium.
This means that if certain factors in a chemical reaction at equilibrium is changed, the reaction will shift either to the left or to the right. If it shifts to the left, the backward reaction is favoured and more reactants are produces, but if it shifts to the right, the forward reaction is favoured, and more products are produced.
In the question above, ammonia (2NH₃) is added to the chemical system. This will cause an increase in the concentration of ammonia; hence, more ammonia will be converted to nitrogen and hydrogen in order to decrease the concentration of ammonia and re-establish equilibrium. This causes the reaction to shift to the right.
Learn more about equilibrium here:
https://brainly.com/question/12381710
#SPJ4
when 56.6 g of calcium is reacted with nitrogen gas, 31.0 g of calcium nitride is produced. what is the percent yield of calcium nitride for this reaction? 3ca(s) n2(g)→ca3n2(s)
Calculation of percent yield requires the theoretical yield to be calculated first. Using that method, the percent yield of the reaction is 44%.
To calculate the percent yield of calcium nitride, we first need to calculate the theoretical yield. To do this, we need the molar mass of both calcium (40 g/mol) and calcium nitride (3 * 40 + 2 * 14) g/mol = 148 g/mol.
3 moles of calcium produce 1 mol of calcium nitride so the proportion we can make will look like this:
120 g of calcium : 148 g of calcium nitride = 56.6 g of calcium : X
X = 148 g of calcium nitride * 56.6 g of calcium / 120 g of calcium
X = 69.8 g of calcium nitride
This is the theoretical yield. Calculating the percent yield works like this - we divide the actual mass by the theoretical yield and then multiply that number (that is always supposed to be between 0 and 1) by 100%:
%yield = 100% * 31.0 g / 69.8 g = 44%
You can learn more about percent yield here:
brainly.com/question/2506978
#SPJ4
a solution containing 3.76 g naoh in 361 ml water is titrated to the endpoint with 491 ml hcl. what is the molar concentration of hcl in the original solution? a. 0.13 b. 130 c. 0.0031 d. 0.00053 e. 0.19
The molar concentration of HCl in the original solution is 0.19
The balanced chemical equation for the reaction must be our starting point because it will provide us with the reactants' mole ratios and allow us to answer this question.
* NaOH + HCl --> NaCl + H2O
this means:
1 mole NaOH reacts with 1 mole HCl
thus the ratio of NaOH to HCl is 1: 1
Next we've got to calculate the moles of NaOH: (molecular Mass = 40 g/mol)
moles(NaOH) = 3.76g/40
= 0.094 moles
Now we can calculate the concentration of NaOH:
Note: 361mL/1000 = 0.361L
conc(NaOH) = 0.094 moles/0.361L
= 0.26 mol/L
Now the mole ratio of NaOH to HCl is 1:1
But we have used only 0.094 moles so since the ratio of NaOH to HCl is 1:1, it means that 0.094moles of NaOH can only react with 0.094 moles of HCl.
Note: 491mL/1000mL = 0.491L
conc(HCl) = 0.094 moles/0.491L
= 0.19 mol/L
Thus the molar concentration of HCl in the original solution is 0.19
To learn more about molar concentration click
https://brainly.com/question/26255204
#SPJ4
A hiker climbs to the top of a mountain at rate of 0.5 me/hr. What are the speed and velocity of the hiker? middle school
A hiker climbs to the top of a mountain at rate of 0.5 m/hr. The speed of hiker is 1.3 x 10⁻⁴ m/s and the velocity of the hiker is 1.3 x 10⁻⁴ m/s west.
Speed is a scalar quantity. It is used to measure the distance traveled in a period of time. It is represented by -
s = d/Δt
where,
s = speed
d = distance
Δt = change in time
Velocity is a vector quantity. It is used to measure the change in position, that is, displacement over the change in time. It is represented by -
v = Δs / Δt
where,
v = velocity
Δs = change in position/displacement
Δt = change in time
The standard unit of velocity and speed both is m/s.
To learn more about speed and velocity,
brainly.com/question/749235
#SPJ1
HELP PLS ASAP
Ben is at the beach by the sea with his parents. After swimming, he dried off in the sun and discovered small, salty tasting white crystals on his skin. Explain what happened.
Answer:
what happened was when he dried off, there was still a little salt water on him. so, since the water has salt in it and the sun is very hot wich makes salty dried up as hard salt on him.