Answer:
Figure out the volume by either measuring the dimensions of the solid or using a measuring jug for a liquid. Convert any units as needed to get a number in meters cubed.
Put the object or material on a scale to figure out its mass.
Divide the mass by the volume to figure out the density (p = m / v).
Explanation:
A 10.05 gram sample of BaCl2 x H20 hydrate is heated and the resulting mass is 8.57 grams. a. What is the formula for the hydrate?b. What is the name of the hydrate?
Step 1: Let's calculate the quantity in moles of anhydrous barium chloride using the resulted mass after the heating divided by its molar mass (molar mass of BaCl2 is 208.23 g/mol)
so:
8.57/208.23 = 0.04 moles of BaCl2
Step 2: Now let's calculate the quantity in moles of water. But first, we need to calculate the mass of H2O. For this, we just subtract the mass before the heating by the mass after the heating. The water evaporated because of the heat.
mass of H2O = 10.05 - 8.57 = 1.48 g
Now we divide the mass by its molar mass to find the quantity in moles (molar mass of water is 18 g/mol)
1.48/18 = 0.082 moles of H2O
Step 3: Now we determine the number ratio:
0.082/0.04 = 2
So the formula is:
Answer: a. BaCl2 x 2H2O
b. barium chloride dihydrate
How many liters of oxygen are required to completely react with 2.0 liters of CH4 at30 °C and 3.0 atm?CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
1) Write the chemical equation.
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]2) List the known and unknown quantities.
Sample: CH4.
Volume: 2.0 L.
Temperature: 30 ºC = 303.15 K.
Pressure: 3.0 atm.
Ideal gas constant: 0.082057 L * atm * K^(-1) * mol^(-1).
Moles: unknown.
3) Moles of CH4.
3.1- Set the equation.
[tex]PV=nRT[/tex]3.2- Plug in the known values and solve for n (moles).
[tex](3.0\text{ }atm)(2.0\text{ }L)=n*(0.082057\text{ }L*atm*K^{-1}mol^{-1})(303.15\text{ }K)[/tex][tex]n=\frac{(3.0\text{ }atm)(2.0\text{ }L)}{(0.082057\text{ }L*atm*K^{-1}*mol^{-1})}=[/tex][tex]n=0.24\text{ }mol\text{ }CH_4[/tex]4) Moles of oxygen that reacted.
The molar ratio between CH4 and O2 is 1 mol CH4: 2 mol O2.
[tex]mol\text{ }O_2=0.24\text{ }CH_4*\frac{2\text{ }mol\text{ }O_2}{1\text{ }mol\text{ }CH_4}=0.48\text{ }mol\text{ }O_2[/tex]5) Volume of oxygen required.
Sample: O2.
Moles: 0.48 mol.
Temperature: 30 ºC = 303.15 K.
Pressure: 3.0 atm.
Ideal gas constant: 0.082057 L * atm * K^(-1) * mol^(-1).
Volume: unknown.
5.1- Set the equation.
[tex]PV=nRT[/tex]5.2- Plug in the known values and solve for V (liters).
[tex](3.0\text{ }atm)(V)=0.48\text{ }O_2*(0.082057\text{ }L*atm*K^{-1}mol^{-1})(303.15\text{ }K)[/tex][tex]V=\frac{(0.48\text{ }mol\text{ }O_2)(0.082057\text{ }L*atm*K^{-1}*mol^{-1})(303.15\text{ }K)}{3.0\text{ }atm}[/tex][tex]V=3.98\text{ }L[/tex]3.98 L of O2 is required to react with 2.0 L CH4.
.
What is the Lewis structure for butyl thiol (CH3CH2CH2CH2SH)?
The Lewis dot structure for butyl thiol.
Lewis systems, also called Lewis dot formulas, Lewis dot systems, electron dot structures, or Lewis electron dot structures, are diagrams that display the bonding among atoms of a molecule, as well as the lone pairs of electrons that could exist inside the molecule.
A Lewis structure is based totally on the idea of the octet rule, in which atoms share electrons so that each atom has 8 electrons in its outer shell. for example, an oxygen atom has six electrons in its outer shell.
A Lewis shape is a totally simplified representation of the valence shell electrons in a molecule. it is used to expose how the electrons are arranged around man or woman atoms in a molecule. Electrons are shown as "dots" or for bonding electrons as a line between the 2 atoms
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a gas mixture at 20.0 C and 2.0 atm contains 0.40 mol of H2, 0.15 mol of O2, and 0.50 mol of N2. Assuming ideal behavior, what is the partial pressure of hydrogen gar [H2] in the mixture?
The partial pressure of hydrogen gas in the mixture is:0.53334 atm.
What is partial pressure?
partial pressure. noun. the pressure that a gas would have if it took up the entire volume that the mixture of gases currently occupies.
P total,and the total number of moles in the mixture would be,
n total=nH2+nO2+nN2
This means that you could write
P total.V=ntotal.RT
p total=n total.RT/V
This is equivalent to
p total=[nH2+nO2+nN2].RT/V
therefore,
P total =PH2+PO2+pN2
now, to get the partial pressure of,let's Hydrogen gas
RT/V=Ptotal/nH2+nO2+nN2
therefore
PN2=XN2.p total
similarly,
PO2=XO2.p total
PN2=XN.p total
The total number of moles will be
[tex]ntotal[/tex] = 0.40+0.15+0.50=1.50 moles.
[tex]PH2[/tex]=0.40/1.50*2.0 atm =0.5334 atm.
[tex]PO2[/tex]=0.15/1.50*2.0 atm =0.2 atm.
[tex]PN2[/tex]=0.50/1.50*2.0 atm =0.66 atm.
Hence, the partial pressure of hydrogen gas in the mixture is:0.53334 atm.
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I need help with this question please
The 0.2 moles of glucose are present in the 0.400 M solution.
What is molarity?
The amount of a substance in a specific volume of solution is known as its molarity (M).
As given in the solution
Volume = 0.500 L
Molarity = 0.400
By using the molarity formula
M = moles of glucose/Volume in liters
Let's say moles of glucose = X
X= 0.400 * 0.500 = 0.2 moles
Hence, the answer is 0.2 moles of glucose .
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What is a major element found in our bones
The major element found in our bones is calcium.
What are the essential and non-essential elements in the bones?
Animals have significant sites for storing elements in their mineralized tissues, including bone, teeth, antlers, and horns. These tissues contain the essential metals iron (Fe), zinc (Zn), manganese (Mn), and cadmium (Cd), as well as important elements including calcium (Ca), phosphorus (P), magnesium (Mg), and sulfur (S) (Cd). Numerous minerals are necessary for good animal physiology.
The main building block of bones and teeth is calcium. In addition to its function as a second messenger, calcium is critical for muscular action, blood coagulation, and membrane permeability. Calcium and phosphorus are both found in bones and teeth. Additionally, phosphorous is a component of ATP, phospholipids, nucleic acids, and other coenzymes.
Hence, calcium plays an important role in bones and also assists in the resorption of the bone.
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The rate constant for a reaction at 40.0°C is exactly 4 times that at 20 0°C Calculate the energy of activation for the reaction.
Explanation:
Data provided:
T2 = 40.0 °C
(absolute temperature = T2 = 40.0 °C + 273 = 313 K)
------
T1 (absolute) = 20.0 °C + 273 = 293 K
------
The rate constant for a reaction at 40.0 °C is exactly 4 times that at 20.0 °C, mathematically:
k2/k1 = 4
------------------------
Here is used the Arrhenius expression as follows:
[tex]ln\text{ }\frac{k2}{k1}=\text{ }\frac{Ea}{R}x\lbrack\frac{1}{T1}-\frac{1}{T2}\rbrack[/tex]R = universal gas constant = 8.314 J/mol K
Ea = activation energy
------------------------
Procedure:
[tex]\begin{gathered} ln\text{ 4 = }\frac{Ea}{8.314\text{ J/mol K}}x\lbrack\frac{1}{293\text{ K}}-\frac{1}{313\text{ K}}\rbrack \\ 1.386\text{ = }\frac{Ea}{8.314}x(2.18x10^{-4}) \\ Ea\text{ = 52858.73 J/mol} \\ \end{gathered}[/tex]Answer: Ea = 52858.73 J/mol
Complete and balance the following half reaction. Assume the reaction occurs in basic media.
Cl−⟶ClO3−
Balance the following half reaction occurs in basic media then Cl → ClO₃⁻
6OH⁻ + Cl⁻¹ → ClO₃⁻¹ + 3H₂O + 6e⁻
The concentration of OH⁻ is more than the solution called as basic medium
Here given reaction is
Cl → ClO₃⁻
Then the steps we have to follow are:
Balancing in basic solution then
First get the acidic answer means in acidic answer, Break into half reaction Balance all element except H and OBalance O by adding H₂OBalance H by adding H⁺Then add electron to the more positive sideBalance electronCancel the likes substances on opposite sideThen rewrite the correct equationAdd as many OH⁻ as you have H⁺ to both sideThen simplify and cancel out like H₂OThen 2H⁺ + 2OH⁻ → 2H₂OAnd then 1 H = 1H⁺2Oxygen = 2H₂OThen rewrite the correct equationAnd the equation is 6OH⁻ + Cl⁻¹ → ClO₃⁻¹ + 3H₂O + 6e⁻ in basic media
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How many calories are provided by a medium sized quarter pounder with cheese value meal from McDonald’s. The nutrition information is provided below?
protein: 28
carbs: 38
fat: 30
The calories provided by a medium sized quarter pounder with cheese value meal from McDonald’s is 1050 calories.
What is carbohydrate?Carbohydrate are defined as carbon, hydrogen, and oxygen atoms make up biomolecules. They are a vital source of energy.
Carbohydrates supply the body with glucose, which is converted into energy for use.
There are three main types of carbohydrates.
SugarStarch FiberProteins are defined as the large biomolecules and macromolecules consisting of one or more long chains of amino acid residues.
There are seven types of proteins.
AntibioticContractile proteinsEnzymesHormonal proteinsStructural proteinsStorage proteins Transport proteinsFats are defined as the triglycerides are macronutrient compounds that are an important part of our diet, along with carbohydrates, vitamins, and protein.
Thus, the calories provided by a medium sized quarter pounder with cheese value meal from McDonald’s is 1050 calories.
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Answer the following question: Ethanol, C2H5OH, is considered clean fuel because it burns in oxygen to produce carbon dioxide and water with few trace pollutants. If 500.0 g of H2O are produced during the combustion of ethanol, how many grams of ethanol were present at the beginning of the reaction? When answering this question include the following:
Have both the unbalanced and balanced chemical equations.
Explain how to find the molar mass of the compounds.
Explain how the balanced chemical equation is used to find the ratio of moles (hint: step 3 in the video).
Explain how many significant figures your answer needs to have.
The numerical answer
The amount, in grams, of ethanol that was present at the beginning of the reaction, would be 430 grams.
Stoichiometric problemEthanol burns in oxygen according to the following equation:
[tex]C_2H_5OH + O_2 -- > CO_2 + H_2O[/tex]
The balanced equation of the reaction will be:
[tex]C_2H_5OH + 3O_2 -- > 2CO_2 + 3H_2O[/tex]
The mole ratio of ethanol to water is 1:3.
The molar weight of H = 1 g/mol.
The molar weight of O = 16 g/mol
Molar weight of C = 12
Molar mass of water, [tex]H_2O[/tex] = (1 x 2) + 16 = 18 g/mol
Molar mass of ethanol, [tex]C_2H_5OH[/tex] = (12x2) + (1x5) + 16 + 1 = 46 g/mol
If, mole = mass/molar mass; mole of 500.0 g water will be:
500/18 = 27.778 moles
Then, the equivalent mole of ethanol that burned, from the stoichiometric mole ratio, would be:
27.778/3 = 9.259 moles
If, mass = mole x molar mass,
Then, 9.259 moles ethanol = 9.259 x 46 = 425.914
Since the molar mass has the least significant figures (two significant figures), the final answer will also have two significant figures.
Thus, the amount of ethanol that was present at the beginning of the reaction is 430 grams.
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What is the pressure exerted by 2.10 g Ar gas at 18.0 °C in a 660-ml flask?
1.91*10^-3 atm
4.71 atm
1.91 atm
0.118 atm
76.1 atm
Answer:
1.91 atm
Explanation:
To start this question I would first look at what the question is giving us:
M= 2.10g Argon
T= 18.0°C
V= 660-mL
P= ?atm
We now would recognize that from the things given, the formula that suits it would be PV=nRT because it would have the given data present were we can solve for P.
R is a constant that is 0.082 L*atm/K*mol. This constant lets us know what units we need to convert in order move forward.
We would need our volume to be in Liters, our pressure in atm, our temperature in K and our mass in mols.
So then in order to convert the mass given, we would need to go from grams to mols. We do this by starting off with our given mass (2.10g) and then dividing it by the molar mass of the element Argon (39.948g). This would make a total of 0.052mols.
To convert the Celsius to Kelvin, we just need to add 273 to the temperature given. 18.0°C + 273 = 291K.
To convert our volume, 1000mL=1L, so we would divide our given mL by 1000. 600/1000= 0.660L.
Now we can go ahead and use our formula and plug in the numbers to solve for P.
PV=nRT
(x atm)(0.660 L)=(0.0526 mol)(0.082 L*atm/K*mol)(291 K)
When solved, we would get a final answer of 1.90173 atm. Our closest answer being 1.91 atm.
which of the following have expressions has a product of 36
Answer:
3/4
Explanation:
I need help with this chem equation
The percentage yield is 81.08.
calculation:-
The percentage yield = actual yield/ theoretical yield × 100
= 150 grams / 185 grams ×100
= 81.08
The percentage yield method is calculated to be the experimental yield divided by way of theoretical yield improved through a hundred. If the actual and theoretical yield is the same, the percentage yield is a hundred%. generally, the percentage yield is lower than 100% due to the fact the real yield is regularly much less than the theoretical value.
In chemistry, yield also referred to as reaction yield, is a degree of the number of moles of a product shaped in relation to the reactant consumed, and received in a chemical reaction, typically expressed as a percent.
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At what temperature does sulfur hexafluoride have a density of 0.4450 g/L at 0.8210 atm
The temperature at which sulfur hexafluoride have a density of 0.4450 g/L at 0.8210 atm is 32.40K.
We know that density is the mass of the substance divided by the volume of the substance.
so mass of SF6 = 146.05 g
Density = 0.4450g/L
D = M/V
0.4450 = 146.05 /V
V= 146.05/ 0.4450
V= 328.20L
Now we know that ideal gas equation,
PV = nRT
Where P = Pressure of the gas = 0.8210 atm
T=?
R = 8.314
V = 328.20L
thus, putting values inthe formula,
0.8210 × 328.20 = 1 × 8.314 × T
T = 269.45 / 8.314
T =32.40K
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Seven 5.0 mL aliquots of a dilute solution of HCl were titrated with 0.1245 M sodiumhydroxide. The following volumes were needed to neutralize the acid solution:
In this question, we have to determine the molar concentration of the acid HCl, we have the following information:
5.0 mL of HCl
0.1245 M of NaOH
7 different volumes of NaOH, if we take the average value, we will have 58.8 mL of average
Now we can use the titration formula, which is:
MaVa = MbVb
Ma = molar concentration of acid
Va = volume of acid
Mb = molar concentration of base
Vb = volume of base
Now we add the values into the formula:
Ma * 5.0 = 0.1245 * 58.8
5Ma = 7.32
Ma = 7.32/5.0
Ma = 1.46 M
The molar concentration of HCl, based on the information provided and using the average value of volume for the base is 1.46 M
Convert 5.25 moles of Ne to particles of Ne
Answer
Explanation
Given:
Moles of Ne = 5.25 mol
What to find:
The number of particles of Ne in 5.25 moles of Ne.
Step-by-step solution:
Conversion factor: 1 mole of any substance = 6.022 x 10²³ particles
Therefore, 5.25 moles of Ne will be equal
[tex]undefined[/tex]List or draw three things that come to mind when you think about outer space.
An atom of Astatine-214, 21485At, undergoes alpha-decay. Using the chart above, what new isotope will be produced?
If the atom of Astatine-214 undergo alpha particle, it will emit helium element as shown;
[tex]_{85}^{214}At\rightarrow_{83}^{210}Bi+_2^4He[/tex]According to the decay, 4 is subtracted from the mass number and 2 from the atomic number.
According to the reaction, the new isotope produced is Bismuth-210
Using the Mole: Empirical Formulas, Molecular Formulas, % Composition 2. Find the empirical formulas for the following compounds: a. e. 46.2% Mg, 7.69% H, 46.2% O
ANSWER
the empirical formula is MgH8O3
EXPLANATION
Given that;
The % composition of Mg is 46.2%
The % composition of H is 7.69%
The % composition composition of O is 46.2%
Assume the mass of the sample is 100g
To find the empirical formula, follow the steps below
Step 1; Find the mass of the elements
For Magnesium
[tex]\begin{gathered} \text{ Mg }=\text{ }\frac{46.2}{100}\times100 \\ \text{ mass of Mg }=\text{ 46.2 g} \end{gathered}[/tex]For hydrogen
[tex]\begin{gathered} \text{ mass of H }=\text{ }\frac{7.69}{100}\times\text{ 100} \\ \text{ mass of H }=7.69\text{ grams} \end{gathered}[/tex]For oxygen
[tex]\begin{gathered} \text{ Mass of O}=\text{ }\frac{46.2}{100}\times100 \\ \text{ Mass of O }=\text{ 46.2 grams} \end{gathered}[/tex]Step 2; Find the molar mass of the elements
The molar mass of oxygen is 15.999 g/mol
The molar mass of hydrogen is 1.00 g/mol
The molar mass of magnesium is 21.904.305 g/mol
Find the mole of the element
[tex]\text{ mole }=\text{ }\frac{\text{ mass}}{\text{ molar mass}}[/tex]For Mg
[tex]\begin{gathered} \text{ mole }=\text{ }\frac{46.2}{24.305} \\ \text{ mole }=1.900\text{ mole} \end{gathered}[/tex]For Hydrogen
[tex]\begin{gathered} \text{ mole }=\frac{7.69}{1} \\ \text{ mole }=\text{ 7.69 mol} \end{gathered}[/tex]For Oxygen
[tex]\begin{gathered} \text{ Mole}=\text{ }\frac{46.2}{15.999} \\ \text{ mole}=\text{ 2.889 mol} \end{gathered}[/tex]Step 3; find the mole ratio
In the above calculations, Mg has the least number of moles. Therefore to find the mole ratio divide the moles by the smallest moles
[tex]\begin{gathered} \text{ For mg} \\ \text{ mole ratio}=\frac{1.900}{1.999} \\ mole\text{ ration }=\text{ 1} \\ \\ \text{ For H} \\ Mole\text{ ratio }=\frac{7.69}{1} \\ \text{ molenration }=\text{ 7.69} \\ \\ fOR \\ \text{ MOLE RATION }=\frac{42.6}{15.999} \\ 2.64\text{ mol} \end{gathered}[/tex]Therefore, the empirical formula is MgH8O3
What is the "percent
abundance" of the black eyed
peas in this sample?
Sample Number Abundance Mass
of Beans
(%)
(g)
187
[?]
1.3
Black
Eyed Peas
Cannellini
Beans
113
2.9
Weighted
Average (g)
1.9
The percentage abundance of the blacked-eyed peas in the sample is 39.6%.
What is the percentage abundance ?
It is the ratio in which a particular substance occurs to the total occurrence of similar substances of the same kind.
Percentage abundance = (occurrence of substance/total occurrence of substance of similar kind) × 100
Thus the percent abundance of the black eyed peas in this sample can be calculated as:
total number of beans = 187
number of blacked-eyed peas = 187 - 113 = 74
Percentage abundance = 74/187 × 100 %
= 39.6%
Thus we can conclude, the percentage abundance of the blacked-eyed peas in the sample is 39.6%.
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witch color of light has the least energy?
Answer: Red
Explanation:
questions about energy
Scientists define energy as the ability to do work.
In physics, power is the quantitative asset this is transferred to a frame or to a physical system, recognizable inside the overall performance of labor and within the form of warmth and light. power is a conserved quantity the regulation of conservation of electricity states that power may be converted in shape, however not created or destroyed.
Strength is defined as the capacity to do paintings, that's the ability to exert pressure inflicting displacement of an object. in spite of this complicated definition, its means is quite simple: energy is simply the pressure that causes matters to move. energy is split into sorts capacity and kinetic.
Power exists in many special forms. Examples of those are mild energy, warmth power, mechanical electricity, gravitational energy, electric energy, sound strength, chemical power, nuclear or atomic strength, and so on. every form may be converted or changed into the opposite form.
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The ammonia (NH3)molecule is the conjugate base of the NH4+ (called "ammonium") ion. a weak acid. An aqueous solution of NH3 has a pH of 1 1.6. Write the net ionic equation for the reaction that makes an aqueous solution of NH3 basic. (The answer looks very similar to Eq. 5 in the introduction to this experiment.)
NH3 is a weak base. In solution we write NH3(aq).
The question says NH3 because ammonia is a weak base and does not ionize strongly in water. To write the net ion equation, we need to remove the spectator ion. Removing the spectator ion leaves the net ion equation. This process can be repeated for each reaction to obtain the net ionic equation.
The net ionic equation describes only the species participating in the reaction while the full ionic equation also includes the spectator ion. A net ionic equation is a chemical equation of a reaction that lists only the species involved in the reaction. The net ionic equation is commonly used in acid-base neutralization reactions double displacement reactions, and redox reactions.
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You have 25.00 g of nonane C9H20 and 15.00 g oxygen (O2) for a combustion reaction. If you actually make 0.99 grams of water, what is the percent yield?
The first step to solve this question is to state the combustion reaction for nonane:
[tex]C_9H_{20}+14O_2\rightarrow9CO_2+10H_2O[/tex]After this, we have to convert the given masses of nonane and oxygen to moles using their molecular masses:
[tex]25.00gC_9H_{20}\cdot\frac{1mol}{128.2gC_9H_{20}}=0.20molC_9H_{20}[/tex][tex]15.00gO_2\cdot\frac{1mol}{32gO_2}=0.47molO_2[/tex]Use the stoichiometric ratio to determine the number of moles of oxygen that react with 0.20 moles of nonane.
[tex]0.20molC_9H_{20}\cdot\frac{14molO_2}{1molC_9H_{20}}=2.8molO_2[/tex]From this, we can conclude that the limiting reactant of the reaction is oxygen, which means that we have to base our calculations on the amount of oxygen that reacts. Use the stoichiometric ratio of oxygen to water to find the amount of water produced:
[tex]0.47molO_2\cdot\frac{10molH_2O}{14molO_2}=0.34molH_2O[/tex]Convert the amount of moles to grams using its molecular mass:
[tex]0.34molesH_2O\cdot\frac{18gH_2O}{molH_2O}=6.12gH_2O[/tex]To find the percent yield, divide the actual amount of water produced by the theoretical amount of water produced and multiply by 100:
[tex]\%y=\frac{0.99gH_2O}{6.12gH_2O}\cdot100=16.2\%[/tex]The percent yield is 16.2%.
How many molecules are in 3.41 kg glucose, C6H₁2O6?
114.05× 10²³ molecules are present in 3.41kg or 3410g of glucose
We know the relationship between no of moles and molar mass:
n = W / M
where,
n = no of moles = ( ?)
W = Given mass = (3.41kg)
M = Molar mass = ( molar mass of glucose is 180g)
Convert 3.41kg into grams we get 3.41 × 1000 = 3410g
n = W / M
= 3410 / 180
= 18.94 moles
Number of molecules is related to no of moles and Avogadro's number as:
N = n × NA
where,
N = no of molecules/no of particles/no of atoms = ?
n = no of moles = ( 18.94 moles - found out from above formula )
NA = Avogadro's number = ( 6.022 × 10²³ )
N = n × NA
= 18.94 × 6.022 × 10²³
= 114.05× 10²³ molecules
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An engineer turns the temperature of a gas down, holding the volume constant at 1,250 L.Initially, the temperature of the gas was 732.°C and had a pressure of 294. kPa. Determine the pressure of the gas when the temperature decreased to 156°C.
125.49kPa
Explanations:
According to the Gay's Lussac law, the pressure of the given mass of a gas is directly proportional to its absolute temperature provided that the volume is constant. Mathematically;
[tex]\begin{gathered} P\alpha T \\ P=kT \\ T=\frac{P_1}{T_1}=\frac{P_2}{T_2} \end{gathered}[/tex]Given the following parameters
Iinitial pressure P1 = 294kPa
Initial temperature = 732.°C = 732+273 = 1005K
Final temperature = 156°C + 273 = 429K
Required
New pressure P2
Substitute the given parameters
[tex]\begin{gathered} P_2=\frac{P_1T_2}{T_1} \\ P_2=\frac{294\times429}{1005} \\ P_2=125.49kPa \end{gathered}[/tex]Therefore the pressure of the gas when the temperature decreased to 156°C is 125.49kPa
(a) Explain the process by which these dark lines are generated by the elements in the sun's atmosphere.
Specifically, why are they black and not colored, and why do they match the colored line spectra of
those elements?
These substances absorb black body radiation energy at a very particular wavelength of light that is particular to them. The black (absorption) line is the result of energy being absorbed from the spectrum when an electron jumps from an orbit with low energy to an orbit with high energy.
Why dark lines appear in the absorption spectra?A substance's light transmission spectrum that displays black bands or lines where light has been absorbed by atoms, generating a dip in the spectrum, is called an absorption spectrum. By descending the energy ladder, electrons produce an emission spectrum.Some of the light at specific wavelengths is scattered when it travels through the atmosphere's gas, producing darker bands. The wavelengths of light released when common materials were heated to form lines that became known as "spectral lines" were recorded.To learn more about : Absorption spectra
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For her science project, a student collects data on deer spotted in a field each day. For the first five days of her study, she counted 23, 16, 18, 27, and 19 deer. What type of observation do these data represent?
A. an inferred observation
B. a quantitative observation
C. a qualitative observation
D. a classified observation
The type of observation the data represent is a quantitative observation.
What is quantitative observation?Quantitative observation can be described as a method of gathering and analyzing data. Quantitative observation uses numerical data and statistical calculations to measure research and draw conclusions. It usually involves variables with a numerical value.
From the data given above which are in numerical dorm, we can conclude that the observation represented is a quantitative observation.
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Balance the following redox reactions by inspection:
a) KCl(s) + O2(g) --> KClO3
b) NH3(g) + O2(g) --> NO(g) + H2O(g)
To see the number of atoms of any element in a molecule multiply the stoichiometry of that molecule to the number that is written on the foot of that element in that molecule the balanced equation are
[tex]2KCL+3O_{2} \rightarrow 2KClO_{3}[/tex]
[tex]2NH_{3} +\frac{5}{2} O_{2} \rightarrow 2NO+3H_{2} O[/tex]
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side
In first , The skeletal reaction is
[tex]KCl+O_{2} \rightarrow KClO_{3}[/tex]
The number of oxygen atoms on left side is 2 while on product side it is 3 so to balance multiply by 3 to [tex]O_{2}[/tex] and by 2 to product side
[tex]KCl+3O_{2} \rightarrow 2KClO_{3}[/tex]
The number of atoms of Potassium and chlorine on left and right are 1 and 1 while on right side it is 2,2 so multiply [tex]KCl[/tex] by 2
The balanced equation is
[tex]2KCl+3O_{2} \rightarrow 2KClO_{3}[/tex]
In second the skeltal equation is
[tex]NH_{3} +O_{2} \rightarrow NO+H_{2} O[/tex]
The number of hydrogen atom is 3 while on produt side it is 2 so multiply [tex]NH_{3}[/tex] by 2 and [tex]H_{2} O[/tex] by 3
[tex]2NH_{3} +O_{2} \rightarrow NO+3H_{2} O[/tex]
now balance nitrogen
[tex]2NH_{3} +O_{2} \rightarrow 2NO+3H_{2} O[/tex]
Now balance oxygen and the balanced equation is
[tex]2NH_{3} +\frac{5}{2} O_{2} \rightarrow 2NO+3H_{2} O[/tex]
Thus the two balanced equation are
[tex]2KCL+3O_{2} \rightarrow 2KClO_{3}[/tex] and
[tex]2NH_{3} +\frac{5}{2} O_{2} \rightarrow 2NO+3H_{2} O[/tex]
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Everybody wants to be us.
Alkalai Metals
Alkalai Earth Metals
Noble Gasses
Halogens
Answer:
Noble Gases
Explanation:
For this question, what does one of them have that the others don't?
Alkali Metals - These are in column 1 of the periodic table. They are the ones that have a charge of positive 1 since they give away their 1 electron in order to be stable.
Alkali Earth Metals - These are in column 2 of the periodic table. They are the ones that have a charge of positive 2 since they give away their 2 electrons in order to be stable.
Noble Gases - These are the elements in the last column of the periodic table. These elements do not need to give away or accept electrons because they are complete and stable!
Halogens - These are in column 17 in the periodic table. They are right next to the halogens, but still are not complete as they need 1 more electron in order to be stable. These elements have a charge of -1 because they take away an electron from another element (mainly the alkali metals) in order to be stable.
So, based off of their definitions, the only ones that do not need to gain or lose electrons are the noble gases. This is because they are complete and stable, the only ones out of these that do not need anything.
