Answer:
Before air is liquefied, water vapor and carbon dioxide are removed, because these substances solidify when cooled and would clog the pipes of the air liquefaction plant.
Why does there appear to be another duck head in the water?
A
The water in the pond reflects light from the Sun, making a mirror image
B
The molecules in the atmosphere refract the light, splitting it into two ima
С
The duck scatters the light, making hundreds of tiny refractions that collec
D
The bottom of the pond absorbs the light, then projects it toward the surfa
Answer:
it's A. The water in the pond reflects light from the Sun, making a mirror image
Explanation:
i just took the test
A major textile dye manufacturer developed a new yellow dye. The dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye.
Answer:
C₁₅N₃H₁₅
Explanation:
Follow the sequence ...
%/100wt => grams/100wt => moles => mole ratio => reduce mole ratio (divide by smaller mole value) => empirical ratio.
Note: If the above calculation comes out with a fraction (for most textbook problems) do the following:
--.25 => multiply empirical ratio by 4
--.50 => multiply empirical ratio by 2
--.75 => multiply empirical ratio by 4
Or, if initial data is given in grams, convert to %/100wt. (example at end of problem)
This Problem:
%/100wt. grams moles =mass/formula wt.
%C = 75.95% => 75.95g => 75.95g/12.0107g·mol⁻¹ = 6.325 mole OS
%N = 17.72% => 17.72g => 17.72g/14.0067g·mol⁻¹ = 1.2651 mole N
%H = 6.33% => 6.33g => 6.33g/1.00794g·mol⁻¹ = 6.28 mol H
(∑ = 100% | assume 100g cpd => ( grams => 100g compound would contain 75.95g C, 17.72g N & 6.33g H )
=> mole ratio => C : N : H => 6.3235 : 1.2651 : 6.28
=> reduce mole ratio ( divide by smaller mole value ) ...
=> 6.3235/1.2651 : 1.2651/1.2651 : 6.28/1.2651 => empirical ratio is => 5:1:5
empirical formula => C₅NH₅
empirical formula wt. = 5C + 1N + 5H = 5(12) + 1(14) + 5(1) = 79
=> molecular ratio (n) => molecular wt (given) = N · empirical formula wt
=> N = molecular wt / empirical wt = 240/79 = 3
∴ Molecular Formula is => C₅NH₅ X 3 => C₁₅N₃H₁₅
________________________________________
EXAMPLE: Empirical Formula Problem with initial data in grams:
Assume an oxide of Osmium (compd wt) = 2.89 grams contains 2.16 gram Osmium, what is the empirical formula?
Use given mass values to calculate %/100wt then use the sequence
% => grams => moles => reduce => emp. ratio => emp. formula
%Os = 2.16g/2.89g x 100% = 74.74%
%Oxy = [(2.89g -2.16g)/2.89] x 100% = 25.26% or use 100% - 74.74% = 25.26%
% => g => moles => reduce => emp formula
%Os = 74.74% => 74.74g => 74.74g/190.23g·mol⁻¹ = 0.3929 mol Os
%Oxy = 25.26% => 25.26g => 25.26g/16g·mol⁻¹ = 1.5788 mole Oxy
Reduce mole ratio (divide by smaller mole value) => empirical ratioo
=> Os:Oxy => 0.3929/0.3929 : 1.5788/0.3929 = 1 : 4
=> Empirical Formula => OsO₄
A steel cylinder contains 4.5 mol of Xenon gas at a pressure of 5 atm and a temperature of 77 degrees Celsius. What is the volume of the Xenon tank?
Answer:
3 × 10 L
Explanation:
Step 1: Given and required data
Moles of Xenon gas (n): 4.5 molPressure of the gas (P): 5 atmTemperature (T): 77 °CIdeal gas constant (R): 0.082 atm.L/mol.KStep 2: Convert "T" to Kelvin
When working with gases, we need to use the absolute temperature. We can convert Celsius to Kelvin using the following expression.
K = °C + 273.15
K = 77°C + 273.15 = 350 K
Step 3: Calculate the volume (V) of the tank
We can calculate the volume occupied by the gas using the ideal gas equation.
P × V = n × R × T
V = n × R × T/P
V = 4.5 mol × (0.082 atm.L/mol.K) × 350 K/5 atm = 3 × 10 L
Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for this purpose too. Let us compare the effectiveness of equal masses of these two compounds in lowering the freezing point of water by calculating the freezing point depression of solutions containing 220. g of each salt in 1.00 kg of water. (An advantage of is that it acts more quickly because it is hygroscopic, that is, it absorbs moisture from the air to create a solution and begin the process. A disadvantage is that this compound is more costly.) Assume full dissociation of ionic compounds. Kfp(H2O)= -1.86 °C/m.
ΔTfp= _________°C for NaCl
ΔTfp=_________ °C for CaCl2
Answer:
[tex]\Delta Tfp_{NaCl}= -14.0\°C\\\\\Delta Tfp_{CaCl_2}=-11.1\°C[/tex]
Explanation:
Hello!
In this case, since the freezing point depression caused by the addition of a solute, we use the following formula:
[tex]\Delta Tfp= i*m*Kfp[/tex]
Thus, we first need to compute the molality of each solute, as shown below:
[tex]m_{NaCl}=\frac{220.g/(58.44g/mol)}{1.00kg} =3.76m\\\\m_{CaCl_2}=\frac{220.g/(110.98g/mol)}{1.00kg} =1.98m[/tex]
Next, since NaCl has two ionic species, one Na⁺ and one Cl⁻, and CaCl₂ three, one Ca²⁺ and two Cl⁻, the van't Hoff's factors are 2 and 3 respectively, therefore the freezing point depressions turn out:
[tex]\Delta Tfp_{NaCl}= 2*3.76m*-1.86\°C/m=-14.0\°C\\\\\Delta Tfp_{CaCl_2}= 3*1.98m*-1.86\°C/m=-11.1\°C[/tex]
It means that CaCl₂ is still better than NaCl because produces involves a higher melting point for the ice, so it would melt faster.
Best regards!
What size volumetric flask would you use to create a 0.50 M
solution using 10.00 g of CaBr2
Answer:
Explanation:
First convert the grams of Calcium Bromide to moles by using the atomic weight. Then use the formula for molarity, which is moles per liter.
CaBr2 = 199.9 g/mol
10/199.9 = 0.05 moles of CaBr2
[tex]0.5M=\frac{0.05mol}{x}[/tex]
x = 0.1L or 100mL
Which circuit would light the light. A or B
Answer:
B
Explanation:
you can tell by looking at the image lol the wires have to be connected
(brainliest please? c:)
( although its fine if not im just glad to have helped )
Answer:
The answer is B
Explanation:
Look for hazard symbols on products currently being used in your home. Name five with the corresponding symbol. You may not repeat a product name.
Answer:
bleach, hair spray,spay cleaner and idek
Explanation:
. Carbamide (CH4N2O), can be synthesized by the reaction of ammonia (NH3) with carbon
dioxide (CO2):
2 NH3 (aq) + CO2 (aq) CH4N2O (aq) + H2O (l)
An industrial synthesis of urea obtains 87.5 kg of urea upon reaction of 68.2 kg of ammonia
with 105 kg of carbon dioxide. Determine the limiting reactant, theoretical yield of urea and percent yeild for the reaction
Answer:
NH₃ is the limiting reactant.Theoretical yield = 120 kg% yield = 72.9 %Explanation:
2NH₃ (aq) + CO₂ (aq) → CH₄N₂O (aq) + H₂O (l)First we convert the given masses of reactants to moles, using their respective molar masses:
68.2 kg NH₃ ÷ 17 kg/kmol = 4.01 kmol NH₃105 kg CO₂ ÷ 44 kg/kmol = 2.39 kmol CO₂2.39 kmol of CO₂ would react completely with (2.39 * 2) 4.78 kmol of NH₃. There are not as many NH₃ kmoles so NH₃ is the limiting reactant.
We calculate how much urea would form with a 100% yield, using the moles of limiting reactant:
4.01 kmol NH₃ * [tex]\frac{1kmolCH_4N_2O}{2kmolNH_3}[/tex] = 2.00 kmol CH₄N₂OWe convert that amount to kg:
2.00 kmol CH₄N₂O * 60 kg/kmol = 120 kg CH₄N₂OFinally we calculate the percent yield:
87.5 kg / 120 kg * 100% = 72.9 %10. How might life in America be different if the Civil Rights Movement had never happened?
a. Public places could still be segregated
b. Voting would be easier for everyone
c. Slavery might still exist
d. Americans would be more tolerant of peaceful protests
Answer: A or C because of the civil right movement changed a lot of stuff as if it never happened blacks would of still be segregated, the U.S wouldn't be the same and they also mentioned that the U.S would not be respected by many other countries which would hurt them from developing even more in the future.
Farsighted people have trouble seeing objects that are close to their eyes.
True
False
As human populations grow, it becomes more important to use renewable sources of energy. Which of the following objects uses energy from a renewable source?
A-a stove that is powered by natural gas
B- a refrigerator that runs on solar power
C- a lantern that burns oil from beneath Earth's surface
D- a toaster that uses electricity from a coal-burning power plant
In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent ___________ in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at __________________. Using a _______, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add _______________ in order to dissolve the solid.
Answer:
just until it covers the sample
a low setting and increasing gradually
pipet
as little solvent as possible
Explanation:
In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent just until it covers the sample in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at a low setting and increasing gradually. Using a pipet, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add as little solvent as possible in order to dissolve the solid.
Complete the following table. The first row has been completed as an example.
Symbol
Atomic number Mass number Number of protons Number of neutrons
17C1
17
37
17
20
238
U
92
92
238
146
92
325
16
32
16
16
5 Fe
54
26
I
19
1.K
41
22
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Answer:
because all chemical reaction involve the rearrangement of atoms, the mass is an electron is negatively charged, it has a mass approximately 1/2000 that of a, Atoms of an element that contain the same number of protons but a different Copy and complete the following tables concerning the isotopes of silicon SI-28.
Explanation:
What are the main parts of a simple electrie motor, like the one found inside a remote control car? O a generator, wires, and turbine magnets and coils of wire O electromagnets only
Answer:
A DC power supply, commutator, rotor armature, axle, and a field magnet.
Which of these is the best definition of sustainable development
Answer:
Sustainable development is a way for people to use resources without the resources running out. ... The term used by the Brundtland Commission defined it as development with sustainability that "meets the needs of the present and also compromising the ability of future generations to meet their own needs."
which planet in are solar system haves most moons
Answer:
Jupiter
Explanation:
HELP ASAP PLS. Which of the following best describes the relationship between air temperature and relative humidity?
A. Cold air cannot hold any water vapor.
B. Warm air can hold less water vapor than cold air.
C. Cold air can hold less water vapor than warm air.
D. Warm air and water vapor are measured in degrees Celsius (⁰C).
Answer:
I think the answer might be C.
Assuming each solution to be 0.10 M , rank the following aqueous solutions in order of decreasing pH.Rank the solutions from the highest to lowest pH. To rank items as equivalent, overlap themN2H2Ba(OH)2HOCLNAOHHCL
Answer:
Ba(OH)₂ > NaOH >N₂H₂ > HOCl > HCl
Explanation:
To get a better understanding of this, we need to know what's the meaning of the pH values.
The pH value of any compound basically gives us information of how acidic or basic is a compound. If this value is higher (>7), means major basicity; if this number is lower (<7) means major acidity in the compound.
According to this, a strong acid would be the one with the lowest pH, and a strong base would be the one with the highest pH.
Among the 5 compounds we have here, only 2 of them are acid, and the rest is basic, so we can assume that both acid would have the lower pH, it's up to us to see which of them have the lowest pH.
To do that, we can use the following expression:
pH = -log[H⁺]
If all solutions have a concentration of 0.10, then the pH would be:
HCl:
pH = -log(0.1) = 1
HOCL:
This one is a weak acid, so it's not completely dissociated in solution and the [H⁺] would be <0.1 M. As its a weak acid, we can assume that it's pH would be near 4, 5 or 6. We cannot know with all certain, because we need the Ka of this acid, and see the dissociation of the acid in solution, but for this case, it's fine and HCl is one of the strongest known acid.
In this case the order is: HOCl > HCl
For the bases, we have 3 bases, 2 of them are strong bases, and 1 of them is a weak base so it doesn't dissociate completely (N₂H₂), so this would have the lowest pH among the bases. In the case of bases, we calculate pOH, (Same formula as before) and then, we substract 14 from the value of pOH. As for the other two:
Ba(OH)₂:
Concentration would be double because we have 2 OH, so:
[OH⁻] = 2 * 0.1 = 0.2 M
pOH = -log(0.2) = 0.69
pH = 14 - 0.69 = 13.31
NaOH:
pOH = -log(0.1) = 1
pH = 14 - 1 = 13
Therefore, Ba(OH)₂ is stronger than NaOH and N₂H₂. So, our order would be:
Ba(OH)₂ > NaOH >N₂H₂ > HOCl > HClHope this helps
How many formula units make up 21.6 g of magnesium chloride (MgCl2)? Express the number of formula units numerically.
1.37 × 10²³ formula units MgCl₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 21.6 g MgCl₂
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of Mg - 24.31 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of MgCl₂ - 24.31 + 2(35.45) = 95.21 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 21.6 \ g \ MgCl_2(\frac{1 \ mol \ MgCl_2}{95.21 \ g \ MgCl_2})(\frac{6.022 \cdot 10^{23} \ formula \ units \ MgCl_2}{1 \ mol \ MgCl_2})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1.36619 \cdot 10^{23} \ formula \ units \ MgCl_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.36619 × 10²³ formula units MgCl₂ ≈ 1.37 × 10²³ formula units MgCl₂
Comparing metalic and covalent bonds in terms of nature of the bond
Answer:
Covalent bond involves the sharing of electrons, while metallic bonds have strong attractions and ionic bonds involve the transferring and accepting of electrons from the valence shell. The adhering property of an atom, in order to arrange themselves in a most stable pattern by filling their outermost electrons orbit.
Write the orbital notation and electron configuration for the following elements. (Worksheet #2)
1. Chlorine
2. Vanadium
3. Arsenic
Answer:
the answer is B
Explanation:
Answer:
answer is number 2.
Explanation:
hope this helps
mineral and nutrient solution is in water epiphyte plants or hydroponic plants
Answer:
hydro ponic plants
Explanation:
coz they are hydro
Which type of bond does the phrase "opposite attract" Apply to the best explain
Answer: The ionic bond. This involves ions of opposite charge. Eelectrostatically charged bodies with opposite charges, + and -, attract one another.
MARK ME BRAINLIST
n = 4, l=2, ml= 2 which orbital?
Answer:
It's the 4d orbital
Explanation:
n is the principal quantum number, n=4, means the 4th orbital, l=2, means 'f'(l=0,1,2,3 which means spdf respectively)
The pKa of an acid depends partly on its environment. Predict the effect of each of the following environmental changes on the pKa of a glutamic acid side chain. (a) A lysine side chain is brought into proximity. (b) The terminal carboxyl group of the protein is brought into close proximity.
Answer:
A. Decrease
B. Increase
Explanation:
A. A lysine side chain is brought into proximity:
lysine is basic in its nature, it would have to stabilize the electrostatic interaction and also weak interactions existing among the acidic amino acids and hydrogen bond. This would then reduce or decrease the pH and thus pKa of the protein.
B. The effect of this on pKA is an increase on the pKA. The carboxyl group is acidic. When it is removed, it would then cause the pKA to be increased. There would be accumulation of more negative change by basic amino acids increasing the pKA.
Which ecosystem likely has the lowest species diversity?
O a habitat with high rainfall and high sunlight
O a habitat with low rainfall and high sunlight
O a habitat with low rainfall and low sunlight
O a habitat with high rainfall and low sunlight
Answer:
a habitat with low rainfall and low sunlight
Explanation:
Because little to nothing grows in ground that is frozen year-round except for some forms of microscopic life
How does a temperature increase cause the rate of a reaction to increase?
O A. It increases the kinetic energy of the molecules.
O B. It decreases orientation requirements of the molecules,
C. It increases the equilibrium constant for the reaction,
D. It decreases the activation energy of the reaction.
Help me please !!!
Answer:
the answer is c because it will have a equilibrium constant for the action
A temperature increase causes the rate of a reaction to increase because it increases the kinetic energy of the molecules. The correct answer is option A.
Kinetic energy is the energy that an object possesses due to its motion. It is defined as one-half of the mass of an object multiplied by the square of its velocity.
This means that the molecules move faster and collide more frequently, which increases the likelihood of successful collisions between reactant molecules. An increase in temperature also increases the average kinetic energy of the molecules, which means that more of them will have enough energy to overcome the activation energy barrier and react.
Therefore, increasing the temperature increases the kinetic energy of the molecule. Option A is the correct answer.
Learn more about kinetic energy here:
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In the benzene molecule, carbon atoms form a ring with alternating single and double bonds in between each of them. Each carbon atom forms one σ bond with one carbon atom and one σ and one π bond with another. The π bonding electrons are delocalized over the entire molecule. Thus, benzene is a resonance hybrid of two equivalent structures, and the single and double bonds oscillate from one position to the other.
Required:
Calculate the bond order for one carbon-carbon bond in the benzene molecule, taking σ and π bonding into consideration.
Answer:
1.5
Explanation:
From;
BO = ½(B – A)
BO= Bond order
B= Number of bonding electrons
A = Number of antibonding electrons
For the sigma bonds, there are 2 bonding electrons and 0 nonbonding electrons.
σ BO = ½(B – A) = ½(2 – 0) = 1
π bond order for 6 C-C bonds;
π BO = ½(B – A) = ½(6 – 0) = 3
For each π bond, BO = 3/6 = 0.5.
Hence, for a single C-C bond in benzene, the total Bond order = σ + π = 1 + 0.5 = 1.5.
How many moles in 2.45 x 10^45 atoms of sodium, Na?
A. 4.07 x 10^21 moles
B. 1.47 x 10^47 moles
C. 4.07 x 10^467 moles
D. 1.678 moles
please only answer if you know and please show your work
Good News! Here is a sheet to show you how to perform mole calculations: http://www.sciencewithmrjones.com/downloads/chemistry/moles/how_to_perform_mole_calculations.pdf
what is the relationship between temperature and kinetic energy?
Answer:
Temperature is directly proportional to the kinetic energy of the atoms that a body is made of. This relation is valid concerning the velocities relative to the center of mass of the body. In other words, concerted movements like translation and rotation do not affect temperature.
Explanation:
Answer:
As stated in the kinetic-molecular theory, the temperature of a substance is related to the average kinetic energy of the particles of that substance. When a substance is heated, some of the absorbed energy is stored within the particles, while some of the energy increases the motion of the particles.
I hope it's helpful!