a. molality-m=1.623
b. molarity-M=0.3
Further explanationa. Boiling point
[tex]\tt \Delta Tb=Kb\times m[/tex]
Kb for ethanol=1.22 °C/m
Boiling point for ethanol = 78.4 °C
ΔTb=80.38-78.4=1.98
[tex]\tt 1.98=1.22\times m\\\\m=\dfrac{1.98}{1.22}=1.623[/tex]
b. osmotic pressure
[tex]\tt \pi =MRT[/tex]
π = 7.65 atm
R = 0.08205 L/atm K
T = 37 + 273 = 310 K
[tex]\tt M=\dfrac{\pi}{RT}=\dfrac{7.65}{0.08205\times 310}=0.3~M[/tex]
According to VSEPR theory, a molecule with the general formula AX4 E1 will have a __________ molecular shape.a. T-shaped square planar b. seesaw c. trigonal planar d. trigonal bipyramidal e. tetrahedral
Answer:
The answer is "Option e"
Explanation:
The ionic bond arousal system of the outer shells (VSEPR) allows us to determine which one of the feasible solutions are found in the majority of instances. It's also supposed to occupy the space with electrical pairs and also to reduce electrical couple repulsive forces to a minimum, its cheapest electricity framework. This theory can be used for predicting a form of electron pairs with a different mass of a particle's core electrons.
1 What is the total number of valence electrons in the Lewis structure of C104?
electrons
2 Draw a Lewis structure for CI04:
What is the correct electron configuration for an element with 5 electrons in
the 3d energy sublevel?
Answer:
[tex]1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^5[/tex]
Explanation:
Hello!
In this case, since electron configurations allows to understand how the electrons in an atoms are arranged depending on the energy levels from 1 to 7 and subshells s, p d and f, considering the attached picture, if we want an element for which the last term in its electrons configuration was 3d⁵, we write:
[tex]1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^5[/tex]
It means that the element has 25 electrons, therefore, it should be manganese.
Best regards!
Answer: it's A the same answer as the dude above me not trying to type all that
Explanation: took the test for ap
Fluorine gas and water vapor react to form hydrogen fluoride gas and oxygen. What volume of oxygen would be produced by this reaction if 2.6em of were consumed? Also, be sure your answer has a unit symbol, and is rounded to the correct number of significant digits
Answer:
The reaction is 2F_2 (g) + 2H_2 O (g) rightarrow 4HF (g) + O_2 (g) 2 moles of fluorine gas (F_2) reacts with 2 moles of water vapors (H_2 O) to produce 4 moles of hy
What is electronegativity and which chemical family has
the strongest electronegativity according the the Periodic
Trends?
Answer:
Of the main group elements, fluorine has the highest electronegativity (EN = 4.0) and cesium the lowest (EN = 0.79). This indicates that fluorine has a high tendency to gain electrons from other elements with lower electronegativities.
Explanation:
What is the normality of a solution prepared by dissolving 75.0 g citric acid, a triprotic acid with molar mass of 192.14 g, in water to make 250. mL solution?
a. 0.0576 N
b. 0.293 N
c. 4.68 N
d. 0.173 N
e. 1.56 N
The normality of the solution which is prepared by dissolving 75 grams of citric acid in water to make 250 ml solution is 4.68 N. Thus, the correct option is C.
What is Normality?Normality is a measure of the concentration of a solution. Normality of a solution is the number of grams equivalent to solute which is present in a given volume of the solution.
Normality of a solution can be calculated by the formula:
N = Gram eq. of solution/ Volume of solution in liters
N = Weight of the solution/ Equivalent weight ×1000/ Volume of solution
N = 75/ 64.4 × 1000/ 250
N = 1.16 × 4
N = 4.64
The normality of the citric acid solution is approximately 4.68 N.
Therefore, the correct option is C.
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3. Find
out the initial energy level (n) of an electron that results in the emi ssion of light of
wavelength 486 nm in the Balmer series?
Answer:
4
Explanation:
The Balmer series refers to a series of spectral emission lines of the hydrogen atom arising from electronic transitions from any higher level and terminating at the the energy level n= 2.
Using the relation;
1/λ = 1.09737*10^7 (1/2^2 -1/n^2initial)
We now have;
1/486 *10^-9 = 1.09737*10^7 (1/2^2 -1/n^2initial)
0.1875 = 1/2^2 -1/n^2initial
1/n^2initial = 1/2^2 - 0.1875
1/n^2initial = 0.0625
n^2initial = 16
ninitial = 4
You perform an electrochemical reaction in which 0.600 mol of Cu are reduced to solid Cu. How many coulombs of charge are transferred?How many electrons are in this amount of charge?
Answer:
[tex]7.22 \times 10^{23}e^{-}[/tex]
[tex]1.16 \times 10^{5}C[/tex]
Explanation:
Step 1: Write the reaction for the electrochemical reduction of copper.
Cu²⁺(aq) + 2 e⁻ → Cu(s)
Step 2: Calculate the number of electrons required in the reduction of 0.600 moles of Cu²⁺
We will use the following relationships:
1 mole of Cu²⁺ requires 2 moles of electrons1 mole of electrons has 6.02 × 10²³ electrons (Avogadro's number)[tex]0.600molCu^{2+} \times \frac{2mole^{-} }{1molCu^{2+} } \times \frac{6.02 \times 10^{23}e^{-} }{1mole^{-}} = 7.22 \times 10^{23}e^{-}[/tex]
Step 3: Calculate the Coulombs corresponding to [tex]7.22 \times 10^{23}e^{-}[/tex]
We will use the following relationships:
1 mole of electrons has 6.02 × 10²³ electrons (Avogadro's number)1 mole of electrons has a charge of 96486 C (Farady's constant)[tex]7.22 \times 10^{23}e^{-} \times \frac{1 mol e^{-}}{6.02 \times 10^{23}e^{-}} \times \frac{96486C}{1 mol e^{-}} =1.16 \times 10^{5}C[/tex]
how many moles of NaCl are dissolved in 250 mL of solution if the solution concentration is 0.150 M?
Answer: ?L=250 mL × 1L =0.25L 1000 mL
0.150 M = moles of solute moles of solute = 0.038 mol.
Explanation:
Fill in the Blank
Complete the following sentence. Remember to spell correctly.
The most common biomass is
which people have used to heat their homes for centuries.
Balance the following redox reaction if it occurs in basic solution. What are the coefficients in front of Br2 and OH- in the balanced reaction?
Br2(l) → BrO3-(aq) + Br(aq)
Possible answers:
Br2 = 3, OH- = 3
Br2 = 2, OH- = 5
Br2 = 3, OH- = 6
Br2 = 1, OH- = 6
Br2 = 1, OH- = 2
The coefficient for Br and OH has been 3 and 6 respectively. Thus option C is correct.
If the reaction takes place in a basic medium, the reaction can be given as:
[tex]\rm Br_2\;+\;OH^-\;\rightarrow\;BrO_3^-\;+\;Br\;+H_2O[/tex]
The coefficient has been placed in the chemical reaction to balance the number of atoms on the product and the reactant side.
The number of atoms of Br on the product side has been 2, and the reactant side has been 2.
The oxygen atoms have been 1 on the reactant side, and 3 on the product side.
It has been balanced as:
[tex]\rm 3\;Br_2\;+\;6\;OH^-\;\rightarrow\;BrO_3^-\;+\;5\;Br^-\;+\;3\;H_2O[/tex]
The coefficient for Br and OH has been 3 and 6 respectively. Thus option C is correct.
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Construction crews sometimes use this reaction for welding underwater structures:
Fe2O3 + 2Al → Al2O3 + 2Fe
How many moles of iron (Fe) would be produced if 2.50 mol Fe2O3 react? Make sure to use the correct number of significant figures in your answer.
2.50 mol Fe2O3 =
Answer:
5 moles of iron formed
Explanation:
Given data:
Moles of iron formed = ?
Moles of iron oxide react = 2.50 mol
Solution:
Chemical equation:
Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
Now we will compare the moles of iron with iron oxide.
Fe₂O₃ : Fe
1 ; 2
2.50 : 2×2.50 = 5 mol
what would happen to an atom in its ground state of external energy was applied to the electrons g
Answer:
See explanation
Explanation:
According to Bohr's theory, when external energy is supplied to an atom, its electrons absorb energy and move from a lower energy level to a higher energy level.They quickly return to their original level and re-radiate the absorbed energy as a photo of light.
Hence, when an atom in ground state receives external energy, it becomes excited because energy is transferred to its electrons and they move from lower to higher energy level.
The electron after getting the energy would jump to an orbital further away from the nucleus.
• Ground state refers to the lowest energy state an atom can be at. When an electron in an atom captivates energy it is considered to be in an excited state.
• An excited atom becomes unstable and seem to align itself to move back to its lowest energy state.
• When an atom in its ground state is supplied with an external energy, the energy is absorbed by the atom and the electron becomes excited and jumps to an orbit , that is, distant from the nucleus.
• It can be said that electron attains higher energy state, with the absorption of more energy by the atom, the electron further moves to higher state till it becomes a free electron and no longer remains the part of the atom.
Thus, the electron after getting the energy would jump to an orbital further away from the nucleus.
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determine moles of 1.5g of sodium carbonate.
Answer:
0.014mol
Explanation:
Given parameters:
Mass of Na₂CO₃ = 1.5g
Unknown:
Number of moles = ?
Solution:
Number of moles of a compound is mathematically expressed as;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = [tex]\frac{1.5}{106}[/tex] = 0.014mol
1. How many Chromium atoms are found in 25.8 milligrams of Chromium?
Answer: 51.9961 g/mol, don't know if it helps :)
Explanation:
Answer:
Chromium is a steel-gray, lustrous, hard metal that takes a high polish, is fusible with difficulty, and is resistant to corrosion and tarnishing.
The most common oxidation states of chromium are +2, +3, and +6, with +3 being the most stable. +4 and +5 are relatively rare. Chromium compounds of oxidation state 6 are powerful oxidants.ion:
Calculate the theoretical yield of aspirin obtained when 2.0 g of salicylic acid and 5.0 mL of acetic anhydride (density = 1.08 g/mL) 2. if 1.9 g f asprin were obtained in this experiment, what would be the percent yield?
Answer:
The percent yield would be 73%
Explanation:
The balanced reaction for the obtention of acetylsalicylic acid (aspirin) is the following:
Salicylic acid + acetic anhydride → acetylsalicylic acid + acetic acid
C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + C₂H₄O₂
According to the reaction, 1 mol of salicylic acid reacts with 1 mol of acetic anhydride to give 1 mol of acetylsalicylic acid (aspirin) and 1 mol of acetic acid.
1 mol aspirin (C₉H₈O₄) = (9 x 12 g/mol) + (8 x 1 g/mol) + (4 x 16 g/mol)
= 180 g
1 mol salicylic acid (C₇H₆O₃) = (7 x 12 g/mol) + (6 x 1 g/mol) + (3 x 16 g/mol)
= 138 g
1 mol acetic anhydride (C₄H₆O₃) = (4 x 12 g/mol) + (6 x 1 g/mol) + (3 x 16 g/mol)
= 102 g
The stoichiometric ratio is = 138 g salicylic acid/102 g acetic anhydride= 1.35
We have:
2.0 g salicylic acid
acetic anhydride = 5.0 mL x 1.08 g/mL = 5.4 g
The reactants ratio is = 2.0 g salicylic acid/5.4 g acetic anhydride = 0.37
0.37 < 1.35 , therefore salicylic acid is the limiting reactant.
Now, we use the amount of salicylic acid to calculate the theoretical amount of aspirin. For this, we know that 1 mol of aspirin (180 g) is obtained from 1 mol of salycilic acid (138 g):
theoretical yield= 180 g aspirin/138 g salycilic acid x 2.0 g salycilic acid = 2.61 g aspirin
actual yield = 1.9 g
Finally, we calculate the yield:
percent yield = actual yield/theoretical yield x 100
= 1.9 g/2.6 g x 100 = 72.8% ≅ 73%
My dog is gonna explode in 20 minutes help!!
Answer:
Call 911 then or run away
Explanation:
The hybrid orbital set used by the central atom in no3- is_____ and why?
a. sp
b. sp3
c. SP2
d. sp3d2
e. sp3d
Answer:
c. SP2
Explanation:
The image in the diagram below shows the structure of NO₃⁻
Nitrogen is the central atom with the electronic configuration of 1s² 2s² 2p³.
So in its outermost shell, it has 3 electrons and the hybridization is sp²
However,
According to Hund's rule:
The ground state of Nitrogen is;
1s² 2s² 2p³
↑↓ ↑ ↑ ↑ ↑
At the excited state when it is attached to 3 different oxygen ions, we have:
1s² 2s² 2p⁵
O⁻ ---> ↑↓ ↑↓ ↑↓ ↑↓ ↑
1s² 2s² 2p⁵
O⁻ ---> ↑↓ ↑↓ ↑↓ ↑↓ ↑
1s² 2s² 2p⁴
O⁻ ---> ↑↓ ↑↓ ↑↓ ↑ ↑
Thus, the 3 sp² orbital lies in a plane and form 3 N - O σ- bond and one π- bond.
Identify at least 5 pure substance found in nature,in the supermarket, grocery storeand even at your home.use the table below to explain your answer based on appearance, separating technique, boiling and melting point.
Answer:
Explanation:
1) Pure substance: Water (found at home)
Appearance: It is homogeneous since it is a single substance that appears as liquid. Homogeneous is when the components of a substance are in a single phase
Separating technique: It's component cannot be separated by physical means
Boiling point: Water boils at 100 °C
Melting point: Water melts/freezes at 0°C
2) Pure substance: Table salt (found at home)
Appearance: It is also homogeneous as it is a single substance that is solid. Separating technique: It's component cannot be separated by physical means
Boiling point: Water boils at 1,465 °C
Melting point: Water melts/freezes at 801 °C
3) Pure substance: Butter (found at home and grocery store)
Appearance: It is homogeneous even though it contains different components
Separating technique: It's component can be separated by physical means since butter is an emulsion of fat in water. The 15% water content can be evaporated/distilled out at 100 °C
Boiling point: Butter starts boiling at about 110-120 °C
Melting point: It melts at about 37 °C
4) Pure substance: Candle (wax) (found at home and grocery store)
Appearance: It is homogeneous
Separating technique: It's component cannot be separated by physical means
Boiling point: It starts boiling around 370 °C
Melting point: It melts at about 37 °C
5) Pure substance: table sugar/sucrose (found at home, grocery stores and in supermarkets)
Appearance: It is homogeneous
Separating technique: It's component cannot be separated by physical means
Boiling point: It starts boiling around 697 °C
Melting point: It melts at about 186 °C
A pure substance is an homogeneous material, having a composition, and
properties that are consistent through out the material.
The chemical properties of a pure substance are defined, such as the
products of its reaction can be predictable.
A chemical is pure when it consist of a single type of particle such as an
element, a molecule or a compound.
The five pure substances are presented as follows;
[tex]\displaystyle\begin{tabular}{|l|l|l|l|l|}\underline{Pure \ Substances}&\underline{Appearance}&\underline{Separaing Tech}&\underline{Boiling \ Point}&\underline{Melting \ point}\\1. Diamond&Translucent \ solid&Inseparable&3550^{\circ}&4830^{\circ}\\2. Table \ salt&White\ crystals&Insepble&801^{\circ}&1413^{\circ}\\3. Water&Tran parent \ liquid&Insepble&0^{\circ}&100^{\circ}\\4. Sugar&Whilte \ crystals&Heating&Decomposes&186^{\circ}\\5. Gold&Yellowish \ metal&Inseparable& 2700^{\circ}&1064^{\circ}\end{array}[/tex]
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What happens to gas particles when they are compressed?
1)Gas molecules move further apart.
2)Gas molecules get closer together.
3)Some gas molecules move further apart and some move closer together.
Answer:
3)Some gas molecules move further apart and some move closer together.
Explanation:
because When more gas particles enter a container, there is less space for the particles to spread out, and they become compressed. The particles exert more force on the interior volume of the container. This force is called pressure. There are several units used to express pressure.
Suppose you light a Bunsen burner and notice that the flame is very yellow and too short. To get a blue flame, you should ________further. To increase the size of the flame, you should _____________the _____________further.
Answer:
In the given case, to get a blue flame, one should open the air inlet further. To increase the size of the flame one should open the gas regulator further. When one opens the air inlet, more amount of oxygen goes within, and thus, one can get a more intense form of blue flame.
When one opens the gas regulator more concentration of gas goes and the larger the size of flame one gets.
To regulate a bunsen burner follow this procedure
To get a blue flame, you should rotate the wheel of the burner anticlockwise further to reduce the level of oxygen flow.
To increase the size of the flame, you should rotate the wheel clockwise further
The bunsen burner is an apparatus in the laboratory used to carry out experiment when heating of substance is required, hence it is used to add heat to substances, it has a wheel used to regulate the flow of air which is required for combustion, it has a hose which is used to tap gas to the burner
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Which description best matches Rutherford's model of the atom?
Group of answer choices
A The atoms is a positive sphere with negative electrons embedded in it.
B Electrons orbit the nucleus in set, circular orbits.
C The atoms has a tiny, massive nucleus at its center with electrons surrounding it
D The atoms is a solid, indivisible sphere
Answer:
C The atoms has a tiny, massive nucleus at its center with electrons surrounding it
Explanation:
From the experiment by Rutherford, he suggested a model of the atom where there is a tiny but massive nucleus at the center with electrons surrounding it.
Rutherford found that most of the alpha particles in his gold foil experiment pass through but a few were deflected back. He suggested an atomic model to explain his observation. In this model, the atom has small positively charged center where the mass of the atom is concentrated. Surrounding the nucleus is a large space containing the electrons.Which of the following statements explain how creativity leads to new investigations? Check all of the boxes that apply.
Creativity lets scientists use their imagination to invent results.
Creativity leads scientists to design new methods to test their hypotheses.
Creativity allows scientists to investigate untestable hypotheses.
Creativity permits scientists to think of new questions to investigate.
Answer:
Creativity leads scientists to design new methods to test their hypotheses.
Creativity permits scientists to think of new questions to investigate.
Explanation:
A scientist must be very creative and must be a critical thinker.
Creativity is the ability of someone to use imaginations to solve a problem.
It is the art of being inventive. To the scientific world, creativity is very essential. It helps scientists to design new methods to validate their hypothesis. It also helps to bring up new questions that might be investigated.Answer:
B and D
Explanation:
A solid substance was tested in the laboratory. The test results are listed below: 1.) dissolves in water 2.) is an electrolyte 3.) melts at a high temperature. Based on these results, the solid substance could be
Answer:
NaCl may be i guess so....
A child is prescribed morphine sulfate at 35.0 mcg/kg/dose. The child weighs 85 lb and the solution is available as a 5.0-mg/mL vial. How many milliliters should be injected?
Answer:
270 mL
Explanation:
First we convert the child's weight to kg:
85 lb * [tex]\frac{453.592g}{1 lb} *\frac{1kg}{1000g}[/tex] = 38.56 kgSo the total mass of morphine sulfate that should be injected is:
38.56 kg * 35.0 mg/kg/dose = 1349.6 mg/doseFinally we calculate the volume that should be injected, using the concentration of the available solution:
1349.6 mg ÷ 5.0 mg/mL = 269.9 ≅ 270 mLThe accurate millilitre is 268 mL.
First of all, we must obtain the mass of the child in kilograms;
1 Ib = 0.45 Kg
85 lb = 85 lb × 0.45 Kg/1 Ib
= 38.25 Kg
If 1 Kg takes 35.0 mcg/kg/dose
38.25 Kg takes 38.25 Kg × 35.0 mcg/kg/dose/1 Kg
= 1338.75 mg/dose
Hence;
1338.75 mg/dose/5.0-mg/mL = 268 mL
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What is the difference between Mega and Milli symbols?
Answer:
Mega = 10^6
Milli = 10^-3
Explanation:
Mega is whatever times 10 to 6th power.
Milli is whatever times 10 to the -3rd power.
A heliox deep-sea diving mixture contains 2.0 gg of oxygen to every 98.0 gg of helium. What is the partial pressure of oxygen when this mixture is delivered at a total pressure of 8.0 atm?
Answer:
The correct answer is 0.020 atm.
Explanation:
Partial pressure is calculated by using the formula,
Partial pressure = Mole fraction × Total pressure
The partial pressure of oxygen in a mixture can be calculated by using the formula,
Mole fraction of oxygen in mixture = Number of moles of oxygen / No. of moles of oxygen + No. of moles of Helium
(1 gg or gigagram is equal to 10⁹ grams)
= 2 × 10⁹/32 /2 × 10⁹/32 + 98 × 10⁹ / 4
= 2.54 × 10⁻³
Now the partial pressure of oxygen = Mole fraction of oxygen × Total pressure of oxygen
= 2.54 × 10⁻³ × 8.0 atm
= 0.02032 atm
= 0.020 atm
Study the image. Earth showing air mass movement. Purple and red arrows are moving in a counterclockwise direction. Based on the arrows, in which direction are air masses moving? from west to east from north to south toward the equator toward the middle latitude
Answer:
A
Explanation:
Based on the arrows, the direction the air masses are moving is from west
to east.
What are Air masses?These contains large volume of air which has a uniform temperature and
humidity. Air masses move in the atmosphere through the process known
as Convection.
The movement of the air tells us that the movement is from the Western
part to the Eastern part of the atmosphere.
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What factors affect the strength of the electromagnet?
Factors that affect the strength of electromagnets are the nature of the core material, strength of the current passing through the core, the number of turns of wire on the core and the shape and size of the core.
Answer:
an effect could be that the battery could be running out of juice or that there isnt enough wire on a nail on the electromagnet.
Explanation:
Bob uses SI units to measure his running distance. Which units should he use
Answer:
Distance measures length. For example, the distance of a road is how long the road is. In the metric system of measurement, the most common units of distance are millimeters, centimeters, meters, and kilometers.
Explanation: