Answer:
To produce a solution that frees at -50°C we need 1668.5 g of ethylene glycol
Explanation:
Formula for freezing point depression is:
Freezing T° of pure solvent - Freezing T° of solution = Kf . m . i
Our solute is the ethylene glycol, then water is our solvent.
As ethylene glycol is a non ionic compound, i = 1 (Van't Hoff factor, numbers of ions dissolved)
Kf = Cryoscopic constant. For water is 1.86 °C/m
We replace data:
0°C - (-50°C) = 1.86 °C/m . m . 1
To determine grams of ethylene glycol needed, we need to find m (molality)
50°C / 1.86 m/°C = m → 26.8 mol/kg
As this moles of solute are contained in 1kg, definetely we need 26.8 moles of ethylene glycol.
To find the answer, we convert moles to mass:
26.8 mol . 62.07g / mol = 1668.5 g
How is wind speed indicated? What is the unit used to define wind speed?
Answer:
AnemometerknotExplanation:
Instrument used to measure wind speed are known as anemometer and can record wind speed, direction, and strength. The normal unit of wind speed is knots (nautical miles per hour)
Chem pls help me thanks very much
Answer:
Flourine reacts with Sodium bromide to give Silver flourine and Bromine
Hope u understand
Thank You
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Answer:
posaaaaaaaaaaaaaaaaaaaaa
Que cantidad de solvente se necesita para obtener una solucion al 20% cuando se mezclan 600mg de alcohol.
Answer:
[tex]m_{solvente}=2400mg[/tex]
Explanation:
¡Hola!
En este caso, con la información dada, es posible inferir que este problema es acerca del porcentaje en masa del soluto y que se calcula de la siguiente manera, en términos de la masa de soluto y solución:
[tex]\% m=\frac{m_{soluto}}{m_{solucion}} *100\%[/tex]
De este modo, como conocemos el porcentage y la masa del soluto, podemos calcular la masa de la solución primero:
[tex]m_{solucion}=\frac{m_{soluto}}{\% m} *100\%\\\\m_{solucion}=\frac{600mg}{20\%} *100\%\\\\m_{solucion}=3000mg[/tex]
Esto quiere decir que la masa del solvente es:
[tex]m_{solvente}=m_{solucion}-m_{soluto}\\\\m_{solvente}=3000mg-600mg\\\\m_{solvente}=2400mg[/tex]
¡Saludos!
Earth's surface is shaped and changed in many ways. Which of these can shape Earth's surface?
water
wind
ice
gravity
organisms (living things)
the sun
none of these
all of the above
1. If 2 moles of hydrogen combine with one mole of oxygen, how many moles of water are
produced?
A mixture of He, Ne, and N2 gases has a pressure of 1.943 atm. If the pressures of He and Ne are 0.137 atm and 0.566 atm, respectively, what is the partial pressure of N2 in the mixture?  A. 0.703 atm  B. 1.24 atm  C. 0.151 atm  D. 1.943 atm
Answer:
The parcial pressure of N₂ in the mixture is 1.24 atm.
Explanation:
The pressure exerted by a particular gas in a mixture is known as its partial pressure. So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone:
PT = PA + PB
This relationship is due to the assumption that there are no attractive forces between the gases.
In this case:
PT=PHe + PNe + PN₂
You know:
PT= 1.943 atmPHe= 0.137 atmPNe= 0.566 atmPN₂= ?Replacing:
1.943 atm= 0.137 atm + 0.566 atm + PN₂
Solving:
1.943 atm= 0.703 atm + PN₂
1.943 atm - 0.703 atm= PN₂
1.24 atm= PN₂
The parcial pressure of N₂ in the mixture is 1.24 atm.
Which type of energy transfer allows the Sun to warm Earth?
C. Radiation is the answer.
As it can happen in vacuum also
Answer: Radiation
Explanation:
Use the periodic table to identify the element indicated by each electron configuration by typing in the
chemical symbol for the element.
Answer:
Explanation:
1s22s22p6: Ne 1s22s22p63s23p3: P 1s22s22p63s23p64s1: K 1s22s22p63s23p64s23d8: Ni 1s22s22p63s23p64s23d104p65s24d3: Nb
We have that an element indicated by its electron configuration, we can determine its Atomic number by selecting the electron represented on each orbit of the atom around the nucleus
Hence using the Periodic table to read the its Atomic Number
The Periodic table is categorized using the atomic number of elements and symbols are to aid search as well
For an element indicated by its electron configuration we can determine its Atomic number by selecting the electron represented on each orbit of the atom around the nucleus
Hence using the Periodic table to read the its Atomic Number
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How will amino acids made with isotopes help scientists to answer this question?
Answer:
Proteins are made up of 20 amino acids. How an Isotope Technique Helps Determine Protein Quality. However be produced by the body and therefore are participated in the labelling process.
Explanation:
Separation of mixtures by removing a layer of liquid
Answer:
Decantation
Explanation:
Question 4 of 10
Which molecule is hexanal?
ОА, НС
ОН
В.
||
Ос. Н?
нсон
D.
Answer:
Hexanal, once commonly called caproic aldehyde, is a six-carbon straight-chain aldehyde. It is a clear liquid with an atmospheric-pressure boiling point of 131 ºC
Answer:
the answer is B the biggest one
Explanation:
If you produce 35.7 grams of sodium chloride how many molecules of Chlorine gas were
needed?
2Na + Cl2 --> 2NaCl
(PLS HELP)
Answer: [tex]7.36\times 10^{23}[/tex] number of molecules of chlorine gas are needed.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of sodium chloride = 35.7 g
Molar mass of sodium chloride = 58.44 g/mol
Plugging values in equation 1:
[tex]\text{Moles of sodium chloride}=\frac{35.7g}{58.44g/mol}=0.611 mol[/tex]
The given chemical equation follows:
[tex]2Na+Cl_2\rightarrow 2NaCl[/tex]
By the stoichiometry of the reaction:
If 1 mole of sodium chloride is produced from 2 moles of chlorine gas
So, 0.611 moles of sodium chloride will be produced from = [tex]\frac{2}{1}\times 0.611=1.222mol[/tex] of chlorine gas
According to the mole concept:
1 mole of a compound contains [tex]6.022\times 10^{23}[/tex] number of molecules
So, 1.222 moles of chlorine gas will contain = [tex]\frac{6.022\times 10^{23}}{1mol}\times 1.222mol=7.36\times 10^{23}[/tex] number of molecules
Hence, [tex]7.36\times 10^{23}[/tex] number of molecules of chlorine gas is needed.
4. How is ethanol made?
A. By fermenting sugars and starches
B. By composting grass cuttings and dinner table scraps
C. By boiling water and corn oi
D. By releasing carbon dioxide into the atmosphere
O
How many particles are in 7.07x10^-6 moles of a substance?
Answer:
4.25*10^18
Explanation:
1 mole =6.023*10^23 particles
so 7.07*10^-6 mole=6.023*10^23*7.07*10^-6 particles=4.25*10^18 particles
Too much Carbon Dioxide in the atmosphere is a bad
thing. However, too little is also bad. Explain why it is important
for Carbon Dioxide to always exist in the atmosphere. Give specific examples of what it is used for to support your response.
Answer:
CO2 is an evil necessary element. co2 is needed for our survival. we need food for survival and food is produced by the plants through photosynthesis. for photosynthesis to take place co2 is one of the vital element. so no co2,no photosyntheseis maeans no food. no food no one will survive.
Why is the C-14/C-12 ratio used to date once-living organisms?
A. C-12 becomes radioactive when an organism dies.
B. The amount of C-12 changes when an organism dies.
C. The half-life of C-14 changes when an organism dies.
D. An organism stops taking in carbon when it dies.
Which of the following diagram is the correct electron dot diagram for AL
Answer:
the answer is a
Explanation:
(reply w the answer or get reported) Ty if you answer this
Answer:
D. 34.5g
Explanation:
Using the following formula to calculate the mass of 1.5moles of sodium (Na);
Mole = mass/molar mass
Molar mass of Na = 23g/mol
mass = mole × molar mass
Mass of Na = 1.5mol × 23g/mol
Mass of Na = 34.5g
Hospital patients are administered oxygen from an pressurized
hyperbaric oxygen chamber. 600.0 L of oxygen is compressed in a
cylinder at 160.0 atm. What volume of oxygen can a cylinder supply at a
pressure of 3.0 atm?
Answer:
32000atm
Explanation:
Using Boyle's law equation;
P1V1 = P2V2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (
V2 = final volume (L)
According to the question below:
P1 = 160.0 atm
P2 = 3.0 atm
V1 = 600L
V2 = ?
Using P1V1 = P2V2
160 × 600 = 3 × V2
96000 = 3V2
V2 = 96000/3
V2 = 32000atm
A solution contains 2.38 g of magnesium chloride, MgCl, in 500 cm3 of solution
What is the concentration of
chloride ions in g/dm3?
Answer:
3.54g Cl-/dm³
Explanation:
To solve this question we must, as first, find the mass of chloride ions finding first, the moles of MgCl2. Then, we must convert the cm³ to dm³ (1cm³ = 0.001dm³).
Moles MgCl2 -Molar mass: 95.211g/mol-
2.38g * (1mol / 95.211g) = 0.0250 moles MgCl2
Moles Cl-:
0.0250 moles MgCl2 * (2mol Cl- / 1mol MgCl2) = 0.0500 moles Cl-
Mass Cl- -Molar mass: 35.45g/mol-:
0.0500 moles Cl- * (35.45g / mol) = 1.77g of chloride ions
dm³:
500cm³ * (0.001dm³ / 1cm³) = 0.500dm³
The concentration is:
1.77g of chloride ions / 0.500dm³ =
3.54g Cl-/dm³What is the ration of H2O:O2? 2H2 + O2 → 2H 20
Explanation:
What are the mole ratio and the mass ratio for H2O to O2 in the reaction 2H2 + O2 → 2H2O? Mole ratio of H2O to O2 in the given reaction is H2O : O2 = 2 : 1. Mass ratio of H2O to O2 in the given reaction is H2O : O2 = 36 : 32 = 1 : 1.1.
During which phase change does the entropy of a sample of H2O increase?
1. H2O(g) -> H2O(l)
2. H2O(g) -> H2O(s)
3. H2O(l) -> H2O(g)
4. H2O(l) ->H2O(s)
Answer: 3. H2O(l) -> H2O(g)
Explanation: Entropy is a measure of the randomness or disorder a substance. Gasses have the greatest amount of entropy and solids have the least amount of entropy. The entropy of a sample of H2O increases as liquid water evaporates and changes to a gas.
The entropy of a sample of H2O increases when the phase of change that is H2O(l) -> H2O(g) occurs. This is because entropy increases when a substance undergoes sublimation (solid to gas) or evaporation (liquid to gas).
What is meant by entropy?The entropy of an object is a measure of the amount of energy that is unavailable to do work.Entropy depends upon the randomness of molecules, number of molecules, and heat content. During which phase does entropy increase?A substance in the solid phase has low entropy.A substance in the liquid phase has medium entropy.A substance in the gas phase has high entropy.When a substance goes from a solid to a gas (sublimation) or from a liquid to a gas (evaporation), entropy increases.When the given sample of H2O changes its phase from liquid to gas, the entropy increases. It also happens when it changes from solid to gas.
Thus, option 3: H2O(l) -> H2O(g), the entropy increases.
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Wetlands provide habitats for many living things because of their sheltered waters and what other feature?
Answer:
large supply of nutrients.
Explanation:
In a wetland, the soil is covered by water or is almost covered by water. This water may be coming upwards from an underground aquifer. Wetlands are covered by water for most of the year.
They are sheltered waters and do provide habitats for many living things.
Nutrients such as; Carbon sulfur, phosphorus, carbon, and nitrogen are cycled within the soil of wetlands hence wetlands have a large supply of nutrients.
. Element X has a nucleon (mass) number of 19 and a proton (atomic) number of 9.
To which group in the Periodic Table does it belong?
a ] I
B] III
C] VII
D] 0
Answer:
C
Explanation:
it belong to that group as it needs 1 electron to be chemically stable
[tex]what \: is \: sound \: \: {?} [/tex]
Answer:
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain.
Explanation:
this is what i found hope it helps :)
Answer:
Sound is a form of energy which is caused due to the vibration of an object.
Unit Test Review
Active
1
2
3
According to the kinetic-molecular theory, what happens to a liquid when it is transferred from one container to
another?
O The volume and the shape stay the same.
O The volume increases to fill the new container, but the shape stays the same.
O The volume stays the same, but the shape changes to fit the new container
O The volume and the shape change to fill the new container
Answer:
the volume stays the same, but the shape changes to fit the new container
Explanation:
because the same amount/volume of liquid is being placed in a new container, the new container has a different shape to the old, thus changing the liquids shape but not volume.
what going on in each spot
nothing ksbsshshhzvsjajbsjshjsgdvdjhsbsj
Answer:
I don't know lol
Drag the tiles to the correct boxes to complete the pairs.
Match each mineral with its main function in the body.
Answer:
Hello calcium maintains healthy bones and muscles. Zinc is for immune function. Iron carrier oxygen to blood. Sodium maintains fluid balance in the body.
Answer: Zinc : plays a role in immune system function
Iron: carries oxygen to all body tissues
Calcium: Maintains healthy bones and muscles
Sodium: maintains fluid balance in the body
Explanation: Got it right on PLATO/edmentum
Please answer correctly I still need help on this. I will give brainliest (No links or fake answers will receive no brainliest)
How many grams of AlCl3 are needed to completely react with 2.25 of NaOH?
Hope the picture help u understand I did it in steps so it would be easier to understand:)
Explain the difference between solid,liquid an gaseous in the theorotical
Answer:
Difference between Solid Liquid and Gases
Solids Liquids Gases
Highly Strong intermolecular forces between the molecules, leads to a definite volume in Solids. The intermolecular forces are stronger than gases but weaker than solids. The intermolecular forces are practically non-existent. Thus, there is no definite volume.
Solids have a definite shape to them. Liquids do not have a definite shape. Gases do not have a definite shape.
The intermolecular space between solids is absent. The intermolecular space is moderate but present. The intermolecular space is free-flowing and plenty.
The force of attraction between the molecules is incredibly high. The force of attraction between molecules is pretty moderate. There is no intermolecular force of attraction between the molecules.