Answer:
The anomalous expansion of water refers to the fact that water, unlike most substances, expands when it freezes. The density of water increases as temperature decreases, but reaches a maximum at 4 degrees C then begins to expand. The significance of this is that ice is less dense than water so it floats in water.
This is of major biological importance. Lakes, ponds and streams freeze from the top down instead of from the bottom.
How many boron (B) and sulfur (S) atoms are in B253?
Answer:
2 boron and 3 sulfur
Explanation:
The subscript/ number behind and under is a subscript this tells you how many atoms there are
How many moles of mercury are equivalent to 3.46 x 1023 atoms?
Answer:
3.02 X1023 atoms Ag limol. - - 0.50 1 moles. 6.02241023 atoms.
1. How many mg of lithium phosphide are in 18.0 mL of a 1.25 M solution?
Answer:
1160mg
Explanation:
Molarity = number of moles ÷ volume
According to the information in the question, molarity = 1.25 M, volume = 18.0 mL = 18/1000 = 0.018L
M = n/V
n = M × V
n = 1.25 × 0.018
n = 0.0225moles.
Using mole = mass/molar mass, to find the mass of lithium phosphide (Li3P)
Molar mass of Li3P = 6.9(3) + 31 = 51.7g/mol
mole = mass/molar mass
0.0225 = mass/51.7
mass = 1.16grams.
In milligrams (mg), mass of Li3P = 1.16 × 1000 = 1160mg
Ammonia (NH3 (g), Delta.Hf = –45.9 kJ/mol ) reacts with oxygen to produce nitrogen and water (H2 O(g), Delta.Hf = –241.8 kJ/mol) according to the equation below. 4 upper N upper H subscript 3 (g) plus 3 upper O subscript 2 (g) right arrow 2 upper N subscript 2 (g) plus 6 upper H subscript 2 upper O (g). What is the enthalpy of the reaction? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants.. –3,572.1 kJ –1,267.2 kJ 1,267.2 kJ 3,572.1 kJ
Answer: –1,267.2 kJ
Explanation: B on edge, thank me later ;-)
–1,267.2 kJ is the enthalpy of the given reaction. Therefore, the correct option is option A among all the given options.
What is enthalpy?Enthalpy is a thermodynamic system's internal energy total as well as the volume times pressure ratio. Enthalpy is a property or state function that resembles energy; it has the same dimensions as energy and is therefore measured in joules or ergs. The value of enthalpy is solely dependent on the temperature, pressure, as well as composition of the system, not on its history.
The shift in the internal energy equals equivalent to the heat transmitted to, much less than the jobs completed by, the system, in accordance with the principle of energy conservation. The enthalpy change is precisely equal to the heat transmitted to the system if the sole work performed is a change in volume at constant pressure.
ΔH = ΔH for product - ΔH for reactant
= 3,572.1 kJ –1,267.2 kJ
= –1,267.2 kJ
Therefore, the correct option is option A.
To learn more about enthalpy, here:
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WILL MARK BRAINLIEST!!! Think about how to determine the molar mass of NH4OH,
In that amount of ammonium hydroxide, how many moles
would you have? In other words, the molar mass of any
compound is equal to
2 moles
1 mole
4 moles
0,5 moles
ZnH2 + Cl2 → 2HCI + Zn
How many grams of Cla are needed to produce 6.2 moles of HCI?
O 868 grams Cl2
O 217 grams Cl2
O 434 grams Cl2
O 108.5 grams Cl2
Answer:
2 moles H
2
Explanation:
Your tool of choice here will be the mole ratio that exists between zinc metal,
Zn
, and hydrochloric acid,
:HCl
, in the balanced chemical equation.
Zn
(s]
+
2
HCl
(aq]
→
ZnCl
2(aq]
+
H
2(g]
↑
⏐
You're dealing with a single replacement reaction in which zinc displaces the hydrogen from hydrochloric acid. The products of the reaction are aqueous zinc chloride and hydrogen gas.
Now, as you can see from the balance chemical equation, a
1
:
2
mole ratio exists between the two reactants.
This tells you that in order for the reaction to take place, you need to have twice as many moles of hydrochloric acid as you do of zinc metal.
http://people.springfield.k12.or.us/jim.tyser/chemcom/Resources/unit1ans.html
http://people.springfield.k12.or.us/jim.tyser/chemcom/Resources/unit1ans.html
At the same time, you have a
2
:
1
mole ratio between hydrochloric acid and hydrogen gas.
This means that the reaction will always produce half as many moles of hydrogen gas as you have moles of hydrochloric acid.
Since you know that
4
moles of hydrochloric acid are taking part in the reaction, and assuming that you have enough zinc metal so that it doesn't act as a limiting reagent, you can say that the reaction will produce
4
moles HCl
⋅
1 mole H
2
2
moles HCl
=
2 moles H
2
Explanation:
Is hc2h3o2 quadraprotic?
HELP !
The provided balanced equation applies to the reaction that takes place between lithium hydroxide and sulfuric acid. 2LiOH + H2SO4 -> Li2SO4 + 2H2O .
If the reaction begins with 26.7 grams of lithium hydroxide (LIOH) and 164.08 grams of suite acid (H2SO4.), how many grams of lithium sulfate (Li2SO4,) is produced? Assume 100% yield . Round your answer to the nearest tenth of a gram .
Answer:
60g or 61.28g
Explanation:
Trust me on this I had the same problem as you
A 0.239 gram sample of a gas in a 100-ml flask exerts a pressure of 603 mm Hg at 14 Celsius. What is the gas? (Hint: don’t forget BRINCLHOF)
A) chlorine
B) nitrogen
C) krypton
D) xenon
D) oxygen
Please help me and explain how u got ur answer
Answer:
A) chlorine
Explanation:
To solve this question we can use:
PV = nRT
In order to solve the moles of the gas. With the moles and the mass we can find the molar mass of the gas to have an idea of its identy:
PV = nRT
PV / RT = n
Where P is pressure: 603mmHg * (1atm / 760mmHg) = 0.7934atm
V = 100mL = 0.100L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 14°C + 273.15 = 287.15K
0.7934atm*0.100L / 0.082atmL/molK*287.15K = n
3.37x10⁻³ moles of the gas
In 0.239g. The molar mass is:
0.239g / 3.37x10⁻³ moles = 70.9g/mol
The gas with this molar mass is Chlorine, Cl₂:
A) chlorinehow many protons are in phosphorous
Answer:
There are 15 protons in phosphorous.
~Hoped this helped~
~Brainiliest?~
When scientist need to work on Sharks and some other fish in water they flip them upside down on their backs because
Answer:
In simple words, Sharks have the ability to enter a trance state. Whenever a shark is flipped upside around it enters a trance-like experience known as tonic immobilization.
That's why, when certain researchers are operating on saw fish with in ocean, they often turn them over. Otherwise, there is a chance that the fish might start panicking and the work of scientist will get tougher.
C3H8 + 5O2 → 3CO2 + 4H2O
Cassandra calculated a percent yield of 75% for grams of water produced. The theoretical yield for water is 8.2 grams. How many grams of water did Cassandra actually produce during the lab?
a)9.0 grams
b)6.2 grams
c)8.2 grams
d)10.9 grams
Answer:
b)6.2 grams
Explanation:
Recall that percentage yield =
actual yield/theoretical yield * 100/1
theoretical yield = 8.2 grams
percentage yield = 75%
Let the actual yield be x
Hence;
75 = x/8.2 * 100
75 = 100x/8.2
75 * 8.2 = 100x
x = 75 * 8.2/100
x = 6.15 g
x = 6.2 g
75 =
please help me with this answer
Answer:
1) Hom DOMINANT
2) Hom recessive
3) Hetero DOMINANT
4) Hom DOMINANT
5) Hetero DOMINANT
6) Hom recessive
Explanation:
The _______ biome is the largest on Earth.
Explanation:
taiga the largest land well forest
What area of mathematics is used to calculate parallax?
algebra
geometry
calculus
trigonometry
Answer:
algebra
Explanation:
The parallax formula states that the distance to a star is equal to 1 divided by the parallax angle,
p
, where
p
is measured in arc-seconds, and
d
is parsecs.
I'm positive that the answer is trigonometry.
Refer to the following passage that I got from the Edg assignment.
"How then do astronomers measure the distance of stars? The parallax, considered very accurate, is one method used by astronomers to measure the distances to nearby stars. The diameter of the earth’s orbit around the sun is about 300 million km. By observing a star one day and then again six months later, these scientists will be able to observe differences in the star the two times it was observed. Using trigonometry, these different angles yield the distance of how far away a star is."
A balloon has a negative charge and a glass rod has a positive charge.
Electromagnetic Forces Review: Mastery Assessment #3: INTEG SCIENCE 7-Jolley
What will happen when the glass rod is brought near the balloon?
Cuando el oxígeno reacciona con el calcio produce un sólido blanco muy utilizado en la preparación de cementos. ¿Cuál de las siguientes reacciones describen el anterior proceso?
Answer:
2Ca + O₂ → 2CaO
Explanation:
Cuando el Calcio (Ca) reacciona con oxígeno (O₂) se produce cal (CaO). La cal es un sólido inodoro de color blanco a grisáceo. La cal es un óxido que se encuentra presente en el cemento y su cuantificación permite determinar la calidad y el tipo de cemento a utilizar.
La reacción que describe el proceso anterior es:
Ca + O₂ → CaO
Para balancear los oxígenos, se deben poner 2 CaO como producto:
Ca + O₂ → 2CaO
Para balancear los calcios, se pone como coeficiente del Ca un 2:
2Ca + O₂ → 2CaOEsta última es la reacción que describe el proceso anterior
Even though the same amount of energy was transferred into both substances from the air, the isopropanol evaporated while the water did not. Why do you think the isopropanol changed phase, but the liquid water did not ... Earlier in the lesson, you observed isopropanol and water drops on a paper towel.HELP HELP PLS
Answer:
The isopropanol evaporated while the water did not because the molecules don't stick together as strongly as the molecules in the water do. The water would need more energy transferred in, in order to evaporate.
Explanation:
The isopropanol evaporates and the water does not because the heat capacity and the latent heat of isopropanol is far lesser than that of water.
The latent heat of vaporization is the amount of heat required by a given amount of substance to change its phase from liquid to gas. The latent heat of vaporization of isopropanol is far less than water, so at the same amount of heat, the isopropanol changes phase as it can easily evaporate even if a small amount of heat is provided. Whereas water requires to absorb a lot of heat energy to change its phase, since its latent heat of vaporization and specific heat capacity is very large as compared to isopropanol.
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Unilt lest
Unit Test Active
TIME REMAINING
01:22:52
Which shower would most likely be the control group in this
study?
Mildew is a fungus that grows in wet areas and can slowly
grow from microscopic to large stains in showers and sinks
Researchers are studying different sprays that could be used
to slow down the growth of mildew. They set up different
showers that are exactly the same and expose them each to
water with the same microscopic amount of mildew. They
then spray some showers with mildew-preventing sprays and
observe how fast mildew grows over time.
O the shower sprayed with many test sprays
the shower not exposed to any mildew at all
O the shower not sprayed with any mildew-preventing spray
O the shower sprayed with a test spray that is already
known to work
Answer:
Option C, the shower not sprayed with any mildew-preventing spray is most likely be the control group in this study
Explanation:
Complete question
Mildew is a fungus that grows in wet areas and can slowly grow from microscopic to large stains in showers and sinks. Researchers are studying different sprays that could be used to slow down the growth of mildew. They set up different showers that are exactly the same and expose them each to water with the same microscopic amount of mildew. They then spray some of the showers with mildew-preventing sprays and observe how fast mildew grows over time. Which show would most likely be the control group in this study? A- the shower sprayed with many test sprays B- the shower not exposed to any mildew at all C- the shower not sprayed with any mildew-preventing spray D- the shower sprayed with a test spray that is already known to work
Solution
In any experiment, a control group is a group of participants that is not exposed to any treatment so that it can be compared with the experimental group on which the treatment is applied/given.
In this case - experimental group are the stained showers that are subjected to the different types of mildew test sprays while the control group is the the shower not sprayed with any mildew-preventing spray.
Hence, option C is the correct answer
What is the chemical compound of CI2P
what are 5 reason masks are important for the virus
Answer:
they reduce viral transmission
They prevent asymptomatic spread
You're protecting others from illness.
They're mandated by law in some states
They're good hygiene in general
Which reaction occurs when equivalent quantities of H" (or H30) and OH" are mixed?
1.
oxidation
2.
reduction
3
hydrolysis
4.
neutralization
Answer: A reaction which occurs when equivalent quantities of H" (or [tex]H_{3}O^{+}[/tex]) and OH" are mixed is a neutralization reaction.
Explanation:
When acid and base chemically combine together to form sat and water then it is know as neutralization reaction.
An acidic substance gives hydrogen ions [tex](H^{+})[/tex] on dissociation and a basic substance gives hydroxide ions [tex](OH^{-})[/tex] on dissociation.
For example, [tex]H^{+} + OH^{-} \rightarrow H_{2}O[/tex] is a neutralization reaction where an acid and base are mixed together to form water.
No salt is formed as because here the reactants are not present as compounds.
In a hydrolysis reaction, water molecule(s) is added to the reactant molecules.
For example, [tex]CH_{3}COOCH_{3} + H_2O \rightarrow CH_{3}COOH + CH_{3}OH[/tex]
Oxidation is the process of addition of oxygen to a molecule and removal of hydrogen.
Reduction is the process of addition of hydrogen in a compound and the removal of oxygen atom.
Therefore, we can conclude that reaction which occurs when equivalent quantities of H" (or [tex]H_{3}O^{+}[/tex]) and OH" are mixed is a neutralization reaction.
Need help ASAP
Will mark BRAINLIST and thank you only for correct answers
Mr. Whiteman has two stock solutions of sulfuric acid (H2SO4) in the supply closet: 12.1 M and 6.0 M. If he wants to make 10.0 mL of a 1.0 M solution, which stock solution makes more sense to use? Justify with two calculations.
Answer:
12.1-M requires less volume of stock solution.
Explanation:
Hello there!
In this case, according to the foundations of dilution processes, it turns out convenient to remember that the moles of the solute before and after the dilution remains the same; for that reason we use the following equation:
[tex]M_1V_1=M_2V_2[/tex]
Relating the initial and final molarities and volumes. Now, it is seen that V2 is 10.0 mL and M2 is 1.0 M, which means that if we solve for V1 for 12.1 M and 6.0 M, we obtain the following volumes:
[tex]V_1=\frac{M_2V_2}{M_1} \\\\V_1^{12.1M}=\frac{1.0M*10.0 mL}{12.1M}=0.826mL\\\\V_1^{6.0M}=\frac{1.0M*10.0 mL}{6.0M}=1.67mL[/tex]
Therefore, since the 12.1-M solution requires less volume of stock solution, it makes sense to use this one as the initial solution.
Best regards!
What causes Earth to orbit the sun ?
Answer:
gravity pulls on the earth and putts it in orbit around the sun
Explanation:
PLEASE ANSWER THESE QUESTIONS FOR 21 POINTS AND A BRAINLIEST, KEEP IN MIND THESE QUESTIONS ARE VERY IMPORTANT AND WILL DETERMINE MY GRADE!!!!(NO GUESSING, SPAMMING OR LINKS)
This is energy that is stored for later use.
kinetic energy
potential energy
mechanical energy
electromagnetic energy.
A ball rolling down the hill is an example of ___ energy.
1 point
Kinetic
Potential
Electrical
Sound
Requires two parents
1 point
Sexual reproduction
Asexual Reproduction
Small grains that contain a plant's male reproductive cells.
1 point
stamen
pollen
pistil
stigma
C, D , and E are collectively known as the ______.
1 point
Captionless Image
stamen
anther
sepal
pistil
Small leaf-like structures forming an outer circle at the base of a flower.
1 point
petals
sepal
stigma
pistil
The stalk that supports or holds up the anther is the
1 point
style
filament
ovary
pistil
A flower structure that encloses and protects ovules and seeds as they develop.
1 point
Petal
Ovule
Stigma
Ovary
the part of the ovary of seed plants that contains the female germ cell and after fertilization becomes the seed.
1 point
Ovule
Style
Stamen
.Pistil
Supports the stigma, serves as passageway for pollen
1 point
Anther
Style
Stem
Ovule
Renewable energy resources are?
1 point
A resource that cannot be readily replaced by natural means on a level equal to its use.
Invisible resources
Renewable resources that can be naturally restored.
All the above
Coal and oil are?
1 point
Non-Renewable energy resources
Renewable energy resources
None of the above
Bio-fuel and geothermal energy are examples of?
1 point
Non-renewable energy resources
Hydro energy
Renewable energy resources
None of the above
What is the name of flower part #10 ?
1 point
Captionless Image
sepal
pollen tube
filament
stigma
Which of the following is NOT a Natural Resource?
1 point
Coal
Paper
Solar
Wind
What is the disadvantage of using non-renewable resources?
1 point
They have a large carbon footprint.
They can all be used up over time.
They can lead to global warming.
All of these.
Quicklime is an incredibly caustic substance that has been used during plagues to quickly dissolve diseased corpses. Calcium carbonate can be heated to produce quicklime (CaO) and carbon dioxide gas. What mass of quicklime could be produced from a 4,500g bag of calcium carbonate?
Answer:I just want points
Explanation:because I need them for future questions
What is the difference between the total number of California condors in 1982 and the total population in 2016?
Answer:
The California Condor is on the verge of extinction. There were three individuals, all males, known to be living free in late 1986. That was a drop from fifteen wild birds (including five breeding pairs) known to have been present in 1984. Twenty-one condors were also alive in captivity toward the end of 1986.
Explanation:
Why are isotopes with short half-lives not useful for dating very old rocks?
-because not enough of the parent isotope remains to measure accurately
-because not enough of the daughter product has formed to be detectable
-because neither the parent isotope nor the daughter product will be detectable
-because very old rocks would never have contained these isotopes
Answer:
The radioactive isotopes within these brains typically record the ages of the grains-not the time when the sedimentary rock was formed, making it difficult to date using radiometric dating. The half-life of U-235 is 704 million years.
Explanation:
hope this helps but if i'm wrong then i'm sorry..
Answer:
D
Explanation:
Very old rocks would be been formed before said isotopes with short half-lives. We're thinking of a very long geological time. The original rock might be rock C, then years and years later rock Y would be measured. Y can't match C since there's too much unknowns in between.
Which of the following actions decreases the entropy of a system?
A-mixing baking soda and salt
b- freezing water
c- dissolving salt in water
d-boiling water
Answer:
b- freezing water
Explanation:
Solid<liquid<gas is the general rule for entropy increase
Freezing water would change the phase from liquid to solid which would lead to less entropy