External fertilization in animals usually occurs in water or in damp areas in a process called spawning.
Chemistry question on enthalpy HELP!!!!
Answer: The enthalpy change for this reaction is, -803 kJ
Explanation:
The balanced chemical reaction is,
[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g)[/tex]
The expression for enthalpy change is,
[tex]\Delta H=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]
[tex]\Delta H=[(n_{CO_2}\times \Delta H_{CO_2})+(n_{H_2O}\times \Delta H_{H_2O})]-[(n_{O_2}\times \Delta H_{O_2})+(n_{CH_4}\times \Delta H_{CH_4})][/tex]
where,
n = number of moles
Now put all the given values in this expression, we get
[tex]\Delta H=[(1\times -394)+(2\times -242]-[(2\times 0)+(1\times -75)][/tex]
[tex]\Delta H=-803kJ[/tex]
Therefore, the enthalpy change for combustion of methane is, -803 kJ
How many moles are in 5.5 x 10-23 molecules of H2O
Answer:
0.914moles
Explanation:
The number of moles in a substance can be got by dividing the number of atoms/molecules/particles by Avagadro's constant (6.02 × 10^23).
That is;
number of moles (n) = number of atom (nA) ÷ 6.02 × 10^23
According to this question, there are 5.5 x 10-23 molecules of H2O
n = 5.5 x 10^23 ÷ 6.02 × 10^23
n = 0.914 × 10^(23-23)
n = 0.914 × 10^0
n = 0.914 × 1
n = 0.914moles
How many moles are there in 3.9 grams of potassium
Answer:
0.0997 mol K
Explanation:
First of all, the picture and your question do NOT match so I will solve for what you are asking for.
3.9g x 1 mol/39.10 g = 0.0997 mol K
The 39.10 grams is the atomic mass of potassium
How does solar energy affect climate?
Answer:
It makes it things grow and it is renewable energy meaning that its infinite and will help life grow fruits grass and with that comes how animals live including us human how does it effect climate it make thing warm and sometimes hot and can cause thunder to make the place cool down sorry if wrong
Match the special cases of each gas law with its description. A law may be used more than once. In the equations, K is a constant.
A. Boyle's law
B. Charles's law
C. Avogadro's law
D. Dalton's law
____ P1 V1 = P2 V2
____ V/T = k
____ V1 / T1 = V2 / T2
____ V = kn
____ PV = k
____ Ptotal = P1 + P2 + P3 + .
The special cases of gas laws and its description includes:
A. Boyle's law: P1 V1 = P2 V2
B. Charles's law: V/T = k or V1 / T1 = V2 / T2
C. Avogadro's law: V = kn
D. Dalton's law: Ptotal = P1 + P2 + P3 + .
What is gas law?Gas laws are laws that relate a gas's pressure, volume, and temperature. Boyle's law, named after Robert Boyle, states that the pressure P of a gas varies inversely with its volume V at constant temperature, or PV = k, where k is a constant. Charles' law is named after J. -A. -C.
They also include; Gay-Lussac's Law, Avogadro's Law and Dalton's law of partial pressures.
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A closed container has 5.60 x 1023 molecules of oxygen gas (O2). How many moles is that?
What is the purpose of the stairstep pattern on the periodic table of the elements?
Answer: The bold staircase in the periodic table allows us to classify which elements are metalloids.
Explanation: Additionally, it acts like a "divider" that allows us to properly distinguish the metals from the non-metals in the periodic table.
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How many atoms of oxygen are in 75.6g of silver nitrate (AgNO3)?
Answer:
1.50x10^21 molecules O2
Explanation:
photosynthesis is chemical change that happens in the plant what substance within the plant allows light energy to be captured
Explanation:
Sunlight provides the energy needed for photosynthesis to take place. In this process carbon dioxide and water are converted into oxygen (a waste product that is released back into the air) and glucose (the source of energy for the plant).
How many meters are in 21.5 km?
Answer:
21500m
Explanation:
Answer:
21, 500 meters
Explanation:
There are 1000 meters in a kilometer. Muliply 21.5 x 1000 to find this.
Hope it helps!
A substance has a fixed volume. What else do you need to know to determine its state of matter?
Answer:
If it can change shapes easily.
Explanation:
A fixed volume eliminates gas as a possible state of matter, therefore leaving liquid and solid.
If the substance can easily change shape, it is a liquid. If it cannot change shape, then it is a solid.
Another way to determine the state of matter is through particle movement.
If particles slip past each other, it is a liquid. If particles vibrate in place, it is a solid.
why do molecules and atoms speed up when the amount of heat increases
Heat is the energy that a thing possesses as a result of the movement of its atoms and molecules, which are always bouncing off of one another and other objects. An object's atoms and molecules move more quickly when we add energy to it, which increases the object's energy of motion or heat.
The gas will travel more quickly in the container if the temperature is raised. This occurs as a result of the particles' increased kinetic energy caused by heating. There will be more collisions between particles if they are traveling faster.
A substance's atoms and molecules move more quickly when it is heated. Whether the substance is a solid, liquid, or gas, this occurs.
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GIVE ME ANSWERS
i will give you a brain list
Part II: Fill in the Blank-Complete each sentence; you may put more than one word in a
blank.
9. _____________ have a mass number of 0.
10. Particles found in the nucleus are called ______________________.
11. _____________________________ is when electrons are released by a hot filament.
12. The number of protons and neutrons in an element is called the _______________ number.
13. ____________________ was the first atomic bomb dropped.
14. _________________ would be an example of a spontaneous change to the nucleus.
15. _____________ decay results in the release of two protons and two neutrons.
16. __________________ are particles that would be attracted to a positively charged plate.
17. __________________________ coined the word radioactivity.
18. ____________________________________ is used to produced radioactive isotopes by
forcing nuclear reactions.
19. During __________________, the nucleus of a Uranium 235 atom is split into lighter
elements, neutrons, and energy.
20. _________________ are the fastest form of radiation.
21. The number of protons in an element is called the _______________ number.
22. Irene Curie used ___________________ as the source of alpha particles for her research.
23. Uranium goes through _____________ decay ____________ (a number) times to produce
Plutonium.
24. ________________ is a raw Uranium ore which was central to the discovery of radioactivity.
25. The ____________________ was cited in the letter signed by Einstein as having ore with
high concentrations of U-235.
Answer:
uh.. How many do you want done??
Explanation:
Regardless of how much mass they have, all stars will become a ______?
Answer:
high mass- a red supergiant
low mass-red giant
Explanation:
All stars, regardless of their size, eventually run out of fuel and collapse due to gravity
Suppose you have an ice cube with mass of 8.00 g at a temperature of 295 K. If that ice cube is heated until it is completely converted to steam at 373 K how many joules of heat must be added ?
Explanation:
In order to be able to answer this question, you must know the value of water's enthalpy of fusion, ΔHfus
2H20 → 2H2 + O2
Type of reaction?
Answer:
Notice how the elements splitIt is a decomposition reaction I do exams and quizzes if ur interestedHelp ASAP!!!!10 Points
The sun’s mass is about 30 million times greater than the moon. Why does the gravitational pull between Earth and the moon affect Earth’s tides more than the gravitational pull between Earth and the sun?
a The moon is denser than the sun.
b The moon is closer to Earth than the sun.
c The moon has phases, but the sun does not.
d The moon orbits Earth, but the sun does not.
Answer:
B
Explanation:
stronger gravitational gradient
1) If a rod of chromium weighing about 323.98 grams is cooled in a
bucket containing 35 grams of water, and the final temperature is.
54.5°C, what is the specific heat of chromium?
Answer:
See explanation below
Explanation:
In order to do this, you are missing two important data, which are the initial temperatures of the water and the rod.
For practical purposes, I will assume this data, and then you'll just replace the procedure with your data to get an accurate result.
So, for this exercise, I will assume that the rod of Chromiun was heat to 100 °C and then cooled with water at 20 °C, so the final temperature is 54.5 °C.
To get the specific heat, we need to use the following expression:
q = m.C.ΔT (1)
Where:
q: Heat of the substance/compound
m: mass
C: specific heat
ΔT: Difference of temperature of the mixture.
With this expression, we need to calculate first the heat of the water, because:
q₁ + q₂ = 0
Therefore, with the value of the transfered heat, we can determine later the specific heat. So, As we have the specific heat of water which is 4.18 J/g °C, and the temperature and mass, we can determine the heat of the mixture:
ΔT = 54.5 - 20 = 34.5 °C
q₁ = 35 * 4.18 * 34.5
q₁ = 5047.35 J
Now, we can determine the specific heat of the rod:
q₁ = -q₂
-5047.35 = 323.98 * (54.5 - 100) * C
-5047.35 = -14741.09C
C = 0.34 J/g °CHope this helps
what is the product for the synthesis reaction Na+O2
1-NaO
2-NaO2
3-Na2O
4-Na3O2
5-Na2O3
6-Na2O2
How many significant figures are in this measurement: 1,250,500
The periodic table notation for nitrogen (N) is shown below. An atom of nitrogen has how many neutrons?
N
Nitrogen
14.01
A.0 7 or 8
B.Cannot be determined with the information given.
C.7
D.14 or 15
Which substance is the least toxic?
a. chlorine (LD50 = 850 mg/kg)
b. vitamin A (LD50 = 2000 mg/kg)
c. cola (LD50 = 140 mg/kg)
d. aspirin (LD50 = 200 mg/kg)
Answer:
I believe it's D. I searched up a lethal table chart and it states Aspirin is even more toxic than chlorine. As for the other two, it didn't specifically state it was toxic with one dose - meaning you have to take more than one dose for toxicity to take effect.
Explanation:
If I combine atoms then I must be performing which process?
A) Radiation Reaction
B) Strong Force
C) fission
D)Fusion
Answer:
D: fussion
Explanation:
The process called nuclear fussion.
for example, four hydrogen atoms combine in a nuclear fussion reaction to form one helium atom.
500.0 mL of a gas is collected at 745 K. What will the volume be at standard temperature?
Answer:
183.22mL
Explanation:
Using Charles law equation, which is as follows:
V1/T1 = V2/T2
Where;
V1 = initial volume (mL)
T1 = initial temperature (K)
V2 = final volume (mL)
T2 = final temperature (K)
Note that standard temperature of a gas is 273K.
Hence, based on the provided information, V1 = 500.0mL, T1 = 745K, V2 = ?, T2 = 273K
Using the formula; V1/T1 = V2/T2
500/745 = V2/273
Cross multiply
V2 × 745 = 500 × 273
745V2 = 136500
V2 = 136500/745
V2 = 183.22
At standard temperature (273K), the new volume will be 183.22mL.
Answer:
183 ml
Explanation:
22. Which of the following are examples of mixtures?
I
a jar of nuts and bolts
II trail mix consisting of a variety of nuts and dried fruits
III carbon monoxide gas coming out of a car's exhaust pipe
an
pare
A. I and II only
C. I and III only
B. I and III only
D. I, II, and I
23. Which of the following lists contains only individual elements?
A. water, sugar, and salt
B. carbon, copper, and iron
C. tomato juice, propane,
D. sulfuric acid, magnesium, and chocolate chip cookies
and soda pop
Answer:
22.)B. l and lll only
23.)D.sulfuric acid, magnesium, and chocolate chip cookies
and soda pop
Which have a mass of 0 amu?
A. Protons
B. Neutrons
C. Electrons
D. Protons and neutrons
E. Protons and electrons
F. Neutrons and electrons
I give Brainliest!
Answer:
c
Explanation:
Answer:
C. electrons. They also have a charge of -1
Escucho activamente a mis compañeros y compañeras, reconozco otros puntos de vista, los comparo con los míos y puedo modificar lo que pienso ante argumentos más sólidos.
Answer:
Explanation:
Vale, y entonces que ahora???
How are different elements determined?
Calculate the number of nitrogen atoms in 20.9 grams of nitrogen.
Answer:
N=5.47×10^23
Explanation:
n=
[tex]n = \frac{m }{ar} [/tex]
N=n×la
for an atom to be considered electrically neutral it must contain the same number of