Answer:
exothermic reaction
Explanation:
because it occurs in the presence of heat
Which stage in a frog's life cycle is most similar to a plant seed?
A Eggs
B. Tadpole
C. Froglet
D. Adult Frog
PLEASE HELP WILL GIVE BRAINLIEST
Answer: B
We use stoichiometric amounts of P4 and PH3
NO.9) It's actual yield
How much heat is necessary to vaporize 685 g of H20 at 100°C? The heat of vaporization
of H2O is 540 cal/g.
0 370,000 cal
O 1.22 x 103 cal
O 88,400 cal
01.27 kcal
h
Question 8
3.33 pts
Answer:
370,000 cal
Explanation:
Step 1: Given data
Mass of water (m): 685 gHeat of vaporization of water (ΔH°vap): 540 cal/gStep 2: Calculate the heat necessary to vaporize 685 g of water
Vaporization is the process in which a liquid converts to a gas, at a constant temperature. The heat required (Q) is:
Q = ΔH°vap × m
Q = 540 cal/g × 685 g
Q = 3.70 × 10⁵ cal
How many moles are present in 2.126 g of H2O2 ?
Answer:
molecular weight of H2O2 or grams. This compound is also known as Hydrogen Peroxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O2, or 34.01468 grams.
1 grams H2O2 is equal to 0.029399071224542 mole.
1 grams H2O2 to mol = 0.0294 mol
10 grams H2O2 to mol = 0.29399 mol
20 grams H2O2 to mol = 0.58798 mol
30 grams H2O2 to mol = 0.88197 mol
40 grams H2O2 to mol = 1.17596 mol
50 grams H2O2 to mol = 1.46995 mol
100 grams H2O2 to mol = 2.93991 mol
200 grams H2O2 to mol = 5.87981 mol
There are 0.0625mol in 2.126 g of H2O2.
HOW TO CALCULATE MOLES:
The number of moles of a substance can be calculated by dividing the mass of the substance by its molar mass. That is;no. of moles (mol) = mass (g) ÷ molar mass (g/mol)According to this question, 2.126 g of H2O2 were given. The number of moles of H2O2 can be calculated as follows:Molar mass of H2O2 = 1(2) + 16(2)= 2 + 32
= 34g/mol
no. of moles = 2.126g ÷ 34g/molno. of moles = 0.0625molTherefore, there are 0.0625mol in 2.126 g of H2O2..Learn more at: https://brainly.com/question/21085277?referrer=searchResults
A sample is in the second half-life. What percent of the sample is stable at this point?
A. 12.5%
B. 25%
C. 50%
D. 75%
Answer:
75%
Explanation:
on edg :)
Which of these sentences probably comes from a work of classic literature?) PLEASE HELP ILL GIVE YOU BRAINLEIST!
A. The greedy man was harsh as winter, and had never done a generous deed in his long life; he was a hermit.
B. The man who refused to share with those in need had never felt the warmth that comes from giving.
C. The most selfish man in town was one who lived alone and never had visitors of any sort, except maybe lawyers.
D. The miser was hard and sharp as flint, from which no steel had ever struck out generous fire; he was as solitary as an oyster.
The sentences that probably comes from a work of classic literature are:
The most selfish man in town was one who lived alone and never had visitors of any sort, except maybe lawyers. The miser was hard and sharp as flint, from which no steel had ever struck out generous fire; he was as solitary as an oyster.What types of books are regarded as classics?The great literary works of Greek, Roman, and other prehistoric civilizations are referred to as classical literature. Classical literature includes the writings of Homer, Ovid, and Sophocles. The phrase isn't just applicable to books. It can also incorporate other types of writing, such as epic, lyric, tragedy, comedy, and pastoral.
Classical literature enables us to take a profound plunge into the lives, worldviews, and mindsets of individuals we have never met, to travel to unfamiliar settings, and to comprehend eras we will never be able to experience ourselves.
Therefore, option C and D are correct.
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True or False: All metals have high melting points.
Answer:
True. All metals have a melting point when it reaches a certain degree of temperature
Explanation:
5 A snowball sits at the top of the hill. Which of the following changes will increase the kinetic energy of the snowball? A Additional snow falls on the snowball, increasing its mass. B The snowball is pushed and rolls down the hill, gaining speed. The weather warms and the snowball melts, decreasing its mass. D The snowball is moved and now sits on a hill that is higher.
Answer:
B
Explanation:
it is B because in order to have kinetic energy the object has to be in motion, because if it wasnt in motion and sitting on the hill then it has potentail energy, hope this helps
How is continental crust different from oceanic crust?
A: Oceanic crust is thicker and more dense.
B: Oceanic crust is thinner and more likely to sink.
C: Continental crust is thicker and more likely to sink.
D: Continental crust is more dense and lighter.
Answer:
b
Explanation:
google lol ur welcome
B: Oceanic crust is thinner and more likely to sink.
what does the phrase sea of electrons describe?? please help
Answer: Metallic Bonding.In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a “sea” of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions.
Explanation:
What are the rules for writing
names/formulas for covalent
compounds? Give examples
where you need to produce
the formula from the name
AND the name from the
formula
Answer:
When naming molecular compounds prefixes are used to dictate the number of a given element present in the compound. ” Mono-” indicates one, “Di-” indicates two, “Tri-” is three, “Tetra-” is four, “Penta-” is five, and “Hexa-” is six, “Hepta-” is seven, “Octo-” is eight, “Nona-” is nine, and “Deca-” is ten.
why is it important to prepare for disaster? what are the things you need to prepare?
Explanation:
The reason why it is important to prepare for an disaster is because Being prepared can reduce fear, anxiety, and losses that accompany disasters. People also can reduce the impact of disasters (flood proofing, elevating a home or moving a home out of one's harm's way, and securing items that could shake loose in an earthquake) and sometimes avoid the danger completely.
The things you need to prepare for an disaster is
WaterFoodClothing Money if neededFlash lightBatteriesFirst aid kitYou can even need an radio( to keep updated).What are the rules for writing
names/formulas for ionic
compounds? Give examples
where you need to produce
the formula from the name
AND the name from the
formula. Make sure to
include examples of
transition metals and
polyatomic ions.
What 3 particles make up an atom and what is their electrical charge?
How are the three intermolecular forces related?
Explanation:
Intermolecular forces are electrostatic in nature and include van der Waals forces and hydrogen bonds. ... The three major types of intermolecular interactions are dipole–dipole interactions, London dispersion forces (these two are often referred to collectively as van der Waals forces), and hydrogen bonds.May 20, 2018
What else is produced when sodium carbonate decomposes?
Na2Co3 - Na2O+
Answer:When a single compound breaks down into two or more compounds or elements in a chemical reaction then it is known as decomposition reaction.
The chemical symbol for sodium carbonate is .
The decomposition of sodium carbonate is:
The decomposition of sodium bicarbonate, will result in the formation of sodium oxide, and carbon dioxide, .
Hence, carbon dioxide, will produce with sodium oxide, on decomposition of .
Explanation:Na2CO3 Na2O +CO2 CO2 is the answer
In the acetylene torch, acetylene gas (C2H2)(C2H2) burns in oxygen to produce carbon dioxide, water, and energy: 2C2H2(g)+5O2(g)⟶Δ4CO2(g)+2H2O(g)2C2H2(g)+5O2(g)⟶Δ4CO2(g)+2H2O(g) You may want to reference (Pages 241 - 243) Section 7.7 while completing this problem. Part A How many moles of O2O2 are needed to react with 1.85 molmol of C2H2C2H2? Express your answer to three significant figures and include the appropriate units. nn(O2O2) = nothingnothing SubmitRequest Answer
Answer:
4.63 mol
Explanation:
Step 1: Write the balanced complete combustion reaction of acetylene
2 C₂H₂(g) + 5 O₂(g) ⟶ 4 CO₂(g) + 2 H₂O(g)
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of C₂H₂ to O₂ is 2:5.
Step 3: Calculate the number of moles of O₂ needed to react with 1.85 moles of C₂H₂
We will use the stoichiometric molar ratio.
1.85 mol C₂H₂ × (5 mol O₂/2 mol C₂H₂) = 4.63 mol O₂
In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?
A. one
B. two
C. three
D. four
E. none
Also, state why.
Answer:
E
because it forms the ionic bond but not covalent.
What is the mass percent of oxygen (0) in SO2?
32.1 g
A.
x 100%
16.0 g + 16.0 g
(16.0 g +16g)(6.02 x 1023)
B.
100 g
16.0 g
x 100%
(32.1 g + 16.0 g + 16.0 g)
D.
(16.0 g + 16.0 g)
X 100%
(32.1 g + 16.0 g + 16.0 g)
SUIRMIT
Answer:
D. (16.0 g + 16.0 g) × 100% / (32.1 g + 16.0 g + 16.0 g) = 49.9%
Explanation:
Step 1: Detemine the mass of O in SO₂
There are 2 atoms of O in 1 molecule of SO₂. Then,
m(O) = 2 × 16.0 g = 16.0 g + 16.0 g = 32.0 g
Step 2: Determine the mass of SO₂
m(SO₂) = 1 × mS + 2 × mO = 1 × 32.1 g + 2 × 16.0 g = 32.1 g + 16.0 g + 16.0 g = 64.1 g
Step 3: Detemine the mass percent of oxygen in SO₂
We will use the following expression.
m(O)/m(SO₂) × 100%
(16.0 g + 16.0 g) × 100% / (32.1 g + 16.0 g + 16.0 g) = 49.9%
Answer:
16.0 g + 16.0 g) × 100% / (32.1 g + 16.0 g + 16.0 g) = 49.9%
Explanation:
The molar solubility of CaSO4 in water is 0 .67 gram per liter of solution. Calculate the Ksp.
Answer:
Ksp = 2.4 * 10⁻⁵
Explanation:
The equation for the dissolution and dissociation of CaSO4 in water is given as: CaSO₄ ---> Ca²⁺ + SO₄²⁻
The expression for the Ksp of the dissociation equation above is:
Ksp = [Ca²⁺] [SO₄²⁻]
The molar ratio of the dissociated ions and the solute is 1 : 1, this means that every 1 mole of CaSO₄ that dissolves produces 1 mole of Ca²⁺ and SO₄²⁻ each
The molar solubility of a substance is the number of moles that dissolve per liter of solution.
molar solubility of CaSO₄ = number of moles /liter of solution
number of moles of CaSO₄ = mass/molar mass
molar mass of CaSO₄ = 136 g/mol
number of moles of CaSO₄ = 0.67/136 = 0.0049 moles
molar solubility of CaSO₄ = 0.0049 mol/ 1 L = 4.9 * 10⁻³ moles per liter
therefore, molar solubility of CaSO₄ = 4.9 * 10⁻³
Ksp = (4.9 * 10⁻³) (4.9 * 10⁻³)
Ksp = 2.4 * 10⁻⁵
Answer:
2.4 * 10^-5
Explanation:
Molar solubility of CaSO4 = 0 .67 g/L/136 g/mol = 4.9 * 10^-3 Mol/L
Given that;
CaSO4(s) -------> Ca^2+(aq) + SO4^2-(aq)
Hence, Ksp = [Ca^2+] [SO4^2-]
Where [Ca^2+] =[SO4^2-]=s
Ksp = s^2
since s = 4.9 * 10^-3 Mol/L
Ksp = (4.9 * 10^-3 Mol/L)^2
Ksp = 2.4 * 10^-5
Melting can be best described as a process in which molecules?
Answer:
... lose kinetic energy and move slowly.
Melting can be best described as a process in which molecules gain enough kinetic energy to get past each other.
Create an atom diagram using the Bohr model. Directions Choose three elements from the following list. Use a periodic table to determine the number of protons, neutrons, and electrons. Draw a diagram of each element you have selected. Use a separate piece of paper for each element. Be sure your drawing is neat, legible, and accurate. Use this data table to record information about each element. Element #1 Element #2 Element #3 Element #4
Answer:
Explanation:
proposed an early model of the atom as a central nucleus containing protons and neutrons being orbited by electrons in shells. As previously discussed, there is a connection between the number of protons in an element, the atomic number that distinguishes one element from another, and the number of electrons it has. In all electrically-neutral atoms, the number of electrons is the same as the number of protons. Each element, when electrically neutral, has a number of electrons equal to its atomic number.
Answer:
You can check diagram with number of proton neutron and electrons
Explanation:
Ramps make work easier by decreasing the amount of force needed to move an object by ______ the distance it travels.
A. reducing
B. increasing
C. equalizing
The Lewis diagram for BH2 is:
[H-B-H]-
The electron- pair geometry around the B atom in BH2 is:__________.
There are______lone pair(s) around the central atom, so the geometry of BH2 is________ .
Answer:
Electron pair geometry- trigonal planar
There is one lone pair around the boron atom
The geometry of BH2 is bent
Explanation:
The valence shell electron pair repulsion theory offers a frame work for determining the shape of molecules based on the number of electron pairs of the valence shell of the central atom in the molecule.
In BH2-, the central atom is boron. There is a lone pair on boron. Owing to the lone pair on boron, the molecular geometry of BH2 is bent.
The geometry of the electron pair around the Boron atom in [tex]BH_2[/tex] is called the trigonal planar. In this case, there is a pair of isolated electrons around Boron, which is the central atom, allowing the [tex]BH2[/tex] molecule to have a folded geometry.
We can arrive at this answer because:
Boron is an element that has three electrons in its valence layer.With this, we can find out that it can make three covalent bonds or donate these electrons to achieve chemical stability.In the case of the [tex]BH_2[/tex] molecule, boron forms covalent bonds with Hydrogen.These bonds allow the Hydrogens to be positioned on either side of the Boron molecule, forcing a pair of their electrons to focus on the center of that molecule, until it is attracted to the extremities.This allows for a folded geometry around the molecule, allowing Boron to be an exception to the octet rule and achieve stability with 5 electrons in the valence layer.
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ASAP PLZ HELP I WILL MARK BRAINLIEST Based on the diagram, what can you conclude about the pole of the magnet? O It is a south pole because the field lines spread out from this end. O It is a north pole because the field lines spread out from this end, O It is a south pole because the field lines enter the magnet at this end. O It is a north pole because the field lines enter the magnet at this end.
Answer:C
Explanation:I took the test
Answer:
It is a south pole because the field lines enter the magnet at this end.
Explanation:
How does adding a lone pair affect the position of existing atoms and lone pairs
Answer:
How does adding a lone pair affect the position of existing atoms and lone pairs? It decreases the angles between the atoms - the atoms are moving closer because they are being repelled further away from the lone pairs then they are from the other atoms
Explanation:
hope it helps!
Please help....thank you
Answer:
a. volcanic changes create new land
Help plz 11 points i need help plz give me TWO not one TWO
!!
in which type of bond are electron shared between atoms?
A. ionic
B.covalent
C.metallic
If 765 mL of a gas at 2.78 atm, has the volume Change to 2.47 L , What is the pressure of the
gas in atm?
Answer:
0.87 atmExplanation:
The new pressure can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new pressure
[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]
From the question
2.47 L = 2470 mL
We have
[tex]P_2 = \frac{765 \times 2.78}{2470} = \frac{2142}{2470} \\ = 0.867206...[/tex]
We have the final answer as
0.87 atmHope this helps you