The % yield of Ca(OH)₂ : 62.98%
Further eplanationPercent yield is the compare of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
CaO + H₂O ⇒ Ca(OH)₂
mass CaO= 4.2 g
mol CaO(MW=56,0774 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{4.2}{56,0774 g/mol}\\\\mol=0.075[/tex]
mol Ca(OH)₂ based on mol CaO
mol ratio CaO : Ca(OH)₂,= 1 : 1, so mol Ca(OH)₂ = 0.075
mass Ca(OH)₂(MW=74,093 g/mol) ⇒ theoretical
[tex]\tt mass=mol\times MW\\\\mass=0.075\times 74,093 g/mol\\\\mass=5.557~g[/tex]
% yield :
[tex]\tt =\dfrac{actual}{theoretical}\times 100\%\\\\=\dfrac{3.5}{5.557}\times 100\%\\\\=62.98\%[/tex]
Which statement about the alkali metals is correct?
A. They are usually gases.
B. They are extremely unreactive.
C. They are located in the left-most column of The Periodic Table
D. They form negative ions with a -1 charge
Answer:
its c they are located in the left most column of the periodic table
What happens yo temperature in your layer as u you go higher in altitude?
Answer:
Temperatures decrease with increasing height as the ozone layer is left behind and the air thins out with increasing altitude. The lowest portion of the low-pressure mesosphere is heated by the warm air of the upper stratosphere. This heat radiates upward, getting less intense as altitude increases.
Explanation:
Brainliest please?
Which Bohr diagram is drawn INCORRECTLY?
0 iv
O i
Oii
Pls helppp
Answer:
It is indeed c (II) because there can only be 2 electrons on the first layer
Explanation:
What is Newton's 1-3rd laws of motion? Give examples for each
Answer:
In the first law, an object will not change its motion unless a force acts on it
In the second law, the force on an object is equal to its mass times its acceleration
In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.
Explanation:
Hope this helped :)
Separate the following gene sequence into codons: TACGTCTTACGCTATGTC
Answer really quick plssss
Answer:
I think it's AUGCAGAAUGCGAUACAG
3. Two substances, both liquids, start at the same temperature. You transfer
the same amount of energy out of both liquids, but substance 1 becomes a
solid before substance 2. Which substalice has a stronger molecular
attraction?
A Substance 1
B Substance 2
Pleas help I will give you Brainlyest
Answer:
Substance 1
Explanation:
Because if it becomes a solid BEFORE the other it means that the structure is more sound than the other substance. and if you add heat to something that becomes a solid it means it will come closer
I Hope this helps <3 and again i don't need the crown
help help help plsss
Answer:
4.58×10^3
3.72×10^7
Explanation:
3.8×10^2 =380
+ 4.2×10^3=4200
= 4580 = 4.58×10^3
What is the amplitude ?
Answer: The amplitude is a measure of the strength or intensity of the wave
Explanation: when looking at a sound wave, the amplitude will measure the loudness of the sound.
When drawing a covalent lewis dot diagram its important to ensure that:
A each atom is surrounded by 6 electrons
B all symbols are in lower case letters
C all the elements have a charge in the top right side
D each atom is surrounded by 8 electrons
Please help RN!! It’s due in 10 mins T^T I’ll give brainliest !!
Select the correct location on the image.
Which of these four elements is the most reactive metal?
Explanation:
the answer is rubidium
Answer:
the answer is Rb
Explanation:
i got it right
can someone help me please
Answer:
c
Explanation:its the ansr
1, If the “R” under the group title represent the elements in that group, then how any atoms of Na (sodium) will react with 1 atom of O (oxygen).
2. If the “R” under the group title represent the elements in that group, then how any atoms of Na (sodium) will react with 1 atom of H (hydrogen).
Answer:
NaH one atom of sodium react with one hydrogen to form sodium hydride
Explanation:
Which elements belong to the same group?
N, P, As,Sb
Ne, F, Ar,Kr
Rb, Sr, Y, Zr
K, Ca, Mg, Be
What are the three types of protist and how are they similar and how are they different (this is science but there is no tab for it)
Answer:
They are eukaryotic, which means they have a nucleus. Most have mitochondria
How do coastal sand dunes form in Florida?
Answer:
They are formed by windblown sand collecting around an obstruction. As organic matter is deposited by wind and waves, low herbs colonize the dune. As these plants collect more sand and organic matter, the dune increases in height becoming the fore dune.
. Which of the following natural disasters is likely to cause the most widespread damage in a coastal ecosystem?
Answer:
Wildfire
Explanation:
Fire go brrrr
A tropical cyclone is a natural disaster which is likely to cause the most widespread damage in a coastal ecosystem.
What is ecosystem?
Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
Learn more about ecosystem,here:
https://brainly.com/question/1673533
#SPJ6
3. What is found around the roots of some plants that turns nitrogen from the form we cannot use to the form we can use?
Answer:
Bacteria
Explanation:
Some plants, specifically leguminous plants form a symbiotic relationship with certain bacteria species called NITROGEN-FIXING BACTERIA in their root nodules. In this relationship, the bacteria species e.g nitrosomonas, nitrobacter etc help the plants fix atmospheric nitrogen (N2) or ammonium compounds, which are forms of nitrogen that are unusable to the plant into nitrates, a usable form.
Therefore, BACTERIA are the organisms found around the roots of these set of plants (legumes) that turns nitrogen from the form we cannot use to the form we can use.
Which of the following is an example of a chemical change?
a. freezing water to make ice.
b. a firework exploding.
c. breaking a glass bottle.
d. melting gold jewelry to make a gold bar.
Answer:
b. a firework exploding
Explanation:
what orbital represents the transition metals?
Answer:
The name transition metal refers to the position in the periodic table of elements. The transition elements represent the successive addition of electrons to the d atomic orbitals of the atoms. In this way, the transition metals represent the transition between group 2 (2A) elements and group 13 (3A) elements.
Explanation:
what atoms are in Au(NO2)2
In science, all ideas are not tested with evidence from the natural world.
Question 4 options:
True
False
Answer:
i belive its trrue
Explanation:
Answer:
i think its false i hope this helps
Explanation:
Which of the following are possible characteristics for the element this atom represents?
A.
Hard, can be flattened by a hammer
B
A non-reactive colorless gas
C.
Dull, non-conductor of heat and electricity
D
Shiny silver, can be coiled into a wire
Answer:
B
Explanation:
Sorry if i'm wrong
Compute the number of ions in 58.5 g oh nacl
Answer: Explanation:
58.5 g of Na Cl = 1 mole 5.85 g ofNaCl = 1 X 5.85/58.5 = 0.1 mole Each molecule of NaCI contains one Na ion and one Cl ion = 2 ions Total moles of ions in 0.1 mole of NaCI = 2 x 0.1 = 0.2 molesPlease help
As the temperature increases, the molecular motion of the molecules decreases and it
becomes difficult to overcome the polar attractions.
a. TRUE
b. FALSE
What is energy? Write a paragraph describing the following forms of energy: mechanical energy, chemical energy, Sound energy and radiant energy. Include examples of each in your paragraph.
Answer and Explanation
According to Science J Rank,
__________________________________________________________
Heat EnergyHeat energy is the movement of energy from one object to another. It is also called thermal energy. It can move in three ways: through conduction, convection, or radiation.
__________________________________________________________
Conduction occurs when heat moves directly from one object to another. What happens when you leave your car parked in a sunny parking lot on a hot day? The heat of the sun passes directly through the metal of the car and heats the air (and seats) on the inside.
__________________________________________________________
Energy Hot vehicles in the summer are a form of heat energy.
Convection is the movement of hot liquids or gases. For example, when you boil water, the liquid nearest the flame heats up first. As it gets hot, it rises, and the cooler water goes to the bottom where it gets heated. This continues until the water is boiled.
__________________________________________________________
Radiant EnergyRadiant energy is the energy created through electromagnetic waves, such as light, heat, or radio waves. The sun is our major source of radiant energy because it gives off a great amount of heat and light. Scientists use the electromagnetic spectrum to discuss the types of radiant energy. The electromagnetic spectrum lists all the types of radiant energy by the length of their waves. The shorter the wave, the more energy and heat are created.
__________________________________________________________
Electrical EnergyA huge maze of wires in every house carries electrical energy to do many different jobs, from lighting your home to cooking food.
Electricity starts at the atomic level. Atoms are made up of a nucleus, protons, and electrons. We create electricity by forcing electrons to move from atom to atom. Electrical energy is the movement of electrons through a conductor. A conductor is a material that can carry electricity, like the wiring in homes.
__________________________________________________________
Generators create the electricity used in our everyday lives, but other forms of electric energy occur naturally.
Lightning occurs when electrons are discharged from a cloud. Lightning is so powerful that if we could capture the electricity in a single bolt, it could power our entire home for days.
__________________________________________________________
Static Electricity occurs when an object (or person) gets charged with electrons. You may have experienced this when scuffing your feet on a carpet and then touching a doorknob. The electrons you built up jump from your hand to the metal of the doorknob, causing a powerful shock!
__________________________________________________________
Chemical EnergyChemicals contain stored, or potential, energy to hold their atoms together. When chemicals are mixed together, a reaction can occur. Chemical energy is the energy released through a chemical reaction.
We can use the heat that these reactions give off. We can use it to cook, to heat our homes, and to burn the gasoline that moves our cars.
One of the major uses of chemical energy is to help produce electrical energy. Coal, gas, and other fuels are burned to run electric generators.
The chemical energy in batteries is changed into the electrical energy we need to run everything from flashlights to toys.
__________________________________________________________
Nuclear EnergyAtoms are so small that until recently even the most powerful microscopes could not see them. Yet when we split the nucleus of an atom, a tremendous amount of energy is released. Nuclear energy is the potential energy stored in the nucleus of an atom.
In a nuclear power plant, a reactor is used to split uranium atoms. This heat is used to turn water to steam. The steam powers a generator that creates electricity.
Nuclear power plants create about 20 percent of the electricity in the United States. Coal, oil, and natural gas help produce the rest.
__________________________________________________________
Hope this helps! <3
__________________________________________________________
Plz help
A candle burning is an example of
A. an endothermic change
B. a physical change
C. energy being taken in
D. an exothermic change
Answer:
D
Explanation: An exothermic change is Because it has heat.
What is meant by the term isotopes?
Sodium is a soft, white metal that reacts violently with water. Chlorine is a poisonous yellow-green gas. During the chemical reaction between sodium and chlorine, table salt is produced. Which of the following statements correctly compares and contrasts the reactants with the resulting products used in a chemical equation?
A. The reactants are dangerous and the product can be eaten
B. The reactants and the products observe the law of conservation of mass
C. The reactants are a solid and a gas and the product is a gas
D. The reactants and the products are the same color
Answer:
B. The reactants and the products observe the law of conservation of mass
Explanation:
The reaction equation is given as:
2Na + Cl₂ → 2NaCl
Such a chemical reactions usually obeys the law of conservation of mass. The law states that "in a chemical reaction, matter is neither created nor destroyed but bonds are rearranged".
So, the most correct thing is that reactants and products observe the law of conservation of mass. The number of atoms on both sides of the expression will be the same. Therefore, option B is correct.the first question please!
Where was the first permanent European settlement in what is now the United States?
A.
St. Augustine, Florida
B.
New Orleans, Louisiana
C. Plymouth, Massachusetts
D
Jamestown, Virginia
Need help ASAP
Answer:
Jamestown, Virginia
Explanation:
Answer:
jamstown
Explanation: