What type of element has 8 electrons in their outer most level?
non-metals
metals
noble gases
alkali metals
Answer:
Noble gases
Explanation:
Neon and argon have 8 electrons in their outermost shells. The elements which have 8 electrons in the outermost shell or in the valence shell,are known as the noble gases.
It's the third one or Noble gases.
Question 5
2 pts
How many atoms of helium are found in a helium balloon if it has 3.9g of helium
inside?
The answer should be
x1023
Type the number that precedes the x1023
Answer: There are [tex]6.2\times 10^{23}[/tex] atoms of helium are found in a helium balloon if it has 3.9 g of helium inside.
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=\frac{3.9g}{4.00g/mol}=0.975moles[/tex]
1 mole of helium contains = [tex]6.023\times 10^{23}[/tex] atoms
Thus 0.975 moles of helium contain = [tex]\frac{6.023\times 10^{23}}{1}\times 0.975=6.2\times 10^{23}[/tex] atoms
2NH3+2O2- N2o+3H2O
If 80.0 grams of O2 are reacted in the above reaction,how many grams of N2O will be produced?
Answer:
55.025g of N2O
Explanation:
2 NH3 + 2 O2 → N2O + 3 H2O
moles of O2 = 80.0/32 = 2.5 moles O2
moles of N2O = 2.5 moles O2 * 1 mole N2O
= 1.25 moles N2O
moles = mass/Molar mass
mass = moles * Molar mass = 1.25 x 44.02 = 55.025 g
Question 9 a N20(9) + CO(9) - N2(9) + CO2(9) The rate of the reaction represented above increases significantly in the presence of Pd(s). Which of the following best explains this observation?
А Pd increases the activation energy of the reaction.
B Pd absorbs the heat produced in the reaction. C One of the reactants binds on the surface of Pd, which introduces an alternative reaction pathway with a lower activation energy.
D One of the products binds on the surface of Pd, which increases the reaction rate by decreasing the concentration of products in the mixture.
Answer:
Ans choise B
Explanation:
Increasing rates of reaction by catalysts always results because of decrease in activation energy occurs.
chemical formula for calculating pressure
Answer:
First, let's review the ideal gas law, PV = nRT. In this equation, 'P' is the pressure in atmospheres, 'V' is the volumes in liters, 'N' is the number of particles in moles, 'T' is the temperature in Kelvin and 'R' is the ideal gas constant (0.0821 liter atmosphere per moles Kelvin).
Explanation:
I majored in Chemistry
what are called conductors of electricity
Answer:
Some materials let electricity pass through them easily. These materials are known as electrical conductors. Many metals, such as copper, iron and steel, are good electrical conductors.
I hope it's helpful!
A tank contains one hundred fifty kmol of an aqueous phosphoric acid solution with 5.00 mole% H3PO4. The solution is concentrated by adding pure phosphoric acid at a rate of 30.0 L/min. Molecular weight of phosphoric acid is 98. Density of phosphoric acid is 1.834 kg/L. Determine the mole fraction of phosphoric acid in the tank at 25 minutes.
Answer:
Mole fraction = 0.1313
Explanation:
given data
Addition rate of pure phosphoric acid = 30L/min
Phosphoric acid added in 25 min = 750 L
solution
mass is express as here
mass = density × volume and number of moles = mass ÷ molar mass
So, In terms of moles
phosphoric acid added = (750 × 1.834) ÷ 98
phosphoric acid added = 14.036 kmol
and
moles of phosphoric acid in tank = 0.05 × 150 + 14.036
moles of phosphoric acid in tank = 21.536 kmol
and
Moles of water in tank = 0.95 × 150
Moles of water in tank = 142.5 kmol
So that Mole fraction of phosphoric acid in tank
Mole fraction = 21.536 ÷ (21.536+142.5)
Mole fraction = 0.1313
HCl (aq) + H2O (l) ⇌ H3O^+ (aq) + Cl^- (aq)
In 1.0 M HCl (aq), is nearly 100 percent dissociated, as represented by the equation above. Which of the following best helps to explain why, in 0.01 M HCN (aq), less than 1 percent of HCN is dissociated?
A. Compared to the HCl (aq) solution, the concentration of the HCN (aq) solution is much too dilute to achieve 100 percent dissociation.
B. The CN^- ion is not very soluble in water, and a solid precipitate would form if more of the HCN dissociated..
C. The equilibrium constant for the dissociation of HCN (aq) is much smaller than that for the dissociation of HCl (aq).
D. HCN (aq) reacts with water to form a basic solution, and the high concentration of OH^- (aq) interferes with the dissociation process.
There is lesser dissociation of hydrogen cyanide as compared to HCl, as equilibrium constant for the dissociation of hydrogen cyanide has been smaller than HCl. Hence, option C is correct.
Hydrogen cyanide has been a weak acid that has been dissociated into the constituent ions. The dissociation of the compound in water has been corresponds to the equilibrium constant.
Equilibrium constant for hydrogen cyanide and HClThe equilibrium constant has been defined as the ratio of the concentration of solute and solvent ions at equilibrium.
The sample with lesser equilibrium constant tends to dissociate at lesser concentration as well.
The equilibrium constant for the dissociation of hydrogen cyanide has been smaller than HCl. Thus, there will be lesser dissociation of hydrogen cyanide as compared to HCl. Hence, option C is correct.
Learn more about equilibrium constant, here:
https://brainly.com/question/17960050
how many litres of hydrogen is present in 12 grams of hydrogen
Answer:
10 the power of 23 hydrogen atom
what is used to create motion
Answer:
These forces make objects change their motion or movement , the act of going from one place to another.
Explanation:
HELP!!! TIMED! THANK YOU!
Answer:
The answer is A.
Explanation:
Answer:
Explanation:
I believe it is a
Please help me answer this I will mark brainliest
Answer:
A is brain, ND the fact that u don't know this stuff is a lil bit sad, u can so look it
Explanation:
According to Markovnikov's rule of the electrophilic addition to an alkene, the electrophile, usually a proton, is more likely to add to the ___________ in a double bond. This arrangement places the intermediate carbocation on the ________ , which stabilizes it with the presence of _________. In the major product of a reaction following Markovnikov's rule, the___________ will then end up on the more-substituted carbon in a double
Answer:
Explanation:
To fill in the gaps with the appropriate words, we need to rewrite the whole text in the question while adding the right answers to it.
[tex]According \ to \ Markovnikov's \ rule \ of \ the \ electrophilic \ addition \ to \ an \ alkene, \\ \\ the \ electrophile, \ usually, \ a \ proton, \ is \ more \ likely \ to \ add \ to \ the \ \mathbf{less \ substituted \ carbon} \\ \\ \ in \ a \ double \ bond.[/tex]
[tex]This \ arrangement \ place \ the \ intermediate \ carbocation \ on \ the \ \mathbf{more \ substituted \ carbon.}[/tex][tex]Which \ stabilizer \ it \ with \ the\ presence \ of \ \mathbf{more \ substituents} \ the \ major \ product \ of[/tex]
[tex]the \ reaction \ following \ markovnikov \ rules \ the \ \mathbf{nucleophile} \ will \ then \ end \ up[/tex]
[tex]with \ the \ m ore \ substituted \ carbon \ in \ the \ double \ bond.[/tex]
3. What is an
electrolyte?
Answer:
An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. ... A substance that dissociates into ions in solution acquires the capacity to conduct electricity. Sodium, potassium, chloride, calcium, magnesium, and phosphate are examples of electrolytes.
Explanation:
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What might be one potential solution for eliminating the crown-of-thorns starfish from the Great Barrier Reef?
introducing a predator to eat the starfish
eliminating their food supply to starve them
introducing a different species that outcompetes them
hunting or culling by humans
Answer:
hunting or culling by humans
Explanation:
The hunting will decrease the starfish
A certain rock has a mixture of several different elements. It contains 33g of zinc, 22g of
iron and 16g of oxygen. What percentage of the rock, by mass, is zinc?
Answer:
46.5%
Explanation:
mass of rock = 33g + 22g + 16g = 71g
% mass of zinc = (33/71) * 100%
= 0.465 * 100%
= 46.5%
Which of the following is not a valid conversion factor?
Answer:
d
Explanation:
Sodium benzoate, the sodium salt of benzoic acid, is used as a food preservative. A sample containing solid sodium benzoate mixed with sodium chloride is dissolved in 50.0 mL of .5 M HCl, giving an acidic solution (benzoic acid mixed with HCl ). This mixture is then titrated with .393 M NaOH. After the addition of 46.50 mL of the solution, the pH is found to be 8.2. At this point, the addition of one more drop ( .02 mL) of NaOH raises the pH to 9.3 . Calculate the mass of sodium benzoate (NaC6H5COO) in the original sample. (Hint: At the equivalence point, the total number of moles of acid [here HCl] equals the total number of moles of base [here, both NaOH and NaC6H5COO]
Answer:
Protegerte Freddy Gerrard Reverte Freddy Buffett irrefutables
Explanation:
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The PH of a solution of Hcl is 2.find out the amount of acid present in a litre of the solution
Answer:
The solution is 10^-2 or 0.01M in HCl.
Explanation:
meaning of pH is "power of hydrogen".
what is the molar concentration of a HCl solution with pH=2?
Let say pH=2
[H+]=10^-2M
HCL is a strong acid that dissociates completely:
[H+]=[HCL]
Therefore solution is 10^-2 or 0.01M in HCL.
Dos Identy each statement whether TRUE or FALSE. Write you answer m
1. Mammals are warm blooded animals that are born alive.
2. Reptiles are cold blooded vertebrates that are hatched from egs.
3. Vertebrates have no economic importance to our environment.
4. There is a significant relationship between vertebrates
5. Invertebrate animals are important to human beings.
and invertebrates.
Answer:
1=true
2=false
3=false
4=true
5=true
What animal has a see through body?
what is the overall equilibrium constant of 4NH3+7O2=4NO2+6H2O
Answer:
An apple, potato, and onion all taste the same if you eat them with your nose plugged
Explanation:
Gold is yellow, shiny, smooth, and is found in the ground. A geologist finds a material that she thinks may be gold. Which of the following tests would reveal that
the material is not gold and not an element?
A. Its density is different from that of gold.
B. Its melting point is different from that of gold.
C. The material is composed of two different substances.
D. Its boiling point differs from that of gold.
WHEN TWO CARBONS FORM A DOUBLE BOND IT IS CALLEDD AN
Answer:
A carbon–carbon bond is a covalent bond between two carbon atoms. ... Carbon atoms can also form double bonds in compounds called alkenes or triple bonds in compounds called alkynes. A double bond is formed with an sp2-hybridized orbital and a p-orbital that is not involved in the hybridization.
Explanation:
The empirical formula of a sample of gold bromide was found by adding aluminum metal to an aqueous solution of gold bromide, displacing gold metal.
a. True
b. False
Answer:
a. True
Explanation:
The formula for determining the gold bromide formula, aqueous solution is added. When the solution is introduced with aluminum metal, the gold bromide reacts and displaces the gold metal. This is an electrolysis technique which is used for metals.
HELP ASAP PLS. The melting of a glacier is an example of the interactions among which of Earth’s spheres?
A. geosphere, troposphere, cryosphere
B. atmosphere, geosphere, cryosphere
C. atmosphere, asthenosphere, biosphere
D. hydrosphere, asthenosphere, atmosphere
Answer:
d. hydrospher, asthenosphere, atmosphere
Answer:
its actually b atmosphere, geosphere, cryosphere atmosphere
Explanation: atmosphere is most likely the heat in the air or the water evaporating , cryosphere is the ice that forms the glaciers. and thats how i know im not sure about geosphere but i know its none of the others ones hope this helps :D
What the mechanisms of action of acidic acid with asprin
Synthesis. The synthesis of aspirin is classified as an esterification reaction. Salicylic acid is treated with acetic anhydride, an acid derivative, causing a chemical reaction that turns salicylic acid's hydroxyl group into an ester group (R-OH → R-OCOCH3).
hope it's help
#carryONlearningjohn roller skates with a constant speed of 8 miles per hour. how long will he take to travel a distance of 28 miles? please use the formula Speed = Distance/Time
Answer:
3.5hrs
Explanation:
Using the formula Speed = Distance/Time
Given
Speed = 8mi/hr
Distance = 28miles
Get the time
Time = Distance/Speed
Time = 28/8
Tme = 3.5hrs
Hence it will take 3.5hrs to travel
Helpppppp plsssssssss
Answer:
air,water,rocks,and the ibex
Explanation:
these are the non living things I'm pretty sure
nitrophenol is more acidic than phenol.
Answer:
The p- nitrophenol is more acidic than phenol because the deactivating nature of nitro group and after loosing the protons it makes more resonance stabilization as nitro group is having strong deactivating nature so it attracts electrons towards it.