Answer: 0.25
Explanation: M = moles of solute / volume of solution (L)
First, you need to calculate the number of moles using the given mass and the molar mass.
15 g74.692 g/mol≈0.20 mol
Then, you can solve for molarity using the molarity equation. The answer should be reported to two significant figures.
M=0.20 mol/ 0.800 L = 0.25 M
The molar concentration of NiO solution is 0.251 M.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Considering the given example, molar concentration of NiO is found out as follows,
molar concentration=15/74.69 ×1/0.8= 0.251 M.
where 74.69 is molar mass of NiO.
Thus, the molar concentration of NiO is 0.251 M.
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Which of these is the best definition of sustainable development
Answer:
Sustainable development is a way for people to use resources without the resources running out. ... The term used by the Brundtland Commission defined it as development with sustainability that "meets the needs of the present and also compromising the ability of future generations to meet their own needs."
Which of the following is not a valid conversion factor?
Answer:
d
Explanation:
The pKa of an acid depends partly on its environment. Predict the effect of each of the following environmental changes on the pKa of a glutamic acid side chain. (a) A lysine side chain is brought into proximity. (b) The terminal carboxyl group of the protein is brought into close proximity.
Answer:
A. Decrease
B. Increase
Explanation:
A. A lysine side chain is brought into proximity:
lysine is basic in its nature, it would have to stabilize the electrostatic interaction and also weak interactions existing among the acidic amino acids and hydrogen bond. This would then reduce or decrease the pH and thus pKa of the protein.
B. The effect of this on pKA is an increase on the pKA. The carboxyl group is acidic. When it is removed, it would then cause the pKA to be increased. There would be accumulation of more negative change by basic amino acids increasing the pKA.
HELP ASAP PLS. Which of the following best describes the relationship between air temperature and relative humidity?
A. Cold air cannot hold any water vapor.
B. Warm air can hold less water vapor than cold air.
C. Cold air can hold less water vapor than warm air.
D. Warm air and water vapor are measured in degrees Celsius (⁰C).
Answer:
I think the answer might be C.
How many formula units make up 21.6 g of magnesium chloride (MgCl2)? Express the number of formula units numerically.
1.37 × 10²³ formula units MgCl₂
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 21.6 g MgCl₂
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of Mg - 24.31 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of MgCl₂ - 24.31 + 2(35.45) = 95.21 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 21.6 \ g \ MgCl_2(\frac{1 \ mol \ MgCl_2}{95.21 \ g \ MgCl_2})(\frac{6.022 \cdot 10^{23} \ formula \ units \ MgCl_2}{1 \ mol \ MgCl_2})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 1.36619 \cdot 10^{23} \ formula \ units \ MgCl_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.36619 × 10²³ formula units MgCl₂ ≈ 1.37 × 10²³ formula units MgCl₂
State the postulate of Bohr theory
Answer:
Bohr's model of the hydrogen atom is based on three postulates:
1) An electron moves around the nucleus in a circular orbit,
2) An electron's angular momentum in the orbit is quantised,
3) The change in an electron's energy as it makes a quantum jump from one orbit to another is always accompanied by the emission or absorption of a photon. Bohr's model is semi-classical because it combines the classical concept of electron orbit (postulate 1) with the new concept of quantisation ( postulates 2 and ).
10. How might life in America be different if the Civil Rights Movement had never happened?
a. Public places could still be segregated
b. Voting would be easier for everyone
c. Slavery might still exist
d. Americans would be more tolerant of peaceful protests
Answer: A or C because of the civil right movement changed a lot of stuff as if it never happened blacks would of still be segregated, the U.S wouldn't be the same and they also mentioned that the U.S would not be respected by many other countries which would hurt them from developing even more in the future.
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:
Is ionization complete or incomplete when sodium hydroxide compounds are dissolved in water and why?
Answer: Ionization is complete when sodium hydroxide compound is dissolved in water as it is strong electrolyte.
Explanation:
Strong bases are good electrolytes as they completely dissociate to give ions which help in the conduction of electrical current.
Weak bases are those substances which dissociate partially to give hydroxide ions [tex](OH^-)[/tex] when dissolved in water.
Example: [tex]NH_4OH\rightleftharpoons NH_4^++OH^-[/tex]
Strong bases are those substances which dissociate completely to give hydroxide ions [tex](OH^-)[/tex] ions when dissolved in water.
Example: [tex]NaOH\rightarrow Na^++OH^-[/tex]
When sodium hydroxide (NaOH) compounds are dissolved in water (H₂O), ionization takes place completely.
What is ionization?Ionization is a process, where compound on dissociation coverts into ions.
Dissociation of NaOH takes place as follow:
NaOH → Na⁺ + OH⁻
Here NaOH, is a strong electrolyte or strong base which completely dissociate into ions and never combine to again form NaOH. Whereas weak electrolytes are those which partially dissociate into ions and gives reaction like as:
AB ↔ A⁺ + B⁻
Complete ionization takes place when sodium hydroxide compounds are dissolved in water.
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In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent ___________ in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at __________________. Using a _______, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add _______________ in order to dissolve the solid.
Answer:
just until it covers the sample
a low setting and increasing gradually
pipet
as little solvent as possible
Explanation:
In order to dissolve a chemical sample in a recrystallization solvent, add the room-temperature solvent just until it covers the sample in an Erlenmeyer flask on a hot plate. Turn on the heat, starting at a low setting and increasing gradually. Using a pipet, add additional solvent from a second container on the heat source. Swirl the sample flask after each addition, and try to add as little solvent as possible in order to dissolve the solid.
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!
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
n = 4, l=2, ml= 2 which orbital?
Answer:
It's the 4d orbital
Explanation:
n is the principal quantum number, n=4, means the 4th orbital, l=2, means 'f'(l=0,1,2,3 which means spdf respectively)
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
mineral and nutrient solution is in water epiphyte plants or hydroponic plants
Answer:
hydro ponic plants
Explanation:
coz they are hydro
How many moles in 2.45 x 10^45 atoms of sodium, Na?
A. 4.07 x 10^21 moles
B. 1.47 x 10^47 moles
C. 4.07 x 10^467 moles
D. 1.678 moles
please only answer if you know and please show your work
Good News! Here is a sheet to show you how to perform mole calculations: http://www.sciencewithmrjones.com/downloads/chemistry/moles/how_to_perform_mole_calculations.pdf
Which of the following molecules is least soluble in water?
Answer:
CCl4
Explanation:
Because it is non polar and non polar substances are insoluble in water.
The molecule which is least soluble in water is C(Cl)₄
Which molecules are soluble in water?Water is polar molecule and only polar molecules are soluble in water.
(CH₃)₂CO is a polar molecule as due to partial positive and negative charges on carbon and oxygen atom as a result of which it is soluble in water.C(Cl)₄ is a non polar molecule as net dipole moment of the molecule is zero, so it is insoluble in water.CH₃OH is also polar molecule and shows solubility in water.(CH₃)₂O is also polar and dissolve in water.Hence tetra chloro carbon is insoluble in water.
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which planet in are solar system haves most moons
Answer:
Jupiter
Explanation:
What animal has a see through body?
Which ecosystem likely has the lowest species diversity?
O a habitat with high rainfall and high sunlight
O a habitat with low rainfall and high sunlight
O a habitat with low rainfall and low sunlight
O a habitat with high rainfall and low sunlight
Answer:
a habitat with low rainfall and low sunlight
Explanation:
Because little to nothing grows in ground that is frozen year-round except for some forms of microscopic life
Write the orbital notation and electron configuration for the following elements. (Worksheet #2)
1. Chlorine
2. Vanadium
3. Arsenic
Answer:
the answer is B
Explanation:
Answer:
answer is number 2.
Explanation:
hope this helps
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.
Comparing metalic and covalent bonds in terms of nature of the bond
Answer:
Covalent bond involves the sharing of electrons, while metallic bonds have strong attractions and ionic bonds involve the transferring and accepting of electrons from the valence shell. The adhering property of an atom, in order to arrange themselves in a most stable pattern by filling their outermost electrons orbit.
Why does there appear to be another duck head in the water?
A
The water in the pond reflects light from the Sun, making a mirror image
B
The molecules in the atmosphere refract the light, splitting it into two ima
С
The duck scatters the light, making hundreds of tiny refractions that collec
D
The bottom of the pond absorbs the light, then projects it toward the surfa
Answer:
it's A. The water in the pond reflects light from the Sun, making a mirror image
Explanation:
i just took the test
Ve. In what layer do weather balloons fly?
Earth layers
Answer:
stratosphere
Explanation:
Plsss help
a. Given that the density of oxygen is 1.439 g/L, how many liters of oxygen gas
can be produced if 5.0 moles of mercury (II) oxide are heated?
Assuming each solution to be 0.10 M , rank the following aqueous solutions in order of decreasing pH.Rank the solutions from the highest to lowest pH. To rank items as equivalent, overlap themN2H2Ba(OH)2HOCLNAOHHCL
Answer:
Ba(OH)₂ > NaOH >N₂H₂ > HOCl > HCl
Explanation:
To get a better understanding of this, we need to know what's the meaning of the pH values.
The pH value of any compound basically gives us information of how acidic or basic is a compound. If this value is higher (>7), means major basicity; if this number is lower (<7) means major acidity in the compound.
According to this, a strong acid would be the one with the lowest pH, and a strong base would be the one with the highest pH.
Among the 5 compounds we have here, only 2 of them are acid, and the rest is basic, so we can assume that both acid would have the lower pH, it's up to us to see which of them have the lowest pH.
To do that, we can use the following expression:
pH = -log[H⁺]
If all solutions have a concentration of 0.10, then the pH would be:
HCl:
pH = -log(0.1) = 1
HOCL:
This one is a weak acid, so it's not completely dissociated in solution and the [H⁺] would be <0.1 M. As its a weak acid, we can assume that it's pH would be near 4, 5 or 6. We cannot know with all certain, because we need the Ka of this acid, and see the dissociation of the acid in solution, but for this case, it's fine and HCl is one of the strongest known acid.
In this case the order is: HOCl > HCl
For the bases, we have 3 bases, 2 of them are strong bases, and 1 of them is a weak base so it doesn't dissociate completely (N₂H₂), so this would have the lowest pH among the bases. In the case of bases, we calculate pOH, (Same formula as before) and then, we substract 14 from the value of pOH. As for the other two:
Ba(OH)₂:
Concentration would be double because we have 2 OH, so:
[OH⁻] = 2 * 0.1 = 0.2 M
pOH = -log(0.2) = 0.69
pH = 14 - 0.69 = 13.31
NaOH:
pOH = -log(0.1) = 1
pH = 14 - 1 = 13
Therefore, Ba(OH)₂ is stronger than NaOH and N₂H₂. So, our order would be:
Ba(OH)₂ > NaOH >N₂H₂ > HOCl > HClHope this helps
How does a temperature increase cause the rate of a reaction to increase?
O A. It increases the kinetic energy of the molecules.
O B. It decreases orientation requirements of the molecules,
C. It increases the equilibrium constant for the reaction,
D. It decreases the activation energy of the reaction.
Help me please !!!
Answer:
the answer is c because it will have a equilibrium constant for the action
A temperature increase causes the rate of a reaction to increase because it increases the kinetic energy of the molecules. The correct answer is option A.
Kinetic energy is the energy that an object possesses due to its motion. It is defined as one-half of the mass of an object multiplied by the square of its velocity.
This means that the molecules move faster and collide more frequently, which increases the likelihood of successful collisions between reactant molecules. An increase in temperature also increases the average kinetic energy of the molecules, which means that more of them will have enough energy to overcome the activation energy barrier and react.
Therefore, increasing the temperature increases the kinetic energy of the molecule. Option A is the correct answer.
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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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