Answer:
The answer is "4.37."
Explanation:
at [tex]0^{\circ} C\ Ka = 1.76 \times 10^{-5}[/tex]
[tex]\to pKa = - \log \ Ka[/tex]
[tex]= - \log \ 1.76 \times 10^{-5}\\\\ = 4.75[/tex]
[tex]pH = pKa + \log \frac{[sodium \ acetate]}{[acetic \ acid]}[/tex]
[tex]= 4.75 + \log \frac{[0.123]}{[0.291]}\\\\= 4.75+ \lg(0.422680412)\\\\=4.75-0.373987878\\\\=4.37601212\\\\=4.37[/tex]
Which statement best describes why a chemical property change is different from a physical change?
A. A chemical change results in a different state of matter; and a physical change results in a new substance being formed.
B. A chemical change results in a new substance being formed; whereas, a physical change will result in a different state of matter.
C. A chemical change is used by scientists to create new substances, and a physical change happens naturally.
D. A chemical change is used to identify characteristics of a substance, and a physical change identifies the behavior of a substance when in a reaction.
Answer:
B
Explanation:
a chemical change is making a new substance and physical change with a result in a different state of matter:)
Convert 85km/hr to cm/s(factor label conversion)
Answer:
23.61m/s
Explanation:
Km/hr is a unit of expressing the speed of a body. Speed is the rate of change of distance with time. Also, the same unit is applicable for expressing the velocity of a body. But to find the velocity, we must emphasize the direction of motion of the body.
Given parameter:
85km/hr to cm/s
Note:
1000m =1km
3600s = 1hr
So;
85 x
Cancelling out km and hr;
= 85 x 0.278m/s
= 23.61m/s
3
Which chemical equation below is balanced to correctly represent the Law of
Conservation of Mass?
04 Al + 3O2 + 2 Al2O3
O2 AL + O2 + 2 Al2O3
O AL + O2 + Al2O3
Answer:
4Al + 3O₂ → 2Al₂O₃
Explanation:
4Al + 3O₂ → 2Al₂O₃
Only this reaction above obeys the law of conservation of mass. The others flout the rule.
The law of conservation of mass states that "matter is neither created nor destroyed in a chemical reaction but are simply transformed from one form to another".
By this law, the number of atoms on both sides of expression must be the same;
Number of atoms
Elements Left hand side Right hand side
Al 4 4
O 6 6
what is a formula car? (This is for my chemistry project)
Answer:
A formula car is a single seat, open cockpit, open wheel racing car with substantial front and rear wings and an engine positioned behind the driver intended to be used in competition.
Can anyone help pretty please
Which is the best example and explanation that a physical change has occurred?
fireworks exploding, because energy is released as light and heat
gasoline burning, because it forms water vapor and carbon dioxide
O crushing an ice cube, because the chemical structure of the ice cube is changed
dicing potatoes, because the molecules are separated but remain the same substance
dicing potatoes, because the molecules are separated but remain the same substance
Answer:
For the people wondering, yes, dicing potatoes is the correct answer. Because a new substance has not formed.
Given this reaction: 4K(s) + O2(g)→2K2O(s). Calculate how many grams of product is produced if 2.50 g of each reactant is reacted.
PLEASE HURRY!!!
Answer:
[tex]m_{K_2O}^{by\ K} =3.01gK_2O[/tex]
Explanation:
Hello!
In this case, since 2.50 g of both potassium (molar mass = 39.1 g/mol) and gaseous oxygen (molar mass = 32.0 g/mol) react in a 4:1 and 1:2 mole ratio respectively, to produce potassium oxide (molar mass = 94.2 g/mol), we evaluate the mass of potassium oxide yielded by each reactant in order to identify the limiting one via stoichiometry:
[tex]m_{K_2O}^{by\ K}=2.50gK*\frac{1molK}{39.1gK}*\frac{2molK_2O}{4molK}*\frac{94.2gK_2O}{1molK_2O} =3.01gK_2O\\\\m_{K_2O}^{by\ O_2}=2.50gO_2*\frac{1molO_2}{32.0gO_2}*\frac{2molK_2O}{1molO_2}*\frac{94.2gK_2O}{1molK_2O} =14.7gK_2O[/tex]
Thus, since the 2.50 g of potassium yields 3.01 g of potassium oxide, we infer it is the limiting reactant and that is the mass of produced product by the reaction.
Best regards!
Answer: Calculating mass quick check
1. The mass of the reactants must be equal to the mass of the products. The total number of moles of the reactants can be more or less than the total number of moles of the products.
2. Divide the mass of the reactant by its molar mass to find the number of moles of the reactant. Use the chemical equation to find the number of moles of the product. Multiply the number of moles of the product by its molar mass to find the mass of the product.
3. 2(108 g/mol)+32 g/mol=248 g/mol; (248 g/mol)(0.02 mol)=4.96 g
4. 19.5 g
5. 853.5 g
You're welcome
A gaseous compound is placed in a rigid container of volume 10.0 L at temperature 300.0 K and at pressure 1.0 atm. The container is placed in an evacuated chamber and a small hole of area 2.65 mm2 is made in one of the container walls. It takes 1.00 minutes for the gas pressure in the container to fall to half of its original value. Determine the molar mass of the gas.
calculate the (m/v) of nacl of a solution made by diluting 25.0 ml of a 7.50 (m/v)% NaCl solution to a total volume of 75.00 ml
Answer:
2.5%
Explanation:
Given
M1 = 7.50%
M2 = ?
V1 = 25.0mL
V2 = 75.00mL
M1V1=M2V2
7.5x25=M2x75
M2=2.5%
The NaCl of a solution made by diluting 25.0 ml of a 7.50 (m/v)% NaCl solution to a total volume of 75.00 ml is 2.5 (m/v)%.
What is solution?Solution is defined as a continuous variation of two or more substances in their relative proportions up to what is known as the limit of solubility. A solute is the name for the substance that dissolves to create a solution. A solvent is the material that a solute will dissolve in. Sugar is the solute and water is the solvent in a sugar-water solution.
To calculate the molarity of NaCl
We use M1V1 = M2V2
Given M1 = 7.50 (m/v)%
V1 = 25.0 ml
V2 = 75.0 ml
M2 = M1 V1 / V2
M2 = 7.50 x 25.0 / 75.0
M2 = 2.5 (m/v)%
Thus, the NaCl of a solution made by diluting 25.0 ml of a 7.50 (m/v)% NaCl solution to a total volume of 75.00 ml is 2.5 (m/v)%.
To learn more about solution, refer to the link below:
https://brainly.com/question/7932885
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Explain why ionic compounds are formed when a metal bonds with a nonmetal, but covalent compounds are formed when two nonmetals bond
Answer:
Ionic bonds form when a nonmetal and a metal exchange electrons, while covalent bonds form when electrons are shared between two nonmetals. ... Atoms form covalent bonds in order to reach a more stable state. A given nonmetal atom can form a single, double, or triple bond with another nonmetal.
Ionic bonds form when a nonmetal and a metal exchange electrons, while covalent bonds form when electrons are shared between two nonmetals. ... Atoms form covalent bonds in order to reach a more stable state. A given nonmetal atom can form a single, double, or triple bond with another nonmetal.
Which of the following belong to a category called the main group of elements
A halogens
B nonmetals
C alkaline metal
D transition elements
Answer:
C. Alkaline Metal ok thanks
Titration of a strong acid with a strong base. The pH curve for titration of 50.0 mL of a 0.100 M solution of hydrochloric acid with a 0.100 M solution of NaOH (aq). For clarity, water molecules have been omitted from the molecular art.
Required:
What volume of NaOH(aq) would be needed to reach the equivalence point if the concentration of the added base were 0.270 M?
The volume of NaOH that would be needed to reach the equivalence point is : 19 mL
Given data
volume of HCL = 50 mL = 0.05 L
conc of HCL = 0.100 M
volume of NaOH = ?
conc of NaOH = 0.100 M
Determine the volume of NaOH needed to reach equivalence pointNew conc of added base = 0.270 M
At equivalence ;
moles of OH⁻ ions = moles of H⁺ ions
0.05 * 0.1 = 0.27 * v
therefore the volume ( v ) = ( 0.05 * 0.1 ) / 0.27
= 0.019 L = 19 mL
Hence we can conclude that The volume of NaOH that would be needed to reach the equivalence point is : 19 mL .
Learn more about Titration : https://brainly.com/question/186765
how many neutrons are in neon which has 10 protons and 10 electrons?
Answer:
It has 10 neutrons
Explanation:
An egg sinks in fresh water but it floats on salty water.why?
the cell cycle describes the processes that take place as a cell?
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Question 10 of 12- POS
GR8 Sci U03 USA FY21 Question: 1-10
Hannah added a silvery white metal to a beaker of cold water and noticed that gas bubbles were given off and a different substance formed. When she repeated the activity with hot water she noticed the gas bubbles were
released much more rapidly. Which statement best explains why the reaction occurred faster in hot water?
M
The correct answer is Hot water increases the collision rate of molecules, causing the reaction to occur faster.
Explanation:
Temperature is directly related to the kinetic energy or movement of molecules in a substance. In this context, a higher temperature leads to more kinetic energy or more collision between molecules. At the same time, a chemical reaction involves molecules of two or more substances colliding and creating bonds to form new substances. This implies an increase in temperature means molecules colliding faster, new substances forming in a shorter time, and therefore a faster chemical reaction. According to this, the first answer is correct.
Calculate the number of iron atoms in a sample of iron(III) oxide . Be sure your answer has a unit symbol if necessary, and round it to significant digits.
Answer:
[tex]atoms\ Fe=6.03x10^{24}atoms[/tex]
Explanation:
Hello!
In this case, since the mass of iron (III) oxide is missing we use 80.0 g as found on similar problems. In such a way, since iron (III) molar mass is 159.70 g/mol, one mole of iron (III) oxide has two moles of iron (subscript) and one mole of atoms of iron have 6.022x10²³ atoms (Avogadro's number), the correct number of atoms in such sample is:
[tex]atoms \ Fe=80.0gFe_2O_3*\frac{1molFe_2O_3}{159.70gFe_2O_3}*\frac{2molFe}{1molFe_2O_3}*\frac{6.022x10^{23}atoms}{1molFe} \\\\atoms\ Fe=6.03x10^{24}atoms[/tex]
Which is shown with three significant figures as 80.0 g has three as well.
Best regards!
A gas has a pressure of 645 Torr at 128 ºC. What is the temperature (ºC) of the pressure increases to 824 Torr at constant volume and moles?
Answer:
512 K
Explanation:
Initial pressure P1 = 645 Torr
Initial Temperature T1 = 128 ºC + 273 = 401 K (Upon converting to kelvin temperature)
Final Pressure P2 = 824 Torr
Final Temperature T2 = ?
The relationship between the variables is given as;
P1 / T1 = P2 / T2
Making T2 subject if formula we have;
T2 = P2T1 / P1
Inserting the values we have;
T2 = 824 * 401 / 645 = 512 K
How much heat is required to heat 1.8 kg of water from 8.4oC to 17.3oC? The heat capacity of water is 4.1813 J/g*oC
Answer:
Q = 66984.43 J
Explanation:
Given data:
Mass of water = 1.8 Kg (1.8Kg×1000 g/1 Kg =1800 g)
Initial temperature = 8.4°C
Final temperature = 17.3°C
Specific heat capacity of water = 4.1813 J/g.°C
Heat required = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 17.3°C - 8.4°C
ΔT = 8.9°C
Q = 1800 g × 4.1813 J/g.°C ×8.9°C
Q = 66984.43 J
Which of the following set of properties is most likely for a liquid with large, attractive intermolecular forces?
Answer:
is it ok na I hope this answers are ok
Answer:
Answer is: C) high melting point and high boiling point.
Explanation:
HOPE IT HELPS
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Which sentence best describes a bond formed between two unlike atoms?
Answer:B apez
Explanation:
Answer:
The type of bond is determined by the difference in elecronegtivity of the atom
Explanation:
A P E X
defferent between crysttiline solid and amerphus solid
Answer:
Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points. In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.
Explanation:
Hope this helped!
Answer:
Crystalline solids have well-defined edges and faces, diffract x-rays, and tend to have sharp melting points. In contrast, amorphous solids have irregular or curved surfaces, do not give well-resolved x-ray diffraction patterns, and melt over a wide range of temperatures.
Explanation:
You are given 3.0 grams of solid sodium to react to pure water which has a molarity of 55.6 M. How many milligrams of H2 can be produced if you react 6 mL of the water with 3.0 grams of solid sodium.
Na (s) + H2O ------> NaOH (aq) + H2 (g)
Answer:
= 15.51 mL
Explanation:
Here's is the reaction:
2HgO(s) ⇒ 2 Hg(s)+O₂(g)
In this reaction 2mol HgO = 1mol O₂
The molecular weight of HgO = 216.59g
so, 3.0g HgO = 3.0g x 1.00molHgO/216.59gHgO
= 0.0138511 molHgO
The amount of Oxygen follows:
0.0138511 molHgOx1/2= 0.00692555 mol O₂
Now, volume of 1 any gas = 22400mL
so, 0.00692555 mol O₂ x22400mLO₂/1mol O₂
= 15.513232mL O₂
Balance the following equations ___Fe + __O2= ___Fe3O4
A rigid 3.80 L sealed vessel contains 0.650 mol Ne, 0.321 mol Kr, and 0.190 mol Xe. Find the density of the mixture in g/L.
Answer:
17.09g/L
Explanation:
Density = total mass of elements/ volume
We need to find the mass of each mixture constituents using their molar mass:
mole = mass/molar mass
For Neon (Ne) which contains 0.650mol;
0.650 = mass/20.18
mass = 0.650 × 20.18
mass = 13.12g
For Krypton (Kr) which contains 0.321mol;
0.321 = mass/83.79
mass = 0.321 × 83.79
mass = 26.89g
For Xenon (Xe) which contains 0.190mol;
0.190 = mass/131.3
mass = 0.190 × 131.3
mass = 24.95g
Total mass = 13.12g + 26.89g + 24.95g = 64.96g
Density = total mass / volume
Density = 64.96g / 3.80L
Density of the mixture = 17.09g/L
A photon of blue light has a wavelength of 4.62 x 10m (462 nm). Calculate the energy of this photon
Answer:
[tex]E=4.3\times 10^{-19}\ J[/tex]
Explanation:
Given that,
The wavelength of a photon of blue light is 462 nm
We need to find the energy of this photon. The formula for the energy of a photon is given by :
[tex]E=\dfrac{hc}{\lambda}\\\\E=\dfrac{6.63\times 10^{-34}\times 3\times 10^8}{462\times 10^{-9}}\\\\=4.3\times 10^{-19}\ J[/tex]
So, the energy of this photon is [tex]4.3\times 10^{-19}\ J[/tex].
Find the pH and fraction of association of a 0.100 M solution of the weak base B with Kb = 1.00 x 10^5.
Answer:
Fraction of association = 0.01
pH = 11
Explanation:
A weak base, B, is in equilibrium with water as follows:
B(aq) + H2O(l) ⇄ BH⁺(aq) + OH⁻(aq)
Where Kb is defined as:
Kb = 1.00x10⁻⁵ = [BH⁺] [OH⁻] / [B]
Some B will react producing BH⁺ and OH⁻:
[BH⁺] = X
[OH⁻] = X
[B] = 0.100M - X
As Kb <<< [B] we can say:
[B] ≈ 0.100M
Replacing:
1.00x10⁻⁵ = [X] [X] / [0.100]
1.00x10⁻⁶ = X²
X = 1x10⁻³M = [BH⁺] = [OH⁻]
The fraction of association is [BH⁺] / [B] = 1x10⁻³M / 0.100M = 0.01
As [OH⁻] = 1x10⁻³M, pOH = -log[OH⁻] = 3
pH = 14- pOH
pH = 11
From the combinations of substances listed below, which would most likely be miscible in
each other?
(33 Points)
A.polar water, nonpolar oil
B.polar vinegar, nonpolar nail polish
C. polar bleach, polar water
D.nonpolar mineral oil, polar alcohol
Answer:
C
Explanation:
polar has unequal sharing of electrons that has the lone pairs which has the electronegativity difference. can be mixed with water.
If a fluorine atom and nitrogen atom combine to form a compound, what type of bond will they form
Answer:
I guess covalent bond is formed
How many atoms are in 80.7 g of pure aluminum?
Answer:
Like Roman said Avogadro's number is the key to your problem. The value that you'll use on paper is 6.022x10^23. Luckily in our case a mol specifically refers to the amount of atoms. Its a weird concept but 1.97 mol of Aluminum is the exact same amount of atoms as say helium. The only differences lay in the total mass of the sample.