Answer:
False
Explanation:
From the question given above, the following data were obtained:
Electron number = 6
Proton number = 6
Neutron number = 6
From the question given above, we can see clearly that the model has the same number of protons and electrons. Hence the model is not an ion.
This can further be explained if we determine the charge.
Electron number = 6
Proton number = 6
Charge =?
Charge = Proton – Electron
Charge = 6 – 6
Charge = 0
Since the charge is zero, the model is not an ion.
HELP HELP
why are more common bone fractures among senior citizens than among young people
What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH
Answer:
a) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = pKa?
Step 1: Data given
Volume of HC2H3O2 = 1.0 L
Molarity of HC2H3O2 = 1.8 M
Ka = 1.8*10^-5
ph = pK = -log(1.8*10^-5) = 4.74
Step 2:
Use the Henderson-Hasselbalch equation.
pH = pKa + log(A-/HA)
4.74 = 4.74 + log(A-/HA)
0 = log(A-/HA)
A-/HA = 1
Consider X = moles of NaOH added (and moles of A- formed)
Remaining moles of HA = 1.8 - X
moles of A- = X
HA = 1.8 - X
X/(1.8-X) = 1
X =0.9
We have to add 0.9 mole NaOH to 1.0 L of 1.8 M HC2H3O2
To control we can do the following equation:
4.74 = 4.74 + log(0.9/0.9) = 4.74
b) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = 4.00?
Step 1: Data given
Volume of HC2H3O2 = 1.0 L
Molarity of HC2H3O2 = 1.8 M
Ka = 1.8*10^-5
ph = 4
Step 2:
Use the Henderson-Hasselbalch equation.
pH = pKa + log(A-/HA)
4 = 4.74 + log(A-/HA)
-0.74 = log(A-/HA)
A-/HA = 0.182
Consider X = moles of NaOH added (and moles of A- formed)
Remaining moles of HA = 1.8 - X
moles of A- = X
HA = 1.8 - X
X/(1.8-X) = 0.182
X =0.277
We have to add 0.277 mole NaOH to 1.0 L of 1.8 M HC2H3O2
To control we can do the following equation:
4 = 4.74 + log(0.277/1.523)
c) What quantity (moles) of NaOH must be added to 1.0 L of 1.8 M HC2H3O2 to produce a solution buffered at pH = 5.00
Step 1: Data given
Volume of HC2H3O2 = 1.0 L
Molarity of HC2H3O2 = 1.8 M
Ka = 1.8*10^-5
ph = 5
Step 2:
Use the Henderson-Hasselbalch equation.
pH = pKa + log(A-/HA)
5 = 4.74 + log(A-/HA)
0.26 = log(A-/HA)
A-/HA = 1.82
Consider X = moles of NaOH added (and moles of A- formed)
Remaining moles of HA = 1.8 - X
moles of A- = X
HA = 1.8 - X
X/(1.8-X) = 1.82
X =1.16
We have to add 1.16 mole NaOH to 1.0 L of 1.8 M HC2H3O2
To control we can do the following equation:
5 = 4.74 + log(1.16/0.64) = 5
Explanation:
Is Kool-Aid dissolved in water in element compound or mixture?
Answer:
mixture
Explanation:
Kool-Aid is a mixture of sugar, water, dye, and flavoring.
A bomb calorimeter with a heat capacity of 837 J∘C contains 745 g of water. It burns 2.50 g C8H18 resulting in the temperature going from 15.0∘C to 33.8∘C. What is the value of the heat transferred (in kilojoules) by the reaction from the perspective of the system?
Answer:
74.3kJ are transeferred
Explanation:
In the bomb calorimeter, the burning of C₈H₁₈ is producing heat that is been absorbed for the calorimeter and the water.
Heat absorbed calorimeter:
837J/°C * (33.8°C-15.0°C) = 15735.6J
Heat absorbed water:
C*m*ΔT
C specific heat of water (4.184J/g°C), m is mass of water (745g), and ΔT change in temperature (33.8°C - 15°C = 18.8°C)
4.184J/g°C*745g*18.8°C = 58601.1J
Heat released by the reaction:
15735.6J + 58601.1J = 74336.7J
74.3kJ are transeferred
The pair of elements with the most familiar chemical properties are
A. Mg and S
B. Ca and Br
C. Mg and Ca
D. S and Ar
Answer:
C. mg and Ca
Explanation:
These chemical elements are collectively called as the Alkaline Earth Metals. Calcium and Magnesium are two of the six elements that fall into this category. The outer electronic structure of all these elements is similar due to which they all have similarity in their chemical and physical properties. They are all shiny, though fairly soft but still harder than alkali metals. Further, these are usually white or silvery coloured elements.They react with water to form hydrogen gas and metal hydroxide and with oxygen, they form oxides.
1) Why does polysubstitution frequently occur with Friedel-Crafts alkylation but not with Friedel-Crafts acylation?2) If Benzene is reacted with t-butyl chloride, why is the chief disubstituted product the para rather than ortho isomer?
Answer:
See explanation
Explanation:
Friedel-Crafts alkylation frequently undergo polysubstitution because the process leads to the addition of an electron donating alkyl group, which activates the benzene ring to further alkylation. The acyl group rather deactivates the ring towards electrophilic substitution.
When benzene is reacted with t-butyl chloride, the chief disubstituted product is the para rather than ortho isomer because the increased bulk of the tert-butyl group hinders attack at the ortho-sites.
Sulfur dioxide and oxygen react to form sulfur trioxide during one of the key steps in sulfuric acid synthesis. An industrial chemist studying this reaction fills a 50.0L tank with 14. mol of sulfur dioxide gas and 2.6 mol of oxygen gas, and when the mixture has come to equilibrium measures the amount of sulfur trioxide gas to be 1.6 mol. Calculate the concentration equilibrium constant for the reaction of sulfur dioxide and oxygen at the final temperature of the mixture. Round your answer to 2 significant digits.
Answer:
Explanation:
From the given information:
The equation for the reaction can be represented as:
[tex]2SO_2 + O_2 \to 2SO_3[/tex]
The I.C.E table can be represented as:
2SO₂ O₂ 2SO₃
Initial: 14 2.6 0
Change: -2x -x +2x
Equilibrium: 14 - 2x 2.6 - x 2x
However, Since the amount of sulfur trioxide gas to be 1.6 mol.
SO₃ = 2x,
then x = 1.6/2
x = 0.8 mol
For 2SO₂; we have 14 - 2x
= 14 - 2(0.8)
= 14 - 1.6
= 12.4 mol
For O₂; we have 2.6 - x
= 2.6 - 1.6
= 1.0 mol
Thus;
[SO₂] = moles / volume = ( 12.4/50) = 0.248 M ,
[O₂] = 1/50 = 0.02 M ,
[SO₃] = 1.6/50 = 0.032 M
Kc = [SO₃]² / [SO₂]² [O₂]
= ( 0.032²) / ( 0.248² x 0.02)
= 0.8325
Recall that; the equilibrium constant for the reaction [tex]2SO_2 + O_2 \to 2SO_3[/tex] = 0.8325;
If we want to find:
[tex]SO_2 + \dfrac{1}{2}O_2 \to SO_3[/tex]
Then:
[tex]K_c = (0.8325)^{1/2}[/tex]
[tex]\mathbf{K_c = 0.912}[/tex]
Since no temperature is given to use in the question, it will be impossible to find the final temperature of the mixture.
What happens when the sound waves released by a bat hit an object?
O The sound waves are diffused.
O The sound waves are reflected.
O The sound waves are refracted.
O The sound waves are absorbed.
Answer:
O The sound waves are reflected.
Explanation:
When sound waves released by a bat hits an object, the sound waves are reflected back.
Bats used sound reflection for echolocation to determine the position of nearby objects.
Also, they use it to determine the shape and size of objects.
The mechanism where bats use sound to determine location is known as echolocation. The bat picks up the reflected sound and projects the location of their targets.Answer:
B
The sound waves are reflected.
Explanation:
When 60 mL of 0.22 M NH4Cl is added to 60 mL of 0.22 M NH3, relative to the pH of the 0.10 M NH3 solution the pH of the resulting solution will:____________.
Answer:
Will be more acidic
Explanation:
The equilibrium of NH3 in water is:
NH3(aq) + H2O(l) ⇄ NH4⁺(aq) + OH⁻(aq).
Where equilibrium constant, Kb, is:
Kb = 1.85x10⁻⁵ = [NH4⁺] [OH⁻] / [NH3]
From 0.10M NH3, the reaction will produce X of NH4⁺ and X of OH⁻ and Kb will be:
1.85x10⁻⁵ = [X] [X] / [0.10M]
1.8x10⁻⁶ = X²
X = 1.34x10⁻³ = [OH⁻]
As pOH = -log[OH⁻] = 2.87
And as pH = 14 - pOH
pH of the 0.10M NH3 is 11.13
Now, to find the pH of the NH4Cl and NH3 we need to use H-H equation for bases:
pOH = pKb + log [NH4⁺] / [NH3]
Where pKb is -log Kb = 4.74 and [] are moles of both compounds.
Moles of [NH4⁺] = [NH3] = 60mL, 0.060L*0.22M = 0.0132moles:
pOH = 4.74 + log [0.0132] / [0.0132]
pOH = 4.74
pH = 14 - 4.74 = 9.26
That means the pH of the resulting solution will be more acidic
What stress causes this type of fault to form? O compression O gravity O tension O shearing
Answer: It’s D
Explanation:
Cuz I said so
Answer: d. Shearing
Explanation:
1. How does thermal energy move between objects?
A. It moves from objects of lower mass to objects with higher mass
B. It moves from objects of higher mass to object with lower mass
C. It moves from objects of lower temperature to objects with higher temperature
D. It moves from objects of higher temperatures to objects with lower temperature
Answer:
D
Explanation:
Answer:
D
Explanation:
So. Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else.... When the heat waves hits the cooler thing, they make the molecules of the cooler object speed up.
The heat of vaporization for benzaldehyde is 48.8 kJ/mol, and its normal boiling point is 451.0 K. Use this information to determine benzaldehyde’s vapor pressure (in torr) at 53.5°C. Report your answer to three significant digits.
Answer:
[tex]p_2=5.17torr[/tex]
Explanation:
Hello.
In this case, by using the Clausius-Clapeyron Equation which allows us to relate the vapor pressure, temperature and heat of vaporization as shown below:
[tex]ln(\frac{p_1}{p_2} )=\frac{\Delta _vH}{R}(\frac{1}{T_2}-\frac{1}{T_1} )[/tex]
Whereas [tex]p_1[/tex] is 760 torr due to the normal conditions. In such a way, for computing the vapor pressure of benzaldehyde at 53.5 °C (326.65 K), we proceed as shown below:
[tex]\frac{p_1}{p_2} =exp[\frac{48800J/mol}{8.314\frac{J}{mol*K}}(\frac{1}{326.65K}-\frac{1}{451.0K} )]\\\\\frac{p_1}{p_2}=147.0[/tex]
Thus, the vapor pressure at the final T is:
[tex]p_2=\frac{p_1}{147.0}=\frac{760torr}{147.0}\\ \\p_2=5.17torr[/tex]
Best regards!
You are trying to confirm that your bottle of hydrochloric acid is supposedly 1.0 M, as labeled. You decided to perform a titration with 1.3 M sodium hydroxide and 100 mL of your hydrochloric acid. You expect to use 77 mL of sodium hydroxide to neutralize the acid, but in the experiment it actually took 89.13 mL of NaOH to reach the endpoint. What is the actual concentration of the hydrochloric acid?
Answer:
The actual concentration of the hydrochloric acid is 1.2M
Explanation:
The formula to be used here is that of concentration (popularly used during titration);
CₐVₐ/CbVb =nₐ/nb
where Cₐ is the concentration of acid (supposed to be 1.0 M but unsure)
Vₐ is the volume of acid (100 ml)
Cb is the concentration of base (1.3 M)
Vb is the volume of base (89.13 ml)
nₐ is the volume of acid
nb is the volume of base
The equation for the reaction described in the question is
HCl + NaOH ⇒ NaCl + H₂O
we can see from the above equation the ratio of the number of moles for both the acid and the base is 1:1
Thus;
Cₐ × 100/1.3 × 89.13 =1/1
Cₐ = 1.3 × 89.13/100
Cₐ = 1.2M
The actual concentration of the hydrochloric acid is 1.2M
Sodium is located above potassium in Group 1 of the periodic table. If a potassium ion has a charge of +1, what is the charge on a sodium ion?
A. -1
B 0
C. +1
D +2
Answer:
C
Explanation:
It will be the same. That's what moving down a column means. The properties are going to be quite similar.
You make up a solution of a diprotic acid, H2A, having pKa values of 5.0 and 9.0. Identify the primary, secondary, and tertiary species when you set the pH equal to 8.0 by addition of KOH.
Answer:
Explanation:
A solution with a pH value of 7 is neutral i.e neither acidic nor alkaline. A solution with a pH less than 7 is said to be acidic, while one with a pH value more than 7 is alkaline. Acidity increases as the value decrease below 7, while alkalinity increases as the value increase about 7.
Given that H2A is a diprotic weak acid have pKa values of 5.0 ad 9.0, it will undergo dissociation in the solution as:
NOTE: These reactions are reversible reactions.
[tex]\mathbf{H_2A \to H^+ + HA^- \ \ \ pKa = 5.0}[/tex]
[tex]\mathbf{HA^- \to H^+ +A^{2-} \ \ \ pKa = 9.0}[/tex]
Thus;
The primary species is HA⁻
The secondary species is A²⁻
Lamark goes to a bowling alley to test his belief that rolling a bowling ball slowly will result in knocking down more pins. He gently rolls his bowling ball towards the bowling pins lined up at the end of the lane. The bowling ball stops in the middle of the lane without striking the pins. Which statement below best explains what happened?
Answer:
The ball's kinetic energy is transforming to potential energy.
Explanation:
the ball is stopping resulting in potential energy
Sam washed his favorite pair of jeans. He hung the wet jeans on a clothesline outside. An hour later the jeans were dry.
Which answer best describes that happened to the water that was in the wet jeans an hour later?
State your answer and provide an explanation for your answer
A It soaked into the ground.
B It disappeared and no longer exists.
C It is in the air in an invisible form.
D It moved up to the clouds.
E It chemically changed into a new substance.
F It went up to the Sun.
G It broke down into atoms of hydrogen and oxygen.
Please help D:
Answer:
THe sun evapored the water and the wind helped dry it to.
Explanation:
Calculate the freezing point of a solution containing 10 grams of KCl and 1100.0 grams of water. The molal freezing point depression constant (Kf) for water is 1.86
Answer:
- 0.454 °C
Explanation:
From the given information:
The mass of KCl = 10 grams
The molar mass of KCl = 74.55 g/mol
The molality can be calculated as:
[tex]Molality \ m = \dfrac{mass \ of \ KCl \times 1000}{molar \ mass \ of \ KCl \times 1100.0}[/tex]
[tex]Molality \ m = \dfrac{10 \ g \times 1000}{74.55 \ g/mol \times 1100.0}[/tex]
Molality m = 0.1219 M
For freezing point depression;
[tex]\Delta T_R = i \times k_f \times m[/tex]
The van't Hoff's Factor (i) for KCl = 2
The molar depression of freezing point constant [tex]k_f[/tex] = 1.86° C/m
∴
[tex]\Delta T_R = 2 \times 1.86 \times 0.1219[/tex]
[tex]\mathbf{\Delta T_R = 0.454^0\ C }[/tex]
However, the freezing point of water is known to be = 0°C
Therefore, the freezing point of the solution
= 0 °C - 0.454 °C
= - 0.454 °C
Now
Selec
BI
Toda
OOOOOO
How and why do ionic bonds form? Check all of the boxes that apply
lonic bonds form between metal atoms and other metal atoms.
Ionic bonds form between metal atoms and nonmetal atoms
The more electronegative atoms transfer one or more electrons to the less electronegative atom
The less electronegative atoms transfers one or more electrons to the more electronegative atom,
The metal atom forms a cation and the nonmetal atom forms an anion
The attraction between ions with the same charge forms an ionic bond,
The attraction between ions with an opposite charge forms an ionic bond.
BLO
I lo
DONE
Elo
Yous
Answer:
✔️Ionic bonds form between metal atoms and nonmetal atoms.
✔️The less electronegative atoms transfers one or more electrons to the more electronegative atom
✔️The metal atom forms a cation and the nonmetal atom forms an anion.
✔️The attraction between ions with an opposite charge forms an ionic bond.
Explanation:
Ionic bond refers to the bond formation which occurs when there is complete and permanent transfer of electrons from one metal atom to another non-metal atom. The metals, which are electropositive (less electronegative) loose their electrons while the non-metals, which are less electropositive (more electronegative) gain the electrons.
When the metal atom looses electrons, they form cations(become positively charged) while non-metal atom forms anions (become negatively charged). When the opposite charges attract each other, they form ionic bond.
Answer:
✔️ Ionic bonds form between metal atoms and nonmetal atoms.
✔️ The less electronegative atoms transfers one or more electrons to the more electronegative atom.
✔️ The metal atom forms a cation and the nonmetal atom forms an anion.
✔️ The attraction between ions with an opposite charge forms an ionic bond.
Please select the word from the list that best fits the definition
Represents a range of responses to a question:
Caption
Legend/Key
Scale
Answer:
The answer is B(scale)
Explanation:
Since the question asked about a range, the scale would be the most logical answer since scales are used to measure.
Answer:
the answer is C.
Explanation:
How many distinct dichlorination products can result when isobutane is subjected to free radical chlorination?
a. 1
b. 2
c. 3
d. 4
e. 6
Answer:
c. 3
Explanation:
Dicholorination of tertiary alkane ( i.e. isobutane) is a halogenation reaction which makes it possible to replace the alkyl functional group with halogenated chlorine.
When Isobutane is subjected to free radicals chlorination, three distinct dichlorination can be formed.
The mechanism of the formation of these products can be seen in the image attached below.
Define dynamic equilibrium.
a) no reactants react no products are formed the rate of the forward reaction
b) is faster than the rate of the reverse reaction the rate of the reverse reaction
c) is faster than the rate of the forward reaction the rate of the forward reaction
d) equals the rate of the reverse reaction
Answer:
d) The rate of forward reaction equals the rate of the reverse reaction
Explanation:
A dynamic equilibrium is attained when the rate of forward reaction is the same as reverse reaction. It occurs majorly in a reversible reaction. Thus, no change occurs in the reaction.
The process can be control by the immediate removal of the product as it is formed. This ensure that the reaction stops when all reactants are used up.
Object A has a mass of 12g and a volume of 8cm3. object B has a mass of 20g and a volume of 8cm3 . which object has a greater density and by how much
Answer:
Object B has a density of 2.5 g/cm³ which is greater than object A by 1 g/cm³
Explanation:
Since we know that the formula for density is d=m/v, we can divide each mass by its corresponding volume to find the densities
12/8=1.5
20/8=2.5
So we know that object B has a greater density than object A by 1 g/cm³ (gram per cubic centimeter). Also the standard unit for density is kilograms per cubic meter but I used gram per cubic centimeter since they were the given units. 1cm=100m, 1000g=1km
Using Gizmo ,describe the main use for each fuel Coal: Petroleum: In each case, what is the end product of burning the fossil fuel,and where does it go? Help is for today
Answer:
See explanation
Explanation:
Coal is primarily used for electricity generation. The burning of coal leads to emission of gases such as oxides of carbon, oxides of sulphur, oxides of nitrogen and water vapour. All these go straight into the atmosphere.
Petroleum is primarily used as transportation fuels. The burning of petroleum oils mostly leads to the emission of oxides of carbon and sulphur together with water vapour into the atmosphere.
Which of the following rock will form if it is broken into sediment then emulsified over a long period of time?
Sedimentary rock
Magma rock
Metamorphic rock
Igneous rock
Which of the following represents the equation for volume?
L x H
L x W
L x W x H
W x H
Answer:
L× W×H
Please mark me as brainlist.Answer:
The correct answer is L x W x H :)
an area of high pressure occurs when
Answer:
A high-pressure area, high, or anticyclone, is a region where the atmospheric pressure at the surface of the planet is greater than its surrounding environment. Winds within high-pressure areas flow outward from the higher pressure areas near their centers towards the lower pressure areas further from their centers.
Explanation:
The idea that the earth is divided into a number of small plates that float on the mantle and slide,collide,and slip past each other. Law or Theories
Answer:
Theories
Explanation:
It is theories because it was a generalistee abstract or thinking generalising the principle of fact about Earth tectonic plates ,it was formulated and concluded as plate tectonic theories after many findings. The theories conclude that the Earth has an outer layer called lithosphere and lies overly a plastic layer called asthenosphere. The lithosphere is divided into several plates and they move close to each other where they diverge, converge or slip over one another.
Calculate the mass of dinitrogen tetroxide(N2O4) that contains a billion oxygen atoms. Be sure your answer has a unit symbol if necessary, and round it to significant digits.
Answer:
23 * 10^ 9 atoms of oxygen
Explanation:
From the molecular formula of dinitrogen tetraoxide;
molar mass of dinitrogen tetraoxide = 92 g/mol
hence;
92 g of dinitrogen tetraoxide contains 4 atoms of oxygen
x g of dinitrogen tetraoxide will contain 1 * 10^ 9 atoms of oxygen
x = 92 * 1 * 10^ 9/4
x =23 * 10^ 9 atoms of oxygen
What are the factors affecting your limitations? How about possibilities?
Explanation:
My physiological make-up that governs the attributes I have and my climate, i.e. the conditions I have, are the variables influencing my limits. Biological make-up also regulates my prospects when they depend on my attributes, i.e. my ability and my environment , i.e. the conditions under which I am. This has been shown by experiments on twins, that our limits and opportunities are controlled by both genetics and environment.