Answer:
4.5425806678891E+22mol
Explanation:
hello guys what is good!
What are all the elements of the P block?
boron, carbon, nitrogen, oxygen and flourine families in addition to the noble gases.
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also to answer the 'hello guys what is good!':nothin u?
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write the conjugate bases of the following acids ? H₂S , HCOOH ,HSO₃¯ , HSO¯₄ , HS¯, HNO₂ ,HCN,?
Answer:
HS(-)
HCOO(-)
SO3(2-)
SO4(2-)
S(2-)
NO2(-)
CN(-)
Explanation:
The parenthesis are the charges of the compounds. When an acid is introduced in a base, it dissociates its Hydrogens giving protons to the base. In this case, if you remove one hydrogen of a compound, you will reduce the charge of a compound since basically you're removing a positive charge from a compound. If you need to, I can explain how the thing of the charges work.
In fact, the definition of a conjugate base is a compound created when the original (an acid) compound dissacioate an atom of hydrogen (a proton) in a base.
17.42 mL of 0.1M NaOH was needed to reach the endpoint in the titration. How many moles of NaOH are in 17.42 mL of 0.1M NaOH
Answer:
0.001742moles
Explanation:
1000ml of NaOH contain 0.1moles
17.42ml of NaOH contain (0.1*17.42)/1000 moles
= 0.001742moles
In which case would recalibrating a thermometer be an important next step in an experiment dealing with boiling points?
A) The results of several trials are all very close to each other, but they are noticeably different from the accepted value for the boiling point.
B) A small number of trials are conducted, with results quite different from each other, and with an average that is noticeably different from the accepted value.
C) A single trial is conducted, and the result is very close to the accepted value of the boiling point.
D) The results of several trials vary by a large amount, but the average is close to the accepted value for the boiling point.
I believe the answer would be D
. What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH
4.85? [Kb(NH3) = 1.8 x 10-1
a. 4.7 g
b. 75 g
c.2.3 x 10-ºg
d. 19 g
e.10g
The mass of ammonium chloride that must be added is : ( A ) 4.7 g
Given data :
Volume of water ( V ) = 250 mL = 0.25 L
pH of solution = 4.85
Kb = 1.8 * 10⁻⁵
Kw = 10⁻¹⁴
Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :
NH₄CI + H₂O ⇄ NH₃ + H₃O⁺
where conc of H₃O⁺
[ H₃O⁺ ] = [tex]\sqrt{Ka.C}[/tex] and Ka = Kw / Kb
∴ Ka = 5.56 * 10⁻¹⁰
Next step : Determine the concentration of H₃O⁺ in the solution
pH = - log [ H₃O⁺ ] = 4.85
∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵
Next step : Determine the concentration of NH₄CI in the solution
C = [ H₃O⁺ ]² / Ka
= ( 1.14125 * 10⁻⁵ )² / 5.56 * 10⁻¹⁰
= 0.359 mol / L
Determine the number of moles of NH₄CI in the solution
n = C . V
= 0.359 mol / L * 0.25 L = 0.08979 mole
Final step : determine the mass of ammonium chloride that must be added to 250 mL
mass = n * molar mass
= 0.08979 * 53.5 g/mol
= 4.80 g ≈ 4.7 grams
Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g
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In each of the combinations, predict the more electronegative element based on its position on the
periodic table. Then look up the actual electronegativities. Circle the reaction pair that should
actually caust a reaction.
More
Combination Combination electronegative
A
B
element based on
position on table
Ba + Fe2-
Ba?- + Fe
Actual
Actual
electronegativity electronegativity
of element of element
a)
Ba =
Fe=
b)
)
Sn + Hg
Sn- + Hg
Sn =
Hg =
c)
)
Na + Mg2+
Na + Mg
Na=
Mg =
=
Zn + CO2-
Zn?- + Co
Zn =
Co=
c)
)
Na + Mg2+
Na + Mg
Na=
Mg =
=
Zn + CO2-
Zn?- + Co
Zn =
Co=
Michelle is trying to find the average atomic mass of a sample of an unknown
element. She finds that her sample contains 59.34% of an isotope with a mass of
113.6459, while the rest of the sample is an isotope with a mass of 115.8488. What
is the average atomic mass of her sample? Please round your answer to 0.01 amu.
The average atomic mass of her sample is 114.54 amu
Let the 1st isotope be A
Let the 2nd isotope be B
From the question given above, the following data were obtained:
Abundance of isotope A (A%) = 59.34% Mass of isotope A = 113.6459 amuMass of isotope B = 115.8488 amuAbundance of isotope B (B%) = 100 – 59.34 = 40.66%Average atomic mass =?The average atomic mass of the sample can be obtained as follow:
[tex]Average \: atomic \: mass \: = \frac{mass \: of \: A \times A\%}{100} + \frac{mass \: of \: B \times B\%}{100} \\ \\ Average \: atomic \: mass \: = \frac{113.6459\times 59.34}{100} + \frac{115.8488\times 40.66}{100} \\ \\ Average \: atomic \: mass \: = 114.54 \: amu \\ \\ [/tex]
Thus, the average atomic mass of the sample is 114.54 amu
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What is the correct form of the equilibrium constant for the reaction of hydrogen and oxygen to form water? The equation is:
2H 2( g) + O 2( g) ⇌ H 2O( g)
Kc = ([H2O]/[O2] [H2])
Kc = ([H2O]/[O2] [H2]2)
Kc = ([H2O]/[O2] [H22])
Kc = ([H2O]2/[O2] [H22])
Kc = ([H2O]/[O2] [2H2])
does the following atomic model of a chemical reaction correctly demonstrate the law of conversation of matter why or why not
plzzz help
Answer:
Yes
Explanation:
You can tell because there are 2 moles of H2 on the reactants side and 1 mole of O2, and on the products side we see the same amount, meaning that no moles of H2 or O2 were added or destroyed, meaning that it follows the law of conservation of matter.
natural gas has been stored in an expandable tank that keeps a constant pressure as gas is added or removed. the tank has a volume of 4.50x 104 ft 3 when it contains 77.4 million mole natural gas at - 5 °c. what is the new volume of the tank if consumers use up 5.3 million mole and temperature increase to 7 °c?
Answer:
5-3. Ice water 0 "C. A steel tank contains carbon dioxide at 27 "C and a pressure of 12.0 atm.
Explanation:
explain how materials are suited for different uses based on their physical and chemical properties?
true or false
a. very little oxygen and nitrogen are found in air.
b. oxygen is the main cause of the formation of rust in iron.
c. impure air is odourless.
d. plants take in oxygen gas during respiration.
e. air contains water vapour.
Answer:
true or false
a. very little oxygen and nitrogen are found in air. false
b. oxygen is the main cause of the formation of rust in iron. false
c. impure air is odourless true
.d. plants take in oxygen gas during respiration. true
e. air contains water vapour. true
Explanation:
Mole problems. See the image for reference. Please show your work.
define conjugate Base and conjugate acid
Explanation:
conjugated base is substance formed when an acid loses
a hydrogen ion.
conjugated acid is a type of acid that is formed when a base accepts a proton in solution
how are homogeneous mixtures different from heterogeneous mixtures
Answer:
In Homogenous mixtures, the whole mixture is in the same phase whereas in Heterogeneous mixture, substances can be of two phases and layers may separate. ... Homogeneous mixture could be exemplified as a sugar solution or salt solution whereas Mixture of salt and sand could be used as an example of Heterogeneous mixture.
You already converted mass to moles for the reactants. Now convert mass to moles for the product, copper. 0.71 g Cu equals moles.
Answer: it wound'nt let me type the equations out so i did it on g.o.o.gl.e docs :')
Explanation:
hope this helps <3
have a great day/night/noon
:)
Which of these objects will most likely float?
Answer:
plastic,palstic bottle,balloon,cap of water bottle,plastic slippers and plastic comb.
Explanation:
hope it helps :D
A chemical engineer must be able to predict the changes in chemical concentration in a reaction. dC/dt = -kCn where C is chemical concentration and k is rate constant. Order of reaction is the value of n. The first order reaction that combines tert-butyl bromide and water to produce tert-butyl alcohol and hydrogen bromide is shown below; (CH3)3CBr + H2O (CH3)3COH +HBr From the experimental data, k was estimated to be k = 0.0537 (h -1 ). Determine concentration after 1 hour, if C(0) = 0.2 mol/L
Answer:
Explanation:
Consider the general chemical reaction
[tex]\mathrm{A} \ \overset{k}{\longrightarrow} \ \mathrm{product}[/tex] .
If [A] is the concentration of A (reactant) at any time t and n is the reaction order for the whole equation, the rate is then related to the concentration of reactant A with the following differential form of equation
[tex]Rate \ = \ -\displaystyle\frac{d[\mathrm{A}]}{dt} \ = \ k[\mathrm{A}]^{n}[/tex] .
where k is the rate constant.
*Note that the differential term [tex]\displaystyle\frac{d[\mathrm{A}]}{dt}[/tex] has a negative sign to denote that the concentration of A is decreasing over time t.
Since the chemical reaction between tert-butyl bromide and water is given to be a first-order reaction, hence n = 1, and the resulting differential equation becomes
[tex]Rate \ = \ -\displaystyle\frac{d[\mathrm{A}]}{dt} \ = \ k[\mathrm{A}]^{1} \ = \ k[\mathrm{A}][/tex]
To solve this first-order linear homogenous differential equation, the method of separation of variables can be used.
[tex]\-\hspace{1cm} \displaystyle\frac{d[\mathrm{A}]}{dt} \ = -\ k[\mathrm{A}] \\ \\ \-\hspace{0.5cm} \displaystyle\frac{1}{[\mathrm{A}]} \, d[\mathrm{A}] \ = -\ k \, dt \\ \\ \int\ {\displaystyle\frac{1}{[\mathrm{A}]} \, d[\mathrm{A}] \ = \ -\int {k} \, {dt}[/tex]
[tex]\ln{[\mathrm{A}]} \ = \ -kt \ + \ C \\ \\ \-\hspace{0.45cm} $[A]$ \ = \ e^{-kt \ + \ C} \\ \\ \-\hspace{0.45cm} $[A]$ \ = \ e^{-kt}e^{C} \ \ \ \ \ \ \ \ \ (e^{a \ + \ b} \ = \ e^{a}e^{b} \ \ \ \mathrm{by \ the \ law \ of \ indices})[/tex]
Since the term [tex]e^{C}[/tex] is a constant, let [tex]\alpha \ = \ e^{C}[/tex], hence [tex][\mathrm{A}] \ = \ \alpha e^{-kt}[/tex] or [tex]C \ = \ \alpha e^{-kt}[/tex] according to the question. Given that the initial concentration (t = 0) of tert-butyl bromide is 0.2 mol/L and k = 0.0537[tex]\mathrm{h^{-1}}[/tex], so
[tex]0.2 \ = \ \alpha e^{-0.0537 \ \times \ 0} \\ \\ 0.2 \ = \ \alpha \ \ \ \ \ (e^{0} \ = \ 1)[/tex]
Therefore, the rate equation is [tex]C \ = \ 0.2e^{-0.0537t}[/tex].
The concentration of tert-butyl alcohol after 1 hour is
[tex]C \ = \ 0.2e^{-0.0537 \ \times \ 1} \\ \\ C \ = \ 0.2e^{-0.0537} \\ \\ C \ = \ 0.190 \ \mathrm{mol/L} \ \ \ (3 \ \ \mathrm{s.f.})[/tex]
Which statement describes a homogeneous catalyst?
It is in a gaseous phase only.
It is in the same phase as the reactants.
It is completely consumed by reactants.
It forms different products than the uncatalyzed reaction forms.
Answer:
it is in the same phase as the reactants
The statement describes a homogeneous catalyst is,
It is in the same as the reactants.So, option B is correct one.
What is homogeneous catalyst?The homogeneous catalyst is refer to catalytic system.In this, the phase of substrates for a reaction and catalytic components are same.Mainly it is in liquid phase.Example: Production of acetic acidWhat is catalyst?
The substance which increases the rate of the reaction without being itself change at the end of the reaction is called catalyst.
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The diagram below shows the reaction between iron oxide and carbon that produces iron and carbon dioxide. The reaction takes place in a closed system. What is true about the carbon atoms in the reaction? A. The mass of carbon atoms in the reactants is the same as the mass of carbon atoms in the products. B. The total mass of the carbon atoms is the same as the total mass of the iron atoms. C. The mass of the carbon atoms increases between the reactants and the products of the reaction. D. The total mass of the carbon atoms is the same as the total mass of the oxygen atoms.
Answer:
A
Explanation:
The trick here is to know what the conservation of mass means.
It means that no matter what happens and how much change there is, the mass of the carbons on the reactants = the mass of the carbons on the products.
That's exactly what A says.
A mixture of 0.384 M H2O, 0.384 M Cl2O, and 0.652 M HClO are placed in a vessel at 25 oC. Calculate the equilibrium concentration (in molarity) of HClO at the same temperature.
Equilibrium concentration of HOCl at 25°C is 0.140 M
The equation of the reaction at equilibrium is given below:
H₂O (g) + Cl₂O (g) ⇄ 2 HOCl (g)
Equilibrium constant, Kc = 0.0900 at 25°C
An ICE chart for the reaction is set up below
H₂O (g) + Cl₂O (g) ⇄ 2 HOCl (g)
I 0.384 0.384 0.652
C -x -x + 2x
E 0.384 - x 0.384 - x 0.652 + 2x
The equation of the equilibrium constant is given as;
Kc = [tex]\frac{[HOCl]^2}{[H_{2}O][Cl_{2}O]}[/tex]
substituting the values into the equation:
Kc = [tex]\frac{(0.652 + 2x)^2}{( 0.384 - x)( 0.384 - x)}[/tex] = 0.0900
4x² + 2.608x + 0.425 = 0.0900 (0.147 - 0.768x + x²)
4x² - 0.09x² + 2.677x - 0.069x + 0.425 - 0.013 = 0
3.910x² + 2.677x + 0.412 = 0
Solving using the quadratic formula:
a = 3.910, b = 2.677, c = 0.412
x = [tex]\frac{-2.677\±\sqrt{2.677^2 - 4*3.910*0.412}}{2*3.910}[/tex]
x = -0.256 or -0.431
The negative sign indicates that equilibrium is to the left of the reaction
Since x cannot be greater than 0.384, x = -0.256.
Equilibrium concentration of HOCl = 0.652 + 2(-0.256)
Equilibrium concentration of HOCl at 25°C is 0.140 M
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The valence electrons of a krypton (Kr) atom in the ground state are located in the
A. first energy level (shell).
B. second energy level (shell).
C. third energy level (shell).
D. fourth energy level (shell).
Answer:
D
Explanation:
The valence electrons are the outer electrons and must be located in the outermost shell. In this case, D.
1. How many atoms are in 1.00 mole of H?
Answer:
6.022 × 1023
Explanation:
1 mole of H:
The definition of Avogadro's number of 6.022 × 1023/mole is the number of atoms or molecules per one gram atomic weight. For one gram atomic weight of hydrogen with an atomic weight of one gram, one mole of hydrogen contains 6.022 × 1023 hydrogen atoms. 1.45⋅6.02⋅1023≈8.73⋅1023 hydrogen atoms.
1 mole:
The value of the mole is equal to the number of atoms in exactly 12 grams of pure carbon-12. 12.00 g C-12 = 1 mol C-12 atoms = 6.022 × 1023 atoms • The number of particles in 1 mole is called Avogadro's Number (6.0221421 x 1023).
in an H:
H: 2×2×4=16 atoms of hydrogen. C: It only appears once and without a subscript, so 1×4=4 . O : Like carbon, it's 1×4=4 .
1.00 mole:
One mole is equal to 6.02214179×1023 atoms, or other elementary units such as molecules.
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Why does adding salt allow ice to freeze milk?
A.It increases the freezing point
B.Salt is colder than point
C.It increases the boiling point
D.It decreases the freezing point
Answer:
It increases the freezing point
Explanation:
The salt lowers the temperature at which water freezes. :)
An electrolysis reaction is
A) spontaneous
B) exothermic
C) non-spontaneous
D) hydrophobic
Answer:
it's non-spontaneous
Explanation:
I hope it helps you
In one to two sentences, describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).(2 points)
An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.
Intramolecular forces are the forces of attraction that hold atoms together within a molecule. Intramolecular forces require a high amount of energy to splits atoms or molecules in a chemical bonding.
Intermolecular forces are weaker forces of attraction that occur between molecules. They require lesser energy to splits molecules compared to intramolecular forces.
An experiment that would show that intramolecular forces are stronger than intermolecular forces will be heating a block of ice in a sealed container then allowing it to change to steam.
In the process, the energy required to change the state from ice to steam water is more than intermolecular forces.
Thus, we can conclude that this experiment shows that the intramolecular forces are stronger than the intermolecular forces.
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How many oxygen do we have in the FE2(so4)3
Explanation:
What do you mean by 'how many oxygen'?
oxygen atoms? or oxygen percentage?
if oxygen atoms is 12 atoms
I don’t wanna fail if you know the answer pls help me :(
Answer:
liquid and gas........................
Which bond is the most polar?
Answer:
A
Explanation:
reason:
H-F is most polar
because bond is polarized negative towards F which is the more electronegative atom.
iDENTIFY THE NAME OF THE ELEMENTS OF THE ATOMS ABOVE
Answer:
oxygen carbon hydrogen nitrogen
Explanation:
identified by the number of protons in its atoms