Answer:
[tex]1.242 \times 10^{25}\text{ atoms H}[/tex]
Explanation:
You must convert the mass of B₄H₁₀ to moles of B₄H₁₀, then to molecules of B₄H₁₀, and finally to atoms of H.
1. Moles of B₄H₁₀
[tex]\text{Moles of B$_{4}$H}_{10} = \text{110.0 g B$_{4}$H}_{10} \times \dfrac{\text{1 mol B$_{4}$H}_{10}}{\text{53.32 g B$_{4}$H}_{10}} = \text{2.063 mol B$_{4}$H}_{10}[/tex]
2. Molecules of B₄H₁₀
[tex]\text{No. of molecules} = \text{2.063 mol B$_{4}$H}_{10} \times \dfrac{6.022 \times 10^{23}\text{ molecules B$_{4}$H}_{10}}{\text{1 mol B$_{4}$H}_{10}}\\\\=1.242 \times 10^{24}\text{ molecules B$_{4}$H}_{10}[/tex]
3. Atoms of H
[tex]\text{Atoms of H} = 1.242 \times 10^{24}\text{ molecules B$_{4}$H}_{10} \times \dfrac{\text{10 atoms H}}{\text{1 molecule B$_{4}$H}_{10}}\\\\= \mathbf{1.242 \times 10^{25}}\textbf{ atoms H}[/tex]
Using only sodium carbonate, Na2CO3, sodium bicarbonate, NaHCO3, and distilled water determine how you could prepare 50.0 mL of a 0.20 M solution that is buffered to a pH of 10.3. The total molarity of the ions should be 0.20 M. The Ka of the hydrogen carbonate ion, HCO3 - , is 4.7 x 10-11 .
Answer:
Weight 0.4326 g of sodium bicarbonate and 0.5141 g of sodium carbonate, dissolve it in distilled water and then bring the solution to a final volume of 50.0 mL using distilled water.
Explanation:
The pH of a buffered solution can be calculated using the Henderson-Hasselbalch equation:
[tex] pH = pKa + log(\frac{[Na_{2}CO_{3}]}{[NaHCO_{3}]}) [/tex]
We have that pH = 10.3 and the Ka is 4.7x10⁻¹¹, so:
[tex] 10.3 = -log(4.7 \cdot 10^{-11}) + log(\frac{[Na_{2}CO_{3}]}{[NaHCO_{3}]}) [/tex]
[tex] \frac{[Na_{2}CO_{3}]}{[NaHCO_{3}]} = 0.94 [/tex] (1)
Also, we know that:
[tex] [Na_{2}CO_{3}] + [NaHCO_{3}] = 0.20 M [/tex] (2)
From equation (2) we have:
[tex] [Na_{2}CO_{3}] = 0.20 - [NaHCO_{3}] [/tex] (3)
By entering (3) into (1):
[tex] \frac{0.20 - [NaHCO_{3}]}{[NaHCO_{3}]} = 0.94 [/tex]
[tex] 0.94*[NaHCO_{3}] + [NaHCO_{3}] = 0.20 [/tex]
[tex] [NaHCO_{3}] = 0.103 M [/tex]
Hence, the [Na_{2}CO_{3}] is:
[tex] [Na_{2}CO_{3}] = 0.20 - [NaHCO_{3}] = 0.20 M - 0.103 M = 0.097 M [/tex]
Now, having the concentrations and knowing the volume of the buffer solution we can find the mass of the sodium carbonate and the sodium bicarbonate, as follows:
[tex]m_{Na_{2}CO_{3}} = C*V*M = 0.097 mol/L*0.050 L*105.99 g/mol = 0.5141 g[/tex]
[tex]m_{NaHCO_{3}} = C*V*M = 0.103 mol/L*0.050 L*84.007 g/mol = 0.4326 g[/tex]
Therefore, to prepare 50.0 mL of a 0.20 M solution that is buffered to a pH of 10.3 we need to weight 0.4326 g of sodium bicarbonate and 0.5141 g of sodium carbonate, dissolve it in distilled water and then bring the solution to a final volume of 50.0 mL using distilled water.
I hope it helps you!
Which statements about spontaneous processes are true? Select all that apply: A spontaneous process is one that occurs very quickly.
Answer: Here are the complete options.
A spontaneous process is one that occurs very quickly. A process that is spontaneous in one direction is nonspontaneous in the other direction under a given set of conditions, provided the system is not at equilibrium. A spontaneous process is one that occurs without continuous input of energy from outside the system. A process is spontaneous if it must be continuously forced or driven.
The correct option is
A spontaneous process is one that occurs without continuous input of energy from outside the system.
A process that is spontaneous in one direction is nonspontaneous in the other direction under a given set of conditions, provided the system is not at equilibrium
Explanation:
spontaneous process is one that occurs without continuous input of energy from outside the system and occur on its own because spontaneous processes are thermodynamically favorable characterized by a decrease in the system's free energy, they do not need to be driven by an outside source of energy. Which means that the initial energy is higher than the final energy.
A process that is spontaneous in one direction is nonspontaneous in the other direction under a given set of conditions, provided the system is not at equilibrium which will result to The sign of ΔG will change from positive to negative (or vice versa) where T = ΔH/ΔS. In cases where ΔG is: negative
Consider the following chemical equation: NH4NO3(s)⟶NH+4(aq)+NO−3(aq) What is the standard change in free energy in kJmol at 298.15K? The heat of formation data are as follows: ΔH∘f,NH4NO3(s)=-365.6kJmolΔH∘f,NH+4(aq)=-132.5kJmolΔH∘f,NO−3(aq)=-205.0kJmol The standard entropy data are as follows: S∘NH4NO3(s)=151.1Jmol KS∘NH+4(aq)=113.4Jmol KS∘NO−3(aq)=146.4Jmol K Your answer should include two significant figures.
Answer:
[tex]\Delta _rG=-4.3\frac{kJ}{mol}[/tex]
Explanation:
Hello,
In this case, for the given dissociation reaction, we can compute the enthalpy of reaction considering the enthalpy of formation of each involved species (products minus reactants):
[tex]\Delta _rH=\Delta _fH_{NH^{4+}}+\Delta _fH_{NO_3^-}-\Delta _fH_{NH_4NO_3}\\\\\Delta _rH=-132.5+(-205.0)-(-365.6)=28.1kJ/mol[/tex]
Next, the entropy of reaction considering the standard entropy for each involved species (products minus reactants):
[tex]\Delta _rS=S_{NH^{4+}}+S_{NO_3^-}-S_{NH_4NO_3}\\\\\Delta _rS=113.4+146.4-151.1=108.7J/mol*K[/tex]
Next, since the Gibbs free energy of reaction is computed in terms of both the enthalpy and entropy of reaction at the given temperature (298.15 K), we finally obtain (two significant figures):
[tex]\Delta _rG=\Delta _rH-T\Delta _rS\\\\\Delta _rG=28.1kJ/mol-(298.15 K)(108.7\frac{J}{mol*K}*\frac{1kJ}{1000J} )\\\\\Delta _rG=-4.3\frac{kJ}{mol}[/tex]
Best regards.
The decomposition of nitramide in aqueous solution at 25 °C NH2NO2(aq)N2O(g) + H2O(l) is first order in NH2NO2 with a rate constant of 4.70×10-5 s-1. If an experiment is performed in which the initial concentration of NH2NO2 is 0.384 M, what is the concentration of NH2NO2 after 31642.0 s have passed? M
Answer:
[tex][NH_2NO_2]=0.0868M[/tex]
Explanation:
Hello,
In this case, for the given chemical reaction, the first-order rate law is:
[tex]r=\frac{d[NH_2NO_2]}{dt} =-k[NH_2NO_2][/tex]
Which integrated is:
[tex][NH_2NO_2]=[NH_2NO_2]_0exp(-kt)[/tex]
Thus, the concentration after 31642.0 s for a 0.384-M solution is:
[tex][NH_2NO_2]=0.384M*exp(-4.70x10^{-5}s^{-1}*31642.0s)\\[/tex]
[tex][NH_2NO_2]=0.0868M[/tex]
Best regards.
Answer:
[A] = 0.0868 M
Explanation:
Rate constant = 4.70×10-5 s-1
First order reaction
Initial concentration, [A]o = 0.384 M
Final concentration, [A] = ?
Time, t = 31642.0 s
All these variables are related by the following equation;
[A] = [A]o e^(-kt)
[A] = 0.384 e^(-4.70×10-5 x 31642.0)
[A] = 0.384 e^(-1.4872)
[A] = 0.384 * 0.2260
[A] = 0.0868 M
When 0.100 M NaOH is titrated with 25.00 mL 0.0500 M HBr, which of the following is correct for this titration?
A. Initially the pH will be less than 1.00.
B. The pH at the equivalence point will be 7.00.
C. It will require 12.50 mL of NaOH to reach the equivalence point.
When 0.100 M NaOH is titrated with 25.00 mL 0.0500 M HBr, which of the following is correct for this titration?
A. Initially the pH will be less than 1.00.
B. The pH at the equivalence point will be 7.00.
C. It will require 12.50 mL of NaOH to reach the equivalence point.
a)A, C
b) A, B
c) B, C
d) B
Answer:
c) B, C
Explanation:
NaOH(aq) + HBr(aq) -----> NaBr(aq) +H2O(l)
1) concentration of acid CA= 0.05 M
Concentration of base CB= 0.1 M
Volume of acid VA= 25.00ml
Volume of base VB= unknown
Number of moles of acid NA= 1
Number of moles of base NB= 1
CAVA/CBVB = NA/NB
CAVANB =CBVBNA
VB= CAVANB/CB NB
VB= 0.05 × 25 × 1/ 0.1 ×1
VB= 12.5 ML
2.
Divers often inflate heavy duty balloons attached to salvage items on the sea floor. If a balloon is filled to a volume of 1.20 L at a pressure of 6.25 atm, what is the volume of the balloon when it reaches the surface?
Answer:
7.50 L
Explanation:
The balloon has a volume of 1.20 L (V₁) when the pressure at the sea floor is 6.25 atm (P₁). When it reaches the surface, the pressure is that of the atmosphere, that is, 1.00 atm (P₂). If we consider the gas to behave as an ideal gas and the temperature to be constant, we can calculate the final volume (V₂) using Boyle's law.
P₁ × V₁ = P₂ × V₂
V₂ = P₁ × V₁ / P₂
V₂ = 6.25 atm × 1.20 L / 1.00 atm
V₂ = 7.50 L
Solution of the Schrödinger wave equation for the hydrogen atom results in a set of functions (orbitals) that describe the behavior of the electron. Each function is characterized by 3 quantum numbers: n, l, and ml. If the value of n = 3 ... The quantum number l can have values from ? to ? . ... The total number of orbitals possible at the n = 3 energy level is ? . If the value of l = 3 ... The quantum number ml can have values from to ? . ... The total number of orbitals possible at the l = 3 sublevel is ?? .
Answer:
1) The quantum number l can have values from
2 to 0
2)The total number of orbitals possible at the n = 3 energy level is 3'2=9
3) If the value of l = 3 ... The quantum number ml can have values from 3 to -3
The quantum number l determines the shape of the orbital. In this case, if the value of n is 3, then the quantum number l can have values from 0 to (3-1), which is 2.
The total number of orbitals possible at the n = 3 energy level can be determined using the formula 2l + 1. So, for l = 0, there is 1 orbital. For l = 1, there are 3 orbitals. And for l = 2, there are 5 orbitals. Therefore, the total number of orbitals possible at the n = 3 energy level is 1 + 3 + 5 = 9.
On the other hand, the quantum number ml represents the magnetic quantum number. It specifies the orientation of the orbital in space. The value of ml ranges from -l to +l. So, if the value of l is 3, then the quantum number ml can have values from -3 to +3.
The total number of orbitals possible at the l = 3 sublevel can be determined using the formula 2ml + 1. So, for ml = -3, there is 1 orbital. For ml = -2, there is 3 orbitals. For ml = -1, there is 5 orbitals. For ml = 0, there is 7 orbitals. For ml = 1, there is 5 orbitals. For ml = 2, there is 3 orbitals. And for ml = 3, there is 1 orbital.
Therefore, the total number of orbitals possible at the l = 3 sublevel is 1 + 3 + 5 + 7 + 5 + 3 + 1 = 25.
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How many moles of NaOH is needed to neutralize 45.0 ml of 0.30M H2SeO4? Question 2 options: A) 0.00675 B) 27.0 C) 0.027 D) 0.0135
Answer:
C) 0.027
Explanation:
In this case we can start with the reaction between [tex]NaOH[/tex] and [tex]H_2SeO_4[/tex], so:
[tex]H_2SeO_4~+~NaOH~->~Na_2SeO_4~+~H_2O[/tex]
We have an acid ([tex]H_2SeO_4[/tex]) and a base ([tex]NaOH[/tex]), therefore we will have an acid-base reaction in which a salt is produced ([tex]Na_2SeO_4[/tex]) and water ([tex]H_2O[/tex]).
Now we can balance the reaction:
[tex]H_2SeO_4~+~2NaOH~->~Na_2SeO_4~+~2H_2O[/tex]
If we have the volume (45 mL= 0.045 L) and the concentration (0.3 M) of the acid we can calculate the moles using the molarity equation:
[tex]M=\frac{mol}{L}[/tex]
[tex]0.3~M~=~\frac{mol}{0.045~L}[/tex]
[tex]mol=0.3~M*0.045~L=0.0135~mol~of~H_2SeO_4[/tex]
In the balanced reaction, we have a 2:1 molar ratio between the acid and the base (for each mol of [tex]H_2SeO_4[/tex] 2 moles of [tex]NaOH[/tex] are consumed), with this in mind we can calculate the moles of NaOH:
[tex]0.0135~mol~of~H_2SeO_4\frac{2~mol~NaOH}{1~mol~of~H_2SeO_4}=0.027~mol~NaOH[/tex]
I hope it helps!
What chemical bonds hold atoms?
Write a net ionic equation for the reaction that occurs when aqueous solutions of hydrofluoric acid and sodium hydroxide are combined. (Use the lowest possible coefficients. Use the pull-down boxes to specify states such as (aq) or (s). If a box is not needed, leave it blank. If needed, use H for the hydronium ion.)
Answer:
The net ionic reaction is : H⁺ (aq) + OH⁻ (aq) ---> H₂O (l)
Explanation:
The reaction between aqueous solutions of hydrofluoric acid and sodium hydroxide is an example of a neutralization reaction.
A neutralization reaction is a reaction between and acid and an abase to produce salt and water only.
Hydrofluoric acid is the acid while sodium hydroxide is the base. during the reaction the hydrofluoric acid will produce hydrogen and fluoride ions, while sodium hydroxide will produce hydroxide and sodium ions. The hydroxide and hydrogen ions will combine to produce water while the sodium and fluoride ions remain in solution as ions.
The equation of the reaction is as follows:
H⁺F⁻ (aq) + Na⁺OH⁻ (aq) ----> Na⁺F⁻ (aq) + H₂O (l)
Since the sodium and fluoride ions appear on both sides of the equation, they are known as spectator ions and are cancelled out to give the net ionic equation.
The net ionic reaction is : H⁺ (aq) + OH⁻ (aq) ---> H₂O (l)
How are pH and pOH ?
A. pH = 14 + pOH
B. pOH = 14 - pH
C. pOH = 14 + pH
D. pH = 14 - pOH
Answer:
B. pOH = 14 - pH and D. pH = 14 - pOH.
Explanation:
Hello,
In this case, we must remember that pH and pOH are referred to a measure of acidity and basicity respectively, since pH accounts for the concentration of H⁺ and pOH for the concentration of OH⁻ in a solution. In such a way, since the maximum scale is 14, we say that the addition between the pH and pOH must be 14:
[tex]pH+pOH=14[/tex]
Therefore, the correct answers are B. pOH = 14 - pH and D. pH = 14 - pOH since the both of them are derived from the previous definition.
Best regards.
Answer:
D: by subtracting the pOH from 14.
Explanation:
The frequency of a signal is found to be 6389 with an uncertainty of 436 Hz. To the correct number of significant digits, it should be reported as:
Answer:
i hope it work
Explanation:
as
accurate reading range = reading ± uncertainty
so you have to say about accurate reading that its,lies in range
=(6389-436) →(6389+436)
=5953→6825
and the correct number of significant would be 3
Consider the acid H3PO4. This acid will react with water by the following equation. H3PO4+H2O↽−−⇀H2PO−4+H3O+ What will be true of the resulting conjugate base H2PO−4? Select the correct answer below: H2PO−4 can act as an acid.
Answer:
H+/PO-4^-2
Explanation:
hydrogen has dissolved completely
In the given reaction conjugate base is H₂PO₄⁻, it also behave as a weak acid.
What is acid - conjugate base pair?
An acid and conjugate base pairs are those pairs in which they are differentiated by the one atom of hydrogen atom.
Given chemical reaction is:
H₃PO₄ + H₂O → H₂PO₄⁻ + H₃O⁺
In the above reaction H₃PO₄ is an acid as it gives H⁺ ion to the solution and formed H₂PO₄⁻, which is a conjugate base of H₃PO₄ acid. H₂PO₄⁻ will also behave as an acid because it have H⁺ ion to gives in the solution but nature of this acid is weak as they not readily dissociates.
Hence, H₂PO₄⁻ is a conjugate base.
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The total kinetic energy of a body is known as:
A. Thermal energy
B. Convection
C. Potential energy
D. Temperature
The total kinetic energy of a body is known as Thermal energy. Option A
What is thermal energy?Thermal energy is the direct sum of all the available random kinetic energies of molecules.
Also note that thermal energy is directly proportional to temperature in Kelvin.
Thus, the total kinetic energy of a body is known as Thermal energy. Option A
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Answer:
A.) Thermal energy
Explanation:
I got it correct on founders edtell
11mg of cyanide per kilogram of body weight is lethal for 50% of domestic chickens. If a chicken weighs 3kg, how many grams of cyanide would it need to ingest to kill 50% of domestic chickens?
Answer:
[tex]0.033g[/tex]
Explanation:
Hello,
In this case, since 11 mg per kilogram of body weight has the given lethality, the mg that turn out lethal for a chicken weighting 3 kg is computed by using a rule of three:
[tex]11mg\longrightarrow 1kg\\\\?\ \ \ \ \ \ \longrightarrow 3kg[/tex]
Thus, we obtain:
[tex]?=\frac{3kg*11mg}{1kg}\\ \\?=33mg[/tex]
That in grams is:
[tex]=33mg*\frac{1g}{1000mg} \\\\=0.033g[/tex]
Regards.
discuss four factors of learning
Answer:
plz mark as BRAINLIEST plz...
Explanation:
●Intellectual factor: The term refers to the individual mental level. ...
●Learning factors: ...
●Physical factors: ...
●Mental factors: ...
What happens to the rate of dissolution as the temperature is increased in a gas solution?
A.
The rate stays the same.
B.
The rate decreases.
C.
The rate increases.
D.
There is no way to tell.
Answer:
The rate decreases
Explanation:
When we dissolve a gas in a water, the process is exothermic. This implies that heat is evolved upon dissolution of a gas in water.
Recall from Le Chateliers principle that for exothermic reactions, an increase in temperature favours the reverse reaction. The implication of these is that when the temperature of the gas is increased, less gas will dissolve in water.
Hence increase in temperature decreases the rate of solubility of a gas in water.
Answer:
B.
The rate decreases.
Explanation:
Explain your reasoning. Match each explanation to the appropriate blanks in the sentences on the right.
1. the atomic radius decreases
2. the number of gas molecules decreases
3. molar mass and structure complexity decreases
4. structure complexity decreases
5. molar mass decreases
6. each phase (gas, liquid, solid) becomes more ordered
A (I_2(g), Br_2 (g), Cl_2 (g), F_2 (B): The ranking can best be explained by the trend entropy decreases as______.
B (H_2O_2 (g), H_2S(g), H_2O(g): The ranking can best be explained by the decreases a trend entropy decreases as_______.
C. (C(s, amorphous), C(s, graphite), C(s, diamond): The ranking can best be explained by the trend entropy decreases as_______.
Answer:
A (I_2(g), Br_2 (g), Cl_2 (g), F_2 (B): The ranking can best be explained by the trend entropy decreases as 5. molar mass decreases.
B (H_2O_2 (g), H_2S(g), H_2O(g): The ranking can best be explained by the decreases a trend entropy decreases as 3. molar mass and structure complexity decreases.
C. (C(s, amorphous), C(s, graphite), C(s, diamond): The ranking can best be explained by the trend entropy decreases as 4. structure complexity decreases.
Explanation:
Hello.
In this case, we can understand a higher entropy when more disorder is present and a lower entropy when less disorder is present, thus:
A (I_2(g), Br_2 (g), Cl_2 (g), F_2 (B): The ranking can best be explained by the trend entropy decreases as 5. molar mass decreases since iodine has the greatest molar mass (254 g/mol) and fluorine the least molar mass (38 g/mol).
B (H_2O_2 (g), H_2S(g), H_2O(g): The ranking can best be explained by the decreases a trend entropy decreases as 3. molar mass and structure complexity decreases since hydrogen peroxide weights 34 g/mol as well as hydrogen sulfide but the peroxide has more bonds (more complex, higher entropy).
C. (C(s, amorphous), C(s, graphite), C(s, diamond): The ranking can best be explained by the trend entropy decreases as 4. structure complexity decreases since diamond has a well-ordered structure and amorphous carbon has a very disordered one.
Best regards.
One gram is approximately the same as half the mass of a new U.S.
A) penny.
B) dime.
C) quarter.
D) dollar.
Answer:
b) dime
Explanation:
a dime is approximately 2.2g
half of this is 1.1g, which can be rounded down to one gram.
hope this helps
A 100.0 mL sample of 0.10 M NH3 is titrated with 0.10 M HNO3. Determine the pH of the solution before the addition of any HNO3. The Kb of NH3 is 1.8 × 10-5.
Answer:
[tex]pH=11.12[/tex]
Explanation:
Hello,
In this case, ammonia dissociation is:
[tex]NH_3(aq)+H_2O(l)\rightleftharpoons NH_4^+(aq)+OH^-(aq)[/tex]
So the equilibrium expression:
[tex]Kb=\frac{[NH_4^+][OH^-]}{[NH_3]}[/tex]
That in terms of the reaction extent and the initial concentration of ammonia is written as:
[tex]1.8x10^{-5}=\frac{x*x}{0.10M-x}[/tex]
Thus, solving by using solver or quadratic equation we find:
[tex]x=0.00133M[/tex]
Which actually equals the concentration of hydroxyl ion, therefore the pOH is computed:
[tex]pOH=-log([OH^-])=-log(0.00133)=2.88[/tex]
And the pH from the pOH is:
[tex]pH=14-pOH=14-2.88\\\\pH=11.12[/tex]
Best regards.
place the following substances in Order of decreasing boiling point H20 N2 CO
Answer:
-195.8º < -191.5º < 100º
Explanation:
Water, or H20, starts boiling at 100ºC.
Nitrogen, or N2, starts boiling at -195.8ºC.
Carbon monoxide, or C0, starts boiling at -191.5ºC.
When we place these in order from decreasing boiling point:
-195.8º goes first, then -191.5º, and 100º goes last.
Answer:
therefore, N2, CO, H20
Decreasing boiling point
Explanation:
the bond existing in H2O is hydrogen bond
bond existing in N2 is covalent bond, force existing is dipole-dipole-interaction
bond existing in CO is covalent bond , force existing between is induced -dipole- induced dipole-interaction
hydrogen bond is the strongest , followed by dipole-dipole-interaction and induced -dipole- induced dipole-interaction
the stronger the bond , the higher the boiling point
therefore, N2, CO, H20
-------------------------------------->
Decreasing boiling point
In the pictured cell, the side containing zinc is the Choose... and the side containing copper is the Choose... . The purpose of the N a 2 S O 4 NaX2SOX4 is to
Answer:
Zinc- anode
Copper- cathode
Sodium sulphate- salt bridge
Explanation:
A galvanic cell is an electrochemical cell in which electrical energy is produced by a spontaneous chemical reaction.
In the pictured galvanic cell, zinc is the anode since it looses electrons according to the reaction; Zn(s) -----> Zn^2+(aq) + 2e
Copper is the cathode as shown here; Cu^2+(aq) + 2e ----> Cu(s)
Sodium sulphate functions as the salt bridge. It keeps the both solutions neutral by ensuring charge balance in the both half cells.
Answer:
zinc=anode
copper=cathode
Explanation:
Consider the following practical aspects of titration.
(a) how can you tell when nearing the end point in titration?
(b) What volume of NaOH is required to permanently change the indicator at the end point?
(c) If KHP sample #1 requires 19.90 mL of NaOH solution to reach an end point, what volume is required for samples #2 and #3?
(d) if vinegar sample #1 requires 29.05 mL of NaOH solution to reach an endpoint, what volume is required for samole #2 and #3?
Answer:
A) when the titration is nearing the end point in titration the color of the solution starts to change and the change in color does not disappear as fast as it was during the beginning of the titration
B) The volume of NaOH required to permanently change the indicator at the end point is a drop of NaOH
c) The volume required by samples #2 and #3 will be the same i.e 19.90 mL of NaOH, if the concentration of KHP base used for the samples are the same
D) The volume required by samples #2 and #3 will be the same i.e 29.05 mL OF NaOH, if the concentration of Vinegar and base for the samples are the same
Explanation:
A) when the titration is nearing the end point in titration the color of the solution starts to change and the change in color does not disappear as fast as it was during the beginning of the titration
B) The volume of NaOH required to permanently change the indicator at the end point is a drop of NaOH
c) The volume required by samples #2 and #3 will be the same i.e 19.90 mL of NaOH, if the concentration of KHP base used for the samples are the same
D) The volume required by samples #2 and #3 will be the same i.e 29.05 mL OF NaOH, if the concentration of Vinegar and base for the samples are the same
21. What are the two main ways of working with clay?
Answer:
Diferentes tipos de arcilla
ARCILLA DE LADRILLOS. Contiene muchas impurezas. ...
ARCILLA DE ALFARERO. Llamada también barro rojo y utilizada en alfarería y para modelar. ...
ARCILLA DE GRES. Es una arcilla con gran contenido de feldespato. ...
ARCILLAS “BALL CLAY” O DE BOLA. ...
CAOLIN. ...
ARCILLA REFRACTARIA. ...
BENTONITA.
Explanation:
Answer:
Coil method and the slab method.
Explanation:
Question 14 (5 points)
What's the acid ionization constant for an acid with a pH of 2.11 and an equilibrium
concentration of 0.30 M?
O A) 4.87x10-8
B) 1.99x10-6
C) 3.32x10-4
OD) 2.01x10-4
Answer:
D) 2.01 x 10⁻⁴ .
Explanation:
pH = 2.11
[ H⁺ ] = [tex]10^{-2.11}[/tex]
Let the acid be HA
It will ionise as follows .
HA ⇄ H⁺ + A⁻
in equilibrium .30 [tex]10^{-2.11}[/tex] [tex]10^{-2.11}[/tex]
Acid ionisation constant Ka = [tex]\frac{(10^{-2.11})^2}{0.3}[/tex]
= 2 x 10⁻⁴
Answer:
D) 2.01 x 10⁻⁴ is correct!
Explanation:
I got it in class!
Hope this Helps!! :))
Which of the following represents a compound made of five molecules? CO 5 C 2O 5 C 5O 5CO 2
Answer:
Co5
Please mark me brainliest so that I get encouraged to make more great answers like this one!
Answer:
GUYS ITS 5CO 2
Explanation:
What's the name for the part of Earth made of rock?
A. Geosphere
B. Atmosphere
C. Hydrosphere
D. Biosphere
SUBMIT
Answer:I think it's Geosphere
Explanation:
Answer:
A
Explanation:
Geo means rock, or earth. Hydro means water, Atmosphere is space, and Bio global ecosystem composed of living organisms
4NH3(g) 5O2(g)4NO(g) 6H2O(g) Using standard thermodynamic data at 298K, calculate the free energy change when 1.81 moles of NH3(g) react at standard conditions.
Answer:
-434.14 kJ
Explanation:
Step 1: Write the balanced equation
4 NH₃(g) + 5 O₂(g) ⇒ 4 NO(g) + 6 H₂O(g)
Step 2: Calculate the standard free energy change (ΔG°r) for the reaction
We will use the following expression.
ΔG°r = 4 mol × ΔG°f(NO(g)) + 6 mol × ΔG°f(H₂O(g)) - 4 mol × ΔG°f(NH₃(g)) - 5 mol × ΔG°f(O₂(g))
ΔG°r = 4 mol × (86.55 kJ/mol) + 6 mol × (-228.57 kJ/mol) - 4 mol × (-16.45 kJ/mol) - 5 mol × (0 kJ/mol)
ΔG°r = -959.42 kJ
Step 3: Calculate the standard free energy change for 1.81 moles of NH₃
959.42 kJ are released per 4 moles of NH₃.
[tex]\frac{-959.42 kJ}{4mol} \times 1.81mol = -434.14 kJ[/tex]
Ammonia, methane, and phosphorus trihydride are three different compounds with three different boiling points. Rank their boiling points in order from lowest to highest.
A. CH4< NH3 < PH3
B. NH3 < PH3< CH4
C. CH4 < PH3 < NH3
D. NH3 < CH4< PH3
E. PH3< NH3 < CH4
Answer:
B. NH3 < PH3< CH4
Explanation:
Hello,
In this case, taking into account that the boiling point of ammonia, methane and phosphorous trihydrate are -33.34 °C , -161.5 °C and -87.7 °C , clearly, methane has the lowest boiling point (most negative) and ammonia the greatest boiling point (least negative), therefore, ranking is:
B. NH3 < PH3< CH4
Best regards.
Calculate the energy required to heat 566.0mg of graphite from 5.2°C to 23.2°C. Assume the specific heat capacity of graphite under these conditions is ·0.710J·g−1K−1 . Be sure your answer has the correct number of significant digits.
Answer:
7.23 J
Explanation:
Step 1: Given data
Mass of graphite (m): 566.0 mgInitial temperature: 5.2 °CFinal temperature: 23.2 °CSpecific heat capacity of graphite (c): 0.710J·g⁻¹K⁻¹Step 2: Calculate the energy required (Q)
We will use the following expression.
Q = c × m × ΔT
Q = 0.710J·g⁻¹K⁻¹ × 0.5660 g × (23.2°C-5.2°C)
Q = 7.23 J
