Answer:
0.80 g
Explanation:
First we calculate the required pOH from the given pH value:
pOH = 14 - pHpOH = 14 - 12.20 = 1.80Then we calculate the required concentration of OH⁻, using the pOH:
pOH = -log[OH⁻][OH⁻] = [tex]10^{-1.80}[/tex] = 0.0158 MAs the concentration of OH⁻ species is the sames as the concentration of KOH, we need to prepare 900 mL of a 0.0158 M KOH solution:
We calculate how many KOH moles are required, using the concentration and volume:
Converting 900 mL ⇒ 900 / 1000 = 0.900 Lmoles = 0.0158 M * 0.900 L = 0.01422 molFinally we convert 0.01422 moles of KOH to grams, using its molar mass:
0.01422 mol * 56 g/mol = 0.80 gAn eccentric chemistry professor (not mentioning any names) stops in every day and orders 200ml of Sumatran coffee at precisely 75.0°C. You then need to add enough milk at 5.00°C to drop the temperature of the coffee, initially at 95.0°C, to the ordered temperature.
Answer:
68.97g of milk must be added
Explanation:
To solve this problem we need to use the equation:
Q = C*m*ΔT -Coffee cup calorimeter equation-
This equation relates mass and change in temperature with heat of solution, Q.
The energy that decreases in the milk is the same that increases in the milk. That is:
Q(milk) = Q(tea)
Using the equation:
4.184J/molK* Mass milk * (65.0°C - 7.00°C) = 4.184J /molK * 200g (Tea) * (85.0°C - 65.0°C)
Mass milk * 58.0°C = 200g * 20.0°C
Mass milk = 4000g°C / 58.0°C
Mass milk =
68.97g of milk must be added
What three parts of your eye work together to create a clear image?
Answer:
cornea,Jens and pupil
tma Po yan
What is the pH of a solution whose hydronium ion [H20+] (or proton [H+1)
concentration is 7.6' 10-5 M?
Answer:
[tex]pH = - log(7.6 \times {10}^{ - 5} ) \\ pH = 4.12[/tex]
An ion has 38 protons, 36 electrons, and 40 neutrons, what us the elements symbol
The symbol of the element in which it's ion has 38 protons, 36 electrons, and 40 neutrons is ⁷⁸₃₈Sr
How do I determine the symbol of the element?To obtain the symbol of the element, we shall obtain the mass number of the element. This is shown below:
Proton = 38Neutron = 40Mass number = ?Mass number = Proton + Neutron
Mass number = 38 + 40
Mass number = 78
Finally, we shall determine the symbol of the element. Details below:
Proton = 38Atomic number (z) = Proton = 38Mass number (A) = 78Symol of element =?From the periodic table, the element with atomic number of 38 is Strontium.
Thus, the symbol of the element will be ⁷⁸₃₈Sr
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Verdadero o falso si un átomo presenta de 5 a 7 electrones en su nivel más extremo tenderá a perderlos?
Write the equation showing the formation of a monosubstituted product when butane reacts with chlorine. Use molecular formulas for the organic compounds (C before H, halogen last) and the smallest possible integer coefficients.
Answer:
CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl
Explanation:
Alkanes react with halogens in the presence of light to yield alkyl halides. The degree of substitution increases as the reaction progresses. The reaction occurs by free radical mechanism.
The reaction between butane and chlorine molecule to yields a monosubstitution product occurs as follows;
CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl
given two equations representing reactions: which type of reaction is represented by each of these equations?
Answer:
Equation 1 - nuclear fission
Equation 2 - nuclear fusion
Explanation:
Nuclear fission is a reaction in which a large nucleus is split into smaller nuclei when it is bombarded by neutrons. The process produces more neutrons to continue the chain reaction. This is clearly depicted in equation 1 as shown in the question.
Nuclear fusion is a reaction in which two light nuclei combine in order to form a larger nuclei. This is clearly depicted in equation 2 as shown in the question.
In the first reaction, a neutron is released, and in the second a helium atom is released. The given two equations represent nuclear fission and fusion.
What are nuclear reactions?A nuclear reaction is a reaction that involves the nuclei of the atom and the absorption and release of energy. In the first reaction, a big nucleus is split by the neutron bombardment into smaller nuclei.
In the second reaction the process of nuclear fusion, two nuclei combine into a single larger nucleus that is shown as:
₁¹H+ ²₁H → ³₂He
Therefore, nuclear fission and fusion are represented by each of these equations.
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How many grams of hydrogen gas, H, are necessary to produce 119.0 g of ammonia, NH3?
Answer:
What's the equation?
Answer:
14.5 g
Explanation:
its true
A concentration cell is constructed by using the same half-reaction for both the cathode and anode. What is the value of standard cell potential, for a concentration cell that combines a silver anode in contact with 0.10 M silver nitrate and a silver cathode in contact with 0.00003 M silver nitrate
Solution :
A cell that is concentrated is constructed by the same half reaction for the anode as well as he cathode.
We know,
In a standard cell,
the reduction half cell reaction is :
[tex]$Ag^+(aq)+e^- \rightarrow Ag(s) E^0 = -0.80 \ V$[/tex]
The oxidation half ell reaction :
[tex]$Ag(s) \rightarrow Ag^+(aq) + e^- \ E^0= +0.80 \ V$[/tex]
Thus the complete reaction of the cell is :
[tex]$Ag^+(aq)+ Ag(s) \rightarrow Ag^+(aq)+Ag(s)$[/tex]
[tex]$E^0 $[/tex] cell = [tex]$E_R - E_L = 0.00 \ \text{volts}$[/tex]
Phenols do not exhibit the same pka values as other alcohols; they are generally more acidic. Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane
Answer:
Phenols do not exhibit the same pka values as other alcohols;
They are generally more acidic.
Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane.
Explanation:
According to Bromsted=Lowry acid-base theory,
an acid is a substance that can release [tex]H^{+}[/tex] ions when dissolved in water.
So, acid is a proton donor.
If the conjugate base of an acid is more stable then, that acid is a strong acid.
In the case of phenol,
the phenoxide ion formed is stabilized by resonance.
[tex]C_6H_5OH -> C_6H_5O^- +H^+[/tex]
The resonance in phenoxide ion is shown below:
Whereas in the case of cyclohexanol resonance is not possible.
So, cyclohexanol is a weak acid compared to phenol.
Studying and got stuck if someone can help me.
Answer:
Ph level 0-7 is a acid
ph level 7-14 is base
bases turn paper blue
acids dissolve metal
acids contain hydrogen ions
Explanation:
I dont know the last one all I know that they become neutral when acids and bases are mixed.
How many molecules are there in 4.27 mol of tungsten(VI) oxide, WO3
Answer:
Molar mass of WO3 = 231.8382 g/mol Convert grams Tungsten(VI) Oxide to moles or moles Tungsten(VI) Oxide to grams Molecular weight calculation: 183.84 + 15.9994*3Explanation:
#hopeithelpsbrainliest me later.25.71 × 10²³ molecules are there in 4.27 mol of tungsten (VI) oxide, [tex]WO_3[/tex].
How to find the number of molecules ?To find the Number of molecules of substance multiply the number of moles of given substance by Avogadro number
Number of molecules = Number of moles × Avogadro's Number
Avogadro's NumberAvogadro's number [tex](N_{A})[/tex] is the number of particles in one mole of substance. 6.023 × 10²³ is known as Avogadro's constant / Avogadro's number.
Avogadro's number = 6.023 × 10²³ [tex]mol^{-}[/tex]
Now,
Number of molecules in 4.27 moles of [tex]WO_{3}[/tex]
= Number of moles of [tex]WO_{3}[/tex] × Avogadro's Number
= 4.27 × 6.023 × 10²³
= 25.71 × 10²³ molecules
Thus, we can say that 25.71 × 10²³ molecules are there in 4.27 moles of tungsten (VI) oxide, [tex]WO_3[/tex].
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What is one way in which a field investigation can differ from a classroom or laboratory experiment?
Answer:
□In field investigations, you are usually working with much larger animals than in the lab. In field investigations, it is much more difficult to separate your control and experimental groups.
There are many ways in which a field experiment can differ form of a classroom or a laboratory experiment, one of which can be the environmental condition.
What is a field experiment?A field experiment Is an experiment which is performed in practically Outside the classroom or a laboratory in live situtations .
Environmental factors may deter the results of a field experiment or may alter the physical conditions of the object, For example an anhydrous substance may become hygroscopic, Which may Alter the result of the field experiment.
Hence, field experiment can differ from a classroom or a laboratory experiment due to environmental conditions .
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Which of the following is formed last in daughter cells when plant cells divide?
The nucleus
The nuclear envelope
The cell membrane
The cell wall
Answer:
The Cell Wall
Explanation:
Ammonia burns in the presence of a copper catalyst to form nitrogen gas. 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g) ΔΗ = -1267 kJ What is the enthalpy change to burn 38.4 g of ammonia?
Answer:
-713 kJ
Explanation:
Step 1: Write the balaned thermochemical equation
4 NH₃(g) + 3 O₂(g) → 2 N₂(g) + 6 H₂O(g) ΔΗ = -1267 kJ
Step 2: Calculate the moles corresponding to 38.4 g of NH₃
The molar mass of NH₃ is 17.03 g/mol.
38.4 g × 1 mol/17.03 g = 2.25 mol
Step 3: Calculate the enthalpy change to burn 2.25 mol of ammonia
According to the thermochemical equation, 1267 kJ are released per 4 moles of ammonia that react.
2.25 mol × (-1267 kJ/4 mol) = -713 kJ
Naturally occurring gallium is a mixture of isotopes
that contains 90.11% of Ga-69 (atomic mass = 68.93
u) and 9.89% of Ga-71 (atomic mass 70.92 u).
What is the average atomic mass of naturally
occurring gallium?
A) 69.93 amu
C) 69.50 amu
B) 69.12 amu
D) 69.00 amu
You are given a solution containing a pair of enantiomers (A and B). Careful measurements show that the solution contains 98% A and 2% B. What is the ee of this solution
Answer:
ee = 96%
Explanation:
Enantiomeric excess, ee, is a way to express a mixture that is not enantiomerically pure. It is defined as 100 times the ratio between the differences of amounts of enantiomers and the total amunt. that is:
ee = |A-B|/ A+B * 100
ee = |98%-2%| / 98+2 * 100
ee = 96%In the electrolysis of water, how long will it take to produce 75.00 L of H2 at 1.0 atm and 273 K using an electrolytic cell through which the current is 205.0 mA
answer is 2546 h
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The mass percent of element X
in X(NO3)2 is 52.55%.
Chemical analysis of a pure
sample of X(NO3)2 shows that
it contains 67.50 g of element
X. What is the total mass of
the pure sample?
Answer:
128.4 g
Explanation:
Step 1: Given data
Mass percent of element X in X(NO₃)₂: 52.55%Mass of the element X in the sample: 67.50 gStep 2: Determine the total mass of the sample
The mass percent of element X in X(NO₃)₂ is 52.55%, that is, there are 52.55 g of X every 100 g of X(NO₃)₂. Then, the mass of X(NO₃)₂ that contains 67.50 g of X is:
67.50 g X × 100 g X(NO₃)₂/52.55 g X = 128.4 g X(NO₃)₂
Using the periodic table,
choose the more reactive nonmetal. Br or as
Answer:
Br
Explanation:
because bromine is more reactive as reactivity increases on moving from left to right in p-block. hope this make sense :)
Chromium (VI) forms two different oxyanions, the orange dichromate ion, Cr2o72-, And the yellow chromate ion, CrO4 2-. The equilibrium reaction between the ions is:
Cr2O7 2- (aq) + H2O(l)→ 2CrO4 2-(aq) + 2H(aq)
Explain
a) Why does the orange dichromate solution turn yellow when sodium hydroxide is added. Write the net ionic equation for this shift.
b) How will this system shift at equilibrium if the temperature is increased
Answer:
See explanation
Explanation:
Let us look at the reaction again;
Cr2O7 2- (aq) + H2O(l)⇄ 2CrO4 2-(aq) + 2H^+(aq)
When we add sodium hydroxide to the system as shown, the hydroxide ion removes the hydrogen ion thereby leaving a large concentration CrO4^2-(aq) in the system this causes the solution to turn green(equilibrium position shifts to the right).
The net ionic equation is;
OH^-(aq) + H^+(aq) ----> H2O(l)
The reaction;
OH^-(aq) + H^+(aq) ----> H2O(l) is exothermic hence, if the temperature of the system is increased, the equilibrium position will shift towards the left hand side and the solution turns orange.
A. Direction: Identify the word or phrase being described in the sentence. Write your
answers in your notebook.
1. It is an electronic measuring instrument that combines several
measurement functions in one unit.
2. In diodes, what do the silver stripe represents?
3. This is an Electronic/Electrical component that stores energy in
the form of Electric Charge.
4. This allows you to change the function between volts, ohms, and
amps, and to change the scale of the meter.
5. In testing capacitor, if the multimeter shows very low resistance,
it means that the capacitor is .
6. These are components used to resist the flow of electric current.
7. It is a system used to determine the value of a resistor without
using a multimeter.
8. What defective capacitor that shows very low Resistance?
9. A type of transformer that is used to increase the output voltage.
10. A type of transformer that is used to decrease the output voltage.
Answer:
1. Multimeter
2. Cathode
3. Capacitor
4. Selector switch
5. Short or Shorted
6. Resistors
7. Resistor color coding
8. Open Capacitor
9. Step-up transformer
10. Step-down transformer
Explanation:
The above-described elements are electronic components. Resistors for instance are designed to resist the flow of electric current. They are also standardized such that a deviation from the set resistance level will indicate a problem. The capacitor is another electrical component that stores energy as an electrical charge. Knowledge of these electrical components and the ways they are tested will make a person proficient in electrical electronics.
Before the lab student needs to make necessary chemical reagent solutions, the teacher asked them to make 50.0mL of 1.0 M H2SO4 from a 6.0 M sock
V1=
M1=
V2=
M2=
Answer:
V1 = 8.3 mL
Explanation:
Step 1: Given data
Initial volume (V1): ?
Initial concentration (M1): 6.0 M
Final volume (V2): 50.0 mL
Final concentration (M2): 1.0 M
Step 2: Calculate the volume of the initial solution
We want to prepare a dilute solution from a concentrated one. We can calculate the volume of the initial solution using the dilution rule.
M1 × V1 = M2 × V2
V1 = M2 × V2 / M1
V1 = 1.0 M × 50.0 mL / 6.0 M = 8.3 mL
We will take 8.3 mL of the 6.0 M solution and add water until we have 50.0 mL.
Why does glucose and acentic acid have the same empirical formula
Answer:
Examples. Glucose (C6H12O6), ribose (C5H10O5), Acetic acid (C2H4O2), and formaldehyde (CH2O) all have different molecular formulas but the same empirical formula: CH2O.
Explanation:In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound.
Almost 99% of Earth's atmosphere is made up of two gases. What are the two gases and the percents of each?
A)
21% oxygen and 78% nitrogen
B)
21% water vapor and 78% oxygen
09
21% nitrogen and 78% oxygen
D)
21% carbon dioxide and 78% oxygen
Classify each of the following as a Strong acid (sa) or a Weak acid (wa) and indicate how each should be written in aqueous solution.
1. hydrobromic acid
2. hydrochloric acid
3. carbonic acid
Write a net ionic equation for the reaction that occurs when aqueous solutions of hydrochloric acid and barium hydroxide are combined.
Answer:
A. 1. Strong acid (sa): Hydrobromic acid: HBr (aq)
2. Strong acid (sa); Hydrochloric acid: HCl (aq)
3. Weak acid (wa); Carbonic acid: H₂CO₃ (aq)
B. H+ (aq) + OH- (aq) ----> H₂O (l)
Explanation:
Strong acids are which ionize completely in aqueous solution into hydrogen ions and the corresponding anion. Examples of strong acids include hydrobromic acid, hydrochloric acid, tetraoxosulfate (vi) acid.
The ionization of hdyrobromic and hydrochloric acids in aqueous solution is given below:
1. Hydrobromic acid: HBr (aq) ----> H+ (aq) + Br- (aq)
Hydrobromic acid in aqueous solution ionizes completely into hydrogen ions and bromide ions
2. Hydrochloric acid: HCl (aq) ----> H+ (aq) + Cl- (aq)
Hydrochloric acid in aqueous solution ionizes completely into hydrogen ions and chloride ions
Weak acids are acids which ionizes only partially in aqueous solutions to hydrogen ions and the corresponding anions. Examples of weak acids are carbonic acid and ethanoic acid. The ionization of carbonic acid in aqueous solution is shown below:
3. Carbonic acid: H₂CO₃ (aq) ⇄ 2 H+ (aq) + CO₃²- (aq)
Carbonic acid ionizes partially only to give hydrogen ions and trioxocarbonate (iv) ions. The unionized acid exists in equilibrium with the ions produced by the partial ionization of the acid.
Part B:
The reaction between hydrochloric acid and barium hydroxide is a neutralization reaction producing barium chloride salt and water.
The net ionic equation of the neutralization reaction is given below :
H+ (aq) + OH- (aq) ----> H₂O (l)
which of the following experiments raises ethical concerns
Answer:
Research that releases a poisonous gas into the air.
Explanation:
Since I don't know the options I will guess it is ^
Completa las siguientes reacciones, nombrando todos los compuestos que intervienen:
a) CH2=CH2 + energía
b) CH2=CH2 + H2O
c) CH2=CH2 + HCl
d) CH2=CH2 + Cl2
e) CH2=CH2 + H2
2 Completa las siguientes reacciones, nombrando todos los compuestos que intervienen:
a) CH4 + Cl2
b) CH2=CH2 + H2O
c) CH≡CH + H2
d) CH3-COOH + KOH
e) CH3OH + CH3-COOH
3 Completa y ajusta la siguientes reacciones nombrando todos los compuestos que intervienen en cada una de ellas:
a) CH3-COOH + NaOH
b) CH3-CH2I + NH3
c) CH2=CH2 + H2O
d) CH3-CH=CH2 + Br2
Answer:
1
Explanation:
hhihh2
P4 + NaOH + H2O——> PH3 + Na2HPO3
Balance given equation by oxidation no. Method
Answer:
P4 + 4NaOH + 2H2O → 2PH3 + 2Na2HPO3
Explanation:
A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and the charge are both equal.
A chemical equation must balance according to the rule of conservation of mass. According to the rule, mass cannot be generated or removed during a chemical process.
Chemical equations must be balanced, which means that the atom types and numbers on both sides of the reaction arrow must match. Coefficients are the values added in front of formulas to balance equations; they multiply each atom in a formula.
Here the given equation is balanced as:
P₄ + 4NaOH + 2H₂O——> 2PH₃ + 2Na₂HPO₃
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Help guys please question 3 in picture ASAP pls
Answer:
1 Spinal fluid
2 Milk
3 Saliva
4 Urine
5 Gastric content
Explanation:
Hello there!
In this case, according to the given information, it turns out firstly necessary for us to calculate the pH of both gastric content and spinal fluid by using the following equations and works:
[tex]pH_{gastric}=-log(10^{-2})=2.0\\\\pH_{spinal}=14+log(10^{-6.6})=7.4[/tex]
Thus, we rank them as follows:
1 Spinal fluid
2 Milk
3 Saliva
4 Urine
5 Gastric content
Regards!
