Answer:
true
Explanation:
The standard laboratory rule is to always add acids or bases to solvent and not the other way round.
The dissolution of concentrated acids/bases in solvents (water) generates heat energy. Thus, if the solvent is added to them, a layer of hot weak acid or base will be formed and this will boil and spray around, causing an explosion.
On the other hand, if acid/base is added to solvents, they flow into the solvents and get diluted immediately without any boiling taking place. Hence, it is safe to add acid/base to solvents and not the other way round.
Is this example of a direct proportion or an inverse proportion?
A. Direct proportion
B. inverse proportion
Answer:
Inverse proportion occurs when one value increases and the other decreases. For example, more workers on a job would reduce the time to complete the task. They are inversely proportional.
Answer:
A
Explanation:
What is the formula of the ion hydrogen sulfite, which has a charge of -1
There are two types of ions in chemistry, one is cation and the other is anion. Anion is the negative charge ion. Therefore, the formula of hydrogen sulfite ion is HSO₃⁻
What is chemical Compound?Chemical Compound is a combination of ions, ions forms by combination of element and element forms by combination of atoms in fixed proportion.
According to our question the chemical compound from which hydrogen sulfite ion is coming is sulfurous acid that is H₂SO₃. So to get hydrogen sulfite ion we need to remove one hydrogen ion that is H⁺ from the chemical compound sulfurous acid.
The balanced reaction is
H₂SO₃[tex]\rightarrow[/tex]H⁺ + HSO₃⁻
From above reaction we can see that the charge over hydrogen sulfite ion is -1
Therefore the formula of hydrogen sulfite is HSO3-
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In a reversible reaction, the endothermic reaction absorbs ____________ the exothermic reaction releases.
A. None of these, endothermic reactions release energy
B. more energy than
C. the same amount of energy as
D. less energy than
Answer:
C. the same amount of energy as
Explanation:
Firstly, a chemical reaction can either absorb energy from its surroundings to occur or release energy into its surroundings as a product. The former and latter descriptions are called ENDOTHERMIC and EXOTHERMIC reactions respectively. An exothermic reaction is that which transfers energy, in form of heat, to its surroundings while an Endothermic reaction is that which absorbs energy (heat) from its surroundings.
However, a reversible reaction is that reaction in which the formation of products from reactants and reformation of the reactants from products occur simultaneously. Hence, the products of a reversible reaction can become the reactants and move in the opposite direction. For example:
Reversible reaction: A + B ⇆ C + D means;
A + B → C + D and;
C + D → A + B
In a case whereby the opposite reactions consist of an endothermic and exothermic reactions, the endothermic reaction absorbs the same amount of energy as the exothermic reaction releases.
According to the law of conservation of energy, no energy is lost during a reversible reaction. Hence, in order to achieve an equilibrium, the amount of energy absorbed by the endothermic reaction is the same as the amount of energy released in the opposite exothermic reaction.
plz answer fast i beg u
Which are not particles that enable electrical conductivity?
Select one:
a. delocalised electrons
b. molecules
c. mobile ions
Answer:
The correct option is;
a. Delocalised electrons
Explanation:
The particles that enable electrical conductivity are the delocalised electrons
The metallic structure consists of identically shaped elements having positive ions that have a resultant alignment, surrounded by a vast array of deloclised electrons, which move freely in the metallic structure such that a metallic part usually has a high electrical conductivity.
Therefore, the freely moving delocalised electron in a metal give them the property of good conductors of electricity.
2.A helium-filled balloon has a
volume of 48.0 L at 25°C and
1.05 atm. What volume will it
have at 0.860 atm and 15°C?
Answer:
The volume at 0.860 atm and 15°C will be 56.638 L
Explanation:
Gay Lussac's law explains the variation in the pressure of a gas by modifying its temperature, keeping the volume constant: it determines that pressure and temperature are directly proportional quantities. In other words, Gay-Lussac's law states that when a gas undergoes a constant volume transformation, the ratio of the pressure exerted by the temperature of the gas remains constant:
[tex]\frac{P}{T}=k[/tex]
On the other hand, Boyle's law determines that the pressure exerted by a gas is inversely proportional to its volume at constant temperature. This is expressed mathematically as:
P*V=k
Finally, Charles's law says that at constant pressure, the volume of an ideal gas is directly proportional to its absolute temperature and is expressed mathematically as:
[tex]\frac{V}{T}=k[/tex]
Combined law equation is the combination of three gas laws called Boyle's, Charles's and Gay-Lussac's law:
[tex]\frac{P*V}{T}=k[/tex]
When you want to study two different states, an initial one and a final one of a gas, you use:
[tex]\frac{P1*V1}{T1}=\frac{P2*V2}{T2}[/tex]
In this case:
P1= 1.05 atmV1= 48 LT1= 25 C= 298 K (being 0 C= 273 K)P2= 0.86 atmV2= ?T2= 15 C= 288 KReplacing:
[tex]\frac{1.05 atm*48 L}{298 K}=\frac{0.86atm*V2}{288 K}[/tex]
and solving:
[tex]V2=\frac{288 K}{0.86 atm} *\frac{1.05 atm*48 L}{298 K}[/tex]
you get:
V2= 56.638 L
The volume at 0.860 atm and 15°C will be 56.638 L
formula for soda glass
Answer:
composition of soda-lime glass is 73% SiO2 – 15% Na2O − 7% CaO − 4% MgO − 1% Al2O3 [129,132,133].
The Soda glass formula is SiO2, Na2O, CaO, Al2O3, K2O, SO3, MgO, Fe2O3, TiO2
Soda glass is a chemical compound that stands out for being the most widely used material to make windows, bottles, glasses, among others.
This compound is characterized by being chemically stable, reasonably hard, and extremely versatile because it can be recycled since it can be melted to make new products.
Its chemical formula is made up of other compounds such as:
SiO2, is Silicon OxideNa2O, is sodium oxideCaO, is calcium oxideAl2O3, is aluminum oxideK2O, is potassium oxideSO3, is sulfur oxideMgO, is magnesium oxideFe2O3, is iron oxideTiO2, is Titanium OxideAdditionally, the compounds found in the highest proportion in glass are SiO2 (74 atoms) and Na2O (13 atoms).
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What mass of Fe(OH)3 is produced when 35 mL of 0.250 M Fe(NO3)3 solution is mixed with 55 mL of a 0.180 M
KOH solution? (this is a limiting reactant problem).
Answer:
0.35 g.
Explanation:
We'll begin by calculating the number of mole of Fe(NO3)3 in 35 mL of 0.250 M Fe(NO3)3 solution.
This is illustrated below:
Molarity of Fe(NO3)3 = 0.250 M
Volume = 35 mL = 35/1000 = 0.035 L
Mole of Fe(NO3)3 =?
Molarity = mole /Volume
0.250 = mole of Fe(NO3)3 / 0.035
Cross multiply
Mole of Fe(NO3)3 = 0.25 x 0.035
Mole of Fe(NO3)3 = 8.75×10¯³ mole
Next, we shall determine the number of mole of KOH in 55 mL of 0.180 M
KOH solution. This is illustrated below:
Molarity of KOH = 0.180 M
Volume = 55 mL = 55/1000 = 0.055 L
Mole of KOH =.?
Molarity = mole /Volume
0.180 = mole of KOH /0.055
Cross multiply
Mole of KOH = 0.180 x 0.055
Mole of KOH = 9.9×10¯³ mole.
Next, we shall write the balanced equation for the reaction. This is given below:
3KOH + Fe(NO3)3 —> Fe(OH)3 + 3KNO3
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3 to produce 1 mole of Fe(OH)3.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted with 1 mole of Fe(NO3)3.
Therefore, 9.9×10¯³ mole of KOH will react with = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(NO3)3.
From the above illustration, we can see that only 3.3×10¯³ mole out of 8.75×10¯³ mole of Fe(NO3)3 given is needed to react completely with 9.9×10¯³ mole of KOH.
Therefore, KOH is the limiting reactant and Fe(NO3)3 is the excess reactant.
Next, we shall determine the number of mole of Fe(OH)3 produced from the reaction.
In this case, we shall use the limiting reactant because it will give the maximum yield of Fe(OH)3 as all of it is consumed in the reaction.
The limiting reactant is KOH and the mole of Fe(OH)3 produce can be obtained as follow:
From the balanced equation above,
3 moles of KOH reacted to produce 1 mole of Fe(OH)3.
Therefore, 9.9×10¯³ mole of KOH will react to produce = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(OH)3.
Finally, we shall convert 3.3×10¯³ mole of Fe(OH)3 to grams. This can be obtained as follow:
Molar mass of Fe(OH)3 = 56 + 3(16 + 1) = 56 + 3(17) = 107 g/mol
Mole of Fe(OH)3 = 3.3×10¯³ mole
Mass of Fe(OH)3 =?
Mole = mass /Molar mass
3.3×10¯³ = Mass of Fe(OH)3 / 107
Cross multiply
Mass of Fe(OH)3 = 3.3×10¯³ x 107
Mass of Fe(OH)3 = 0.3531 ≈ 0.35 g.
Therefore, 0.35 g of Fe(OH)3 was produced from the reaction.
The number of atoms in 2.0 moles of NaOH is _____ of 1.0 mole of H2O.
twice that
less than
more than
the same as
Answer:
The answer is the same as .
Explanation:
There are 3 atoms in NaOH, 1 sodium, 1 oxygen and 1 hydrogen.
There are 3 atoms in H2O, 2 hydrogen and 1 oxygen.
What does the second law of thermodynamics say about entropy?
A. Only changes in entropy can be measured.
B. Entropy cannot be created or destroyed.
C. The entropy in a system and its surroundings tends to increase.
D. The entropy in a system is zero at equilibrium.
Answer:
The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, and is constant if and only if all processes are reversible.
Explanation:
Isolated systems spontaneously evolve towards thermodynamic equilibrium, the state with maximum entropy. hope this helps you :)
The second law of thermodynamics say about entropy The entropy in a system and its surroundings tends to increase.
What is second law of Thermodynamics?According to the second law of thermodynamics, Entropy of the universe keeps on increasing overtime. When the entropy decreases and enthalpy increases the free energy change, ΔG, is positive and not spontaneous, and it does not matter what the temperature of the system is. Temperature comes into play when the entropy and enthalpy both increase or both decrease. The reaction is not spontaneous when both entropy and enthalpy are positive and at low temperatures, and the reaction is spontaneous when both entropy and enthalpy are positive and at high temperatures. The reactions are spontaneous when the entropy and enthalpy are negative at low temperatures, and the reaction is not spontaneous when the entropy and enthalpy are negative at high temperatures.
Therefore, The second law of thermodynamics say about entropy The entropy in a system and its surroundings tends to increase.
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calculate the volume of hydrogen produced at s.t.p when 25g and zinc are added to excess dilute hydrochloric acid at 31 degrees and 778 mm Hg pressure ( H= 1 , Zn = 65 , cl = 35.5 , volume of gas at stop = 22.4 dm cube
Answer:
The volume of hydrogen gas produced at s.t.p. is 9.419 dm³
Explanation:
The balanced chemical equation for the reaction is given as follows;
Zn + 2HCl → ZnCl₂ + H₂
Therefore, we have;
One mole of Zn reacts with 2 moles of HCl to produce one mole of ZnCl₂ and one mole of H₂
Number of moles of Zn present = 25/65 = 5/13 = 0.385 moles
Therefore, number of moles of H₂ produced = 0.385 moles
The volume of hydrogen gas produced is given by the relation
PV = nRT, we have;
R = 8.3145 J/(mol·K)
V = nRT/P = 0.385 ×8.3145 ×298.15/(101325)= 0.009419 m³ = 9.419 dm³
The volume of hydrogen gas produced at s.t.p. = 9.419 dm³.
4. (01.05 MC)
Rubbing alcohol evaporates from your arm quickly, leaving a cooling effect on your skin. How do the molecules of gas compare to the molecules as a liquid? (4 points)
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
The gas particles move faster than the liquid particles, and the bonds of the molecules are broken during evaporation to allow gas atoms to spread apart.
The gas particles move slower but have the same molecular structure and the same attraction between them as the liquid particles.
The gas and liquid particles move at the same speed, but the bonds of the molecules are broken during evaporation to allow the gas atoms to spread apart
Answer:
The correct option is;
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
Explanation:
The properties of the gas molecules in comparison to liquids are
1) The gas molecules are widely spread out
2) After evaporation and while in conditions favorable to the gaseous state, the kinetic energy of a gas is larger than the inter molecular attractive forces
3) A gas fills the container in which it is placed
For liquids
1) There are strong intermolecular forces holding the molecules together in a liquid
2) Liquid attractive forces in a liquid are strong enough to hold neighboring molecules
3) The volume of a liquid is definite.
Which bond type is found in ammonium chloride. Select one: a. metallic b. covalent c. ionic
Answer:
ionic
Explanation:
In NH4Cl molecule, ionic bond is formed between NH4+ and Cl– ions, 3 covalent bonds are formed between N and three H atoms and one coordinate bond is formed between N and 1 H atom.
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Answer:
[tex]\boxed{\sf c. \ ionic}[/tex]
Explanation:
NH₄Cl is formed by an ionic bond between NH₄⁺ and Cl⁻ ions.
NH₄Cl (solid) ⇒ NH4⁺ (aqueous) + Cl⁻ (aqueous)
Mike wants to galvanize iron to protect it from rusting. Which metal should he use?
A
platinum
B.
aluminum
C.
copper
D.
zinc
E.
tungsten
Answer:
D. Zinc.
Explanation:
Galvanization is a metal-coating process which involves the application of a thin layer of zinc to an iron or steel, so as to prevent rusting or corrosion.
The zinc metal protects the iron from rusting by sealing the surface of the iron and thus, preventing weathering and oxidation.
Hence, if Mike wants to galvanize iron to protect it from rusting. The metal he should use is zinc (Zn) because a coating of zinc would protect the iron (Fe) by corroding first when exposed to moisture or the atmosphere.
Answer:
b
Explanation:
I'll GIVE BRAINLIEST: In a redox reaction, CO is changed to CO2. How many electrons must be lost or gained by C and why?
Answer:
C is gaining 2 electrons
Explanation:
O has a 2- charge so for CO to pick up another O atom would add 2 more electrons.
Answer:
C gains 2 electrons
Explanation:
In the redox reaction, CO is changed into CO2 which means there is an additional oxygen. Oxygen loses 2 of its electrons in order to neutralize. So, C must be gaining 2 electrons in order to make the bond.
How many moles of lithium are in 83 grams of lithium? pls answer :(
Explanation:
89cjowdncu8wncuhrwionu9wjvionajofhjowednuiw4fmji2rn most jom4opr
.hlp me to solve mcq
Answer:
i) b
ii) c
Explanation:
Please see attached picture for full solution.
Ranjana has two unknown solutions X and Y
Question 9 of 10
How could an electron configuration be used to predict relative atomic size?
A. The more valence electrons listed, the larger the atomic radius.
B. The larger the highest energy level number, the larger the atomic
radius.
C. The more sublevels occupied, the larger the atomic radius.
D. The greater number of total electrons, the larger the atomic radius.
SUBMIT
Answer: B
Explanation: Apex
An electron configuration be used to predict relative atomic size because the larger the highest energy level number, the larger the atomic
radius.
The electron configuration of an element shows the arrangement of electrons in atoms of that element.
As more sublevels are added, repulsion between electrons occupying shells increases causing a greater shielding and consequent increase in the size of the atom.
Hence, the larger the highest energy level number, the larger the atomic
radius.
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11. Samantha was asked to measure out 10 g of salt in a lab. She mistakenly measures out 15 g instead. Calculate
the percent error. Make sure your answer has the correct number of significant figures!
Answer:
50%
Explanation:
Expected measurement required = 10g
Actual measurement observed = 15g
The percentage error is given as proportion the difference between the actual and expected measurement or values and the expected value value expressed as a percentage.
[(Actual - Expected) / Expected] × 100%
[(15 - 10) / 10)] × 100%
(5 / 10) × 100%
0.5 × 100%
50%
Therefore, the percentage error in the measurement is 50%
What is conservation area write in 8 points
Answer:
The Conservation area is the pay way to the special architectural and historic interest these are special character.
Explanation:
Conservation area is the features of building and use that historical development to contribute to its special character material and style.
Conservation area is that contain process to the application management development process and local residents.Conservation is that the produce demolition of a building structure with the conservation area,contribute to the group in individually.Conservation area that are special protection in the trees to the dangerous tree and some of the fruit trees.Conservation area are often to the protected by their building, planning works, these character area of appearance.Development rights to the conservation area require to the planning and permission to the outside area.Conservation area is classified to the regulation and the restricted area to the department planning.Conservation area is a composed to the impact of materials and building and the setting of impact.The new development in the conservation area is to the process of the renewal and the managed in the conservation area.what is a disavanege for renewable solor power
Determine whether the statement is true or false, and why. "If a theory becomes supported by evidence, it can become a law."
A. False, it should read, "A theory and a hypothesis are already equally supported by evidence, but they have different functions."
B. False, it should read, "If a theory becomes supported by evidence, it can become a hypothesis."
C. True
D. False, it should read, "A theory and a law are already both supported by evidence and are equal, but they have different functions."
Answer: D. False, it should read, "A theory and a law are already both supported by evidence and are equal, but they have different functions."
Explanation:
A "Theory" and a'' Law" in scientific method are already both supported by evidence but they have different function,
The function of " Theory" in scientific method is to give an explanation to the observations and findings gathered during the process. It can be modified, improved or even rejected as more information is being gathered.
While a '' Law '' tends to describe an observed event in nature that is true whenever it is put to test. It does not explain why the occurence or event is true.
0.10 moles of sodium sulfate is dissolved into 12 mL of solution. What is the molar concentration of the solution?
Your answer should have two significant figures (round your answer to one decimal place).
the molar concentration should be atleast 5mL off the solution since its disolved
Answer:
8.3
Explanation:
Convert mL to L.
12 mL×1 L1000 mL=0.012 L
Solve for molarity.
Molarity=moles of solute
liters of solution=0.10 mol0.012 L=8.3 M
How many protons does an atom of zinc contain?
It contains an amount
a single neutral atom of zinc has 30 protons
The number of ATPs per NADH generated by the electron transport system is higher than the number generated per FADH2 because __________. The number of ATPs per NADH generated by the electron transport system is higher than the number generated per FADH2 because __________. NADH is converted to NAD , which increases the charge gradient for ATP synthesis FADH2 has a higher (more negative) redox potential than NADH does electrons from FADH2 are not oxidized all the way to water FADH2 has a lower (less negative) redox potential than NADH does
Answer:
FADH2 has a lower (less negative) redox potential than NADH does
Explanation:
Flavin Adenine Dinucleotide (FAD) and Nicotinamide Adenine Dinucleotide (NAD) are redox cofactors that play important functions for mitochondrial activity and cellular redox balance. Both coenzymes exist in two forms: an oxidized and a reduced, which are abbreviated as NAD/FAD and NADH/FADH2, respectively. These reduced forms (NADH and FADH2) are produced in the Krebs cycle during respiration. FADH2 has lower redox potential than NADH because FADH2 is only capable of activating 2 proton pumps, while NADH can activate 3 proton pumps during the electron transport chain, thereby FADH2 generates a minor number of ATP molecules than NADH.
Propane (C3H8), a common fuel, reacts with oxygen to form carbon dioxide and water according to the equation below: C3H8 + 5O2 → 3CO2 + 4H2O If a propane heater burns 38.95 g C3H8, it consumes
Answer:
0.8833 mole of C3H8
Explanation:
Given:
Mass of C₃H₈ (Propane) = 38.95 gram
Computation:
Molar mass of C = 12.01
Molar mass of H = 1.008
Molar mass of C₃H₈ (Propane) = 3(12.01) + 8(1.008)
Molar mass of C₃H₈ (Propane) = 36.03 + 8.064
Molar mass of C₃H₈ (Propane) = 44.094
Number of mol in 38.95 gram Propane = Mass / Molar mass
Number of mol in 38.95 gram Propane = 38.95 / 44.094
Number of mol in 38.95 gram Propane = 0.88334
Answer:
Use the Periodic Table to find molar masses.
Propane (C3H8), a common fuel, reacts with oxygen to form carbon dioxide and water according to the equation below:
C3H8 + 5O2 → 3CO2 + 4H2O
If a propane heater burns 38.95 g C3H8, it consumes
38.95 mol C3H8.
0.8830 mol C3H8.
1 mol C3H8.
44.10 mol C3H8.
Part 2
How many moles of oxygen are required to produce 37.15 g CO2?
37.15 g CO2 = 1.407 mol O2
Part 3
What mass of propane is necessary to react with the amount of oxygen calculated in the previous question?
12.41 g C3H8
An element’s most stable ion forms an ionic compound with bromine, having the formula XBr2. If the ion of element "X" has a mass number of 230 and has 86 electrons, what is the identity of the element, and how many neutrons does it have?
Answer:
88
Explanation:
The ion has a charge of 2+, therefore the number of neutrons it possess is 86+2
which equals 88
The element X having a mass number of 230 and has 86 electrons is radium and has 142 neutrons.
An atom is composed basically of electrons, protons and neutrons. In a neutral atom, the number of protons and electrons are equal. The number of neutrons is the difference between the mass number and the number of protons (atomic number).
Since we know that the ion of the element X has 86 electrons and the compound formed is XBr2, it then means that neutral X has 88 electrons.
The number of electrons in the neutral atom is the same as the number of protons or atomic number. An element can be identified by its atomic number. The element having atomic number 88 is radium.
The number of neutrons is obtained as;
Mass number - atomic number
230 - 88 = 142 neutrons
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Write down the dissolution equation for nickel(II) perchlorate dissolving in water. (Perchlorate is a polyatomic ion with the formula ClO41-.) If four moles of the ionic compound are dissolved, then how many moles of the ANION are present in the solution?
Answer:
Ni(ClO₄)₂(aq) ⇒ Ni²⁺(aq) + 2 ClO₄⁻(aq)
8 mol ClO₄⁻
Explanation:
Let's consider the dissolution equation for nickel(II) perchlorate dissolving in water.
Ni(ClO₄)₂(aq) ⇒ Ni²⁺(aq) + 2 ClO₄⁻(aq)
The molar ratio of Ni(ClO₄)₂ to ClO₄⁻ is 1:2. If 4 moles of Ni(ClO₄)₂ are dissolved, the moles of ClO₄⁻ formed are:
4 mol Ni(ClO₄)₂ × (2 mol ClO₄⁻/ 1 mol Ni(ClO₄)₂) = 8 mol ClO₄⁻
Oil and water do not mix. What can be said about oil?
It is nonpolar.
It is polar.
It is saturated.
It is unsaturated.
Answer:
It is non - polar
Explanation:
Oil is a non-polar chemical substance that is a viscous liquid at ambient temperatures and is both hydrophobic (does not mix with water).
Water and oil do not mix. They are said to be immiscible. This is because water is a polar molecule.
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A chemical engineer is developing a process for producing a new chemical. One step in the process involves allowing a solution of potassium hydroxide to react with a solid. Which action would most likely increase the reaction rate for this step? using larger pieces of the solid using a more concentrated potassium hydroxide solution adding water to the system
Answer:
using a more concentrated potassium hydroxide
Explanation:
The option that would likely increase the rate of reaction would be to use a more concentrated potassium hydroxide.
The concentration of reactants is one of the factors that affect the rate of reaction. The more the concentration of the reactants, the faster the rate of reaction.
Granted that there are enough of the other reactants, increasing the concentration of one of the reactants will lead to an increased rate of reaction.
Hence, using a more concentrated potassium hydroxide which happens to be one of the reactants would likely increase the rate of reaction.
Answer:
using a more concentrated potassium hydroxide
Explanation:
