Answer:
Kb = 7.1 x 10⁻¹³
Explanation:
Ka x Kb = Kw => Kb = 1 x 10⁻¹⁴/1.4 x 10⁻² = 7.1 x 10⁻¹³
The Kb for SO32- at 25ºC is approximately 1.5 x 10^-7.
therefore correct option (b).
Explanation:To find the Kb for SO32-, we can use the relationship between Ka and Kb. Since the diprotic acid, H2SO3, forms SO32- in the second dissociation step, we can use the formula Kb = Kw/Ka. Kb is the equilibrium constant for the reaction of a base with water to form the hydroxide ion. Kw is the ion product of water, which is 1.0 x 10^-14 at 25ºC. So, using the given Ka2 value of 6.7 x 10^-8, we can calculate the Kb for SO32-:
Kb = Kw/Ka = (1.0 x 10^-14) / (6.7 x 10^-8)
Kb ≈ 1.5 x 10^-7
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Which of the given statements are true of low molecular weight carboxylic acids? Low molecular weight carboxylic acids are volatile. Low molecular weight carboxylic acids are completely safe for handling and can even be used without laboratory protection. The vapors of low molecular weight carboxylic acids are harmless. One should use caution when handling low molecular weight carboxylic acids.
Answer:
Low molecular weight carboxylic acids are volatile.
One should use caution when handling low molecular weight carboxylic acids.
Final answer:
Low molecular weight carboxylic acids are volatile and can have strong odors. They are not completely safe for handling without protection due to possible irritation from the vapors. Therefore, caution and appropriate safety measures are necessary when handling these substances.
Explanation:
Low molecular weight carboxylic acids tend to be volatile, implying they can easily vaporize at room temperature, and often have strong, sharp odors. One commonly known example is ethanoic acid (acetic acid), which is found in household vinegar. While they are usually colorless and can be found in everyday products such as foods and household items, it is not accurate to say that they are completely safe and can be handled without protection. The vapors of low molecular weight carboxylic acids can be irritating and, in some cases, harmful if inhaled in large amounts. Therefore, caution should be used when handling these substances.
Carboxylic acids are weak acids that do not completely ionize in water. This characteristic makes them less dangerous than strong acids; however, they can still cause irritation and should be treated with respect in a laboratory setting. Carboxylic acids such as propionic acid, while not highly toxic, can still pose safety risks if not handled properly, reinforcing the need for appropriate safety measures such as gloves and eye protection when handling these compounds.
A galvanic cell is powered by the following redox reaction: Br2 H2 2OH Answer the following questions about this cell. If you need any electrochemical data, be sure you get it from the ALEKS Data tab. Write a balanced equation for the half-reaction that takes place at the cathode. Write a balanced equation for the half-reaction that takes place at the anode. Calculate the cell voltage under standard conditions. Round your answer to decimal places.
Final answer:
In a galvanic cell, half-reactions occur at separate electrodes: reduction at the cathode and oxidation at the anode. The cathode is the positive electrode, while the anode is the negative electrode. Standard cell potential can be calculated but requires the standard reduction potentials for the specific half-reactions.
Explanation:
Galvanic Cell Half-Reactions, Electrodes, and Potentials
In a galvanic cell, a spontaneous redox reaction occurs that drives the flow of electrons from the anode to the cathode through an external circuit. The original question does not provide a complete redox reaction, but assuming it involves bromine (Br2), hydrogen (H2), and hydroxide ions (OH-), the following can be considered:
For the provided redox reaction, the half-reaction that occurs at the cathode (reduction) might be:
2H+ + 2e- → H2
And the half-reaction at the anode (oxidation) could be:
2Br- → Br2 + 2e-
The cathode is the positive electrode, as it undergoes reduction, and the anode is the negative electrode, as it undergoes oxidation. Without actual potential values given, the cell voltage under standard conditions cannot be calculated here. However, the standard cell potential can be found by using standard reduction potential tables and subtracting the anode potential from the cathode potential.
A correct name for the following compound is: a. 1-Methylbicyclo[4.3.0]nonane b. 1-Methylbicyclo[4.3.1]nonane c. 2-Methylbicyclo[4.3.1]nonane d. 2-Methylbicyclo[4.3.0]nonane e. 7-Methylbicyclo[4.3.0]nonane
Answer:
The correct name for the following compound is
2 - methylbicyclo[4.3.0]nonane
Explanation:
Rule 1
Numbering of bicyclic compound is done from bridgehead carbon
Rule 2
The system is numbered with one of the bridgeheads, numbering proceeding by the longest possible path to the second bridgehead.
Name of the given bicyclic compound is 2 - methylbicyclo[4.3.0]nonane
The reaction A2 + 2 B → 2 BA is thought to occur by the following mechanism:
Step 1: A2 + Z → ZA2
Step 2: ZA2 + B → BA + Z + A
Step 3: A + B → BA
Which of the following statements is correct? Select one:
a. ZA2 and A are catalysts, and Z is a reaction intermediate.
b. There are no catalysts or reaction intermediates.
c. Z is a catalyst, and ZA2 and A are reaction intermediates.
d. Z, ZA2, and A are all catalysts.
e. Z, ZA2, and A are all reaction intermediates.
Answer:
c. Z is a catalyst, and ZA2 and A are reaction intermediates.
Explanation:
Overall reaction is given as;
A2 + 2 B → 2 BA
Mechanism:
Step 1: A2 + Z → ZA2
Step 2: ZA2 + B → BA + Z + A
Step 3: A + B → BA
The options given are centered upon catalysts and reaction intermediates. So before proceeding, we have to understand the difference between the two and how to identify them.
A catalyst is basically a reaction booster to speed up the rate of the reaction and the reaction intermediate is an unstable, temporl species formed from the reactants before getting to the products.
The difference is given as;
Catalysts are present as reactants in the very beginning and products at the end of the reaction.
Intermediates, on the other hand, are not present in the initial reaction but are produced within one of the steps and then consumed within another step.
Following the above, we can deduce that;
Z is a catalyst because it is present as a reactant in the beginning.
ZA2 and A are a reaction intermediates because they are not present in the overall reaction but are produced and consumed in one of the steps.
Correct option is given as;
c. Z is a catalyst, and ZA2 and A are reaction intermediates.
Ok yea need some help on this Chem question.
Answer:
Combustion
Explanation:
Combustion reactions are the one where the oxygen is a reactant and the products are always water and carbon dioxide.
It is also a redox type because the oxygen is reduced and the carbon from the C₄H₁₀O oxidized to CO₂
C₄H₁₀O + 6O₂ → 4CO₂ + 5H₂O
1 mol of butyl alcohol burns in prescence of 6 moles of oxygen in order to produce 4 moles of carbon dioxide and 5 moles of water.
Answer:
This is a combustion reaction
Explanation:
Step 1: Data given
A single-replacement reaction is a reaction where we will replace one element with a similar element in the compound.
A single-replacement or displacement reaction has the following form:
A+BC→AC+B
Element A is usually a metal and will replace element B in the compound , this should also be a metal.
If the elemnent isn't a metal ( so a nonmetal), the replacing element will either be a metal.
In a double-replacement reaction we will exchange positive and negative ions of two ionic compounds, what will cause the formation of two new compounds.
A double-replacement reaction has the following form:
AB+CD→AD+BC
IIn this example, A and C are positively-charged ions (cations), and B and D are negatively-charged ions (anions).
In a decomposition reaction a compound will break down into two or more substances ( those are smaller, more simple).
A decomposition reaction uses the following form.
AB→A+B
In a combustion reaction a substance will react with oxygen gas (O2). Oxygen gas is needed to start the reaction.CO2 gas and water vapor (H2O) will be produced.
In a combination reaction we will combine two or more substances to form a single new substance. This is also known as a synthesis reaction, and uses the general form:
A+B→AB
Step 2: The equation
C4H10(g) + 6O2(g) → 4CO2(g) + 5H2O(g)
Step 3: What kind of reaction is this
Since the reaction requires oxygen and will produce carbon dioxie and water vapor. This means this reaction is a combustion reaction.
(Combustion of butane).
The decomposition of in solution in carbon tetrachloride is a first-order reaction: The rate constant at a given temperature is found to be . If the initial concentration of is 0.200 M, what is its concentration after exactly 10 minutes have passed?
Answer:
see below
Explanation:
The rate constant is missing in question, but use C(final) = C(initial)e^-kt = 0.200M(e^-k·10). Fill in k and compute => remaining concentration of reactant
Answer:
C(initial)e^-kt = 0.200M(e^-k·10).
Explanation:
The rate constant is missing in question, but use C(final) = C(initial)e^-kt = 0.200M(e^-k·10).
Fill in k and compute => remaining concentration of reactant
Calculate the Ka for the following acid. Determine if it is a strong or weak acid. HClO2(aq) dissolves in aqueous solution to form H+(aq) and ClO2−(aq). At equilibrium, the concentrations of each of the species are as follows: [HClO2]=0.24M [H+]=0.051M [ClO2−]=0.051M
Answer:
The value of Ka [tex]= 1.1*10^{-2}[/tex]
It is a weak acid
Explanation:
From the question we are told that
The concentration of [tex][HClO_2]=0.24M[/tex]
The concentration of [tex][H^+]=0.051M[/tex]
The concentration of [tex][ClO_2^-]=0.051M[/tex]
Generally the equation for the ionic dissociation of [tex]HClO_2[/tex] is
[tex]HClO_2_(aq) -------> H^{+}_{(aq)} + ClO_2^{-}_{(aq)}[/tex]
The equilibrium constant is mathematically represented as
[tex]Ka = \frac{concentration \ of \ product }{concentration \ of \ reactant }[/tex]
[tex]= \frac{[H^+][ClO_2^-]}{[HClO_2]}[/tex]
Substituting values since all value of concentration are at equilibrium
[tex]Ka = \frac{0.051 * 0.051}{0.24}[/tex]
[tex]= 1.1*10^{-2}[/tex]
Since the value of is less than 1 it show that in water it dose not completely
disassociated so it an acid that is weak
Calcium carbonate can be broken
down by heating what . What is the scientific
term for this? (Hint: your answer
should be two words.)
Answer:
Thermal decomposition
Explanation:
Calcium carbonate can be broken down by heating. The following equation represents this chemical change.
CaCO₃(s) ⇒ CaO(s) + CO₂(g)
The scientific term for this process is thermal decomposition.
Thermal refers to the fact that heat is required.Decomposition refers to the kind of reaction in which a big substance breaks down into smaller substances.The breakdown of calcium carbonate by heating is called thermal decomposition. This process involves a single substance breaking down into simpler compounds upon heating. The process is demonstrated in the reaction - CaCO3 (s) -> CaO(s) + CO2 (g), where calcium carbonate decomposes into calcium oxide and carbon dioxide.
The process of breaking down Calcium Carbonate (CaCO3) by heating is scientifically known as Thermal Decomposition. This is a chemical process where a single substance breaks down into two or more simpler substances when heated. To demonstrate this, let's use the following reaction:
CaCO3(s) → CaO(s) + CO2(g)
In this instance, calcium carbonate (which can come from limestone or chalk) decomposes into calcium oxide and carbon dioxide when heated. It's important to note that the reaction is reversible and to ensure a 100% yield of CaO, the CO2 should be allowed to escape.
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The reaction A + 2B occurs in one step in the gas phase. In each blank below, write the exponent of the concentration in the FORWARD rate law or write none if that concentration does not appear in the rate law.
[A] ...........
[B] ..........
[C] ...........
Answer:
see below
Explanation:
for A + 2B => Products ...
Rate Law => Rate =k[A][B]ˣ
As shown in expression, A & B are included, C is not.
Answer:
Exponent of a is 1, exponent of b is 2 and exponent of c = 0
Explanation:
or the rate equation is the expression which relates the rate of the reaction with the concentration of pressure of the reactants. The rate law is expressed in terms of the molar concentration of the reactants with each term raised to power its stoichiometric coefficient.
1. Is energy absorbed or released when chemical bonds are broken during a chemical reaction?
2. Is energy absorbed or released when chemical bonds are formed during a chemical reaction?
3. What are some real life examples of an exothermic reaction?
4. What are some real life examples of a endothermic reaction?
5. Compare and contrast Endothermic vs. a Exothermic reaction
6. Analyze the folloiwng scenario:
In chemistry class after adding two chemical substances in a test tube ( which is the system) you noticed when you touch the tube that it begin to get very cold. What type of chemical reaction is this? Endothermic or Exothermic ... Use the scenario to explain your response.
7. Define ΔH Enthalpy
8. Compare and Contrast a positive ΔH(Enthalpy) to a negative ΔH( Enthalpy)
9. Explain the relationship between Enthalpy and a Exothermic reaction, and a Endothermic reaction
10. Explain how the Potential Energy curve's of a Endothermic different from a Exothermic reaction
Propose a mechanism for the acid-catalyzed hydrolysis of cyclohexanone dimethyl acetal. (Remember that this reaction is reversible, so each step in the hydrolysis is the same as the acetal synthesis, only in reverse.)
Answer:
The proposed mechanism is shown on the first uploaded image
Explanation:
A microbiologist hypothesized that
Staphylococcus aureus is more susceptible to
antibiotics than Escherichia coli. She tested her
hypothesis by exposing the two species of
bacteria to three different antibiotics. The closer
the bacteria were able to grow to antibiotic-soaked
disks, the more resistant they were to treatment
by that antibiotic.
Which bacterium would you expect to be more
responsive to antibiotic treatment?
MANE
Answer: S. Auresus
Explanation:I just took it
A microbiologist studies the microbes and the disease they cause. The bacterium that will be more responsive to antibiotic treatment will be Staphylococcus aureus.
What are antibiotics?Antibiotics are said to be the medication and drug class that works against bacterial infections. They are used to kill and slow the rate of growth or reproduction of microbes like bacteria to stop diseases or infections like flu, cold, cough, etc.
The bacteria can be resistant or susceptible to the antibiotic and can be tested by exposing them to antibiotics. As Staphylococcus aureus species are vulnerable they will not be able to grow under the antibiotic treatment. Whereas, Escherichia coli being resistant will show some growth.
Therefore, Staphylococcus aureus will be more responsive to antibiotics.
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What are the two main differences between the 2 ecosystem in terms of organism population
Answer:
The answer to the question above is explained below
Explanation:
There are so many differences between the two ecosystem (terrestrial ecosystems and aquatic ecosystems). The most important ones will be highlighted:
1. Aquatic environments are so rich in nutrients they support more live than equivalent terrestrial ecosystems as aquatic ecosystems have availability of water more than the terrestrial ecosystems. Presenting the consequent importance of water as a limiting factor in the terrestrial ecosystems.
2. Aquatic ecosystems are much more stable than terrestrial ecosystems, with smaller fluctuations in temperature and other variables.
3. In terrestrial ecosystems, there is hardly ever a shortage of light, while it can be a limiting factor in some aquatic ecosystems.
4. Gravity has so much influence on terrestrial animals. That is not the case for their aquatic counterparts where water supports aquatic organisms.
An ecosystem is a large community of living organisms (plants, animals and microbes) in a particular area in conjunction with the non-living components of their environment, interacting as a system.
Terrestrial Ecosystem includes: Grasslands, Forests, Desert.
Aquatic Ecosystem includes: Freshwater ecosystem, Marine Ecosystem.
can decomposition determine the property of a substance
Answer:The general properties of matter such as color, density, hardness, are examples of physical properties. Properties that describe how a substance changes into a completely different substance are called chemical properties. Flammability and corrosion/oxidation resistance are examples of chemical properties.
Explanation:
The fuel used in many disposable lighters is liquid butane, C4H10
C
4
H
10
. Butane has a molecular weight of 58.1 grams in one mole. How many carbon atoms are in 3.50 g
g
of butane?
Answer:
1.45 *10^23 atoms C
Explanation:
3.50 g butane * 1 mol butane/58.1 g butane =0.06024 mol butane
in 1 mol C4H10 -------- 4 mol C
in 0.06024 mol C4H10 -------- 4*0.6024 = 0.241 mol C
0.241 mol C * 6.02*10^23 atoms C/1 mol C = 1.45 *10^23 atoms C
For the process O2(g)→2O(g), ΔH° = 498 kJ·mol–1. What would be the predicted sign of ΔS°rxn and the conditions under which this reaction would be spontaneous? Question 13 options: 1) ΔS°rxn is positive, and the process is spontaneous at low temperatures only. 2) ΔS°rxn is positive, and the process is spontaneous at high temperatures only. 3) ΔS°rxn is negative, and the process is spontaneous at high temperatures only. 4) ΔS°rxn is negative, and the process is spontaneous at low temperatures only.
Answer:
2) ΔS°rxn is positive, and the process is spontaneous at high temperatures only.
Explanation:
ΔS = ΔH / T , ΔS is change in entropy , ΔH is change in enthalpy
Since ΔH is positive , ΔS is positive .
ΔG = ΔH - TΔS
For spontaneous reaction . ΔG should be negative .
As ΔS is positive , at high temperature the value of TΔS will be more and hence the value of TΔS will be higher than Δ H . Hence ΔG will be negative.
Hence at higher temperature , the reaction will be spontaneous.
The predicted sign of ΔS°rxn and the conditions under which this reaction would be spontaneous should be option 2) ΔS°rxn is positive, and the process is spontaneous at high temperatures only.
Predicted sign of ΔS°rxn and its conditons:We know that
ΔS = ΔH / T
Here ΔS means a change in entropy
And, ΔH means a change in enthalpy
Since ΔH is positive so ΔS is positive.
Now
ΔG = ΔH - TΔS
However, For spontaneous reaction. ΔG should be negative .
Since ΔS is positive, at high temperature the value of TΔS should be more and due to this the value of TΔS will be more than Δ H . Thus, ΔG will be negative.
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AgNO3 to solutions of each and determined the moles of AgCl precipitated. He also measured and
compared the conductances of solutions of each of these compounds with solutions of simple
electrolytes. Which response below gives all true statements concerning his conclusions from these
experiments?
I. From the moles of AgCl, he determined the total number of Cl ions in each
compound.
II. From the moles of AgCl, he determined the number of uncoordinated Cl ions in each
compound.
III. From the conductance of each solution, he determined the total number of ions present
upon dissolution of each compound.
a. I
b. II
c. III
d. I and II
e. II and III
Answer:
d. I and II
Explanation:
In chemistry, it is an old analytical technique to determine the amount of free chloride ions by silver chloride precipitation. This precipitation method could both be used to determine the initial chloride ion concentration in different analyte solutions or to determine the number of uncoordinated chloride ions in a complex. The number of moles of chloride ions in the silver chloride, shows the number of uncoordinated ions in a chloride ion containing complex.
The concentration of chloride ions in an analyte could be gravimetrically determined by silver chloride precipitation.
Feldspars producing clay is an example of ___
Answer: A
Explanation:
Hydrolysis reactions break down not only feldspars but many other silicate minerals as well, amphiboles, pyroxenes, micas, and olivines.
Arrange the ions N3-, O2-, Mg2 , Na , and F- in order of increasing ionic radius, starting with the smallest first. Arrange the ions N3-, O2-, Mg2 , Na , and F- in order of increasing ionic radius, starting with the smallest first. N3-, O2-, Mg2 , F-, Na Mg2 , Na , F-, O2-, N3- N3-, Mg2 , O2-, Na , F- N3-, O2-, F-, Na , Mg2
Answer:
Order of increasing ionic radius starting from the smallest is
Mg2+ < Na+ < F- < O2- < N3-
Explanation:
Ionic radius is the distance between the nucleus and the electrons in the outermost shell of an ion. In the ions given about, it can be deducted that they all have the same number of electrons and are said to be isoelectronic. This shows us that they all have the same electrons and we can only seperate them by checking the respective charges on the ions. A more positive charge will have a smaller radius while a more negative will have a larger radius. This is because when an atom loses an electron and form a cation (+), the remaining electrons move closer to the nucleus and hence a smaller radius of the atom occurs. But when an atom gains n electron,it forms anion (-), the new electron leads to the shielding of the remaining electrons from the nucleus and a large radius of the atom occurs.
So therefore, the above ions all have 10 electrons in their shells and magnesium with atomic number 12 and having lost 2 electrons to become positively charge has the smallest radius compared to others.
Mg2+ = 12 protons, 10 electrons
Na+ = 11 protons, 10 electrons
F- = 9 protons, 10 electrons
O2- = 8 protons, 10 electrons
N3- = 7 protons, 10 electrons
N3- has the largest ionic radius and Mg2+ has the lowest ionic radius.
The order is thus, Mg2+ , Na+, F-, O2-, N3-
The order of increasing ionic radius is N3-, O2-, F-, Na, Mg2+
The ionic radius is a measure of the size of an ion. In general, ions with more electrons have larger radii. Let's arrange the ions in order of increasing ionic radius:
N3-O2-F-NaMg2+The larger the negative charge on an ion, the larger its ionic radius. Therefore, N3- has the smallest radius, followed by O2-, F-, Na, and finally Mg2+, which has the largest radius among the given ions.
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Which element is an actinoid?
Answer:Neptunium; Protactinium; Thorium; Uranium
Explanation:
Aqueous hydrochloric acid reacts with solid sodium hydroxide to produce aqueous sodium chloride and liquid water . If of sodium chloride is produced from the reaction of of hydrochloric acid and of sodium hydroxide, calculate the percent yield of sodium chloride. Round your answer to significant figures.
The given question is incomplete. The complete question is:
Aqueous hydrochloric acid (HCl) reacts with solid sodium hydroxide (NaOH) to produce aqueous sodium chloride (NaCl) and liquid water (H2O). If 1.60 g of sodium chloride is produced from the reaction of 1.8 g of hydrochloric acid and 1.4 g of sodium hydroxide, calculate the percent yield of sodium chloride. Be sure your answer has the correct number of significant digits in it.
Answer: Thus the percent yield of sodium chloride is 78.0%
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}\times{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} HCl=\frac{1.8g}{36.5g/mol}=0.049moles[/tex]
[tex]\text{Moles of} NaOH=\frac{1.4g}{40g/mol}=0.035moles[/tex]
[tex]HCl(aq)+NaOH(aq)\rightarrow NaCl(aq)+H_2O(l)[/tex]
According to stoichiometry :
1 mole of [tex]NaOH[/tex] require = 1 mole of [tex]HCl[/tex]
Thus 0.035 moles of [tex]NaOH[/tex] will require=[tex]\frac{1}{1}\times 0.035=0.035moles[/tex] of [tex]HCl[/tex]
Thus [tex]NaOH[/tex] is the limiting reagent as it limits the formation of product and [tex]HCl[/tex] is the excess reagent.
As 1 mole of [tex]NaOH[/tex] give = 1 mole of [tex]NaCl[/tex]
Thus 0.035 moles of [tex]NaOH[/tex] give =[tex]\frac{1}{1}\times 0.035=0.035moles[/tex] of [tex]NaCl[/tex]
Mass of [tex]NaCl=moles\times {\text {Molar mass}}=0.035moles\times 58.5g/mol=2.05g[/tex]
[tex]{\text {percentage yield}}=\frac{\text {Experimental yield}}{\text {Theoretical yield}}\times 100\%[/tex]
[tex]{\text {percentage yield}}=\frac{1.60g}{2.05g}\times 100\%=78.0\%[/tex]
Thus the percent yield of sodium chloride is 78.0%
How is a mixture different from a chemical reaction?
Answer:
A mixture is made when two or more substances are combined, but they are not combined chemically. A chemical reaction is a transformation from one set of chemicals into another set.
Explanation:
A mixture can be homogeneous or heterogeneous, when homo, you cannot see each variable but hey are there. Hetero, means you can see each variable in the mixture. It is considered a mixture and not a chemical reaction because it can be reversed. It will always be able to go back to its separate forms and keep its original composition. When there is a chemical reaction, it is hard to separate and go back to the original variables because there is a molecular bond.
A rapid reaction is distinguished by A rapid reaction is distinguished by having a small value of activation energy. having a large value of activation energy. being unaffected by catalysts. having a large heat of reaction. having a small heat of reaction.
Answer:
A rapid reaction is distinguished by having a relatively small value of activation energy.
Explanation:
Chemical kinetics is involved in determining the rate of a reaction, how fast or slow a reaction will occur in a particular condition. The factors affecting the rate of reaction determining whether it will be a rapid reaction includes nature of the reactants, temperature, pressure, surface area of solid state, catalysts, concentration and so on. Based on temperature, temperature affects the collision frequency of a reaction and this contributes to a portion of the increased rate of reaction. At a given temperature, the rate of a reaction depends on the magnitude of the activation energy, pre-exponential factor A, molar gas constant, R, and temperature. This is true based on the Arrhenius equation K = Ae^-Ea/(RT). So therefore, from the equation, it is revealed that at small activation energies, reaction rate is rapid and slow at high activation energies.
Final answer:
A rapid reaction is characterized by a low activation energy, which allows for a faster reaction rate. Catalysts can lower this energy barrier, further speeding up the reaction without altering the overall energy change of the reaction.
Explanation:
A rapid reaction is distinguished by having a small value of activation energy. Activation energy (Ea) is the barrier that must be overcome for reactants to transform into products. A low activation energy indicates that the reactants can more easily reach the transition state and react to form products, leading to a faster reaction rate.
Catalysts are substances that lower the activation energy and provide a new pathway for the reaction to occur, thus speeding up the reaction without being consumed in the process. They do not affect the overall energy change of the reaction (∆H), but they make it easier for the reaction to occur.
This is especially valuable in biological systems where catalysis allows for important cellular reactions to occur at appreciable rates without the need for high temperatures that could harm the cell.
It is the heat of the reaction (∆H) that determines whether a reaction is exothermic or endothermic, not the activation energy.
Therefore, whether a reaction has a large heat of reaction or a small heat of reaction does not directly relate to its speed.
pure potassium hydrogen phthalate is used for the standardization of the sodium hydroxide solution. suppose that the potassium hydrogen phthalate is not completely dry. will the reported molar concentration of the sodium hydroxide solution be too high too low or unaffected because of the moistness of the potassium phthalate ? explain
Answer:
the reported molar concentration of the sodium hydroxide solution will be too high.
Explanation:
The term "standardization" in science or in analytical Chemistry simply means the process involved in the determination of a standard or the concentration of a particular substance.
One of the advantages and the most important of the advantages of Standardization is that it Helps in making sure that we get a result with the least error.
So, let me explain the answer. The reported molar concentration of the sodium hydroxide solution will be TOO HIGH because the potassium hydrogen phthalate is NOT completely dry. The weight of the moisture will create an additional weight which will increase the weight of potassium hydrogen phthalate in the solution
If potassium hydrogen phthalate is not completely dry, it will make the reported molar concentration of the sodium hydroxide solution too low. This is due to the added water from the moisture which causes a dilution effect.
Explanation:In the situation where the potassium hydrogen phthalate is not completely dry, the reported molar concentration of the sodium hydroxide solution will be too low. This is because the water from the phthalate's moisture can dilute the sodium hydroxide solution, which leads to a lower than actual molar concentration. It's essential to have a completely dry potassium hydrogen phthalate when standardizing sodium hydroxide solutions to get an accurate molar concentration.
For instance, when potassium hydroxide, a highly soluble ionic compound, is dissolved in a dilute solution, it completely dissociates, giving a certain concentration of [OH-] ions. Suppose this reaction occurs in an environment where excess water is introduced due to the moisture in potassium hydrogen phthalate. In that case, this equilibrium will be affected, leading to a lower concentration of hydroxide ions and thus, a lower reported molar concentration of the sodium hydroxide solution.
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If you prepared a 3.25 M solution of sucrose (molar mass 342 g/mole) ,
a.How many moles are in 0.25 L of this solution?
b.How many grams is this?
Answer:
a. 0.8125 moles of sucrose
b. 277.8 g of sucrose
Explanation:
Consider these relation's value:
Molarity = Mol / Volume(L)
Mol = Molarity . Volume(L)
Volume(L) = Mol / Molarity
So, Molarity = 3.25M
Volume(L) = 0.25L
Molarity . Volume(L) = Mol → 3.25mol/L . 0.25L = 0.8125 mol
Let's convert the moles to mass → 0.8125 mol . 342 g /1mol = 277.8 g of sucrose
Answer:
We have 0.8125 moles sucrose in this solution. This is 277.9 grams of sucrose
Explanation:
Step 1: Data given
Molarity of a sucose solution = 3.25 M
Molar mass of sucrose = 342 g/mol
Step 2: Calculate moles sucrose
Moles sucrose = molarity sucrose solution * volume solution
Moles sucrose = 3.25 M * 0.25 L
Moles sucrose = 0.8125 moles sucrose
Step 3: Calculate mass of sucrose
Mass sucrose = moles sucrose * molar mass sucrose
Mass sucrose = 0.8125 moles * 342 g/mol
Mass sucrose = 277.9 grams
We have 0.8125 moles sucrose in this solution. This is 277.9 grams of sucrose
Mass is defined as anything that can be observed.
Question 4 options:
True
False
Calculate the pH for the following weak acid. A solution of HCOOH has 0.12M HCOOH at equilibrium. The Ka for HCOOH is 1.8×10−4. What is the pH of this solution at equilibrium?
Answer:
the pH of HCOOH solution is 2.33
Explanation:
The ionization equation for the given acid is written as:
[tex]HCOOH\leftrightarrow H^++HCOO^-[/tex]
Let's say the initial concentration of the acid is c and the change in concentration x.
Then, equilibrium concentration of acid = (c-x)
and the equilibrium concentration for each of the product would be x
Equilibrium expression for the above equation would be:
[tex]\Ka= \frac{[H^+][HCOO^-]}{[HCOOH]}[/tex]
[tex]1.8*10^-^4=\frac{x^2}{c-x}[/tex]
From given info, equilibrium concentration of the acid is 0.12
So, (c-x) = 0.12
hence,
[tex]1.8*10^-^4=\frac{x^2}{0.12}[/tex]
Let's solve this for x. Multiply both sides by 0.12
[tex]2.16*10^-^5=x^2[/tex]
taking square root to both sides:
[tex]x=0.00465[/tex]
Now, we have got the concentration of [tex][H^+] .[/tex]
[tex][H^+] = 0.00465 M[/tex]
We know that, [tex]pH=-log[H^+][/tex]
pH = -log(0.00465)
pH = 2.33
Hence, the pH of HCOOH solution is 2.33.
Answer:
The correct answer is 2.34
Explanation:
HCOOH is formic acid. It is a weak acid so it does not dissociates completely in water. At the beggining (I) the initial concentration is 0.12 M. In water it will dissociate in a certain grade x as follows:
HCOOH → H⁺ + HCOO⁻
I 0.12 M 0 0
C - x x x
E (0.12 M - x) x x
The mathematical expression for the equilibrium constant (Ka) is the following:
[tex]K_{a} = \frac{[H^{+} ][HCOO^{-} ]}{[HCOOH]}[/tex]
[tex]1.8 x 10^{-4} = \frac{(x x)}{(0.12 M -x)}[/tex]
As the value of Ka is too small in comparison with the initial concentration 0.12 M, we can approximate: 0.12 M - X ≅ 0.12 M. Then, we calculate x:
1.8 x 10⁻⁴ = x²/0.12 M
⇒ x= [tex]\sqrt{0.12 x 1.8 x 10^{-4} }[/tex]= 4.65 x 10⁻³
Since x = 4.65 x 10⁻³ , from the equilibrium we have:
[H⁺] = x = 4.65 x 10⁻³
From the definition of pH, we have:
pH = -log [H⁺] = -log (4.65 x 10⁻³)= 2.34
175 mL of Cl2 gas is held in a flexible vessel at STP. If the
vessel is transported to the bottom of the impact basin
Hellas Planitia on the surface of Mars where the pressure is
1.16 kPa and the temperature is -5.0°C. What is the new
volume of Cl2 gas in liters?
The new volume of the Cl2 gas under the conditions at the bottom of Hellas Planitia on Mars would be approximately 4.2 litres, as calculated using the ideal gas law.
Explanation:The question is asking about the adjustment of gas volume under different conditions of pressure and temperature, so the ideal gas law is applicable here which states that: PV = nRT, where P is pressure, V is volume, T is temperature, n is number of moles of the gas and R is gas constant.
At Standard Temperature and Pressure (STP), the conditions are 1 atm pressure and 0°C (273 K). Please note that the volume given is already at STP, so to find the new volume, we should rearrange the ideal gas law to V2 = V1 * P1/P2 * T2/T1.
However, note that all the measurements need to be in the same standard units. Here, the initial pressure (P1) is 1 atm, converted to kPa becomes approximately 101.3 kPa, the final pressure (P2) is given as 1.16 kPa. The initial temperature (T1) is 273K and the final temperature (T2) needs to be converted from Celsius to Kelvin, making it 268 K (-5°C + 273). Thus, applying the equation, we get:
V2 = 0.175L * 101.3 kPa / 1.16 kPa * 268 K / 273 K = 4.2 L approximately
Therefore, the new volume of the Cl2 gas, if it is transported to the conditions at the bottom of Hellas Planitia on Mars, would be approximately 4.2 litres.
Learn more about Ideal gas law here:https://brainly.com/question/30458409
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Using the combined gas law, the new volume of Cl₂ gas at 1.16 kPa pressure and -5.0°C temperature at the bottom of Hellas Planitia on Mars is calculated to be approximately 15.06 liters.
To determine the new volume of Cl₂ gas at the conditions provided, we need to use the combined gas law which is given by the equation: [tex]\frac{P_1 \times V_1}{T_1} = \frac{P_2 \times V_2}{T_2}[/tex], where P is pressure, V is volume and T is temperature in Kelvin.
At STP (Standard Temperature and Pressure), we have a volume of 175 mL (or 0.175 liters), a pressure of 101.3 kPa, and a temperature of 273.15 K. The conditions at the bottom of the Hellas Planitia are 1.16 kPa and -5.0°C or 268.15 K.
First, we convert the initial volume into liters: 175 mL = 0.175 L.
Next, we rearrange the combined gas law to solve for V₂:
Therefore, the new volume of Cl₂ gas at the bottom of Hellas Planitia will be approximately 15.06 liters.
Write the balanced chemical equations for the reactions in which sodium phosphate is added to copper(II) sulfate and iron(III) chloride, respectively. Include states of matter.
Explanation:
1. When sodium phosphate is added to copper (II) sulfate it gives solid precipitate of copper(II) phosphate and solution of sodium sulfate.
The balanced equation is given as:
[tex]2Na_3PO_4(aq)+3CuSO_4(aq)\rightarrow Cu_3(PO_4)_2(s)+3Na_2SO_4(aq)[/tex]
2. When sodium phosphate is added to iron(III) chloride it gives solid precipitate of iron (III) phosphate and solution of sodium chloride.
The balanced equation is given as:
[tex]Na_3PO_4(aq)+Fe(Cl)_3(aq)\rightarrow FePO_4(s)+3NaCl(aq)[/tex]
A chemist adds 435.0mL of a 2.28 M zinc nitrate ZnNO32 solution to a reaction flask. Calculate the millimoles of zinc nitrate the chemist has added to the flask. Round your answer to 3 significant digits.
Answer:
He added 992 milimoles of zinc nitrate (Zn(NO3)2)
Explanation:
Step 1: Data given
Volume of zinc nitrate = 435.0 mL =0.435 L
Molarity of zinc nitrate = 2.28 M
Step 2: Calculate moles zinc nitrate
Moles = molarity* volume
Moles Zn(NO3)2 = 2.28 M * 0.435 L
Moles Zn(NO3)2 = 0.9918 moles
Step 3: Convert moles to milimoles
Moles Zn(NO3)2 = 0.9918 moles
Moles Zn(NO3)2 = 0.9918 * 10^3 milimoles
Moles Zn(NO3)2 = 991.8 milimoles ≈ 992 milimoles
He added 992 milimoles of zinc nitrate (Zn(NO3)2)
Final answer:
To determine the millimoles of zinc nitrate added, convert 435.0 mL to liters, use the molarity of 2.28 M to find moles, and then multiply by 1000 to get 992.4 millimoles.
Explanation:
To calculate the millimoles of zinc nitrate a chemist has added to the reaction flask, you first need to know the concentration of the solution and the volume of the solution used. Here, we have a 2.28 M zinc nitrate solution, and the volume used is 435.0 mL. To find the millimoles, first convert the volume from milliliters to liters (since molarity is moles per liter), then use the molarity to find the moles of zinc nitrate, and finally convert that to millimoles.
Convert volume to liters: 435.0 mL × (1 L / 1000 mL) = 0.435 L
Calculate moles of Zn(NO3)2: 2.28 moles/L × 0.435 L = 0.9924 moles
Convert moles to millimoles: 0.9924 moles × 1000 mmol/mole = 992.4 mmol
Therefore, the chemist has added 992.4 millimoles of zinc nitrate to the flask.