The standard entropy change of a reaction has a positive value. This reaction results in: Select the correct answer below: a decrease in entropy. an increase in entropy. no entropy change. neither an entropy increase nor decrease.
Explanation:
The standard entropy change of a reaction has a positive value. This reaction results in an increase in entropy.
Positive entropy means the system has increased its degree of disorderness.
A buffer is a solution that is a mixture of either a weak acid and its conjugate base or a weak base and its conjugate acid. When strong acids or strong bases are added, buffers either accept protons when they are in excess or donate protons when they have been depleted to minimize changes in pH. Which of the statements correctly describe the properties of a buffer?
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base.
c. An acidic buffer solution is a mixture of a weak base and its conjugate acid.
d. The weak acid of an acidic buffer will accept hydrogen protons when a strong base is added to the solution.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution.
f. The conjugate base of an acidic buffer will donate hydrogen protons when a strong acid is added to the solution.
Answer:
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution.
Explanation:
Which of the statements correctly describe the properties of a buffer?
a. The conjugate base of an acidic buffer will accept hydrogen protons when a strong acid is added to the solution. TRUE. The conjugate base neutralizes the excess of hydrogen protons.
b. An acidic buffer solution is a mixture of a weak acid and its conjugate base. TRUE.
c. An acidic buffer solution is a mixture of a weak base and its conjugate acid. FALSE. This is a basic buffer solution.
d. The weak acid of an acidic buffer will accept hydrogen protons when a strong base is added to the solution. FALSE. The weak acid will react with the hydroxyl ions from the added base.
e. The weak acid of an acidic buffer will donate hydrogen protons when a strong base is added to the solution. TRUE. These hydrogen protons will form water.
f. The conjugate base of an acidic buffer will donate hydrogen protons when a strong acid is added to the solution. FALSE. It will accept hydrogen protons.
Carbon disulfide is formed by the reaction of coke (carbon) with sulfur dioxide. How many moles of CS2 will be generated if 8.0 moles of coke react with a surplus of sulfur dioxide? 5C +2502 - CS2 + 4CO A. 0.8 moles B. 1.6 moles C. 3.2 moles OD. 6.4 moles
All of the following are characteristics of metals except: Group of answer choices good conductors of heat malleable ductile often lustrous tend to gain electrons in chemical reactions
Answer:
Hence the correct option is the last option that is tends to gain electrons in chemical reactions to become anions.
Explanation:
Metals tend to donate electrons in chemical reactions to become cations.
Nitrous oxide, NO, decomposes exothermically into nitrogen gas and oxygen gas. When graphing [NO] versus time, a straight line can be drawn through the experimental points. From this information, determine the reaction order.
Answer:
Zero-Order
Explanation:
The exothermic decaying of nitrous oxide at 575° C will lead to [tex]N_{2} and O_{2}[/tex] as follows:
[tex]2N_{2}O[/tex] → [tex]2N_{2}(g) + O_{2} (g)[/tex]
Hot platinum wire in the above reaction would function as a catalyst in the zero-order. However, if the reaction is considered in the gaseous phase, it will be more inclined towards second-order.
In the given scenario([tex]2N_{2}O[/tex] → [tex]2N_{2}(g) + O_{2} (g)[/tex]), the reactant molecules of Nitrous oxide are restricted to the ones which have linked themselves to the catalyst's surface. Once this limited surface is filled, the extra molecules of gas would remain vacant until the previously attached molecules with the surface are decayed entirely.
Which redox reaction would most likely occur if silver and copper metal were added to a solution that contained silver and copper ions?
A. Cu + Agt Cu2+ + 2Ag
B. Cu2+ + 2Ag* → Cu + 2Ag
C. Cu2+ + 2Ag → Cu + 2Ag+
D. Cu + 2Ag Cu²+ + 2Ag+
give the wrong answer and I'm reporting
Answer:
B
Explanation:
b/c copper is readuction agent
The most likely redox reaction that would occur if silver and copper metal were added to a solution that contained silver and copper ions is [tex]\rm Cu^{2+} + 2Ag \rightarrow Cu + 2Ag^+[/tex]. The correct answer is option C.
Redox reaction is a reaction in which reduction and oxidation takes place simultaneously.
In this reaction:
[tex]\rm Cu^{2+} + 2Ag \rightarrow Cu + 2Ag^+[/tex]
Copper metal has a higher reduction potential than silver metal, which means that it will be oxidized to [tex]\rm Cu^{2+}[/tex] ions before silver metal is oxidized to [tex]\rm Ag^+[/tex] ions.
The [tex]\rm Cu^{2+}[/tex] ions in the solution will then react with the silver metal to form [tex]\rm Ag^+[/tex] ions and Copper metal. This reaction is an example of a displacement reaction, where a more reactive metal removes a less reactive metal from its compound.
Therefore, option C. [tex]\rm Cu^{2+} + 2Ag \rightarrow Cu + 2Ag^+[/tex] is the correct answer.
Learn more about Redox reaction here:
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Hydrogen chloride decomposes to form hydrogen and chlorine, like this:
2HCl(g) + H2(g) â Cl2(g)
Also, a chemist finds that at a certain temperature the equilibrium mixture of hydrogen chloride, hydrogen, and chlorine has the following composition:
compound pressure at equilibrium
HCl 84.4 atm
H2 77.9 atm
Cl2 54.4
Required:
Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits.
Solution :
Given :
Partial pressure of HCl, [tex]$P_{HCl}$[/tex] = 84.4 atm
Partial pressure of [tex]H_2[/tex], [tex]$P_{H_2}$[/tex] = 77.9 atm
Partial pressure of [tex]Cl_2[/tex], [tex]$P_{Cl_2}$[/tex] = 54.4 atm
Reaction :
[tex]$2HCl (g) \leftrightharpoons H_2(g) + Cl_2(g)$[/tex]
Using equilibrium concept,
[tex]$k_p=\frac{(P_{H_2})(P_{Cl_{2}})}{(P_{HCl})^2}$[/tex]
[tex]$k_p=\frac{77.9 \times 54.4}{(84.4)^2}$[/tex]
[tex]$k_p=0.594$[/tex]
[tex]k_p=0.59[/tex] (in 2 significant figures)
or [tex]k_p=5.9 \times 10^{-1}[/tex]
Please help with all 3 parts!
Answer:
1:Part A.
[tex]\bold{42.2 g C_{12}H_{22}O_{11} \:in \:528 g H₂O}[/tex]
Mass Percent=[tex]\bold{\frac{Mass\: of \:Solute}{Mass\: of \:Solution}×100\%}[/tex]
=[tex]\frac{42.2}{528}*100\%=\bold{\underline{7.99\: or \:8\%}}[/tex]
Part B.
[tex]\bold{198\:m g\: C_{6}H_{12}O_{6} \:in\:4.71 g\: H₂O}[/tex]
mass of solute: 198mg
mass of solvent :4.71g=4710g
Mass Percent=[tex]\bold{\frac{Mass\: of \:Solute}{Mass\: of \:Solution}×100\%}[/tex]
=[tex]\frac{198}{4710}*100\%=\bold{\underline{4.20\%}} [/tex]
Part C.
[tex]\bold{8.85 g NaCl \:in \:190 g\: H₂O}[/tex]
Mass Percent=[tex]\bold{\frac{Mass\: of \:Solute}{Mass\: of \:Solution}×100\%}[/tex]
=[tex]\frac{8.85}{190}*100\%=\bold{\underline{4.66\%}}[/tex]
Answer:
It will help you !!!!!!!!!!
In nature, one common strategy to make thermodynamically unfavorable reactions proceed is to couple them chemically to reactions that are thermodynamically favorable. As long as the overall reaction is thermodynamically favorable, even the unfavorable reaction will proceed.
Part A
Consider these hypothetical chemical reactions:
A⇌B,ΔG= 14.8 kJ/mol
B⇌C,ΔG= -29.7 kJ/mol
C⇌D,ΔG= 8.10 kJ/mol
What is the free energy, ΔG, for the overall reaction, A⇌D?
Part B
Firefly luciferase is the enzyme that allows fireflies to illuminate their abdomens. Because this light generation is an ATP-requiring reaction, firefly luciferase can be used to test for the presence of ATP. In this way, luciferase can test for the presence of life. The coupled reactions are
luciferin+O2ATP⇌⇌oxyluciferin+lightAMP+PPi
If the overall ΔG of the coupled reaction is -7.50 kJ/mol , what is the equilibrium constant, K, of the first reactions at 11 ∘C ? The ΔG for the hydrolysis of ATP to AMP is −31.6 kJ/mol.
Answer:
[tex]\triangle G= -6.7 KJ/mol[/tex]
Explanation:
From the question we are told that:
Chemical Reactions:
X=A⇌B,ΔG= 14.8 kJ/mol
Y=B⇌C,ΔG= -29.7 kJ/mol
Z=C⇌D,ΔG= 8.10 kJ/mol
Since
Hess Law
The law states that the total enthalpy change during the complete course of a chemical reaction is independent of the number of steps taken.
Therefore
Generally the equation for the Reaction is mathematically given by
[tex]T = +1 * X +1 * Y +1 *Z[/tex]
Therefore the free energy, ΔG is
[tex]\triangle G=1 * \triangle G*X +1 * \triangle G*Y +1 * \triangle G *Z[/tex]
[tex]\triangle G= +1 * (14.9) +1 * (-29.7) +1 * (8.10)[/tex]
[tex]\triangle G= -6.7 KJ/mol[/tex]
what is the difference between red phosphorus and white phosphorus?
Answer:
White phosphorusRed PhosphorusIt is insoluble in water but soluble in carbon disulphide.It is insoluble in both water and carbon disulphide.It undergoes spontaneous combustion in air.It is relatively
Explanation:
I hope it will help you
Consider the molecule PF5.
Indicate how many lone pairs you would find on the central atom:
Indicate how many total bonds are connected to the central atom (count single bonds as 1 bond, double bonds as 2 bonds, and triple bonds as 3 bonds):
Explanation:
here's the answer to your question
một chất hữu cơ có cấu tạo c2h2 cho khí br2 vào ta được hỗn hợp khí
Answer:
C2H2 + Br2 → C2H2Br2
Explanation:
Why do we need Chemistry in Nursing?
Answer:
We need chemistry in nursing because it deals with various kinds of drugs and the reactions of these drugs on the human body as well as with each other.
Sodium acetate is produced by the reaction of baking soda and vinegar. The resultant solution is then heated until it becomes saturated and allowed to cool. As a result, the solution has become supercooled. Upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes. Its molar enthalpy of fusion is 35.9 kJ/mol. How much thermal energy would be released by 276.0 g of sodium acetate trihydrate (molar mass
Answer: The thermal energy that would be released by 276.0g of sodium acetate trihydrate is 71.8kJ.
Explanation:
Supercooling is the process of lowering the temperature a liquid below its freezing point, without it becoming solid. A liquid below its freezing point will crystallize in the presence of a seed crystal because it serves as a structure for formation of crystals. From the question,
The given mass of sodium acetate trihydrate
(CH3COONa.3H2O)= 276.0g
Molar mass of sodium acetate
trihydrate= 136.08g/mol
Thermal heat of fusion of sodium acetate
trihydrate = 35.9 kJ/mol
From the given mass the number of moles present= 276.0/ 136.08
= 2.0moles
Therefore the heat (thermal) energy of the given mass of sodium acetate
trihydrate = 2.0 × 35.9
= 71.8kJ
Therefore, upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes.
The functional groups in an organic compound can frequently be deduced from its infrared absorption spectrum.
a. True
b. False
Answer:
a. True
Explanation:
The main information that gives an infrared absorption spectrum is the type of functional groups that are present in an organic compound. The infrared (IR) spectroscopy is based on the fact that functional groups absorb light in the IR region of the electromagnetic spectrum (approximately at 2,500-16,000 nm) and induces a vibrational excitation of the covalently bonded atoms in the group. The vibration of the atoms can be of different types, such as stretching, bending, etc. Each functional group (such as the carbonyl group) in an organic compound absorbs at a specific IR frequency so they can be distinguished from an IR spectrum.
An enzyme acts to Group of answer choices raise the activation energy needed to start the reaction. lower the activation energy needed to start the reaction. convert the activation energy into potential energy. convert the activation energy into kinetic energy. stop a chemical reaction.
Answer:
lower the activation energy needed to start the reaction.
Explanation:
The activation energy is defined as the energy barrier that stands between reactants and products.
An enzyme is a biological catalyst. Catalysts are known to lower the activation energy of a reaction.
Hence, a catalyst lowers the activation energy of the reaction. The lower the activation energy of a reaction, the faster the reaction is expected to be.
A student dissolves 12.6g of amonium nitrate(NH4NO3) in 250.g of water in a well-insulated open cup. She then observed the temperature of the water fall from 23.0°C to 18°C over the course of 6.1 minutes.
NH4NO3 â NH4+ (aq) + NO3^-(aq)
a. Is this reaction exothermic, endothermic, or neither?
b. If you said the reaction was exothermic or calculate the amount of heat that was released or absorbed by the reaction in this case.
c. Calculate the reaction enthalpy ÎHrxn per mole of NH4NO3.
Answer:
a. Endothermic.
b. [tex]Q_{rxn}=5493.6J[/tex]
c. [tex]\Delta H_{rxn}=35.0kJ/mol[/tex]
Explanation:
Hello there!
In this case, according to the given information for this calorimetry problem, it turns out possible for us to proceed as follows:
a. Due to the fact that the temperature of water goes from 23.0 °C to 18.0 °C, we infer this reaction is endothermic as the ammonium nitrate absorbed heat from the water.
b. Here, we consider the following heat equation:
[tex]Q_{rxn}=-Q_{water}[/tex]
Whereas we solve for the heat of reaction by means of the mass of the solution (both water and ammonium nitrate), the specific heat of the solution (we assume it is equal to that of water) and the temperature change:
[tex]Q_{rxn}=-m_{solution}C_{solution}(T_f-T_i)\\\\Q_{rxn}=-(12.6g+250.g)(4.184\frac{J}{g\°C} )(18.0\°C-23.0\°C)\\\\Q_{rxn}=5493.6J[/tex]
c. Here, we divide the previously calculated heat by the moles of ammonium nitrate (molar mass = 80.043 g/mol) to obtain the enthalpy of reaction per mole of this compound:
[tex]n_{NH_4NO_3}=12.6g*\frac{1mol}{80.043 g}=0.157mol\\\\\Delta H_{rxn}=\frac{5493.6J}{0.157mol} =34898.7J/mol\\\\\Delta H_{rxn}=35.0kJ/mol[/tex]
Regards!
A functional group introduces heteroatoms into a carbon chain to increase
polarity.
chain length.
molecular mass.
reactivity.
Answer:
reactivaty
Explanation:
here you go for the answer
What volume of a 1.5 M KOH solution is needed to provide 3.0 moles of KOH?
3.0 L
2.0 L
4.5 L
0.50 L
0.22 L
Please explain!
Explanation:
here's the answer to your question
2.0 L
Answer:
Solution given:
no. of mole(n)=3.0mole
molarity(M)=1.5M
we have
Volume of a substance is equal to the ratio of its no of mole to its molarity.
By this we get a relation:
Volume=no.of mole/molarity
substituting value
Volume=3.0/1.5=2
The required volume is 2 litre.
You need to make an aqueous solution of 0.121 M magnesium acetate for an experiment in lab, using a 250 mL volumetric flask. How much solid magnesium acetate should you add
Answer:
4.27 g
Explanation:
Number of moles = concentration × volume
Concentration = 0.121 M
Volume = 250 mL
Number of moles = 0.121 M × 250/1000 L
Number of moles = 0.03 moles
Number of moles = mass/molar mass
Mass= Number of moles × molar mass
Mass= 0.03 moles × 142.394 g/mol
Mass = 4.27 g
Buffer solutions that maintain certain levels of pH or acidity are widely used in biochemical experiments. One common buffer system uses sodium dihydrogenphosphate and sodium monohydrogenphosphate. What are the formulas of these two compounds
Answer:
Sodium dihydrogenphosphate = NaH₂PO₄
Sodium monohydrogenphosphate = Na₂HPO₄
Explanation:
A buffer solution is a solution is a solution that resists changes to its oH when a little quantity of strong acid or strong base is added to it.
They are solutions of weak acids or weak bases and their salts known as conjugate base or conjugate acids respectively for the weak acids and weak bases.
For example, a solution of the weak acid ethanoic acid and its salt or conjugate base, sodium ethanoate serves as a buffer solution.
In biochemical experiments, where the pH of the reaction medium is kept as constant and as close as possible to that of the internal environment, buffer solutions are widely used. One of the commonly used buffers is the phosphate buffer. The phosphate buffer consists of the acid salts sodium dihydrogenphosphate and sodium monohydrogenphosphate. Sodium dihydrogenphosphate serves as the weak acid while sodium monohydrogenphosphate serves as the conjugate base.
The formulas of these two compounds are given below:
Sodium dihydrogenphosphate = NaH₂PO₄
Sodium monohydrogenphosphate = Na₂HPO₄
potassium and chlorine react to form potassium chloride. a.it is a redox reaction,explain why. b.see if u can write a balanced equation for it.
Answer:
K+ClKCl
Explanation:
because the reaction is between metal Potassium and Non-metal Chlorine
Answer:
Explanation:
a) It is a redox reaction because KCl is an ionic compounds with K having a + charge and Cl having a - charge. Originally, both have an oxidation state of 0 and not K has 1+ and Cl has 1-. Therefore, one species was oxidized and one was reduced which is indicative of a redox reactions.
b)
2K + Cl2 => 2KCl
“Enter the conjugate acids of no2- and no3-“
Answer:
nitrit,nitrat
What type of oxide is each of the following? NO2, CO, Fe2O3, Al2O3, P20,
Nitrogen Dioxide
Carbon Monoxide
Iron (II) Oxide
Aluminum Oxide
DiPhosphorus Monoxide
Aspirin that has been stored for a long time may give a vinegar like odour and give a purple colour with FeCl3. What reaction would cause this to happen
?.
Answer:
See explanation
Explanation:
The IUPAC name of aspirin is 2-Acetoxybenzoic acid. It is composed of an acetoxy moiety and a benzoic acid moiety.
The compound can be hydrolysed under prolonged storage conditions to yield acetic acid which causes the vinegar like odour.
Also, one of the products of this hydrolysis bears a phenol group which reacts with FeCl3 to give a purple color.
I NEED A ANSWER FOR THIS QUESTION, ASAP
How many moles of Fe contains 3.41 x 1023 Fe atoms?
Answer:
[tex]\boxed {\boxed {\sf 0.566 \ mol \ Fe}}[/tex]
Explanation:
We are asked to convert a number of atoms to moles.
We can convert atoms to moles using Avogadro's Number, which is 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this problem, the particles are atoms of iron (Fe). There are 6.022 ×10²³ atoms of iron in 1 mole of iron.
We use dimensional analysis to convert atoms to moles. This involves setting up ratios. Use Avogadro's Number and the underlined information to make a ratio.
[tex]\frac {6.022 \times 10^{23}\ atoms \ Fe}{1 \ mol \ Fe}[/tex]
We are converting 3.41 × 10²³ atoms of iron to moles, so we multiply by this value.
[tex]3.41 \times 10^{23} \ atoms \ Fe *\frac {6.022 \times 10^{23}\ atoms \ Fe}{1 \ mol \ Fe}[/tex]
Flip the ratio. It stays equivalent, but it allows the units of atoms of iron to cancel.
[tex]3.41 \times 10^{23} \ atoms \ Fe *\frac{1 \ mol \ Fe} {6.022 \times 10^{23}\ atoms \ Fe}[/tex]
[tex]3.41 \times 10^{23}*\frac{1 \ mol \ Fe} {6.022 \times 10^{23}}[/tex]
[tex]\frac{3.41 \times 10^{23}} {6.022 \times 10^{23}} \ mol \ Fe[/tex]
[tex]0.5662570575\ mol \ Fe[/tex]
The original measure ment of iron atoms ( 3.41 × 10²³ ) has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandths place. The 2 in the ten-thousandths place ( 0.5662570575) tells us to leave the 6 in the thousandths place.
[tex]0.566 \ mol \ Fe[/tex]
3.41 × 10²³ atoms of iron is equal to approximately 0.566 moles of iron.
It is necessary to make 225 mL of 0.222 M solution of nitric acid. Looking on the shelf, you see only 16 M nitric acid. How much concentrated nitric acid is required to make the desired solution?
Explanation:
The required concentration of [tex]HNO_3[/tex] M1 =0.222 M.
The required volume of [tex]HNO_3[/tex] is V1 =225 mL.
The standard solution of [tex]HNO_3[/tex] is M2 =16 M.
The volume of standard solution required can be calculated as shown below:
Since the number of moles of solute does not change on dilution.
The number of moles [tex]n=molarity * volume[/tex]
[tex]M_1.V_1=M_2.V_2[/tex]
[tex]V2=\frac{M_1.V_1}{M_2} \\=0.222M x 225 mL / 16 M\\=3.12 mL[/tex]
Hence, 3.12 mL of 16 m nitric acid is required to prepare 0.222 M and 225 mL of nitric acid.
8. Build a neutral lithium atom.
Now, what must you do to make the lithium atom's charge change to +1?
Hint: Lithium is atomic number 3.
Add 2 electrons
Remove 1 electron
Add 1 electron
Add 1 proton
Answer:
Remove 1 electron
Explanation:
In the atom of each element, there are three subatomic particles viz: proton, neutron and electron. The number of proton (positively charged) and electron (negatively charged) determines the charge of that element. The more the proton, the more positively charged an ion is and vice versa for electron.
According to this question, a neutral atom of lithium (Li) with atomic no. 3 is given i.e. a lithium atom with charge 0. To make the lithium atom's charge change to +1, ONE ELECTRON MUST BE REMOVED OR LOST.
Note that, the proton number (atomic number) of an element does not change, rather the electron number changes in relation to the no. of protons.
Consider the following titration for these three questions:
1.00 L of 2.00 M HCl is titrated with 2.00 M NaOH.
a. How many moles of acid are equal to one equivalent in this titration?
b. How many moles of HCl are found in solution at the halfway point of the titration?
c. How many liters of base will be needed to reach the equivalence point of the titration?
Answer:
a. 1 mole of acid is equal to one equivalent.
b. 1.00 moles of HCl are found.
c. 1L of 2.00M NaOH is needed to reach the equivalence point
Explanation:
HCl reacts with NaOH as follows:
HCl + NaOH → NaCl + H2O
Where 1 mole of HCl reacts with 1 mole of NaOH. The reaction is 1:1
a. As the reaction is 1:1, 1 mole of acid is equal to one equivalent
b. The initial moles of HCl are:
1.00L * (2.00moles HCl / 1L) = 2.00 moles of HCl
At the halfway point, the moles of HCl are the half, that is:
1.00 moles of HCl are found
c. At equivalence point, we need to add the moles of NaOH needed for a complete reaction of the moles of HCl. As the moles of HCl are 2.00 and the reaction is 1:1, we need to add 2.00 moles of NaOH, that is:
2.00moles NaOH * (1L / 2.00mol) =
1L of 2.00M NaOH is needed to reach the equivalence point