It is important for scientists to know how much energy is given off or absorbed in a chemical reaction. Which options below would indicate an exothermic reaction?
delta H = –
delta H = +
Energy is considered a reactant in the reaction: A + B + energy ---> C + D
Energy is considered a product in the reaction: A + B ---> C + D + energy
Energy is released in the reaction.
Energy is absorbed in the reaction.
For exothermic reactions, ΔH is always negative, energy is considered a product, and energy is released in the reaction.
An exothermic reaction is one in which energy, usually in the form of heat, is released to the environment from the reaction. In other words, the final temperature of an exothermic reaction would always be more than the initial temperature.
This also means that heat energy is a product of exothermic reactions and this heat is released to the environment from the reaction.
More on exothermic reactions can be found here: https://brainly.com/question/10373907?referrer=searchResults
Answer:
a, d, and e is correct on edge of the nuity
Explanation:
have a good day
How many significant figures are in a measurement of 28.050 km?
Answer:
has 5, ans 3 decimals.
thats as simple as i can put it.
We can determine the potential of a single electrode by:____________.
a. attaching it to a voltmeter
b. determining the electronegativity of its component elements
c. measuring its mass
d. none of the above
Answer:
d. none of the above
Explanation:
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
The potential of a single electrode in a half-cell is called the Single electrode potential.
The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
However, there is no way of measuring the emf of a single half-cell directly.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Therefore, the correct option is D "none of the above"
An electrochemical cell consists of two half-cells, with each cell containing an electrode.
What is an electrochemical cell?
An electrochemical cell is a device that can generate electrical energy from the chemical reactions occurring in it, or use the electrical energy supplied to it to facilitate chemical reactions in it.
The potential of a single electrode in a half-cell is called the Single electrode potential.The emf of a cell that consists of two half-cells can be determined by connecting them to a voltmeter.
The only way to determine the emf of a single electrode is to combine it with a standard hydrogen electrode (SHE) and measure it with a voltmeter.
Hence the correct option is D.
Learn more about electrochemical cell here:
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cấu hình electron của nguyên tử Ca
Explanation:
Do đó cấu hình electron của canxi là: 1s2 2s2 2p6 3s2 3p6 4s2.
What is the mass of 1 mole of baking soda (sodium hydrogen carbonate) which has a formula of NaHCO ?
Answer:
1 Mole = 84.007 g/mol
Explanation:
Sodium bicarbonate (IUPAC name: sodium hydrogen carbonate), commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3
What is the purpose of the scientific method
Tryptophan, an essential amino acid, is important in the synthesis of the neurotransmitter serotonin in the body.
a. True
b. False
Answer:
B porque si :) y eso Jsksjs
Answer:A
Because it's an amino acid and all amino acids are key to any part of your body.
Element compound2. Select all the compounds from the following elements
HE
Fe2O3
O2
P4
C2H4O2
Answer: [tex]Fe_2O_3[/tex] and [tex]C_2H_4O_2[/tex] are the compounds.
Explanation:
A chemical compound is defined as a chemical substance that is formed by the combination of two or more atoms of different elements which cannot be separated by any physical means but when chemically treated, they decompose into their parent elements.
For example, water is made up of hydrogen and oxygen. This compound is a liquid and its individual components are gases. When water is decomposed, it forms hydrogen and oxygen gas.
For the given options:
He(Helium) is an element formed by the combination of only type of atoms.
[tex]O_2[/tex] and [tex]P_4[/tex] are molecules of same element.
[tex]Fe_2O_3[/tex] is a compound fomed by the combination of iron and oxygen atoms.
[tex]C_2H_4O_2[/tex] is a compound fomed by the combination of carbon, hydrogen, and oxygen atoms.
Hence, [tex]Fe_2O_3[/tex] and [tex]C_2H_4O_2[/tex] are the compounds.
g Select the statement that best answers the following question What effect does the cation of an ionic compound have on the appearance of the solution? The cation affects the intensity of the color more than the color of the solution. The cation affects the color of the solution more than the intensity of the color. The cation does not affect the color or color intensity of the solution. The cation only affects the intensity of the color in a solution.
Answer:
The cation affects the intensity of the color more than the color of the solution.
Explanation:
According to Beer Lambert law, the intensity of the colour of the solution depends on the concentration of the specie responsible for the colour in the solution.
Let us recall that transition metal compounds are coloured in solution due to electronic transitions.
Therefore, the cation affects the intensity of the color more than the color of the solution.
classify the following compounds as chiral, achiral (but not meso), or meso. 1st structure: _________ 2nd structure: _________ 3rd structure: _________
Answer:
1st structure - Meso
2nd structure - Chiral
3rd structure - achiral
Explanation:
In the 1st structure there is nitrogen atom bonded with 4 different groups. It is Meso compound. In the second structure a carbon atom is attached with hydroxide molecule OH and has four different environment. It is Chiral compound. In the third structure no atom have different atom or group surrounding it. Therefore it is Achiral compound.
A 10 M concentrated stock solution of NaCl was used to prepare 5 liters of diluted 1 M solution. Which of the following statements is true about the process used to achieve this required dilution?
The volume of stock solution used was less than 0.4 liters.
The volume of stock solution used was more than 5 liters.
The volume of the solvent used was less than 0.4 liters.
The volume of the solvent used was less than 5 liters.
Answer: D.) The volume of stock solution used was more than 5 liters
Explanation:
Answer:
b
Explanation:
i got it
(iii) Give areason why the nitrogen gas obtained is not pure
Answer:
jhhhhhhhhh
Explanation:
dffffffffffffg
g Using Newman projections, draw the most stable conformation for each of the following compounds. (a) 3-methyl pentane, viewed along the C2-C3 bond (b) 3,3-dimethyl hexane, viewed along the C3-C4 bond
Answer:
Using Newman projections, draw the most stable conformation for each of the following compounds.
(a) 3-methyl pentane, viewed along with the C2-C3 bond.
(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.
Explanation:
(a) The structure of 3-methyl pentane is shown below:
In Newman projection, the most stable conformation is staggard conformation.
In staggard conformation, the torsional strain is very less compared to eclipsed conformation.
(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.
What is the pH of 0.6 M NaOH?
Answer:
pOH = - log[OH-]
[OH-] = 0.6M
[tex]pOH \: = - log(0.6) \\ = 0.2218487496 \\ pH \: + pOH \: = 14 \\ pH \: + 0.221848749 = 14 \\ pH = 14 - 0.221848749 \\ = 13.77815125 \\ 13.8[/tex]
Which statement best describes the formula equation Cl2(g) + 2KBr(aq) Right arrow. 2KCl(aq)+ Br2(l)?
Carbon iodide reacts with potassium bromide to form potassium carbon iodide and bromine.
Bromine gas reacts with a solution of potassium chloride to form potassium bromide and chlorine gas.
Potassium bromine gas reacts with liquid chlorine to form potassium chloride in solution and bromine gas.
Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
Answer:
Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
Explanation:
The balanced equation of the chemical reaction is given below:
Cl2(g) + 2KBr(aq) → 2KCl(aq)+ Br2(l)
According to the above equation, it can be said that chlorine in its gaseous form (Cl2) reacts with pottasium bromide (reactants) to form pottasium chloride (KCl) and bromine, which is a liquid at room temperature.
Answer:
D: Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.
How many molecules are in 0.5 grams of ammonia, NH3?
Answer:
I dont no ma men
Explanation:
Sorry cause a dont no
when ice melts,its volume
Answer:
There isn't enough information to answer you're question.
Explanation:
Have a great day!!!
The sloth is able to camouflage by moving really slowly and
A. changing colors
B. hanging upside down
D. having fur that is a similar color to tree barks with algae growing on it
Answer:
D. having fur that is a similar color to tree barks with algae growing on it
Explanation:
Choice A doesnt make sense because sloths do not change colors, and hanging upside down would not protect you from prey or blend in. D matches the description of a sloth.
Answer:
Having fur that is a similar color to tree barks with algae growing on it.
Explanation:
A central idea in modern quantum mechanics is:
(4 Points)
A wave character exhibited by all particles.
The acceleration of charged particles moving around a nucleus.
The opportunity to locate the position of an electron exactaly.
The continuous range of energies that electrons can have.
Answer:
A wave character exhibited by all particles
Explanation:
The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.
The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.
These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.
Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.
Calculate the number of milliliters of 0.587 M NaOH required to precipitate all of the Fe3 ions in 197 mL of 0.654 M FeCl3 solution as Fe(OH)3. The equation for the reaction is: FeCl3(aq) 3NaOH(aq) Fe(OH)3(s) 3NaCl(aq)
Answer: The number of milliliters of 654 mL for 0.587 M NaOH required to precipitate all of the [tex]Fe^{3+}[/tex] ions in 197 mL of 0.654 M [tex]FeCl_{3}[/tex] solution as [tex]Fe(OH)_{3}[/tex].
Explanation:
The reaction equation is as follows.
[tex]FeCl_{3}(aq) + 3NaOH(aq) \rightarrow Fe(OH)_{3}(s) + 3NaCl(aq)[/tex]
Therefore, moles of [tex]Fe(OH)_{3}[/tex] are calculated as follows.
Moles = Molarity of [tex]Fe(OH)_{3}[/tex] [tex]\times[/tex] Volume (in L)
= 0.654 M [tex]\times[/tex] 0.197 L
= 0.128 mol
Now, according to the given balanced equation 1 mole of [tex]FeCl_{3}(aq)[/tex] reacts with 3 moles of NaOH(aq). Hence, moles of [tex]Fe(OH)_{3}[/tex] reacted are calculated as follows.
3 [tex]\times[/tex] 0.128 mol = 0.384 moles of NaOH
As moles of NaOH present are as follows.
Moles of NaOH = Molarity of NaOH [tex]\times[/tex] Volume (in L)
0.384 mol = 0.587 M [tex]\times[/tex] Volume (in L)
Volume (in L) = 0.654 L (1 L = 1000 mL) = 654 mL
Thus, we can conclude that the number of milliliters of 654 mL for 0.587 M NaOH required to precipitate all of the [tex]Fe^{3+}[/tex] ions in 197 mL of 0.654 M [tex]FeCl_{3}[/tex] solution as [tex]Fe(OH)_{3}[/tex].
Once the race had been completed, the students opened their canisters to see if anything remained inside. They wanted to decide if they should modify their techniques for another race. Designs 1, 2, and 3 all still had some solid Alka-Selzter residue in the canister. Design 4 did not. The teacher asked the students to analyze their results as an engineer would. What worked well in the design? What could be improved? Predict what Design Team 3 decided to change.
A)Use hot water
B)Use more water
C)Not to crush the tablet and to use hot water
D)Not to crush the tablet and to use more water
HURRY! GIVING BRAINLY
Answer:
a
Explanation:because i did the test
Determine which intermolecular forces are the dominant (strongest) forces for a pure sample of each of the following molecules by placing the molecules into the correct bins.
Dispersion Forces; Dipole-Dipole Forces; Hydrogen Bonding Forces
Kr, H2O, CHCI3, HF, C2H6, HBr
Answer:
Kr- Dispersion Forces
H2O- Hydrogen Bonding
CHCI3- Dipole-Dipole Forces
HF- Hydrogen Bonding
C2H6- Dispersion Forces
HBr- Hydrogen Bonding Forces
Explanation:
Dispersion forces occurs in all substances. They are the dominant intermolecular interaction in all non polar substances such as C2H6 and Kr.
Hydrogen bonding occurs when hydrogen is bonded to a highly electronegative atom such as Cl, Br, O etc. It is the dominant intermolecular interaction in HF, HBr and H2O.
Dipole-Dipole interactions occur when a permanent dipole exists in a molecule such as in CHCI3
Write the empirical formula for at least four ionic compounds that could be formed from the following ions:
a). PO3−4
b). NH+4
c). Fe3+
d). ClO−3
Answer:
a. Na₃PO₄
b. NH₄Cl
c. FeCl₃
d. KClO₃
Explanation:
a. Sodium tetraoxophosphate(V) Na₃PO₄
3Na⁺ + PO₄³⁻ → Na₃PO₄
b. Ammonium Chloride NH₄Cl
NH₄⁺ + Cl⁻ → NH₄Cl
c. Iron(III)chloride
Fe³⁺ + Cl⁻ → FeCl₃
d. Potassium trioxochlorate(V) KClO₃
K⁺ + ClO₃⁻ → KClO₃
A substance with two oxygen atoms is combined with a substance with one oxygen atom to form one product. What is true of the product?
There will be no oxygen in the product. Some of the oxygen will evaporate into the air.
Scientist A produces 83.67 g KMnO4 while Scientist B produces 81.35 g KMnO4.
What is the percent yield for Scientist A?
What is the percent yield for Scientist B?
You must show all work to receive full credit.
The equation for the production of potassium permanganate is as follows:
2 MnO2 + 2 KOH + O2 → 2 KMnO4 + H2
Answer:
[tex]Y_A=92.1\%\\\\Y_B=89.6\%[/tex]
Explanation:
Hello there!
In this case, according to the given chemical equation for the reaction for the production of potassium permanganate, we can see a 2:2 mole ratio of this product to the starting manganese (II) oxide, which means, we can calculate the theoretical yield of the former via stoichiometry:
[tex]m_{KMnO_4}=50.0gMnO_2*\frac{1molMnO_2}{86.94gMnO_2}*\frac{2molKMnO_4}{2molMnO_2} *\frac{158.034gKMnO_4}{1molKMnO_4} \\\\m_{KMnO_4}=90.9gKMnO_4[/tex]
Now, we are able to compute the percent yields, by using the actual yield each scientist got:
[tex]Y_A=\frac{83.67g}{90.9g} *100\%=92.1\%\\\\Y_B=\frac{81.35g}{90.9g} *100\%=89.6\%[/tex]
Regards!
A student is examining a chemical reaction the student notes that the reaction requires 7.14 kcal mol energy per biomlecule synthesized the reaction itself produces 21.42 kcal mol energy the sutdent argues this is enough energy to make 3 biomecules. What error has the student made in the analysis?
a. The studentiras not remembered the Second Law of Thermodynamics.
b. The students has not remembered the First Law of Thermodynamics.
c. The student has made a simple calculation error
d. The student has made a conversion error
What is the concentration of a solution that is made by diluting 50.0 mL of a 0.40 M NaCl solution to a final volume of 1000.0 mL?
Answer:
The correct answer is 0.020 M.
Explanation:
To solve this problem, we can use the equation M1V1 = M2V2, where M represents the molarity of the solution and V represents the volume of solution. Since we are given that the original solution is 50 mL and 0.40 M, these values are V1 and M1, respectively. The solution after dilution has a volume of 1000 mL, so this value is V2. We are solving for the molarity after dilution, which represents M2.
If we plug in the values specified above, we get the following:
M1V1 = M2V2
(0.40 M)(50.0 mL) = (M2)(1000.0 mL)
Solving for M2, we get:
M2 = 0.020 M
Notice that our answer has 2 significant figures because 0.40 has 2 significant figures, the least of any values given in the problem.
Therefore, the answer is 0.020 M.
Hope this helps!
I NEED THIS NOW AND NO LINKS OR ILL REPORT
Which material creates the most waste and pollutants when creating one
ton of bottles? *
aluminum
glass
plastic
Answer:
plastic
........................
When heated, magnesium combines readily with excess oxygen in the air to produce magnesium oxide, as shown in the following unbalanced equation.
Mg (s) + O2 (g) → MgO (s) + heat
What two types of reactions could this chemical equation be classified as?
Answer: The given chemical reaction can be classified as synthesis and exothermic.
Explanation:
A synthesis reaction is defined as the reaction where two small chemical species combine in their elemental state to form a single large chemical species.
Exothermic reactions are defined as the reactions in which heat is released by the reaction. The heat is written on the product side of the reaction.
For the given chemical reaction:
[tex]Mg(s)+O_2(g)\rightarrow MgO(s)+\text{heat}[/tex]
The above chemical reaction is a type of synthesis and exothermic as two substances in their elemental state are combining. Also, heat is getting released in the reaction.
Hence, the given chemical reaction can be classified as synthesis and exothermic.
A student obtains a beaker containing a solution that is determined to have a hydrogen ion
concentration (H+) of 6.7x10-14. Based on this information, please answer the following
questions:
a) What is the pH of the solution?
b) is the solution acidic, neutral or basic?
Answer:
pH = 13.1
Basic
Explanation:
Step 1: Given data
Hydrogen ion concentration ([H⁺]): 6.7 × 10⁻¹⁴ M
Step 2: Calculate the pH of the solution
We will use the definition of pH.
pH = -log [H⁺]
pH = -log 6.7 × 10⁻¹⁴ = 13.1
When pH < 7, the solution is acid.When pH = 7, the solution is neutral.When pH > 7, the solution is basic.Since pH > 7, the solution is basic.
