Answer:
Identify each of the following as endothermic or exothermic.
a. Water in a pond evaporates.
b. Methane gas burns on a stovetop.
c. Water freezes to form ice.
d. Energy flows from the system to the surroundings.
e. Energy flows from the surroundings to the system.
Explanation:
An exothermic reaction is the one in which heat energy is released.
An endothermic reaction is one in which heat energy is absorbed.
a. Water in a pond evaporates.
This process absorbs heat energy.
Hence, this is an example of an endothermic process.
b. Methane gas burns on a stovetop and release heat energy and hence this is an example of an exothermic reaction.
c. Water freezes to form ice.
In this process heat energy is released.So this is an example of exothermic reaction.
d. Energy flows from the system to the surroundings.
That means heat energy is released into the surroundings.
So, this is an example of exothermic process.
e. Energy flows from the surroundings to the system.
That means energy is absorbed by the system.
So, it is an endothermic process.
help!! An atomic number of 4, an atomic mass of 8 and a charge of +1.
Answer:
berylium
Explanation:
atomic number 4 atomic mass 8 and charge +1
1) Give the full ground state electron configuration for As.
2) Give the full ground state electron configuration for Pb.
3) Give the ground state electron configuration for the ion that Cs forms. Is it more or less stable than the neutral atom?
4) Identify the isoelectronic (same number of electrons) elements. Show your work.
A) CI-, F., Br, 1-, At
B) N3-S2-, Br, Cst, Sr2+
C) N3, 02-, F., Na+, Mg2+
D) Lit, Nat, K+, Rb.st E) Ne, Ar, Kr, Xe, He
5) Identify the elements correctly shown by decreasing radii size. Provide a brief reason.
A) N3->N
B) K+ >K
C)N > N3
D) Cu2+ > Cut
E) S-> S2
6) What period 3 element has the following ionization energies (all in kJ/moly? And, why? IE1 - 1000; IE2 = 2250; IE3 - 3360: IE4 = 4560; IE5 - 7010; IE6 = 8500; IE7 = 27,100
7) Place the following in order of decreasing IE]. Provide a reason. Cs Ar Mg
8) Write the reaction that represents electron affinity of potassium (K) atom? Is the product more or less stable than the reactant? Why?
9) Give the set of four quantum numbers that could represent the extra electron added (using the Aufbau principle) to the neutral Ne atom.
10) Which 2nd period element has the most negative electron affinity? Why? - Bonus questions
11) Which ionization process requires the most energy? Why?
A) Se(g) Set(g) +e-
B) Set(g) Se2+(g) +
C) Br(g) Br) +-
D) Brt (8) Br2+(g) +e
12) Place the following in order of decreasing metallic character. Explain your reason. P As K -
its answer aExplanation:
what are the answers for these I did four through 10 but I think I got four through nine wrong because I mixed up the radius and the atomic radius but I’m not sure can you please tell me the answers I can send you a picture of my work as well!
Answer:
1) B
2) D
3) A
4) Ga
5) K
6)Po
7) Atomic size increases down the group
8) B<Al<Ga<In<Tl
9)Se<C<Ga
10) ionization energy is the energy required to remove electrons from the outermost shell of an atom.
Explanation:
In the periodic table, the properties of elements reoccur ''periodically'' throughout the table, hence the name 'periodic table'.
Ionization energy increases across the period hence the noble gas He has the highest ionization energy.
Since ionization energy increases across the period, group 1 elements possess the lowest ionization energy.
Since atomic size increases down the group and decreases across the period, gallium is smaller than indium, potassium is smaller than caesium, polonium is smaller than titanium and iodine is larger than bromine.
This explanation above justifies the order of increasing atomic radius of group 13 elements shown in answer number 8 above.
Since atomic size decreases across the period, the order of increasing atomic size shown in answer number 9 above is correct.
Ionization energy is the energy required to remove electrons from the outermost shell of an atom.
The student adds 0.0010 mol of NaOH(s) to solution Y, and adds 0.0010 mol of NaOH(s) to solution Z. Assume that the volume of each solution does not change when the NaOH(s) is added. The pH of solution Y changes much more than the pH of solution Z changes. Explain this observation.
Answer:
The answer is in the explanation.
Explanation:
A buffer is defined as the aqueous mixture of a weak acid and its conjugate base or vice versa. Buffers are able to avoid the pH change of a solution when strong acid or bases are added (As NaOH).
Based on the experiment, it is possible that the solution Z was a buffer and Y another kind of solution. For this reson, pH of the solution Y changes much more than the pH of solution Z changes despite the amount of NaOH added is the same in both solutions.
I’m confused on this review question
Answer:
1.58×10¯⁷ M.
Explanation:
From the question given above, the following data were obtained:
pH = 6.8
Concentration of hydronium ion [H₃O⁺] =?
The pH of a solution is given by the following equation:
pH = –Log [H₃O⁺]
With the above formula, we can obtain the concentration of hydronium ion [H₃O⁺] as follow:
pH = 6.8
Concentration of hydronium ion [H₃O⁺] =?
pH = –Log [H₃O⁺]
6.8 = –Log [H₃O⁺]
Multiply both side by by –1
–6.8 = Log [H₃O⁺]
Take the anti log of –6.8
[H₃O⁺] = antilog (–6.8)
[H₃O⁺] = 1.58×10¯⁷ M
Therefore, the concentration of hydronium ion [H₃O⁺] in the solution is 1.58×10¯⁷ M.
La función de la levadura en quimica
Explanation:
las levaduras son pequeños organismos unicelulares que se alimentan de azúcares simples y los descomponen en dióxido de carbono, alcohol (etanol, específicamente), moléculas de sabor y energía. El proceso se conoce como fermentación.
PLEASE HELP ASAP‼️‼️
A
B
C
D
Answer:
Hey mate......
Explanation:
This is ur answer......
Option C is the correct answer.....molecules in liquids are weaker than solids but stronger than gases......
Hope it helps!
Brainliest pls!
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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
1. Consumers produce their own food.
True or false?
Please help I will give you 50 points
Answer:
false
Explanation:
consumers eat producers
Answer:
False. If they are talking about food today.
Iodide ion catalyzes the decomposition of hydrogen peroxide. The reaction is first-order in H2O2. What is the value of the rate constant, k, if the initial rate is 0.00842 mol/(L·s) and the initial concentration of H2O2 is 0.500 mol/L.
Answer:
0.01684 s⁻¹
Explanation:
In a first-order reaction, the rate is proportional to the concentration of only one reactant (raised by 1). In this case, the reactant is H₂O₂. Thus, the rate law is the following:
rate = k [H₂O₂]
We have the following data for the initial rate:
rate = 0.00842 mol/(L·s)
[H₂O₂] = 0.500 mol/L
So, we introduce the data in the expression for the rate law to calculate k:
k = rate/[H₂O₂] = (0.00842 mol/L·s)/0.500 mol/L = 0.01684 s⁻¹
How many carbon dioxide molecules react to form one glucose molecule during photosynthesis
Answer:
6 molecules
Explanation:
Only three elements are present in the products of photosynthesis: oxygen, carbon, and hydrogen. These same elements are present in the reactants of photosynthesis. Notice that it takes six molecules of water and six molecules of carbon dioxide to make one molecule of glucose
Answer:
6 molecules of carbone dioxide.
Difference between sieving and filtration
my answer
Explanation:
Answer. Filtration is the method of separating a solid from a liquid. A sieve sets a threshold calibration through which all undersized materials pass through. Filtration differs from sieving, where separation occurs at a single perforated layer (a sieve).
What is the density, to the nearest hundredths, of a metal with a volume of 3.00 cm3 and a mass of 8.13 g? Record your answer and fill in the bubbles on your answer document. Be sure to use the correct place values.
Answer:
2.7
Explanation:
It took 2.30 minutes using a current of 3.00 A to plate out all the copper from 0.300 L of a solution containing Cu2 . What was the original concentration of Cu2
Answer:
7.16 × 10⁻³ M
Explanation:
Let's consider the reduction reaction of copper during the electroplating.
Cu²⁺(aq) + 2 e⁻ ⇒ Cu(s)
We can calculate the moles of Cu²⁺ present in the solution using the following relations.
1 A = 1 C/s.1 min = 60 s.1 mole of electrons has a charge of 96486 C (Faraday's constant).1 mole of Cu²⁺ is reduced when 2 moles of electrons are gained.The moles of Cu²⁺ reduced are:
[tex]2.30 min \times \frac{60s}{1min} \times \frac{3.00C}{s} \times \frac{1mole^{-} }{96486C} \times \frac{1molCu^{2+} }{2mole^{-} } = 2.15 \times 10^{-3} molCu^{2+}[/tex]
[tex]2.15 \times 10^{-3} moles[/tex] of Cu²⁺ are in 0.300 L of solution.
[Cu²⁺] = 2.15 × 10⁻³ mol/0.300 L = 7.16 × 10⁻³ M
Which of the following flows through ecosystems in one direction?
1. Water
2. Energy
3. Nitrogen
4. Carbon
Answer:
It is energy
Explanation:
Your welcome! :)
Energy flows in one direction in an ecosystem.
What is an ecosystem?An ecosystem is a system which shows the interaction between the living organisms and the non-living part of their environment.
An ecosystem usually shows a flow of nutrient and energy
Nutrients are cycled in an ecosystem but energy flows in only one direction.
Therefore, in an ecosystem, energy flows in one direction.
Learn more about ecosystem at: https://brainly.com/question/15971107
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identify the limiting reactant
1.4 g of CO2 and 2.2 g of KOH in the reaction: CO2 + 2KOH → K2CO3 + H20
Please show work, will give brainliest
Answer:
KOH is the limiting reactant
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to identify the required limiting reactant by calculating the moles of water vapor produced by each reactant, CO2 and KOH, as shown below:
[tex]1.4gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molH_2O}{1molCO_2}=0.0318mol H_2O\\\\2.2gKOH*\frac{1molKOH}{56.11gKOH}*\frac{1molH_2O}{2molKOH}=0.0196mol H_2O[/tex]
In such a way, since 2.2 grams of KOH yield the fewest moles of water vapor, we infer KOH is the limiting reactant.
Regards!
1 point
What is the correct balanced equation for the double displacement
reaction provided?
CaBr2+2NaOH???
a) CaBr2+2NaOH
>CaNa
+ BrOH
b) CaBr2
+ NaOH → Ca(OH)2
+NaBr
c) CaBr2 NaOH> CaBr2
+NaOH
d)CaBr2
+ 2NaOH
→ Ca(OH)2
+2NaBr
Option A
Option B
Option C
Option D
Answer:
Option D
Explanation:
A double displacement reaction is a type of reaction in which two reactants exchange ions to form two new compounds.
CaBr2 + 2NaOH → Ca(OH)2 + 2NaBr
Calcium Bromide + Sodium Hydroxide = Portlandite + Sodium Bromide
The number of moles of Cu produced in this
reaction is
Answer:
the answer is 0.078
Explanation:
edge 2021
Answer:
The next answers are
4.96
Wax
oxygen
Calculated based on the chemical equation:
✔ theoretical yield
Measured directly:
✔ experimental yield
Determined experimentally:
✔ experimental yield
Determined using stoichiometry:
✔ theoretical yield
BOTH
ALL OF THE ABOVE
using accurate measurements
using pure chemicals
performing the reaction under the most ideal conditions
Explanation:
What is the correct answer question
Answer:
B
Explanation:
Reaction of 2,3-dimethyl-1-butene with HBr leads to an alkyl bromide, C6H13Br. On treatment of this alkyl bromide with KOH in methanol, elimination of HBr occurs and a hydrocarbon that is isomeric with the starting alkene is formed. What is the structure of this hydrocarbon, and how do you think it is formed from the alkyl bromide
Answer:
See explanation and image attached
Explanation:
The image attached shows the entire scheme of reactions mentioned in the question.
The first reaction is an addition reaction which yields a tertiary alkyl halide as shown in accordance with Markovnikov rule.
The second reaction is a dehydrohalogenation in which the base abstracts a proton from the alkyl halide followed by loss of a bromide ion to yield the corresponding alkene.
This alkene is an isomer of the starting material.
The reduced coenzymes generated by the citric acid cycle donate electrons in a series of reactions called the electron transport chain. The energy from the electron transport chain is used for oxidative phosphorylation.
a) Which compounds donate electrons to the electron transport chain?
b) Which of the following is the final electron acceptor?
c) Which of the following are the final products of the electron transport chain and oxidative phosphorylation?
1. H20
2. NADH
3. NAD+
4. ATP
5. ADP
6. O2
7. FADH2
8. FAD
Answer:
a. NADH and FADH₂ donate electrons to the electron transport chain
b. Molecular oxygen, O₂, is the final electron acceptor
c. The final products of the electron transport chain and oxidative phosphorylation are as follows: NAD+, FAD+, H₂O, and ATP
Explanation:
The citric cycle oxidize acetylCoA molecules to carbon dioxide and in the process produce the reduced coenzyme NADH and FADH₂. These reduced coenzymes then are able to donate their electrons to various complexes in the electron transport chain. The flow of these electrons through the electron transport chain is coupled to proton pumping out of the mitochondrial matrix into the intermembrane space. Ultimately, the energy of the proton motive force is used to drive synthesis of ATP from ADP and inorganic phospahte and the electrons are accepted by molecular oxygen to produce water. This process is known as oxidative phosphorylation.
Therefore, the answers to the given questions a, b and c are as follows:
a. NADH and FADH₂ donate electrons to the electron transport chain
b. Molecular oxygen, O₂, is the final electron acceptor
c. The final products of the electron transport chain and oxidative phosphorylation are as follows: NAD+, FAD+, H₂O, and ATP
How is the enthalpy of reaction shown in this potential energy diagram
Answer:
In the given potential energy diagram, the energy of product at higher level and energy of reactant at lower level. The for this reaction will be positive. So, the enthalpy of reaction is defined as the difference of the energy of the reactants and the energy of the products.Hope this is fine for you,,!You have 4 litres of a 3.0 mol/L solution of NaCl in a chemical store room.
How many moles of NaCl are present?
Answer:
12
Explanation:
nNaCl= 4x3=12
How is the enthalpy of reaction shown in this potential energy diagram?
Answer:
as the difference of the energy of the reactants and the energy of the products
In the given potential energy diagram, the energy of product at higher level and energy of reactant at lower level. The for this reaction will be positive. So, the enthalpy of reaction is defined as the difference of the energy of the reactants and the energy of the products.
I hope this helps!
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
Choose the compound that exhibits hydrogen bonding as its strongest intermolecular force. Choose the compound that exhibits hydrogen bonding as its strongest intermolecular force. CH2Br2 CH3NH2 LiF C3H8 CF4
Answer:
The given molecules are:
CH2Br2
CH3NH2
LiF
C3H8
CF4.
Which compound consists of the hydrogen bond as the strongest intermolecular force.
Explanation:
The hydrogen bond is the electrostatic force of attraction that exists between the covalently bonded H-atom of one molecule and a high electronegative atom (N, O, F) of another molecule.
For example, H-bonding in water is represented below:
Among the given molecules,
CH2Br2 does not have H-bond because there is no either N or O or F atom in it.
In LiF also there is no H-atom and no hydrogen bond.
C3H8 also does not have H-bond in it.
CF4 also does not have H-atom or hydrogen bond in it.
The answer is CH3NH2(methylamine).
It has an intermolecular hydrogen bond in it as shown in the attachment.
The dashed line represents the H-bond.
85.4 g of chlorine reacts completely according to the following reaction: P4 (s) + 6 Cl2, (g) 4PC13 (I)
If 104 g of phosphorous trichloride is produced, what is the percent yield for this reaction?
please show work
will give brainliest
Explanation:
hope the picture make sense :)
i need help, do you mind helping me?
In the reaction represented by the equation: N2 + 3H2 → 2NH3, what is the conversion factor of nitrogen to ammonia? Explain by using law of definite proportion
Answer:
10/3
Explanation:
Hope this helps
Answer:
The compound formula for the ammonia is
N
H
3
. It is a colorless gas. It is the result of the chemical reaction between nitrogen and hydrogen gas. The chemical reaction between the gases is shown below:
N
2
+
3
H
2
→
2
N
H
3
Rocks are classified as igneous, metamorphic, or sedimentary according to
Answer:
D. the minerals they contain
Hope this answer is right!!