PLEASE ANSWER ASAP 30 POINTS!!!
In the reaction H−H → H + H, what describes an average energy change of 436 kJ/mol?
A. The energy change will be positive as bonds are being broken.
B. The energy change will be positive as bonds are being formed.
C. The energy change will be negative as bonds are being broken.
D. The energy change will be negative as bonds are being formed.
Answer:
A. The energy change will be positive as bonds are being broken.
Explanation:
The breaking of a bond is an endothermic process. An endothermic process is one in which energy must be absorbed in order for the process to take place.
In breaking a chemical bond,energy is absorbed as the bonding species are being separated from each other.
Hence, the energy change of this process shown will be positive as bonds are being broken.
what will be observed when a piece of Ag metal is added to a Pb(NO3)2 solution?
What will be observed when a piece of Ca metal is added to a AgNO3 solution?
Answer:
Part a)
No Reaction
Part b)
CaNO3 is formed
Explanation:
Part a)
Silver is less reactive than lead and hence when Ag metal is added to a Pb(NO3)2 solution there will be no reaction
Ag (s) + Pb(NO3)2 (aq) --> Ag (s) + Pb(NO3)2 (aq)
Part b)
Calcium is more reactive than silver and hence when calcium is added to the solution of AgNO3, it will replace Ag from the AgNO3 and itself form compound with NO3 2- ion.
The reaction for the same is
Ca (s) + AgNO3 = CaNO3 + Ag (s)
(2-2) Looking at the chemical formula CaF2 (calcium fluoride), what do you think this substance is made of? (Choose ALL that apply)
Metal
Metalloid
Non-metal
Answer:
Metal
Non-metal
Explanation:
CaF2 is an ionic compound. Ionic compounds are mostly composed of a metal and a non metal. Metals donate electrons to non-metals to form ionic compounds.
Calcium is a divalent ion of group two in the periodic table while F is a univalent nonmetal of group 17 in the periodic table. Hence the compound CaF2 is composed of a metal and a nonmetal.
What do you think are the products of cellular respiration? *
Answer:
Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually "burns" glucose for energy.
Explanation:
You are given a small beaker of solution at room temperature. You add a bit of solute to the solution and it dissolves. The original solution was
Answer:
Unsaturated
Explanation:
An unsaturated solution contains less solute than it can normally hold at a particular temperature.
This kind of solution can also dissolve more solute.
Hence, when a bit of solute is added to this solution, the solute dissolves indicating that the original solution was unsaturated.
if 22.1g of CH4 reacts with 31.9g of O2 what is the limiting reactant?
timed test! will mark brainliest please help!!!
Answer:
CH4
Explanation:
because it CH4 have lesa mass than that of O2
Calculate the Molar Mass of Radon pentaiodide (Rnls)
857
349
1237
Explanation:
222.01758 g/mol
3.1Computed Properties
If I have 4.4 moles of nitrous oxide (laughing gas) that is kept at 32.9 °C in a container under 1.6 atm, what is the volume of the container? (R = 0.0821 (L*atm)/(mol*K))
Round your answer to 1 decimal place.
Answer:
Explanation:
Using the ideal gas equation as follows:
PV = nRT
Where:
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas law constant (0.0821 Latm/molK)
T = temperature (K)
Based on the information provided in this question;
P = 1.6atm
n = 4.4 moles
R = 0.0821 L*atm/mol*K
T = 32.9°C = 32.9 + 273 = 305.9K
V = ?
Molar mass of propan-1-ol
Answer:
60g/mol.
Explanation:
TO FIND :-
Molar mass of Propan-1-olFACTS TO KNOW BEFORE FINDING ANSWER :-
Chemical formula of Propan-1-ol = CH₃CH₂CH₂OH [or] C₃H₈OMolar mass of C = 12g/mol.Molar mass of H = 1g/mol.Molar mass of O = 16g/mol.SOLUTION :-
Molar mass of C₃H₈O = 3(Molar mass of C) + 8(Molar mass of H) + 1(Molar mass of O)
⇒ Molar mass of C₃H₈O = (3×12) + (8×1) + 16 = 36 + 8 + 16 = 60g/mol.
Which of the following best describes density?
- the relationship between length and mass
- the relationship between volume and area
- the relationship between mass and area
- the relationship between mass and volume
Answer:
the relationship between mass and volume
3. What happens to the size of a cation (compared to a neutral atom)? Why?
Answer:
Size of cation is lower than neutral atom because as a particular atom looses electron, no of proton become more than no of electron and attraction forces increases so radius decreases.
What is the mole fraction of NaOH in an aqueous solution that
contains 22.9% NaOH by mass?
Na=23
O=16
H= 1.01
Answer:
The mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
Explanation:
We are given that
Aqueous solution that contains 22.9% NaOH by mass means
22.9 g NaOH in 100 g solution.
Mass of NaOH(WB)=22.9 g
Mass of water =100-22.9=77.1
Na=23
O=16
H=1.01
Molar mass of NaOH(MB)=23+16+1.01=40.01
Number of moles =[tex]\frac{Given\;mass}{Molar\;mass}[/tex]
Using the formula
Number of moles of NaOH[tex](n_B)=\frac{W_B}{M_B}=\frac{22.9}{40.01}[/tex]
[tex]n_B=0.572moles[/tex]
Molar mass of water=16+2(1.01)=18.02g
Number of moles of water[tex](n_A)=\frac{77.1}{18.02}[/tex]
[tex]n_A=4.279 moles[/tex]
Now, mole fraction of NaOH
=[tex]\frac{n_B}{n_B+n_A}[/tex]
[tex]=\frac{4.279}{0.572+4.279}[/tex]
=0.882
Hence, the mole fraction of NaOH in an aqueous solution that contain 22.9% NaOH by mass=0.882
A gas is contained in a horizontal cylinder with a moveable piston of cross-sectional area 0.33\text{ m}^20.33 m 2 . The region outside the cylinder is at standard ambient temperature and pressure, 298\text{ K}298 K and 1\text{ bar}1 bar. When 2040\text{ J}2040 J of heat flow into the gas, the internal energy of the gas increases by 1380\text{ J}1380 J. Calculate the distance through which the piston moves. You may assume friction is negligible.
Answer:
0.02 m
Explanation:
∆U = q + w
w = ∆U - q = (1380 - 2040) J = -660 J
w = -p∆V = -pA∆h
∆h = -w/(pA)
p = 1 bar × (100000 Pa/1 bar) = 100000 Pa
∆h = -(-660 J)/(100000 Pa×0.33 m²) = 0.02 m
A gas is contained in a horizontal cylinder with a moveable piston of cross-sectional area 0.33\text{ m}^20.33 m 2. The distance through which the piston moves is 0.02 m.
What is piston ?Among other related systems, pistons are found in reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders, and pneumatic cylinders. It is the moving part that is enclosed in a cylinder and sealed off from the gas by piston rings.
The piston, which is a part of combustion engines, transforms the energy released during combustion into a mechanical action and sends it, via the piston pin and connecting rod, to the crankshaft as a torsional force. The piston in the cylinder goes up and down when the engine is running.
The equation given by
∆ U = q + w
w = ∆ U - q
= ( 1380 - 2040 )
J = -660 J
w = -p∆V
= -pA∆h
∆h = -w / (pA)
p = 1 bar × ( 100000 Pa / 1 bar )
= 100000 Pa
∆h = - ( -660 J) / ( 100000 Pa × 0.33 m² )
= 0.02 m
Thus, The distance through which the piston moves is 0.02 m.
To learn more about piston, follow the link;
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A mixture of oxygen( O2), dinitrogen monoxide (N2O), and argon (Ar) has a total pressure of 0.98 atm. What is the partial pressure of N2O, if the partial pressure of O2 is 0.48 atm and the partial pressure of Ar is 0.15 atm?
Answer: The partial pressure of [tex]N_{2}O[/tex] is 0.35 atm.
Explanation:
Given: Total pressure = 0.98 atm
Partial pressure of [tex]O_{2}[/tex] = 0.48 atm
Partial pressure of Ar = 0.15 atm
Partial pressure of [tex]N_{2}O[/tex] = ?
Total pressure is the sum of partial pressure of each component present in a mixture of gases.
Hence, partial pressure of [tex]N_{2}O[/tex] is calculated as follows.
Total pressure = [tex]P_{N_{2}O} + P_{O_{2}} + P_{Ar}[/tex]
Substitute the values into above formula as follows.
[tex]Total pressure = P_{N_{2}O} + P_{O_{2}} + P_{Ar}\\0.98 atm = P_{N_{2}O} + 0.48 atm + 0.15 atm\\P_{N_{2}O} = 0.35 atm[/tex]
Thus, we can conclude that the partial pressure of [tex]N_{2}O[/tex] is 0.35 atm.
An engine operates on a Carnot cycle that uses 1mole of an ideal gas as the
working substance and operates from a most compressed stage of 100 Nm and
327 K. It expands isothermally to a pressure of 90 Nm and then adiabatically to a
most expanded stage of 27 K. Calculate the AU, 9, and w for each step. Calculate
the net work done and the efficiency of the cycle [Cv,m for the gas) is 25 J/k/mol.
Answer:
Step 1;
q = w = -0.52571 kJ, ΔS = 0.876 J/K
Step 2
q = 0, w = ΔU = -7.5 kJ, ΔH = -5.00574 kJ
Explanation:
The given parameters are;
[tex]P_i[/tex] = 100 N·m
[tex]T_i[/tex] = 327 K
[tex]P_f[/tex] = 90 N·m
Step 1
For isothermal expansion, we have;
ΔU = ΔH = 0
w = n·R·T·ln([tex]P_f[/tex]/[tex]P_i[/tex]) = 1 × 8.314 × 600.15 × ln(90/100) = -525.71
w ≈ -0.52571 kJ
At state 1, q = w = -0.52571 kJ
ΔS = -n·R·ln([tex]P_f[/tex]/[tex]P_i[/tex]) = -1 × 8.314 × ln(90/100) ≈ 0.876
ΔS ≈ 0.876 J/K
Step 2
q = 0 for adiabatic process
ΔU = 25×(27 - 327) = -7,500
w = ΔU = -7.5 kJ
ΔH = ΔU + n·R·ΔT
ΔH = -7,500 + 8.3142 × 300 = -5,005.74
ΔH = ΔU = -5.00574 kJ
Which of the following pH numbers are basic? (Choose 2)
11
5
7
9
Answer:
7 is the only basic number on a pH scale
Can I please get help with chemistry.
I got these three questions wrong and I’m wondering which answers would be right for the questions.
Answer: The 3rd one
Explanation: Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.
I might be wrong
Inicialmente una muestra de neón tiene un volumen de 2,50 L a 15 °C. ¿Cuál es la
temperatura en °C, cuando el volumen de la muestra cambia a cada uno de los
siguientes volúmenes, ¿manteniéndose la presión constante?
a. 5,0 L b. 1250 ml c. 7,50L d. 3550 ml
naoooooooo seiiiiiiiii !!!!!!!!!!!!!!
Balance the following equation by providing the correct coefficients C2H6 + O2 -> CO2 + H2O
During photosynthesis, plants incorporate atmospheric
Cinto more complex energy-storage
molecules that increase the mass of the plants. Plants need sunlight for this process because plants transform light
energy into
energy stored in the molecules.
Answer:
carbon dioxide
oxygen
**
During photosynthesis, plants incorporate atmospheric pressure into more complex energy-storage molecules that increase the mass of the plants. Plants need sunlight for this process because plants transform light energy into chemical energy stored in the molecules.
What is Photosynthesis ?
It is the process by which plants , algae and some bacteria uses water from the carbon dioxide, air and soil and in this process food is prepared in the presence of chlorophyll and sunlight. In this process light energy converted to chemical energy.
Thus, we can say that During photosynthesis, plants incorporate atmospheric pressure into more complex energy-storage molecules that increase the mass of the plants. Plants need sunlight for this process because plants transform light energy into chemical energy stored in the molecules.
Learn more about the Photosynthesis here: https://brainly.com/question/19160081
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Indica el período, el grupo, el nombre y el número atómico de los elementos que se representan con las siguientes configuraciones electrónicas:
Answer:
have g8igcicg9ccgco
Explanation:
gcohogxzrxog floor. gi gi gi gi. r. uvgi7rz. g yde6ifkg. gg g goog oh g of ifz8fd8dti
What are mycelium
??????????
Answer:
Mycelium is a group of hyphae which are fungus.... these are like roots in structure
Answer:
A mycelium is the vegetative part of a fungus, consisting of a network of fine white filaments
Explanation:
Calculate the current in amperes required to produce 18.0g of aluminium in 1.50hrs (al=27.og )
Answer:
35.7 A
Explanation:
Let's consider the reduction half-reaction of Al³⁺.
Al³⁺ + 3 e⁻ ⇒ Al
We will calculate the charge required to produce 18.0 g of Al using the following conversion factors.
1 mole of Al has a mass of 27.0 g1 mole of Al is formed upon the circulation of 3 moles of electrons1 mole of electrons has a charge of 96486 C (Faraday's constant)[tex]18.0gAl \times \frac{1molAl}{27.0gAl} \times \frac{3mole^{-} }{1molAl} \times \frac{96486C}{1mole^{-} } = 1.93 \times 10^{5} C[/tex]
1.93 × 10⁵ C circulate in 1.50 hours. The intensity is:
[tex]I = \frac{1.93 \times 10^{5} C}{1.50h} \times \frac{1h}{3600s} = 35.7 A[/tex]
14. Which of the following is correct about cells?
O They are made of molecules that are made of atoms.
O They are made of organs that are made of organelles.
O They are made of tissues that are made of atoms.
O They are made of atoms that are made of molecules.
W
Can someone help me with this?
H=1.01
What is the molality of a solution containing 75.3 grams of KCI
dissolved in 100.0 grams of water?
K= 39
Cl = 35.45
Answer:
Molality of solution=10.11 m
Explanation:
We are given that
Given mass of KCl(WB)=75.3 g
Given mass of water (WA)=100 g=100/1000=0.1 kg
1 kg=1000 g
Molar mass of H=1.01 g
Molar mass of K=39g
Molar mass of Cl=35.45 g
We have to find the molality of a solution.
Molar mass of KCl(MB)=39+35.45
Molar mass of KCl(MB) =74.45 g
Number of moles of solute (KCl)=[tex]\frac{given\;mass}{molar\;mass}=\frac{W_B}{M_B}[/tex]
Number of moles of solute (KCl)=[tex]\frac{75.3}{74.45}[/tex]
Number of moles of solute (KCl)=1.011 moles
Molality of solution
=[tex]\frac{number\;of\;moles\;of\;solute}{mass\;of\;solvent}[/tex]
Using the formula
Molality of solution=[tex]\frac{1.011}{0.1}[/tex]
Molality of solution=10.11 m
Why does Watney get left behind on Mars?
Answer:
I think it's because he was presumed dead after a storm, or like a problem with his suit
Explanation: I think it was because somebody thought he was dead in the storm? And the remaining of the crew were forced to leave him behind thinking he was dead on mars.
I might be right, might not ^^
All of the following elements are metals EXCEPT?
A. Br B. Co C. Cu D. Zn
Answer:
Br
Explanation:
How many Fluorine atoms are needed to accept the electrons of one Ca atom?
1
2
3
4
2 F atoms
Explanation:
A Ca atom has a valence number of +2, which means that when ionized, it will give up two electrons. In turn, a F atom has a valence number of -1, which means it can only accept 1 electron when ionized. So to accommodate the two electrons from Ca atom, we need 2 F atoms.
The balanced equation for the combustion of Hexane,C6H14 , is
Answer:
[tex]2C _{6}H _{14} + 19O _{2}→12CO _{2} +14H _{2} O[/tex]