The heat associated with the reaction (qrxn, in KJ) when 4.85 grams of H₂ is produced is +693.55 KJ
Balanced equation2H₂O → 2H₂ + O₂ ΔH°rxn = +572 KJ
Molar mass of H₂ = 2 × 1 = 2 g/mol
Mass of H₂ from the balanced equation = 2 × 2 = 4 g
SUMMARY
From the balanced equation above,
When 4 g of H₂ is produced, 572 KJ of heat where needed.
How to determine the heat requiredFrom the balanced equation above,
When 4 g of H₂ is produced, 572 KJ of heat where needed.
Therefore,
When 4.85 g of H₂ is produced = (4.85 × 572) / 4 = +693.55 KJ of heat will be required.
Thus, +693.55 KJ of heat is required for the reaction.
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An element with three valence electrons would most likely be a
A. Metal
B. noble gas
C. non metal
D. metalloid
If an element has three valence electrons, it is most likely a metal.
In the periodic table, metals are found towards the left hand side of the table. Metals have fewer valence electrons than nonmetals. In the periodic table, there are more metallic than nonmetallic elements.
Metals of group 13 typically have three valence electrons. Hence, if an element has three valence electrons, it is most likely a metal of group 13.
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A 95,000g refrigerator is located on the 70th floor of a skyscraper (300 meters above the ground) What is the
potential energy of the refrigerator?
Answer:
285 kJ
Explanation:
potential energy
= m g h
= 95,000 g × 10 m/s² × 300 meters
= 95 kg × 10 m/s² × 300 meters
= 950 kgm/s² × 300 meters
= 285,000 J
= 285 kJ
Consider a hypothetical gas which has the following Van der Waals constants:
a = 2.34 L2 bar mol-2
b = 0.0 L mol-1
Under conditions of very high pressures, what would you predict about the experimental volume of the gas?
The volume would be lower than predicted by the Ideal Gas Law
The volume would be higher than predicted by the Ideal Gas Law
The volume would be exactly the same as predicted by the Ideal Gas Law
Under conditions of very high pressures, the volume would be lower than predicted by the Ideal Gas Law.
According to the kinetic theory of gases, a gas spreads out to fill the volume of the container holding it. Hence a gas does not have a definite volume due to the fact that there is no inter-molecular interaction between gas molecules.
When the gas is subjected to very high pressure, inter-molecular interactions become significant leading to a decrease in the volume of the gas.
Therefore, when subjected to high pressure, the experimental volume would be lower than predicted by the Ideal Gas Law.
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Electrons move around the nucleus of atoms in specific shells, shown by the rings around the atoms in the Gizmo. The first ring holds two electrons, and the second holds eight. Observe the sodium and chlorine atoms. How many electrons are there total in each atom?
Answer:
2 electrons is the correct answer hope u pass !!!!!!
Find the sum of the
following:
89.001 + 0.0001 + 348.4 +
49166
Answer: 49,603.4011
Explanation:
Answer:
49603.4011
Explanation:
89.001
+. 0.0001
348.4
49166
answer: 49603.4011
Help with science ASAP!! Will give brainliest!! :)
An organic compound containing C, H, O gives the following data on analysis. Composition by mass: %
C = 52.2, % H = 13.0, % 0 = 34.8. Relative molecular mass = 46. Identify the molecular formula of the organic compound.
My answer is C2H6O. Is it correct?
1. What is the energy of a microwave photon that has a frequency of 1.07 * 10 ^ 12 * H * z; (h = 6.63 * 10 ^ - 34 * J * s)
Answer:
7.96 x 10^-22 J
Explanation:
Calculate the number of grams of Carbon in Co2?
Answer:
Please click above answer.
Explain how changing the amount of greenhouse gases in the atmosphere affects the flow of heat out of Earth's atmosphere.
Explanation:
The added greenhouse gases absorb the heat. They then radiate this heat. Some of the heat will head away from the Earth, some of it will be absorbed by another greenhouse gas molecule, and some of it will wind up back at the planet's surface again. With more greenhouse gases, heat will stick around, warming the planet.
Using what you know about models, write an explanation from the following prompt
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CAN YOU BRAINLEST ME
Sodium chlorate decomposes into sodium chloride and oxygen gas as seen in the equation below.
2NaClO3 --> 2NaCl +3O2
How many moles of O2 were produced by 2 moles of NaClO3? Round your answer to the nearest whole number.
Explanation:
3 moles of O2 will be produced from 2moles of NaCLO3.
hope this helps you.
Formic acid, from the Latin formica, is the acid present in ants sting. What is the
concentration of HCOO" at equilibrium if the initial concentration of formic acid,
HCOOH, is 1.35 M (Kg = 1.7 x 10-4).
For the reaction of deprotonation of formic acid, the concentration of HCOO⁻ at equilibrium is 0.0151 M if the initial concentration of formic acid is 1.35 M.
The reaction of deprotonation of formic acid is the following:
CHOOH + H₂O ⇄ HCOO⁻ + H₃O⁺
At the equilibrium we have:
CHOOH + H₂O ⇄ HCOO⁻ + H₃O⁺ (1)
1.35 - x x x
The acid equilibrium constant for this reaction is:
[tex] K_{a} = \frac{[HCOO^{-}][H_{3}O^{+}]}{[CHOOH]} = 1.7 \cdot 10^{-4} [/tex] (2)
Entering the values of [CHOOH] = 1.35-x, [HCOO⁻] = [H₃O⁺] = x, into equation (2) we have:
[tex] 1.7 \cdot 10^{-4} = \frac{[HCOO^{-}][H_{3}O^{+}]}{[CHOOH]} = \frac{x^{2}}{(1.35 - x)} [/tex]
[tex]1.7 \cdot 10^{-4}(1.35 - x) - x^{2} = 0[/tex]
After solving the above quadratic equation and taking the positive value for x (concentrations cannot be negative), we have:
[tex] x = [HCOO^{-}] = [H_{3}O^{+}] = 0.0151 M [/tex]
Therefore, the concentration of HCOO⁻ at equilibrium is 0.0151 M.
Learn more about the equilibrium constant here:
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Why should A chemical equation be balanced?
A. To show that the reactants are compounds
B. To show metals from nonmetals
C. To show ionic compounds
D. To show the law of conservation of mass
Please answer. No links please!!!
15.3 Determine the mass of the following: 15.3.1. 2 mol calcium atoms
15.3.2. 0,3 mol nitrogen molecules
15.3.3. 0,5 mol table salt
15.3.4. 0,2 mol hydrochloric acid
15.3.5. 0,08 mol sodium carbonate (Na2CO3)
15.3.6. 0,25 mol ammonium sulphate (NH4)2SO4
Answer:
hh
Explanation:
My grass is dying, and I believe it is because it is not getting enough water. To test my hypothesis I water my backyard every day for a month, and I leave my front yard alone. After 1 month my backyard is green and healthy while my front yard is still dead.
What is the control group?
A.
Front Yard
B.
Back Yard
C.
Water
D.
Grass Health
Answer:
D. Grass Health
Explanation:
why is the Universal Law of Gravitation is a scientific Law and not a theory?
ora
If a student is combining two
substances and sees bubbles and
is probably taking
fizzing, a
place.
A. chemical change
B. physical change
Answer:
A a chemical change
Explanation:
because a chemical change is when you mix tow substance together and they creat a new substance
How many kilograms of nitrogen are present in a 3.50 L sample of N2O
There are 2.72 kilograms of nitrogen present in a 3.50 L sample of N₂O.
To find the mass of nitrogen in N₂O, we must calculate the number of moles of N₂O.
[tex] n_{N_{2}O} = \frac{m_{N_{2}O}}{M{N_{2}O}} [/tex] (1)
Where:
[tex] m_{N_{2}O}[/tex]: is the mass of N₂O
[tex]M_{N_{2}O}[/tex]: is the molar mass of N₂O = 44.013 g/mol
The mass of N₂O can be founded from the density:
[tex] d = \frac{m}{V} [/tex] (2)
Where:
d: is the density of N₂O = 1.22 g/mL
V: is the volume = 3.50 L = 3500 mL
Then, the mass of N₂O is (eq 2):
[tex] m = d*V = 1.22 g/mL*3500 mL = 4270 g [/tex]
Now, the number of moles of N₂O is (eq 1):
[tex] n_{N_{2}O} = \frac{4270 g}{44.013 g/mol} = 97.02 \:moles [/tex]
Knowing that in 1 mol of N₂O we have 2 moles of N, the number of moles of nitrogen is:
[tex] n_{N} = \frac{2\: moles \: N}{1 \:mol \: N_{2}O}*n_{N_{2}O} = \frac{2\: moles \: N}{1 \:mol \: N_{2}O}*97.02 \:moles \:N_{2}O = 194.04 \: moles [/tex]
Finally, with the number of moles of N we can find its mass:
[tex] m = n_{N}*M_{N} = 194.04 \:moles*14.007 g/mol = 2717.9 g = 2.72 kg [/tex]
Therefore, there are 2.72 kilograms of nitrogen.
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I hope it helps you!
1 someone help me please
Answer:
J
Explanation:
Because the vapor can be turned back to water and the vapor is still considered water.
Select the coefficients necessary to balance each equation. Choose a coefficient for every compound.
Photo included
Need help, please teach me how to solve it!
Answer:
See below
Explanation:
2C2H6 + 7O2 = 4CO2 + 6H2O
2C2H2 + 5O2 = 4CO2 + 2H2O
A lot of this is trial and error. I start from left to right. For the first reaction, you had
C2H6 + O2 = CO2 + H2O
You have 2 carbons on the left so you can try adding a 2 in front of the carbons on the right and keep going from there. Now you have
C2H6 + O2 = 2CO2 + H2O
You now have 2 C on each side. C2 is the same as 2C.
The next step is to look at the hydrogens on the left. You have 6 so you need 6 on the right. You can add a 3 in front of the H on the right. The H already has a subscript of a 2 so having the 3 in front will now make it 6H. You now have this
C2H6 + O2 = 2CO2 + 3H2O
So your C are equal (2 on each side) and your H is equal (6 on each side). All that is left is the O. So far you have 2 on the left but you have 7 on the right (4 from the 2CO2 and 3 more from 3H2O). Since you have an even number on one side and an odd number on the other, there is no way to make this work. So it's time to start over.
My next step was to put a 2 in front of C2H6 and keep going as we did above. Start with this
2C2H6 + O2 = CO2 + H2O
You have 4 C on the left. So you need to add a 4 in front of CO2 to get 4 C on the right. Now you have this
2C2H6 + O2 = 4CO2 + H2O
Now on the left you have 12 H (2 in front times the 6 subscript on the H). You need to have 12 on the right. We can get that by putting a 6 in front of the H2O ( again the 6 in front times the 2 subscript of the H is 12 total). You have this now
2C2H6 + O2 = 4CO2 + 6H2O
You now have 4 C on both sides, 12 H on both sides. All that is left now is the O.
On the right side, you have a total of 14 ( 8 from the 4CO2 and 6 from 6H2O). So you'd need to add 7 in front of the O2 to make it 14.
You're done. 4 C on both sides, 12 H on both sides and 14 O on both sides.
The second equation I just did the same process.
how many significant figures are in 5.76 e 15
Answer: 3 significant figures
Explanation: because in scientific notation only the before and after decimal number are considered but in standard form all numbers including exponents are all significant figures
Answer:
3 significant figures
Explanation:
0's are not significant.
I hope it helps you!
[tex]GraceRosalia[/tex]
I WILL MARK YOU BRAINLIST PLEASE HELP
Answer: See below
Explanation: a. The mass of an element is composed of:
protons: 1 amu each
neutrons: 1 amu each
electrons: 0 amu each
Only the protons and neutrons are counted in the atomic mass of an element
b. Electrons are assigned a mass of 0. They do have a mass, but it is exceedingly small compared to the protons and neutrons, so they are left out of the calculation of an element's mass.
c. An element becomes unstable if the neutrons exceed the protons by a certain ratio, dependent on the element.
What quantity is needed to convert between the moles of a
given sample of a substance and its mass in grams?
a the molar mass of the substance
b the density of the substance
C the physical state of the substance
ht?
d all of the above
Answer:
d
Explanation:
thanks so much to you welcomeeee for me and my brother in the same situation and he does it for a year of life in your relationship
How many protons and neutrons are in the nucleus of zinc-72
Answer:
30 protons
Explanation: Each zinc isotope contains 30 protons, 30 massive, positively charged nuclear particles
30 protons, 34 neutrons, and 30 electrons.
E=hv h= 6.62 x 10^-34 m^2 kg/ s
What would be the energy contained in a photon of light that has a frequency of 5.0 x 10^12?
Please show work!!
v=5.0×10^12Hz
[tex]\\ \sf\longmapsto E=hv[/tex]
[tex]\\ \sf\longmapsto E=6.626\times 10^{-34}Js\times 5\times 10^12s^{-1}[/tex]
[tex]\\ \sf\longmapsto E=33.13\times 10^{-22}J[/tex]
Tom tells Greta that his father, an astronomer, is planning a scientific experiment to study another galaxy. Using a powerful telescope, Tom's father will record data of shifts in light patterns and track their different sources every 30 seconds. He will later study the data. Greta says that this is not an experiment. Which of these reasons supports Greta's statement?
It is not performed in a lab.
There are too many variables.
It does not have a control group.
It uses only theoretical predictions.
Answer:
it does not have a control group
The theory of spontaneous generation states that *
A. Even though higher level organisms cannot be created from inanimate objects, it is possible for microorganisms
B. Living organism can be created from nonliving matter
C. Life is created by other living things
D. Only living humans can create other living creatures
Answer:
B. Living organism can be created from nonliving matter
Explanation:
The theory of spontaneous generation states that life could come from non-living things.
C12H22O11 is an example of a(n):
ionic compound
empirical compound
molecular compound
salt compound
Answer:
molecular compound
Explanation:
it has two or more nonmetal elements and are covalently bonded
Hi ! ❤️looking for help you can look at my past questions. giving brainliest if able to
Fill in the blanks. Liquid B is ____________________ then liquid A and liquid B would ___________________ liquid A.
1: more dense, sink under
2: less dense, sink under
3: more dense, float on top of
4: less dense, float on top of
Answer:
I think it's number one option