Answer:
Molar enthalpy change, the enthalpy change for one mole of a pure substance
Explanation: i think
How many atoms of silicon are in 0.75 mol of disilicon hexahydride, Si2H6? A.4.5x 1023 atoms B.6.02 x 1023 atoms C.8.0 x 1023 atoms D.9.0x1023 atoms
Answer:
D. 9.0x10²³ atoms
Explanation:
First we use Avogadro's number to calculate how many molecules of Si₂H₆ are there in 0.75 mol:
0.75 mol * 6.023x10²³ molecules/mol = 4.52x10²³ moleculesThere are 2 Si atoms in one Si₂H₆ molecule, that means that in 4.52x10²³ Si₂H₆ molecules there will be:
2 * 4.52x10²³ = 9.03x10²³ Si atomsThus the answer is option D.
What must be done to calculate the enthalpy of reaction? Check all that apply. The first equation must be halved. The first equation must be reversed. The second equation must be halved. The second equation must be reversed. The third equation must be halved. The third equation must be reversed. What is the overall enthalpy of reaction? Delta.Hrxn = kJ
The overall enthalpy of the reaction has been obtained by reversing the second equation, and third equation must be halved. Thus, option D and E has been correct.
The complete reactions given in the question has been:
[tex]\rm C\;+\;O_2\;\rightarrow\;CO_2\\2\;CO\;+\;O_2\;\rightarrow\;2\;CO_2\\2\;H_2O\rightarrow\;2\;H_2\;+\;O_2[/tex]
The overall reaction has been:
[tex]\rm C\;+\;H_2O\;\rightarrow\;CO\;+\;H_2[/tex]
To obtain the overall enthalpy of the reaction, the intermediate reaction enthalpy has been arranged to give the overall equation.
The first equation has been in the correct sequence for the final reaction.
The second equation has been in in the same order to obtain the overall reaction. The CO has been the product, while carbon dioxide has been the reactant from equation 1. Thus, equation 2 has been reversed.
The third equation has 2 moles of water while the overall reaction has 1 mole of water. Thus, equation third has been halved.
Thus, to obtain the enthalpy of overall final reaction, the second equation must be reversed, and third equation must be halved. Thus, option D and E has been correct.
For more information about the enthalpy of reaction, refer to the link:
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What must be done to calculate the enthalpy of reaction? Check all that apply.
The first equation must be halved.
The first equation must be reversed.
The second equation must be halved.
✔️ The second equation must be reversed.✔️ The third equation must be halved. ✔️ The third equation must be reversed.What is the overall enthalpy of reaction?
ΔH[tex]rxn[/tex]= ✔️131.3 kJ
Dominant genes are represented with lowercase letters while recessive genes are represented with capital letters.
1. True
2.False
Answer:
True
Explanation:
Arrange the following lons in order
of increasing size
giving reasons
Na+, Mg2+, AL3+ (4Na,12Mg,13Al)
Answer:
na+then mg2+ then al3+
Explanation:
this is due to the distance between their nucleus and valence electron
Na * 6.02 * 10^23 pls help an it got to include na
Answer:
6.02E23Na
Explanation:
you just convert the element to a decimal form
How many TOTAL atoms make up the molecule 3K2SO4?
How many orbitals does the s subshell contain?
1
3
5
7
The correct answer to the question is that the s orbital contains only one subshell.
An orbital is a region in space where there is a high probability of finding an electron. The idea of orbital is an offshoot of the wave mechanical model of the atom.
The s orbital is spherically symmetrical. It contains only one subshell. Therefore, the correct answer to the question is that the s orbital contains only one subshell.
Learn more about orbital: https://brainly.com/question/18914648
Answer:
one orbital
Explanation:
Thus the s subshell has only one orbital, the p subshell has three orbitals, and so on
how many atoms are in 3N4010
Answer:
of N ( nitrogen): 12
of O (oxygen): 30
help, please...I have no idea what I'm doing :D
Answer:
Hey!
Multiply the % × amu
27.88×(.922)= 25.71 lmk if you need help with the rest!Air Pollution Quiz - Match the terms e defintions
1) Air pollution
2) Acid rain
3) Smog
4) Ground level ozone
5) Global warming
6) Greenhouse effect
Answer:
1) F. harmful gases and solid particles that enter the atmosphere
2) C. pollutant gases react with water vapor
3) B. mixture of smoke, gas, and fog
4) E. sunlight interacts with pollutant gases
5) A. gradual increase in the overall temperature of the earth
6) D. gases are trapped by heat and raise the temperature of the atmosphere
hope this helps
PLEASE HELP RN ITS URGENT
Answer: transporting oxygen-rich blood to the body
Explanation:
why is there no reaction between copper and sodium chloride
remember I am talking of copper alone and not copper sulfate.
Answer:
If the solution is not in contact with air, nothing will happen. If the solution is in contact with air, it will be not a reaction between copper, water and sodium chloride..
in the end there will be no reaction
Why do scientific experiments need to be repeated?
A. Because scientists often make mistakes
B. To ensure that the same results are achieved every time
C. They only need to be repeated if the results are questionable
D. To discourage other scientists from trying to get the same results
Answer:
B
Explanation:
this is called peer review and your results will be stronger
Pb(NO3)2+K2CrO4 →PbrCrO4 +2KNO3 classify the chemical reaction
Provide an explanation for each of the following strange facts about Mercury:
1. Mercury’s atmosphere is incredibly thin.
2. The length of a Mercury year is about 1.5 times longer than a Mercury day.
3. The temperature range on Mercury is about 590 °C.
Answer:
Explanation:
1. Mercury’s atmosphere is incredibly thin.
It's thin because the atmosphere is made up of atoms blasted off its surface by the Solar wind and also consist of the stream particles coming from the outer layer of the sun
2. The length of a mercury year is about 1.5 times longer than a mercury a day.
Mercury revolves around the sun very quickly but rotates around its axis very very slowly
3.The temperature range on Mercury is about 590 °C.
During the day, temperatures on Mercury's surface can reach Very High But, the planet has no atmosphere to retain that heat
Which is Not part of hydrogen's line-emission spectrum?
Answer: Aufbau series.
Explanation:
how many lbs are in 60 oz
Answer:
3 pounds 13 ounces
Explanation:
Math
Answer:
3.75
Explanation:
Look at the diagram below.
(+
When this atom becomes an ion, it will
(gain, lose)
electrons. The charge of this ion will be
Answer:
gain electrons
charge will be 4-
2
Convert -27°C to Kelvin.
Answer:
-27 C converted to Kelvin is 246.15 Kelvin.
Explanation:
Hope this helps
Answer:
246.15K
Explanation:
Formula: (-27°)C + 273.15 = 246.15K
5. If all the particles in a material are made up of
several smaller particles, and every larger particle
is identical, is the material a pure substance or
not? Explain your reasoning.
Answer:
No. Because a pure substance, no matter if an element, compound, it can only contain one kind of particle .
Explanation:
what must happen for heat to be transferred by thermal conduction?
The transfer of heat between substances by thermal conduction is only possible when they are in direct contact with each other.
What is Thermal Conduction ?The transfer of heat from the hotter end to the colder end of object is known as conduction.
The spontaneous flow of Heat from a hotter to a colder body ie, heat is conducted from the hotplate of an electric stove to the saucepan when it is in contact with it.
The better the conductor, the more rapidly heat will be transferred.
Thus, The transfer of heat between substances by thermal conduction is only possible when they are in direct contact with each other.
Learn more about Conduction here ;
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plzzzzzzzzzz help ASAP
Answer:
i think the answer is c because it says that is all they care
Which of the following do/does not change with the change in temperature?
i. Mole fraction.
ii. Molality.
Select one:
a. only i
b. Only ii
c. Both i & ii
d. Neither of them
(I did D and it was incorrect)
Answer:
c. Both i & ii
Explanation:
Moles do not change with temperature hence Mole fraction does not depends of temperature.
Molality is number of moles of solutes per kilogram of solvent. It has no relationship with temperature.
This means both of them do not change wit the change in temperature.
Correct option;
c. Both i & ii
What conclusions can you make about the relationship between the volume of a gas and its pressure?
Answer:
[tex]V \alpha \frac{1}{P}[/tex]
Explanation:
According to Boyle's law, the volume of a given mass of gas is inversely proportional to its pressure at constant temperature.
This implies that, if the volume of a gas is halved, its pressure is doubled and vice versa.
This is mathematically represented as; [tex]V \alpha \frac{1}{P}[/tex] hence [tex]PV = K[/tex]. This is the mathematical statement of Boyle's law.
Help me!!
Question 5 only!
please help i need to do good in this class
Answer:
Explanation:
di) number of protons is 12 for all, number of neutrons is 13 for mg- 25 and 14 for mg-26
8.
Sulfur trìoxide decomposes to sulfur dioxide and oxygen gas as
shown in the following reaction:
2503 (g) 2502 (g) + O2 (g)
Given a 240.0 g sample of sulfur trioxide (MM = 80.1 g/mol), how many
grams of oxygen (MM = 32.0 g/mol) are produced, assuming the
decomposition goes to completion?
g
Your answer should be rounded to three significant figures. Do not include units in your
answer
Mass of Oxygen : 47.9
Further explanationGiven
2S03 (g)⇒ 2S02 (g) + O2 (g)
240 g SO3
Required
mass of Oxygen
Solution
mol SO3 :
= 240 g : 80.1 g/mol
= 2.996
From the equation, mol O2 :
= 1/2 x mol SO3
= 1/2 x 2.996
= 1.498
mass O2 :
= 1.498 mol x 32 g/mol
= 47.9
Taking into account the reaction stoichiometry, given a 240.0 g sample of sulfur trioxide, 47.95 grams of oxygen are produced, assuming the decomposition goes to completion.
Reaction stoichiometryIn first place, the balanced reaction is:
2 SO₃ → 2 SO₂ + O₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
SO₃: 2 molesSO₂: 2 moles O₂: 1 moleThe molar mass of the compounds is:
SO₃: 80.1 g/moleSO₂: 64.1 g/mole O₂: 32 g/moleThen, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
SO₃: 2 moles ×80.1 g/mole= 160.2 gramsSO₂: 2 moles ×64.1 g/mole= 128.2 grams O₂: 1 mole ×32 g/mole= 32 gramsMass of oxygen producedThe following rule of three can be applied: if by reaction stoichiometry 160.2 grams of SO₃ form 32 grams of O₂, 240 grams of SO₃ form how much mass of O₂?
[tex]mass of O_{2} =\frac{240 grams of SO_{3}x 32 grams of O_{2} }{160.2grams of SO_{3}}[/tex]
mass of O₂= 47.94 grams
Given a 240.0 g sample of sulfur trioxide, 47.95 grams of oxygen are produced, assuming the decomposition goes to completion.
Learn more about the reaction stoichiometry:
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is chex mix an example of a element or compound?
Answer:
Chex mix is not an example of a element or compound.
Chex mix is an example of a mixture
l hope it helps
Which unit is used for measuring atomic mass?
Answer: Amu
Explanation:
Because the rock is irregularly shaped, you used the
method to measure its volume.
Answer:Displacement method
Explanation:
Answer:
The first answer is: Because the rock is irregularly shaped, you used the displacement method to measure its volume.
The second answer is: You used calculations to indirectly find the density of the objects.