This problem is describing the combustion experiment where by the heat of combustion of 1.66 g of liquid C6H14 can be calculated via calorimetry. The calorimeter (C=11.2kJ/°C) contains 2750. grams of water with a temperature rise of 3.54 °C, it means we can calculate the total heat released by the combustion of this hydrocarbon via:
[tex]Q_{combustion}=-(Q_{calorimeter}+Q_{water})[/tex]
Because the heat of combustion is released to the water and the calorimeter. Next, we break down each heat and subsequently plug in the given values:
[tex]Q_{combustion}=-(11200\frac{J}{\°C}*3.54\°C +2750.g*4.184\frac{J}{g\°C}*3.54\°C )\\\\Q_{combustion}=-80,379J=-80.4kJ[/tex]
After that, we calculate the moles of C6H14 by considering the given mass and its molar mass (86.18 g/mol):
[tex]n=1.66g*\frac{1mol}{86.18g} =0.01926mol[/tex]
And finally, we divide the total heat of combistion by the moles to get the heat of combustion:
[tex]\Delta H_{comb}=\frac{-80.4kJ}{0.01926mol} =4,174\frac{kJ}{mol}[/tex]
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https://brainly.com/question/14317568https://brainly.com/question/14154214what are valence electrons? why are they so important in chemistry?
Answer:
Valence electrons are negatively charged particles located in the outermost shell of atoms that can be transferred or shared with other atoms. Valence electrons are important in chemistry because the number of valence electrons in a particular atom can be used to determine how the atom will react chemically with other atoms.
what will you observe when you open a bottle of concentrated hydrochloric acid?
Answer:
Strong affinity of HCl gas for moisture in air results in forming of droplets of liquid solution which appears like a cloudy smoke.
Explanation:
#followformore
Hope this helps :)
N2 + O2 → N205
how do i show my work im trying to balance the equation
Answer:
2N2 + 3O2 –2N2O3 this what I got balancing though
Select the atom that will attract the electron pair (:) more strongly (the atom with the greater electronegativity)
HELP PLEASE
Which three things does a plant need to create a glucose molecule in photosynthesis?
Choose all correct answers.
water
oxygen
carbon dioxide
sunlight
how long does it take cream cheese to get to room temperature?
Since cream cheese has such a high fat content, it doesn't take long to come to room temperature if the room is relatively warm. It takes about thirty minutes on the counter to soften significantly, and about an hour to fully come to room temperature again, depending on the temperature outside and in your kitchen
Can someone answer that first this pls im lost
What type of bond would be formed between hypothetical elements X and Y in the the compound XY based on their electronegativity difference?
A. Nonpolar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7
B. Nonpolar covalent because the difference in electronegativity is greater than 1.7
C. Polar covalent because the difference in electronegativity is greater than 0.4, but
less than 1.7
D. lonic because the difference in electronegativity is greater than 0.4, but less than
1.7
The bond is polar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7.
Electronegativity refers to the ability of an atom in a compound to attract the electrons of the bond towards itself. It is a periodic trend that increases across the period but decreases down the group.
The electronegativity difference between the two atoms as shown in the question is 1.55. This means that the bond is polar covalent because the difference in electronegativity is greater than 0.4, but less than 1.7.
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Determine the rate of reaction at 50 C when the loss of mass is 0.95 g. Show your working. Give your answer to 2 significant figures.
* 20 points for who gets it *
This problem is providing information about the loss of mass for a reaction 50 °C as a function of the time elapse. Thus, when taking a look at the given graph, we can trace a horizontal line on the y-axis at 0.95 g in order to intercept it with the curve, and hence, figure out the time at which that loss of mass takes place.
Thus, we can see that when the loss of mass hits 0.95 g, the corresponding time on the graph is about 80 seconds, and hence, the rate of reaction turns out to be:
[tex]r=\frac{0.95g}{80s}\\\\r=0.012\frac{g}{s}[/tex]
Which has two significant figures as required.
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Answer:
A right? I'm pretty sure it's A
Write a Claim based in this question: What happens in the atmosphere and how
is it related to the water cycle.
Answer:
The atmosphere is the superhighway in the sky that moves water everywhere over the Earth. Water at the Earth's surface evaporates into water vapor which rises up into the sky to become part of a cloud which will float off with the winds, eventually releasing water back to Earth as precipitation.
Explanation:
If you don't want to plagiarize change it up a bit.
Magnesium has three naturally occurring stable isotopes, 24Mg (abundance 78.99%), 25Mg (abundance 10.00%) and 26Mg (abundance 11.01 %). Calculate the relative atomic mass of magnesium, giving your answer to 2 decimal places.(2)
Explanation:
M = molar mass
p= percentage abundance
[tex]rel.atm.mass = \frac{ M1p1 + M2p2 + M3p3}{100} \\ r.a.m = \frac{24 \times 78.99 + 25 \times 10 + 26 \times 11.01}{100} \\ r.a.m = \frac{1895.76 + 250 + 286.26}{100} \\ = \frac{2432.02}{100} \\ 24.32[/tex]
BRAINLIST
In an ionic compound, the total positive charge of all the positive ions ____ the total negative charge of all the negative ions.
Answer:
I think it would be 0 since cations and anions must always combine in such a way so that their charges cancel.
How does calculating the kinetic energy of an object at different velocities help understand the relationship between kinetic energy and velocity?
Answer:
Kinetic energy depends on the velocity of the object squared
Explanation:
Kinetic energy depends on the velocity of the object squared. This means that when the velocity of an object doubles, its kinetic energy quadruples. ... Kinetic energy must always be either zero or a positive value. While velocity can have a positive or negative value, velocity squared is always positive.
A wave is moving towards shore with a velocity of 5.0 MS if it’s frequency is 2.5 Herz what is the wave length
Answer:
2 mExplanation:
The wavelength of a wave can be found by using the formula
[tex]\lambda = \frac{c}{f} \\[/tex]
where
c is the speed of the wave
f is the frequency
From the question
c = 5 m/s
f = 2.5 Hz
We have
[tex] \lambda = \frac{5}{2.5} = 2 \\ [/tex]
We have the final answer as
2 mHope this helps you
During ionization, metals lose electron, this change is called?
Ans
This is called oxidation
Explanation:
the oxidation number of a metal ion is more than the oxidation number of metal atom
A solid magnesium flare has a mass of 1300 g and a volume of 743 cm3. What is the density of the magnesium?
Answer:
1.74 g/cm3
Explanation:
density=mass/volume
Explanation:
density = 1300/743
or density=1.74g/cm3
In the image above, the region labeled “ A “ is called the . . .
White matter
Dorsal Horn
Central Canal
Ventral Root
Answer:
Ans B)=====> Dorsal Horn
Two arms, each known as a Dorsal Horn, are formed by the core grey matter at the back of the spinal cord. In the image, the region labeled “ A “ is called the Dorsal Horn. Therefore, option B is correct.
What is dorsal horn ?One of the gray longitudinal columns discovered inside the spinal cord is the dorsal horn. Through the dorsal roots of the spinal nerves, it predominantly serves as the end of primary afferent fibers.
A complex network of excitatory and inhibitory interneurons, as well as projection neurons, make up the dorsal horn, which serves as an intermediary processing center for this information. It transmits the processed somatosensory information from the spinal cord to the brain.
The cell bodies of sensory neurons are located in the dorsal horns. The ventral horns are two arms of central grey matter that are found at the front of the spinal cord.
Thus, option B is correct.
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¿que otro nombre reciben las órbitas?
which of the following elements forms coloured compounds. A. Normal B. Transition C. Lanthanicles D. Inner transition
Answer:
B. Transition
Explanation:
Transition elements form coloured compounds because they have unfilled d orbitals.
explain why heating a solution increases the solubility of a solute
[tex] \: \: \: \: \: [/tex]
The addition of more heat facilitates the dissolving reaction by providing energy to break bonds in the solid. This is the most common situation where an increase in temperature produces an increase in solubility for solids.hope it helps[tex] \: \: \: \: \: \: [/tex]
Can i get help im not really good at science
Answer:
Cause and effect, easy.
in a battery that uses a licoo2 cathode approximately 50% of the lithium migrates from the cathode to the anode on charging. in a battery that uses a limn2o4 cathode what fraction of the lithium in limn2o4 would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode?
Answer:
92.4%
Explanation:
Assume 100g of the cathode material. The LiCoO2 cathode has 7.09 g of Li. If half of Li migrates during charging, 3.55g Li migrates. 100g of the LiMn2O4 cathode contain 3.84g of Li. The fraction of lithium in LiMn2O4 that would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode:
(3.55g/ 3.84g ) * 100% = 92.4%
From electrolysis, 92.4% would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode.
What is electrolysis?
Electrolysis is a technique that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as ores using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential.
Assume 100 g of the cathode material. The LiCoO₂ cathode has 7.09 g of Li. If half of Li migrates during charging, 3.55 g Li migrates. 100 g of the LiMn₂O₄cathode contain 3.84 g of Li. The fraction of lithium in LiMn₂O₄ that would need to migrate out of the cathode to deliver the same amount of lithium to the graphite anode:(3.55 g/ 3.84 g ) × 100% = 92.4%
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What is collision theory?
A.a theory stating that reactants must collide with products in order for a chemical reaction to occur
B.a theory stating that there must be minimal kinetic energy between products for a chemical reaction to occur
C.a theory stating that a chemical reaction occurs only when reactants strike each other at the correct orientation and with sufficient kinetic energy
D.a theory stating that a chemical reaction occurs only when reactants are placed in separate containers and the containers are then placed close together
Answer:
A
Explanation:
collision theory is a theory used to predict the rates of chemical reactions, particularly for gases. The collision theory is based on the assumption that for a reaction to occur it is necessary for the reacting species (atoms or molecules) to come together or collide with one another
EASY QUESTION (PLEASE HELP THE INTERNET ISN'T SUCH A BIG HELP RIGHT NOW)
Things microscopes have helped scientists discover about cells.
(No links plz)
Answer:
Adding on to the answer said before, microscopes are pretty much one of the most significant tools used in Biology. It helped discover organelles, and smaller stuff like DNA, and prominently allowed Scientists to discover Bacteria and Archaea, the prokaryotic cells that contribute a big role in the functioning of soil, which is essential for our ecosystem.
At what point on a heating curve graph does a phase change occur?
at each plateau
at the first plateau
at each slope
at the last slope
Answer:
Electrical Bonding Investigation Data Quick Check
Explanation:
B. Heat energy is added to the substance, weakening the electrica attraction between molecules.
C. Both the melting point and boiling point are lower
C. The lone pairs of electrons in the oxygen atom causes the molecule to be bent; the oxygen atom has a particle negative charge, while the hydrogen atom have particle positive charges
D. Phase change
C. At each plateau
How many total atoms of Nitrogen are shown in the formula below?
4N₂O
2
4
6
8
Answer:
8
EXPLANATION hope this helps you
Answer:8
Explanation:
are most of the elements on the periodic table classified as a metal or a non-metal?
Answer:
Metals
Explanation:
There are more metals next time trying checking the table they will be in colored squares to count to see which has more! HOPE THIS HELPED!
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The gain of electrons by an element or ion in a reaction is called __.
A. fractionation
B. Disproportionation
C. Oxidation
D. Reducing
Answer:
Reduction
Explanation:
took the test
why does it make sense for the valence electrons to increase going across a period?