How much energy is released if 3705g of octane are burned
I really need some help and explaining with the Heat of Combustion Lab.
1. You may recall that the products of the complete combustion of a hydrocarbon are water vapor and carbon dioxide gas. Write the balanced equation showing the combustion of methane. Do not forget to include the states of matter of the reactants and the products. Hint: Methane is a gas at standard temperature and pressure.
When protons and neutrons join together to make a nucleus, energy is?
Which of the following are changing when a change of state is occurring?
Select all that apply.
temperature change
amount of intermolecular bonds
vibration of particles
position of particles
Mandy is testing an unknown solution to determine whether it is an acid or a base. she places a piece of red litmus paper into the solution and the paper turns blue. mandy's unknown solution
Which of the following statements is true?
-Neon is inert because its outermost shell is complete.
-Nitrogen is inert because its outermost shell has eight electrons.
-Oxygen is more reactive than fluorine because oxygen needs only one electron to fill its outermost shell.
-Fluorine is more reactive than neon because fluorine has to lose only one electron to fill its outermost shell.
The true statement is that neon is inert because its outermost shell is complete. Neon's full outer shell of eight electrons makes it unreactive, unlike fluorine which seeks an additional electron to become stable and is therefore highly reactive.
The correct statement among those provided is that neon is inert because its outermost shell is complete. According to the octet rule, atoms are more stable energetically when they have eight electrons in their valence shell, which is the outermost electron shell, with the exception of helium which has a full shell with two electrons. Neon, with its electron configuration of 1s² 2s²2p6, has a full outer shell and does not tend to gain or lose electrons, making it unreactive or inert.
Contrarily, fluorine, which has seven electrons in its outer shell, is more reactive than neon because it seeks one additional electron to complete its octet. The statement that fluorine is more reactive than neon because fluorine has to gain, not lose, one electron to fill its outermost shell is true. It's important to note that neither nitrogen nor oxygen are considered inert, as their outer shells do not have the complete octet, and moreover, oxygen is not more reactive than fluorine; fluorine is, in fact, the most reactive of the halogens because it needs only one more electron to achieve a full outer shell.
How many moles of sodium acetate (nach3coo) must be added to 1.000 liter of a 0.500 m solution of acetic acid (ch3cooh) to produce a ph of 5.061? the ionization constant of acetic acid is 1.8 Ã 10â5 . answer in units of mol?
To create a buffer with a pH of 5.061 in a 0.500 M acetic acid solution, 0.545 mol of sodium acetate must be added to 1.000 liter of the solution. This calculation uses the Henderson-Hasselbalch equation and takes into account the ionization constant of acetic acid.
To find out how many moles of sodium acetate ([tex]NaCH_3COO[/tex]) must be added to 1.000 liter of a 0.500 M solution of acetic acid ([tex]CH_3COOH[/tex]) to produce a pH of 5.061, we can use the Henderson-Hasselbalch equation:
pH = pKa + log([A-]/[HA])
where [A-] is the concentration of the acetate ion, [HA] is the concentration of acetic acid, and pKa is the negative logarithm of the ionization constant (Ka) of acetic acid.
First, we calculate pKa:
pKa = -log(Ka)
pKa = -log(1.8 * 10-5)
pKa = 4.74
Next, rearrange the Henderson-Hasselbalch equation to solve for [A-]:
[A-] = [HA] * 10(pH-pKa)
[A-] = 0.500 M * 10(5.061-4.74)
[A-] = 0.500 M * 100.321
[A-] = 0.500 M * 2.09
[A-] \\approx 1.045 mol/L
Since the initial concentration of acetic acid is 0.500 M, we need to add 1.045 mol - 0.500 mol = 0.545 mol of sodium acetate to the solution to achieve the desired pH.
When two substances that cannot dissolve each other are mixed, a mixture is formed. a heterogeneous mixture that has very small dispersed particles and stays mixed for a long time is
a. a heterogeneous mixture that has larger dispersed particles that settle over time is
a?
When two substances that cannot dissolve each other are mixed, a mixture is formed. a heterogeneous mixture that has very small dispersed particles and stays mixed for a long time is a "Colloid"
An example of colloid can be gels, sols, or emulsions; where solids or liquids are dispersed in the mixture. It usually takes very long time to settle down.
Answer 2) SuspensionExplanation :A heterogeneous mixture that has larger dispersed particles that settle over time is a "Suspension"
Suspensions are those mixtures which usually has large particles and which takes comparatively less time than colloids to get settled. Like salt water, muddy water, fine sand in water, etc.
Answer:
First one is: heterogeneous
Second one is: colloid
Third one is: suspension
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Explanation:
HELP ASAP!!!
Carbon dioxide (CO2) is a gaseous compound. Calculate the percent composition of this compound. Answer using three significant figures.
What is the percent by mass of carbon?
%
What is the percent by mass of oxygen?
%
is butter melting onto toast a chemical or a physical
Answer: "physical change" .
________________________________________________________
This would be a "physical change" . ________________________________________________________
Note: This would change from a "solid" to a "liquid" / mere rearrangement of molecules/ NOT a new chemical substance—hence, a "physical change".
________________________________________________________
The chart seen here shows the decay of a sample of carbon-14 over a period of 33,000 years. What is the approximate half-life of carbon 14?
5,500 ears if u using usatestprep
If the oxidation number of nitrogen in a certain molecule changes from +3 to -2 during a reaction, is the nitrogen oxidized or reduced? how many electrons are gained or lost by the nitrogen atom?
Since here we can see that there is a negative -2 charge on nitrogen so there is gain of electron and hence it is reduced.
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A chemist requires 0.446 mol na2co3 for a reaction. how many grams does this correspond to?
Final answer:
To calculate the mass of 0.446 mol Na₂CO₃, multiply the number of moles by its molar mass of 105.98 g/mol, resulting in 47.27 grams of Na₂CO₃.
Explanation:
To find out how many grams 0.446 mol of Na₂CO₃ corresponds to, we can use the molar mass of Na₂CO₃.
First, we should recall the molar mass of Na₂CO₃. Using the atomic masses Na (22.99), C (12.00), and O (16.00), the molar mass would be:
(2 × 22.99) + 12.00 + (3 × 16.00) = 105.98 g/mol
Now, we can calculate the mass of 0.446 mol of Na₂CO₃:
0.446 mol Na₂CO₃ × 105.98 g/mol = 47.27 grams
The combustion of acetylene gas is represented by this equation: 2c2h2(g) + 5o2(g) → 4co2(g) + 2h2o(g) how many grams of co2 and grams of h2o are produced when 52.0 g c2h2 burn in oxygen?
A. The mass of CO₂ produced is 176 g.
B. The mass of H₂O produced is 36 g
We'll begin by calculating the mass of C₂H₂ that reacted and the masses of CO₂ and H₂O produced from the balanced equation.
2C₂H₂ + 5O₂ —> 4CO₂ + 2H₂O
Molar mass of C₂H₂ = (2×12) + (2×1) = 26 g/mol
Mass of C₂H₂ from the balanced equation = 2 × 26 = 52 g
Molar mass of CO₂ = 12 + (16×2) = 44 g/mol.
Mass of CO₂ from the balanced equation = 4 × 44 = 176 g
Molar mass of H₂O = (2×1) + 16 = 18 g/mol
Mass of H₂O from the balanced equation = 2 × 18 = 36 g
SUMMARY:
From the balanced equation above,
52 g of C₂H₂ reacted to produce 176 g of CO₂ and 36 g of H₂O.
From the above, we can see that 52 g of C₂H₂ produced:
176 g of CO₂36 g of H₂OLearn more about stoichiometry:
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______ tend to lose electrons in chemical reactions, forming positive ions. nonmetals tend to _____ electrons in chemical reactions, forming negative ¬¬¬¬¬¬¬ions. gaining or losing electrons makes an atom an ____. gaining or losing ______ makes an atom an isotope. however, gaining or losing a ______ makes an atom into a completely different _________.
Sheena wants to list the outer planets from smallest to largest. Which is correct? Jupiter, Saturn, Uranus, Neptune Neptune, Jupiter, Uranus, Saturn Neptune, Uranus, Saturn, Jupiter Saturn, Uranus, Neptune, Jupiter
where is more than two thirds of earth's freshwater stored?
More than two-thirds of Earth's freshwater is stored in ice caps and glaciers, primarily in Antarctica and Greenland. These massive ice sheets contain an enormous amount of freshwater in the form of ice.
Ice Caps and Glaciers: These polar ice sheets hold the majority of the world's freshwater, accounting for roughly 68.7% of the total freshwater on the planet. Antarctica, the southernmost continent, has the largest ice sheet, followed by Greenland. These ice masses contain trillions of cubic meters of freshwater, which is locked up in the form of ice.
Groundwater: Approximately 30.1% of Earth's freshwater is stored underground in aquifers. These are layers of water-bearing rock and sediment beneath the Earth's surface. Groundwater is a vital source of freshwater for drinking, agriculture, and industry.
Surface Water: This includes all the freshwater on the Earth's surface, such as lakes, rivers, and reservoirs. Surface water accounts for about 0.3% of Earth's freshwater. While it represents a small percentage, it is crucial for various human activities and ecosystems.
Atmosphere: Water vapor in the atmosphere accounts for a tiny fraction of Earth's freshwater, approximately 0.001%. This water vapor plays a vital role in the Earth's climate and weather systems.
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Which of these statements is not true?question 20 options:atoms of isotopes of an element have different numbers of protons.atoms of the same elements can have different masses.atoms are mostly empty space.the nucleus of an atom has a positive charge.save?
Which of the following reactions is not an example of an oxidation-reduction reaction? ( 2 points) Select one: a. H2 + F2yields 2HF b. Fe + CuSO4yields FeSO4 + Cu c. CuSO4 + 2NaOH yields Cu(OH)2 + Na2SO4 d. Cl2 + ZnI2yields ZnCl2 + I2
1.) If a neutral atom of chlorine has 17 electrons and 18 neutrons, how many electrons are in the second energy shell of this atom?
2.) If a neutral atom of chlorine has 17 electrons and 18 neutrons, how many electrons are in the outermost, or valence, shell of this atom?
Answer: 1. 8 electrons
2. 7 electrons
Explanation: energy shell are orbits which Carry's electrons around an atom's nucleus.
To determine the number of electrons in an energy shell, use the formula
2(n^2)
n= number of energy shell
Therefore the second energy shell is n=2
Substituting n in the equation above,
2(2^2)=8
2. Valence electrons are the electrons on the outermost shell of an atomic nucleus.
The group number of an element is the same as the valence electrons of that element.
Therefore chlorine which belongs to group 7 elements has 7 valence electron.
We can also get the valence electrons using the K L M N shell.
The K shell which has maximum of 2 electrons, while other shells can contain maximum of 8 electron.
SEE PICTURE ATTACHED TO UNDERSTAND THE K L M N SHELL BETTER.
How many valence electrons are in the trimethylammonium ion ch33nh+ ?
The trimethylammonium ion (CH3)3NH+ has a total of 25 valence electrons after accounting for its positive charge; 26 electrons from the combined valence electrons of nitrogen, carbon, and hydrogen atoms and subtracting one electron for the positive charge.
Explanation:To calculate the number of valence electrons in the trimethylammonium ion (CH3)3NH+, we first need to sum the valence electrons of all the atoms. Nitrogen (N) has 5 valence electrons, each hydrogen (H) atom has 1, and each carbon (C) atom has 4. Since there are three methyl groups (CH3), we have 3 carbons and 9 hydrogens:
Nitrogen: 5 valence electrons3 Carbons: 3 × 4 = 12 valence electrons9 Hydrogens: 9 × 1 = 9 valence electronsAdding these up gives 5 + 12 + 9 = 26 valence electrons. However, since we have a positively charged ion (NH+), we need to subtract one electron to account for the charge. This leaves us with a total of 25 valence electrons in the trimethylammonium ion. When drawing the Lewis structure of this polyatomic ion, it is also common practice to enclose the structure in brackets and denote the charge outside of it.
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The trimethylammonium ion, [tex](CH\(_3\))\(_3\)NH\(^+\)[/tex], has 0 valence electrons.
The trimethylammonium ion, [tex](CH\(_3\))\(_3\)NH\(^+\),[/tex]is composed of a nitrogen atom bonded to three methyl groups [tex](CH\(_3\))[/tex] and a hydrogen atom, with an additional positive charge indicating the loss of an electron compared to the neutral molecule.
First, let's consider the valence electrons in the neutral trimethylamine molecule, [tex](CH\(_3\))\(_3\)NH,[/tex] before it gains a positive charge:
Each hydrogen atom contributes 1 valence electron, and there are 12 hydrogen atoms in total (3 from each methyl group and 1 from the amine group), contributing 12 valence electrons.Each carbon atom contributes 4 valence electrons, and there are 3 carbon atoms in total (one in each methyl group), contributing 12 valence electrons.The nitrogen atom contributes 5 valence electrons. Adding these up gives us the total number of valence electrons in the neutral molecule: 12 (from hydrogen) + 12 (from carbon) + 5 (from nitrogen) = 29 valence electrons. Now, when the molecule gains a positive charge to become the trimethylammonium ion, it loses one electron. Therefore, the number of valence electrons in the ion is 29 - 1 = 28 valence electrons. However, the question asks for the number of valence electrons that are not involved in bonding, which is the definition of a lone pair. In the trimethylammonium ion, all of the valence electrons are involved in bonding: each hydrogen is bonded to a carbon or nitrogen, each carbon is bonded to three hydrogens and the nitrogen, and the nitrogen is bonded to three carbons and one hydrogen. There are no lone pairs of electrons on the nitrogen because it has formed four bonds, which means all eight of its valence electrons are involved in bonding.
Write the net ionic equation for the precipitation of cobalt(ii) carbonate from aqueous solution
Which of the following is a benefit of having a standard measurement system that can be used by scientists worldwide?
1. Scientists can all perform different experiments
2. Scientists can compare and share data with each other.
3. Scientists never have to report their results.
4. Scientists can save their data for future experiments.
I think the answer is answer #2. Is this correct?,
What is the name for this molecule? 3-heptyne 3-heptene 3-hexyne 3-hexene
The iupac name of the compound will be hex-3-yne or 3-hexyne. By marking number of carbon in the given compound, it was found that triple bond comes at third position and there are total 6 carbon in the compound. So it will have Hex as a prefix and as it contains triple bond so it will have yne as a suffix and as the triple bond is at third position, so it will be hex-3-yne or 3-hexyne.
The correct name for the molecule is 3-hexyne.
To determine the name of the molecule, we need to follow the rules of IUPAC nomenclature for alkynes. The molecule has a total of 6 carbon atoms in its longest carbon chain, which makes the base of the name hexyne.
The triple bond, indicated by the yne suffix, is located at the third carbon atom from the end, hence the number 3 in the name. The other options provided contain either an incorrect number of carbon atoms or an incorrect type of bond (alkene instead of alkyne). Therefore, the correct IUPAC name for this molecule is 3-hexyne.
The complete question is- What is the name for this molecule?
a. 3-heptyne
b. 3-heptene
c. 3-hexyne
d. 3-hexene
Can someone eplain how to do this ? : identify the limiting reagent and the volume of CO2 formed when 11 L CS2 reacts with 18 L O2 to produce SO2 gas at STP. CS2(g)+3O2(g) → CO2(g)+2SO2(g),
what are the five indicators of a chemical change
What is the length of the hypotenuse of the right triangle ABC in the figure?
A. 6.2
B. 11.0
C. 5.8
D. 7.2
Explains why anyone in the classroom can hear that loud teacher across the hall even though the door is barley cracked open
A. Reflection
B. Refraction
C. Diffraction
how much water vapor can a cubic meter of air hold at 25 degrees celcius
Upon combustion, a 0.8376 g sample of a compound containing only carbon, hydrogen, and oxygen produces 1.6003 gco2 and 0.9827 gh2o. find the empirical formula of the compound.