The reaction as shown is a combustion reaction. 29.8 kCal of heat is produced when 4.20 g of ethanol reacts with O2 gas.
The equation of this reaction is shown below;
C2H5OH + 3O2 →2CO2(g)+3H2O(l)+327 kcal
From the reaction equation, we can see that 1 mole of ethanol produces 327 kcal of heat.
Now, we have to find the number of moles in 4.20 g of ethanol as follows;
Number of moles = mass/molar mass = 4.20 g/46 g/mol = 0.091 moles
If 1 mole of ethanol yields 327 kcal of heat
0.091 moles of ethanol yields 0.091 moles × 327 kcal / 1 mole
= 29.8 kCal
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The beaker is left until there is no further change in the appearance of the liquid. And the options for the answer are : A : All the liquid is purple. B : None of the liquid is purple. C : Only the bottom half of the liquid is purple. D : Only the top half of the liquid is purple
Answer:
none of the liquid is purple
1. What is the purpose of the advertisement?
Answer:
For enlightenment, development and making people understand the usefulness of the product
Answer:
AKA "AD"AND ADS EXPLAIN WAYS IN WHICH THE PRODUCT IS USEFUL ... PLEASE MARK ME AS BRAINLIST
How can i study smater
Answer:
study....................
Explanation:
1.Short sessions
2.Sleep well
3.Set goal
4Aim to learn as if you were to teach
Which gases contribute more significantly to Global warming
Answer:
Carbon dioxide
Explanation:
A byproduct of fossil fuel combustion, is the principal greenhouse gas contributing to global warming. However, other greenhouse gases including methane, nitrous oxide, and a number of industrial-process gases also are important contributors to climate change.
What is a periodic table ?
Answer:
The periodic table is a tabular array of the chemical elements organized by atomic number, from the element with the lowest atomic number, hydrogen, to the element with the highest atomic number, oganesson.
Answer:
A periodic table is a table filled with chemical elements. They are organised by their atomic number and how many electrons each element contains
When the metallic element sodium combines with the nonmetallic element bromine (Br2), is the product a solid, liquid, or gas at room temperature?
I will give brainliest if you can explain how one would know this information.
Answer: it is a solid at room temperature.
Explanation:
The ions of the two reactants are Na{+} and Br{-}, so the formula of the product is NaBr.
and when the NaCl is a solid a room temperature. and when NaBr has similar properties to NaCl, so NaBr is a solid at room temperature too.
so our chemical formula for the product is NaBr and It's a solid at room temperature.
Help pls 30 POINTS!!
Answer:
protons: 6
neutrons: 8
electrons:6
Vitamin D is produced in the skin when 7-dehydrocholesterol reacts with UVB rays (ultraviolet B) having wavelengths between
270 nm and 300 nm. What is the energy range of the UVB photons?
UVB photons, with wavelengths between 270 nm and 300 nm, have energies in the range of 6.63 × 10⁻¹⁹ J - 7.37 × 10⁻¹⁹ J.
UVB rays have wavelengths (λ) between 270 nm and 300 nm. We can calculate the energy (E) associated with each wavelength using the Planck-Einstein's relation.
[tex]E = \frac{h \times c}{\lambda }[/tex]
where,
h: Planck's constant (6.63 × 10⁻³⁴ J.s)c: speed of light (3.00 × 10⁸ m/s)The energy associated with a wavelength of 270 nm is:
[tex]E = \frac{h \times c}{\lambda } = \frac{(6.63 \times 10^{-34}J.s ) \times (3.00 \times10^{8}m/s )}{270 \times 10^{-9}m } = 7.37 \times 10^{-19} J[/tex]
The energy associated with a wavelength of 300 nm is:
[tex]E = \frac{h \times c}{\lambda } = \frac{(6.63 \times 10^{-34}J.s ) \times (3.00 \times10^{8}m/s )}{300 \times 10^{-9}m } = 6.63 \times 10^{-19} J[/tex]
UVB photons, with wavelengths between 270 nm and 300 nm, have energies in the range of 6.63 × 10⁻¹⁹ J - 7.37 × 10⁻¹⁹ J.
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The negatively charged particle that is released from the nucleus at high speeds is the _____.
a. alpha particle
b. beta particle
c. neutron
d. gamma ray
Answer:
The negatively charged particle that is released from the nucleus at high speeds is the beta particle.
How many grams of carbon are in 243.3 g
of carbon tetrachloride?
Which element has the largest atomic radius?
4 be
56 ba
31 ga
9 f
Answer:
Ba
Explanation:
bc it = 268 pm
The total pressure in a mixture of gases is equal to the partial pressure(s) of ________. the gas that occupies the largest volume the gas with the smallest number of moles all the gases added together the gas with the highest molecular weight the gas with the greatest number of moles
The total pressure in a mixture of gases is equal to the partial pressure of all the gases added together
According to Dalton's Law of Partial Pressure, The total pressure exerted by a mixture of gases which are non reacting is equal to the sum of the partial pressure of each individual gas that make up the mixture
Mathematically, Ut can be written as
P{total}= p1+p2, ....+ pn
where p1, p2, …, pn are partial pressures of each gas component.
For example :A gaseous mixture consisting of Helium and Nitrogen gas . If the pressure exerted by He is 3 atm while Nitrogeb exerted is 9 atm. The total pressure will be:
P{total}= p1+p2, ....+ pn
P{total}= 3+9
P{total}= 12
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state the name of the substance produced by a chemical reaction
Answer:
These starting substances of a chemical reaction are called the reactants, and the new substances that result are called the products.
Explanation:
How many atoms are present in 0.529 moles of Li?
Answer:
3.18 × 10²³ atomsExplanation:
The number of atoms can be found by using the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 0.529 × 6.02 × 10²³
We have the final answer as
3.18 × 10²³ atomsHope this helps you
List the three pieces of evidence for sea floor spreading that also support the theory of continental drift
Answer:
molten material, seafloor drilling, radiometric age dating and fossil ages, and the magnetic stripes
Explanation:
Help I believe it’s B or A
Which term describes the crust and the upper part of the mantle broken into large tectonic
plates?
A ) Outer core
B ) Lithosphere
C ) Asthenosphere
D )Mantle
How many mols are present in 5.24 x 1024 atoms of Carbon tetra fluoride?
Answer: 5.44×10226.022140857(74)×1023⋅mol−1.
Explanation: So the answer is approx. 0.10⋅mol
Which of the following helps us see atoms? (20 points including brainliest if correct)
A. Advanced telescopes
B. Our eyes
C. Large hand lenses
D. Powerful microscopes
Answer:
D.) powerful microscopes ....... telescopes are for space our eyes can't see atoms and hand lenses are not gonna do you any good
A prospector panning for gold (Au) in a river collects 15.00 g of pure gold. How many Au atoms are in this quantity of gold?
Answer:
There are 4.59*10^-24 atoms in 15.00 of pure gold.
Explanation:
Molar mass of gold is 196.996g/mol
[tex]\frac{15}{196.966} =0.076 mol[/tex]
0.076*(6.022*10^-23)=4.59*10^-24
Cereal is an example of what
mixture
Answer:
a heterogenous mixture
Explanation:
a heterogenous mixture is a mixture that you can see the different things in it. A homogenous mixture is when you cant see the objects in the mixture
An adult human lungs can only hold a volume of up to 6.0 L of air when fully expanded. Suppose that at sea level where the pressure is 1.00 atm, a sky diver traps 3.0 L of air in her lungs and holds her breath before rapidly ascending to an altitude where the pressure drops to 0.46 atm. If she doesn't exhale, determine if her lungs will rupture at this high altitude, then complete the sentence:
Answer:why would i know
Explanation: sorry
Assuming an efficiency of 49.70%, calculate the actual yield of magnesium nitrate formed from 139.0 g of magnesium and excess copper(II) nitrate. Mg+Cu(NO3)2⟶Mg(NO3)2+Cu
Answer:
221.5 g
Explanation:
if you want a step by step problem feel free to ask
Determine the formal charge on each atom in the structure.
Answer:
−0.75 , 1.25
Explanation:
Please refer to attachment for more information
Ethan makes the table below to record his observations when mixing baking soda and vinegar in a beaker. Ethan claims that a chemical change has occurred. Which statement provides the BEST evidence to support his claim?
Answer: a
Explanation:
Many bubbles formed after mixing.
The statement which best provides support for the fact that a chemical change has occurred is that many bubbles formed after mixing.
In a chemical change, new substances are formed and there is a recombination of the atoms in reactants as the products are being formed.
There are several cues that indicate that a chemical change has taken place such as;
Appearance of a solid in an aqueous phase reaction.Evolution of gasSudden change in the temperature of the systemChange in the color of the systemIn the particular instance in this question, when baking soda and vinegar were mixed together, a gas was evolved signifying that a chemical change has taken place.
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What’s a nonmetal that gains 3 electrons to be stable like neon
Answer:
Phosphorus would be the correct answer I guess
Every compound is a molecule, but every molecule is not a compound. Why is this? Give an example with your answer. Plz help mehhh TvT
Answer:
By definition, a molecule is a group of atoms bonded together. This means that it can be a mixture of two separate atoms (e.g. atom A and atom B bond together to make molecule AB). Molecules with two or more separate elements are called compounds.
Molecules can also be made of more than one atom of the same element (e.g. atom A bonds to another A atom to make molecule AA). This is not called a compound because they are not different elements.
Perform the following calculation and report the answer with the correct number of significant figures.
81.72 +0.73 =
Answer:
81.72 +0.73=82.45
Explanation:
you need to add it1
81.72
+0.73
= 82.45
82.72 + 0.73 = 82.45
Explanation:
0.72+0.73 = 1.45
Therefore 81+1.45= 82.45 ( Integer in addition with a decimal number).
Balance the following chemical equation and determine the number of moles of Fe(s) produced when 8.1E-1
moles of Fe2O3(s) react with excess C(s) to produce Fe(s) and CO2(g).
Fe2O3(s) + C(s) ——)Fe(s) + CO2(g)
Answer:
2Fe2O3 + 3C → 4Fe + 3CO2
Explanation:
The balanced reaction of Ferric oxide with carbon to form Iron and Carbon dioxide can be written as follows:
[tex]2Fe_{2} O_{3} +3C\rightarrow4Fe+3CO_{2}[/tex]
The moles of iron produced is[tex]16.2*10^{-1}[/tex]
What is balanced equation?Balanced equation is the one where the number of atoms of each species is same on reactant and product side. In balanced equation mass can neither be created nor be destroyed.
The atoms of Oxygen on reactant side is 3 while on product side is 2 so multiply Ferric oxide by 3 and carbon dioxide by 3
so now our equation becomes
[tex]2Fe_{2} O_{3} +C\rightarrow Fe+3CO_{2}[/tex]
The number of Carbon atoms on left side is one while on right side it is 3 so multiply by 3
[tex]2Fe_{2} O_{3} +3C\rightarrow Fe+3CO_{2}[/tex]
The number of Iron atoms on left is 4 while on right it is 1 so multiply by 4
[tex]2Fe_{2} O_{3} +3C\rightarrow4Fe+3CO_{2}[/tex]
From 2 moles of Ferric oxide 4 moles of iron is produced
from 1 mole mole of ferric oxide 2 moles of Iron is produced
From [tex]8.1*10^{-1}[/tex] mole of ferric oxide 2×[tex]8.1*10^{-1}[/tex] moles of iron are produced.
Hence the balanced equation is
[tex]2Fe_{2} O_{3} +3C\rightarrow4Fe+3CO_{2}[/tex]
the number of mole of Iron is [tex]16.2*10^{-1}[/tex]
Learn more about the balanced equations, here:
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How large are dwarf galaxies compared to the Milky Way galaxy?
Answer:
A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars
Answer:
A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars.
Explanation:
same answer for me
3 Physical properties of boron?
Answer:
Atomic Symbol: B
Atomic Number: 5
Element Category: Metalloid
Explanation: