The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol. How much energy is produced by burning 0.8210 g of naphthalene?
The energy produced : -32.89 kJ
Further explanationDelta H reaction (ΔH) is the amount of heat / heat change between the system and its environment
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
The enthalpy of combustion of naphthalene (MW = 128.17 g/mol) is -5139.6 kJ/mol.
For 0.8210 g of naphthalene :
mol =
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{0.8210}{128.17}=0.0064[/tex]
The energy produced :
[tex]\tt Q=\Delta H\times n(mol)\\\\Q=-5139.6\times 0.0064=-32.89~kJ[/tex]
3. Which element is more reactive?
a. Calcium (Ca)
b. Titanium (Ti)
C. Silver (Ag)
d. Rubidium (Rb)
Answer:
titanium
Explanation:
according to my knowledge titanium is more expensive than diamonds....A country becomes powerfull by having more quantity of titanium....all the bombs, nuclear weapons and nuclear enegry are made from titanium so it is expensive and powerfull too..
When testing for hydrogen gas in the laboratory a glowing splint is inserted into the gas which results in a pop sound. What is associated with the formation of the pop sound?
A. physical change
B. chemical change
C. exothermic reaction
D. endothermic reaction
how much work is done in lifting a 2kg objext to a height of 1m
Answer:
19.6 J
Explanation:
The following data were obtained from the question:
Mass (m) of object = 2 Kg
Height (h) = 1 m
Workdone =?
NOTE: Acceleration due to gravity (g) = 9.8 m/s²
Thus, we can obtain the workdone in lifting the object by using the following formula:
Workdone = mgh
Workdone = 2 × 9.8 × 1
Workdone = 19.6 J
Therefore, the workdone in lifting the object to height of 1 m is 19.6 J
In each of the following sets of elements, which
element would be expected to have the highest
ionization energy?
a. Cs, R, Li
b. Ba, Sr, Ca
c. I, Br, C1
d. Mg, Si, S
Answer:
c. I, Br, Cl
Explanation:
The option C group of elements is expected to have the highest ionization energy.
Ionization energy is the energy needed to remove the most loosely held electron from an atom.
As such, ionization energy increases from left to right on the periodic table. It reduces from top to bottom The groups to the right will not readily lose their electrons. Therefore, I, Br and Cl being in group 7 will have the highest ionization energy.Andrew gathered several different species of seed plants. Which three characteristics do all the plants most likely
share?
have pollen and flowers; lack phloem
have pollen and rhizoids; lack xylem
have xylem and phloem; lack pollen
have xylem and phloem; lack rhizoids
Answer:
the correct answer is B.....please give me BRAINLEST
Explanation:
im so sorry for being so late to answer
Answer:
B
Explanation:
The table below gives the numbers of protons, electrons, and neutrons in four atoms.
Atom Number of protons Number of electrons Number of neutrons
1 39 39 52
2 40 40 50
3 39 39 54
4 40 40 51
Based on the information that is given, which atom in the table has the highest mass?
1
2
3
4
Answer:
3. 39 39 54
Explanation:
Atoms are the smallest units of matter that have the characteristics of a chemical element. They consist of small particles called protons, electrons, and neutrons.
Protons are positively charged particles that make up the nucleus of the atom along with neutrons, neutrally charged particles. Their mass is almost the same - about 1 AMU (atomic mass unit). Electrons, the negatively charged particles, are much lighter than them and don't significantly contribute to the mass of the atom. Their mass is equal to about 1/2000 of the mass of a proton or neutron.
This is why we need to determine which atom out of the ones you were given has the highest number of protons and neutrons. The first has 91, the second 90, the third 93, and the fourth 91. This means that the third atom has the highest mass.
which layer of Earth's atmosphere is also home to the biosphere it is home to all living things?
Answer:
Biosphere
Explanation:
The biosphere covers all living organisms on Earth. There is an estimated 20 million to 100 millions different species in the world organized into the 100 phyla that make up the five kingdoms of life forms. These organisms can be found in almost all parts of the geosphere.
Is atomic radius a periodic property of atoms??
Carbon dioxide readily absorbs radiation with an energy of 4.67×10−20 J. What is the wavelength () and frequency () of this radiation?
Frequency is in m. and the wavelength is 7.04 x10^13 s-1
it is not 4.26x10^-7
The carbon dioxide readily absorbs radiation with an energy of 4.67×10⁻²⁰J and wavelength is 7.04 x 10¹³, then the frequency is 4.26 x 10⁻¹¹ m.
What is frequency?Frequency can be defined as the number of occurrences of a repeating event per unit of time. It is also known as temporal frequency to emphasizes the contract to spatial frequency and can be called as ordinary frequency to emphasize the contract to angular frequency. It is denoted by f.
f = hc / ∧
f = 6.626 x 10⁻³⁴ x 3.0 x 10³ / 4.67 x 10⁻²⁰
f = 4.26 x 10⁻¹¹ m
Thus, carbon dioxide readily absorbs radiation with an energy of 4.67×10⁻²⁰J and wavelength is 7.04 x 10¹³, then the frequency is 4.26 x 10⁻¹¹ m.
To learn more about frequency, refer to the link below:
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How many moles of HCL are in 18 grams? (Use the molar mass to convert miles to grams. Round you answer to 2 decimal places.)
Answer:
0.49 mol HCl
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
18 g HCl
Step 2: Identify Conversions
Molar Mass of H - 1.01 g/mol
Molar Mass of Cl - 35.45 g/mol
Molar mass of HCl - 1.01 + 35.45 = 36.46 g/mol
Step 3: Convert
[tex]18 \ g \ HCl(\frac{1 \ mol \ HCl}{36.46 \ g \ HCl} )[/tex] = 0.493692 mol HCl
Step 4: Check
Round our answer to 2 decimal places.
0.493692 mol HCl ≈ 0.49 mol HCl
Answer:
0.49 mol
Explanation:
mol=given mass /molecular mass : = 18/36.5 =0.49A chemist accidentally leaves an open beaker containing 100.0 mL of a 0.400 M CuCl(aq) solution on a lab bench. They return a few days later to find that the volume of the solution has decreased to 30.0 mL. What is the molarity of this partially evaporated solution, assuming the solute does not evaporate? Give your answer to 2 decimal places.
Answer:
Me gusta el triángulo, la respuesta es triángulo.
Explanation:
Which statement describes an important role of carbon dioxide in Earth’s atmosphere? *
Animals breathe carbon dioxide.
Plants use carbon dioxide to make food.
Carbon dioxide helps animals make proteins.
Carbon dioxide forms clouds that produce rain.
Answer:
Plants use carbon dioxide to make food.
Explanation:
Answer:B
Explanation: i did it
why are scientific methods important in the study of science
a.they are useful only for teaching students about science
b.they help scientists understand complex ideas and objects that arent easy to handle
c.they enable scientists to popularize their work in society
d.they are necessary to conduct the peer review process
e.they are necessary for turning a hypothesis into a law
Answer:rrrrrrrrrrrrrrrrrrr
Explanation:
rrrrrrrrrrrrrrrrrrrrrrrr
What is the kinetic energy of a 7.26 kg bowling ball that is rolling at a speed of 2 m/s?
Answer:
its 2.86 kg I believe.......
Answer: 14.52J
Explanation:
At 23°C, 85.0 grams of NaNO3(s) are dissolved in 100. grams of H2O(l).
Based on Table G, determine the additional mass of NaNO3(s) that must be dissolved to
saturate the solution at 23°C.
5g
Anything between 4 and 6 is ok.
The additional mass of solute to be added will be determined by the mass of solute required to saturate a solution of NaNO3 in 100. grams of H2O.
A saturated solution is one that contains just as much solute as it can normally hold at a given temperature. We should now that when additional solute is added to a saturated solution, the additional solute does not dissolve.
The table is not presented hence the question is incomplete. However, the additional mass of solute to be added will be determined by the mass of solute required to saturate a solution of NaNO3 in 100. grams of H2O.
Learn more about solubility: https://brainly.com/question/953809
Elements that accept electrons easily have a
Answer:
Greater electronegativity and these are non metals.
Explanation:
How many neutrons and protons are there in each of the following nuclides:(a) 10B. (b) 24Na, (c) 59Co, (d) 208Pb. and (e) 235U?
Answer:
a. 5 protons and 5 neutrons
b. 11 protons and 13 neutrons
c. 27 protons and 32 neutrons
d. 82 protons and 126 neutrons
e. 92 protons and 143 neutrons
Explanation:
Using isotope notation:
ˣN
X = Amount of neutrons and protons
N is the atom. If N is nitrogen, the atomic number is 7, that means there are 7 protons.
X - Amount of protons = Neutrons
a. ¹⁰B. Atomic number = 5 = Number of protons
10 - 5 = 5 = Number of neutrons
5 protons and 5 neutrons
b. ²⁴N. Atomic number = 11 = Number of protons
24 - 11 = 13 = Number of neutrons
11 protons and 13 neutrons
c. ⁵⁹Co. Atomic number = 27 = Number of protons
59 - 27 = 32 = Number of neutrons
27 protons and 32 neutrons
d. ²⁰⁸Pb. Atomic number = 82 = Number of protons
208 - 82 = 126 = Number of neutrons
82 protons and 126 neutrons
e. ²³⁵U. Atomic number = 92 = Number of protons
235 - 92 = 143 = Number of neutrons
92 protons and 143 neutrons
which of the following is the best definition for volume
a. solids are the only matter with volume
b. all energy has volume
c. volume is the three-dimensional size of an object
d. gases do not have volume
Answer:
C
Explanation:
I hope that helps!!! it kinda gave you the answer though
How is it possible to change electrical devices when the power is out?
(Please help!!)
Answer:
An uninterruptible power supply can save data during an outage, and a surge protector can prevent damage from a surge. Surge protectors absorb or ground overvoltage from spikes. Each time a surge protector does its job, resulting damage can reduce effectiveness for the next surge.
Explanation:
How many molecules are in 6.00 mol He?
HELP!!!!!
4. Which form of asexual reproduction describes the process of a cell dividing to
produce a copy?
Answer:
Mitosis
Mitosis is a method of cell division in which a cell divides and produces identical copies of itself.
Explanation:
Name the region of the atom where protons and
neutrons are located. This region is indicated by
label B.
Name the region of the atom where electrons are
located. This region is indicated by label A.
DONE
Answer:
B. Nucleus
A. Orbitals
Explanation:
Ed22
The region of the atom where protons and neutrons are located (B) is called the nucleus.
The region of the atom where electrons are located (A) is called orbits.
In an atom, the nucleus is the central core that contains protons and neutrons. It is a tiny, dense region located at the center of the atom. Protons have a positive charge, while neutrons are electrically neutral (have no charge). The number of protons in the nucleus determines the element's identity.
Orbits (also called electron shells or energy levels) are the regions around the nucleus where electrons are found. Electrons are negatively charged particles that move within these orbits. Each orbit has a specific energy level, and electrons closer to the nucleus have lower energy levels. Electrons occupy the lowest available energy levels first before moving to higher levels as the atom gains more electrons.
Learn more about Atoms, here:
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The complete question is shown in the image attached below -
according to the big bang theory, which describes the universe before the actual big bang occurred?
Answer:
the answer is hot,dense points; each smaller than an atom
Explanation:
the big bang theory was proposed to suggest the expansion of the universe by describing the origin of all components of the universe and its planetary bodies. its suggested that the whole universe was in a state of high temperature and highly dense points (which were smaller than atoms) but continuously expanded by cooling down which gave rise to the formation of subatomic particles, atoms, etc.
btw I found this on brainly
One of the benefits of nuclear power generation is a reduction in the emission of harmful waste gases into the atmosphere.
Which gas is normally emitted by nuclear power plants?
Select all that apply.
nitrogen oxides
sulfur oxides
carbon dioxide
steam
radon
water vapor
Answer:
carbon dioxide
Explanation:
Putting the Brakes on Carbon Emissions
Every year, nuclear-generated electricity saves our atmosphere from more than 506 million metric tons of carbon dioxide, equivalent to taking more than 110 million passenger cars off the road.
Which statement is always true about a reversible chemical reaction?
Answer:
It is a chemical reaction in which the reactants form products and products react together to give reactants back. That means reversible reactions can go in both directions forward as well as backward direction.
A 10.0-mL sample of an unknown H3PO4 solution requires 112 mL of 0.100 M KOH to completely react with the H3PO4. What was the concentration of the unknown H3PO4 solution
Answer:
The correct answer is 0.373 M.
Explanation:
The reaction will be,
H3PO4 (aq) + 3KOH (aq) ⇔ 3H2O (l) + K3PO4 (aq)
Based on the given information, the molarity of the solution KOH is 0.100 M, the volume of the solution given is 112 ml or 0.112 L.
The molarity of the solution with respect to KOH is,
M = Moles/Volume of Solution (liters)
Moles of solute = Molarity * Volume of solution
Moles = 0.100 M * 0.112 L
= 0.0112 moles
From the reaction it is clear that 3 moles of KOH needed 1 mole of H3PO4, thus, 0.0112 moles of KOH will require,
1/3 * 0.0112 = 0.00373 moles of H3PO4
The volume of the H3PO4 solution is 10 ml or 0.01 L.
The molarity of the solution will be,
M = Moles/ Volume of Solution (liters)
M = 0.00373/0.01 = 0.373 M
Thus, the concentration of the solution is 0.373 M.
The concentration of the H3PO4 would be 0.37 M
Going by the balanced equation of the reaction:
[tex]3KOH + H_3PO_4 ---> 3H_2O + K_3PO_4[/tex]
The mole ratio of KOH to H3PO4 is 3:1.
Using the equation: CaVa/CbVb = 1/3
What we are looking for is Ca:
Ca = CbVb/3Va
= 0.1 x 112/3 x 10
= 0.37 M
More or calculations involving neutralization reactions can be found here: https://brainly.com/question/7305038?referrer=searchResults
Calculate the molarity of the two solutions.
The first solution contains 0.350 mol of NaOH in 1.05 L of solution.
molarity:
The second solution contains 14.3 g of NaCl in 879 mL of solution.
molarity:
1. 0.33 M
2. 0.278 M
Further explanationMolarity is a way to express the concentration of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
1. 0.350 mol of NaOH in 1.05 L of solution.
n=0.35
V=1.05 L
Molarity :
[tex]\tt M=\dfrac{0.35}{1.05}=0.33[/tex]
2. 14.3 g of NaCl in 879 mL of solution.
mol NaCl(MW=58.5 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{14.3~g}{58.5~g/mol}=0.244[/tex]
Molarity :
[tex]\tt M=\dfrac{0.244}{0.879~L}\\\\M=0.278[/tex]
Which of the Atoms shown has an atomic number four
Answer:
B
Explanation:
Atomic # = Protons
it says 4 p in the inside of the orbital
List down 10 different types of minerals (metallic and non metallic) include the different uses and help in the economy of these minerals.
Answer:
names of 10 metallic minerals are Silver, Chromium, Tin, Nickel, Copper, Iron, Lead, Aluminum, Gold, and Zinc.
Explanation: