need little help pls
Answer:
0.354 molal
Explanation:
The molarity (M) or the concentration of a solution is defined as the number of moles of a compound in the solution per liter of solution (mol/L), whereas molality, is defined as the number of moles of a compound in the solution per kg of the compound (mol/kg).
Given that the density of the solution is 1.202 g/mL, which is equivalent to 1.202 kg/L. Since the prefix mili- denotes a factor of one thousandth ( [tex]10^{-3}[/tex] ) and kilo- denotes a factor of one thousand ( [tex]{10}^3[/tex] ),
[tex]1.202 \ \frac{g}{mL} \ = \ 1.202 \ \frac{g}{(10^{-3}) L} \ = \ 1.202 \ \frac{{10}^3g}{L} \ = \ 1.202 \ \frac{kg}{L}[/tex].
To calculate the corresponding molality of the solution, the formula
[tex]Molality \ (mol/kg) \ = \ \frac{Molarity \ (mol/L)}{Density \ (kg/L)}[/tex] is used.
Therefore,
[tex]Molality \ = \ \frac{0.426 \ mol/L}{1.202 \ kg/L} \ = \ 0.354 \ mol/kg \ \ (3 \ s.f.)[/tex]
Which of the following statements are true about energy and bonds?
Check all that apply.
A. The formation of bonds does not absorb or release energy.
B. When bonds are formed, energy is released.
C. Energy is absorbed to break bonds.
D. Breaking bonds does not absorb or release energy.
Answer:
A. Energy is necessary for bond formation.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released.
Energy is always required for bond formation because when a chemical reaction occurs, either molecular bonds are broken or other bonds are formed to make different molecules. Energy is released during bond formation and is an exothermic process because bond formation represents a stable configuration and the energy lost is released as heat energy that makes it more stable. Breaking bonds takes energy and is an endothermic reaction because energy is absorbed to break bonds.
Hope that helps. x
Y’all what’s this I don’t feel like doing it and I’ll give brainlist too
The covalent compounds are soluble in:
a) All acids
b) All bases
c) all solvents
d) nonpolar solvents
Answer:
d) Non-polar solvents
Lead has an atomic number of 82. Which statement describes all neutral atoms and ions of lead?
A) Neutral atoms of lead must have 82 electrons. Ions must have 82 electrons, as well.
B)Neutral atoms of lead must have 82 protons, but ions can have more or fewer.
c) Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer.
D0 Neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
1. The neutral atoms of lead has 82 protons.
2. The ions of lead also have 82 protons.
The correct answer to the question is Option D. Neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
Lead, Pb is a metal with an atomic number (i.e proton number) of 82
Metals can only form ions by losing their valence electron(s)
NOTE: In the formation of ions, only the electrons are involved. The protons are not involved. Thus, the protons of the neutral atom and the ion remains the same.
With the above information in mind, we can conclude that neutral atoms of lead must have 82 protons. Ions must have 82 protons, as well.
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Answer:
C. Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer
Explanation:
O Neutral atoms of lead must have 82 neutrons, but ions can have more or fewer. O Neutral atoms of lead must have 82 protons, but ions can have more or fewer.
How many moles in 44.7 kg of carbon dioxide
Answer:
What is the number of moles of carbon present in 44 grams of carbon dioxide? One. 44 grams is a mole of carbon dioxide and there is one carbon atom in CO 2 so there is one mole of carbon. That’s how chemistry works.
Explanation:
What is the number of moles of carbon present in 44 grams of carbon dioxide? One. 44 grams is a mole of carbon dioxide and there is one carbon atom in CO 2 so there is one mole of carbon. That’s how chemistry works.
Look at the diagram of 2 basic cell types. Which of the following describes cell 2?
A) a plant cell
B) an animal cell
C) a eukaryote cell
D) a prokaryote cell
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In an experiment, equal amounts of water and sand were heated under a lamp. The initial and final temperatures of each were recorded. A partial record of the temperature is shown.
Experimental RecordSubstance Initial Temperature Final Temperature
Sand 20 °C 26 °C
Water 20 °C ?
Which statement about the final temperature of water is correct?
A. It will be less than 26 °C as sand has a relatively higher specific heat than water.
B. It will be less than 26 °C as water has a relatively higher specific heat than sand.
C. It will be more than 26 °C as sand needs relatively higher energy than water to raise its temperature.
D. It will be more than 26 °C as water needs relatively higher energy than sand to raise its temperature.
hi have a nice day
will be less than 26 °C as water has a relatively higher specific heat than sand.
Explanation:
The specific heat of a substance is the amount of heat energy absorbed by one unit of mass of the substance when its temperature increases one unit.
From that, you can derive the equation for the specific heat of a substance:
specific heat = heat / (mass × ΔT)
Thus, assuming that all the heat provided by the lamp to both samples is the same and, as given, the amount (mass) of both samples is also the same, you have that the specific heat of the samples will be:
specific heat = constant / ΔT
So, specific heat and ΔT are inversely related.
It is known that water has a higher specific heat than sand (that is why the sand on the shore of a beach is, during the day, hotter than the water and your feet get burned when you walk on a sandy beach on a sunny day
Answer to question in picture
Answer:
methyl 2-methyl-ethane
Explanation:
soaps do not work well in hard waters. But they can still be effected it large quantities of soap are added to water. Explain why.
For a reversible reaction, what would a large equilibrium constant indicate? Question 9 options: A) At equilibrium, the concentration of the reactants will be much higher than the concentration of the products. B) At equilibrium, the concentration of the products will be about the same as the concentration of the reactants. C) At equilibrium, the concentration of the products will be much higher than the concentration of the reactants. D) At equilibrium, there will be no reactants left because they will all have been turned into products.
What is one advantage of asexual reproduction?
O A. It is advantageous in a changing environment.
B. It is the slowest way to reproduce.
O C. It results in genetically different offspring.
D. It requires only one parent.
Answer: D.
Explanation:
Asexual reproduction requires only one parent, making it more efficient and take a shorter amount of time than sexual reproduction.
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PLEASE ANSWER I HAVE 5 MINS
Answer:
Explanation:
7A 0.2
7B cork
7C Yes because the lighter it is the more likely it will float
7D Density is one of the fundamental scientific principles of life. It can describe any everyday object. Despite its significance, students often struggle to understand what it really is. Density is a measurement of how much space or volume is packed in an object or substance.
8 property means a characteristic or trait that you can use to describe matter by observation, measurement, or combination.
What is the pH of a solution with a 3.2 x 10−5 M hydronium ion concentration? (5 points)
Select one:
a.4.3
b.4.5
c.11
d.12
Answer:
b. 4.5
Explanation:
Since it is hydronium ion concentration, that means it is an acid.
pH formula = -log[H3O+]
-log(3.2 x 10^{-5} = 4.5
Answer ASAP pls
The electromagnetic spectrum is the portion of energy that reaches the Earth from the Sun. However, the human eye can still only detect a portion of that spectrum because of the _____________ of the visible light waves.
wavelengths
troughs
crests
amplitude
Answer:
wavelengths
Explanation:
0.1216 g
wire
All
g
of
20 mL of 1M HCl
neutralized by addition of 50 mL of 0.20 M NaoH
Find the Atomic mass of Mg ?
added
magnisium was added
the excess
acid
was
Keep Scrolling! :D
[tex] \rule{999pt}{66646pt}[/tex]
Which bond is the most polar?
Answer:
A
Explanation:
reason:
H-F is most polar
because bond is polarized negative towards F which is the more electronegative atom.
The stage in which the hair begins to destroy itself as it disconnects from the
papilla is called?
Pressure is exerted in all directions when an object is in fluid/water. *
A. True
B. False
Answer:
False
Explanation:
Fluid pressure has no direction, being a scalar quantity, whereas the forces due to pressure have well-defined directions: They are always exerted perpendicular to any surface. The reason is that fluids cannot withstand or exert shearing forces.
does the following atomic model of a chemical reaction correctly demonstrate the law of conversation of matter why or why not
plzzz help
Answer:
Yes
Explanation:
You can tell because there are 2 moles of H2 on the reactants side and 1 mole of O2, and on the products side we see the same amount, meaning that no moles of H2 or O2 were added or destroyed, meaning that it follows the law of conservation of matter.
A) Oxygen
B) Sulfur
C) nitrogen
D) no elements have that mass
Answer:
The answer would be oxygen.
What is the mass of a 2.5 mole sample of MgO2
. What is meant by periodic in Periodic Table?
a. the table has b. the elements
repeated cycles occur more than
once
c. the table is only d. the table can be
good for so long changed as
needed
Answer:
B
Explanation:
Periodic refers to properties that repeat at certain intervals. Click to see full answer. In respect to this, what does periodic mean in the term periodic table? In the context of chemistry and the periodic table, periodicity refers to trends or recurring variations in element properties with increasing atomic number.
Triple covalent bond can be formed between:
a)C&H
b) N&S
c) C & S
d) C&O
e) O & S
A 33.4−L volume of methane gas is heated from 22°C to 66°C at constant pressure. What is the final volume of the gas?
Answer:
38.38 L (3 d.p.)
Explanation:
In response to questions addressing the expansion of gas via heating, Charles's Law should be considered. Charles's Law is an experimental gas law explaining the tendency of gases to expand when heated.
The law states that the volume ([tex]V[/tex]) of a gas is directly proportional to its temperature ([tex]T[/tex]) given that the pressure ([tex]P[/tex]) and the amount of gas ([tex]N_{A}[/tex]) are constant.
[tex]\displaystyle\frac{V}{T} \ = \ k \ \ \ \ \ \ \ or \ \ \ \ \ \ \ V \ = \ kT[/tex], where k is a proportionality constant.
*Note that when substituting temperature into the equation, the temperature must be in terms of the Kelvin scale and not in degrees Celsius. The relation between the Kelvin scale and the Celsius scale is [tex]\mathrm{K} \ = \ ^{\circ}\mathrm{C} \ + \ 273[/tex].
Charles's law can be used to compare changing conditions of a particular gas. Let [tex]V_{1}[/tex] and [tex]T_{1}[/tex] be the initial volume and temperature for the gas, while [tex]V_{2}[/tex] and [tex]T_{2}[/tex] be the final volume and temperature. The mathematical relationship of Charles's law becomes:
[tex]\displaystyle\frac{V_{1}}{T_{1}} \ = \ \displaystyle\frac{V_{2}}{T_{2}}[/tex].
In accordance with the question,
[tex]V_{1} \ = \ 33.4 \ \mathrm{L}, \ T_{1} \ = \ (22 \ + \ 273) \ \mathrm{K} \ = \ 295 \mathrm{K}, \ T_{2} \ = \ (66 \ + \ 273) \ \mathrm{K} \ = \ 339 \ \mathrm{K}[/tex]
while [tex]V_{2}[/tex] is the final volume of the gas that we would like to find. Therefore,
[tex]V_{2} \ = \ \displaystyle\frac{V_{1} \ \times \ T_{2}}{T_{1}} \\ \\ V_{2} \ = \ \displaystyle\frac{33.4 \ \mathrm{L} \ \times \ 339 \ \mathrm{K}}{295 \ \mathrm{K}} \\ \\ V_{2} \ = \ 38.38 \ \mathrm{L}[/tex].
PLZ HELP ASAP! I need this done tonight please
The importance of wearing a seatbelt while riding in the car can best be explained using:
A) Newton's First Law (Law of Inertia)
B) Newton's Second Law (F=ma)
C) Newton's Third Law (Action-Reaction)
D none of the above
Explanation:
this is a chemistry question ???
anyway, it is clearly A, as seatbelts try to counteract the inertia a moving body (our bodies riding in a car) has, when the environment (the car) of this body is suddenly coming to a stop.
this inertia would otherwise try to move the body still forward resulting in a headfirst crash into and often through the windshield. which causes much more damage to the body than the bruises caused by the pressure of the seatbelts against the body counteracting the body's inertia.
but also clearly, all 3 laws play a role.
the force with which the moving body has to deal when smashing into the windshield and potentially then other objects outside the car is described by the second law.
and for any action (crash) there are corresponding reactions (like the conversion of the crash energy into some absorbing reaction : damaged soft and hard tissue in the human body, crumbled car bodies,...).
Draw the Lewis structures for
Calcium bromide, CaBr2
The Lewis structure is the way of expressing the covalent bonding in molecules. The covalent bond formation takes place by the sharing of electrons in a molecule.
What is Lewis structure?In Lewis dot structures or simply the Lewis structures, the dots are used to represent the electrons. They provide a picture of bonding in molecules in terms of the shared pair of electrons and the octet rule.
The concept of covalent bond is introduced by the scientist G.N Lewis. According to him, the atoms achieve stable octet when they are linked with each other by sharing of one more pairs of electrons. The covalent bonding occurs between the atoms which do not differ much in their electronegativity.
The Lewis structure of CaBr₂ is denoted below. Here two bromine atoms acquires a stable electronic configuration by sharing electrons. There are two single bonds between them.
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what layers of protection can be used tot detect and respond to abnormal reactions or process conditions
In the body, the main protective layer is known as the epithelium, this can be found in the skin as well as other organs such as the lungs.
The body is often exposed to external factors that can damage it; due to this, throughout evolution, most animals and multicellular organisms have developed protective mechanisms.
In the case of humans and other animals, the protective layer is known as the epithelium, which is composed of epithelial cells. This protective layer can be found internally and externally.
External layer: This is the first protective layer, commonly known as skin, this layer protects the inner organs from extreme temperatures, changes in pressure, etc.
Internal layer: Organs such as the lungs or the ones in the gastrointestinal system are all covered by a thin epithelial layer that helps each organ to be protected.
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Which element gives up its valence electrons most readily?
Bi
Fr
Be
Ar
Answer:
Fr
Explanation:
I took the test
Michelle is trying to find the average atomic mass of a sample of an unknown
element. She finds that her sample contains 59.34% of an isotope with a mass of
113.6459, while the rest of the sample is an isotope with a mass of 115.8488. What
is the average atomic mass of her sample? Please round your answer to 0.01 amu.
The average atomic mass of her sample is 114.54 amu
Let the 1st isotope be A
Let the 2nd isotope be B
From the question given above, the following data were obtained:
Abundance of isotope A (A%) = 59.34% Mass of isotope A = 113.6459 amuMass of isotope B = 115.8488 amuAbundance of isotope B (B%) = 100 – 59.34 = 40.66%Average atomic mass =?The average atomic mass of the sample can be obtained as follow:
[tex]Average \: atomic \: mass \: = \frac{mass \: of \: A \times A\%}{100} + \frac{mass \: of \: B \times B\%}{100} \\ \\ Average \: atomic \: mass \: = \frac{113.6459\times 59.34}{100} + \frac{115.8488\times 40.66}{100} \\ \\ Average \: atomic \: mass \: = 114.54 \: amu \\ \\ [/tex]
Thus, the average atomic mass of the sample is 114.54 amu
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