Answer:
Q= ms∆T
Where, m is mass of substance
S is specific heat
∆T is temperature change
As in question , m=8.21 ,s=0.13 ,∆T =6.2
So, Q = 8.21×0.13×6.2=6.61 J
What is the pH when 30.0 ml of 0.005 M HF is mixed with 15.0 ml of 0.01 M NaOH?
Answer:
7.36
Explanation:
my teacher said that was the right answer
why lysine is less basic than arginine
Answer:
Arginine is the most basic among them because it contains guanidine side group, −(CH2)4NHC(=NH)NH2, which is basic. Lysine has two amine groups, which makes it overall basic because of the second isolated amine group (−(CH2)4NH2). Histidine, on the other hand, contains imidazole group, which is also basic.
Explanation:
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what is the result of collisions of particles with an object? *
A. pressure on the object
B. pressure away from the object
C. the object gets lighter
D. the object gets heavier
Answer:
Particle collisions cause pressure.
Explanation:
The fast motion of gas particles gives them a relatively large amount of kinetic energy. Recall that kinetic energy is the energy that an object possesses because of its motion. The particles of a gas move in straight-line motion until they collide with another particle or with one of the walls of its container.
Producers are the most numerous group in an ecosystem. Why?
-------------------------------------------------------------------------------------------------
Producers produce food energy for themselves and all the other levels. ⬜
Soil and temperature conditions in an ecosystem always favor producers. ⬜
As energy flows through the ecosystem, some energy is added at each step. ⬜
There is more room for small organisms than there is for large ones. ⬜
Answer:
The primary producer uses some of that energy. Because we lose energy each time we move up a trophic level, we have more producers than consumers, more herbivores than carnivores, more primary consumers than secondary consumers. See this Socratic answer for more detail.
Explanation:
Answer:
Producers produce food energy for themselves and all the other levels
Explanation:
1. In a heterogeneous mixture, the substances
A. can be physically separated.
B. are chemically combined.
C. can only be separated through chemical
processes.
D. break down into new substances.
Please answer
Select True or False: The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol. Bloom's Level: Understand
True, the entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
The third law of thermodynamics states that, the entropy of a system approaches a constant value as the temperature of the system approaches absolute zero.
The entropy of any perfectly ordered, crystalline substance at absolute zero temperature is zero. That is, the entropy of a pure, perfect crystalline substance at 0 K is 0 J/K.
Thus, we can conclude that the given statement is true. The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
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what percentage of oxygen is attributed fossil fuel combustion
A.43%
B.77%
C.4%
D.17%
Answer:
C. 4%
Explanation:
The answer is 4%
The density of crystalline cl2 at 160K is 2.02g/cm3. calculate the molar volumes
The molar volume (Vm) is the volume occupied by one mole of a chemical element or chemical compound at standard temperature and pressure (STP). The molar volume of Cl₂ is 35.10 cm³/mol.
One mole of any gas has a defined volume when it is at a particular temperature and pressure. The relationship between molar mass and molar volume is direct and inverse, respectively.
Two gases have equal molecules if their volumes are the same at a given temperature and pressure. A gas's volume is directly proportional to the number of moles it contains. One mole of any gas takes up 22.4 L of space at STP.
The expression used to calculate molar volume is:
Molar volume = Molar mass / Density
The molar mass of Cl₂ = 70.906 g/mol
Molar volume = 70.906 / 2.02
Molar volume = 35.10 cm³/mol
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If you add the same amount of heat to two different substances, will they both change phase?
Answer:
It depends on their melting and/or their boiling points, because the heat provides the particles with kinetic energy to break the electrosatic bonds in the substances, which can differ in strength
Explanation:
What are the five different types of leaves? Subject: science
Answer:
Needle and Scale Leaves. This kind of leaves are mostly found in 'evergreen' trees. ...
Lanceolate Leaf. ...
Oblong Leaf. ...
Linear Leaves. ...
Cordate Leaves.
Explanation:
Answer:
Broad
Flat Leaves.
Needle and Scale Leaves.
Oblong Leaf.
Cordate Leaves.
Explanation:
What is chlorine iodine ?
Answer:
Chlorine Iodine is a compound made out of one Chlorine molecule and one Iodine molecule
Explanation:
Which of these is a characteristic of warm air?
It transfers energy through radiation.
Its molecules are far apart.
It sinks due to convection.
It cools the land below it.
Answer: B.
Explanation:
Warm air molecules are far apart, while cool air molecules are packed closer together.
Answer: A It Transfers energy through radiation
Explanation: I jut got done with the exam 15 min ago
why is extra vitamin C excreted in urine from the body but vitamin A in excess is retained in the body
Answer:
Vitamin C is water-soluble and not stored in your body
In contrast to fat-soluble vitamins, water-soluble vitamins do not get stored within the body. Instead, the vitamin C that you consume gets transported to your tissues via body fluids, and any extra gets excreted in urine ( 1 ).
Answer:
The reason vitamin C isn't stored well is because your body can't make it, and vitamin C is a water-soluble vitamin. This means it dissolves in water, and what your body doesn't use right away is excreted through urine. Thus, it is not stored in our body to a significant extent.
Explanation:
In the chemical stockroom, there is a 0.500 L bottle filled with 2.30 M CuSO4 solution. How many moles of CuSO4 are in the bottle?
A. 0.217 moles
B. 4.60 moles
C. 01.15 moles
D. 1.80 moles
The number of moles of the solute in the solution is the product of its volume and molarity. The number of moles of copper sulphate in 0.500 L of 2.30 M solution is 1.15 moles.
What is molarity?Molarity of a solution is the common term used to represent the concentration of a solution. It is the ratio of its number of moles of solute to the volume of solution in liters.
Molarity = no.of moles/volume in L.
Molarity is a temperature dependant quantity.
The given solution has a volume of 0.500 L.
molarity of copper sulphate solution = 2.30 M
Thus, number of moles of copper sulphate solute dissolved in 0.50 L of water is calculated by multiplying the volume with molarity.
No. of. moles of copper sulphate = molarity × volume
= 0.500 L × 2.30 M = 1.15 moles.
Therefore, there will be 1.15 moles of copper sulphate in the solution.
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Help asap plzzzzz!!!!!!!!!!!!!
Answer:
Water will generally require more energy for a phase change compared to a similar substance without hydrogen bonds.
Explanation:
Chlorine is a halogen and has 7 valence electrons, which is represented by crosses on the left
and dots on the right. You'll notice that their orbitals are overlapping and it looks almost like a
Venn Diagram. How many electrons are in the overlapping region?
There are 2 electrons in the overlapping region.
Chlorine is the second member of the halogen group which are form of family of elements that resemble one another very closely.
The electronic configuration of chlorine shows the arrangement of chlorine electrons within it's atom.
At the outer most shell of the atom is seven electrons, therefore requires only one electron each to attain the octet arrangement.
The overlapping of the orbitals indicates the chemical bond formed by sharing of electrons between atoms called covalent bonding.
To complete it's outer most shell, it will need to share electron with another chlorine atom.
Therefore, there are 2 electrons in the overlapping region.
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Which line of evidence has been traditionally accepted as conclusive proof of evolution? the presumed age of the Earth the fossil record Darwin's treatise on the Origin of the Species absolute dating of rocks
The most generally accepted form of conclusive evidence for the theory of Evolution is the fossil record.
What is the theory of Evolution?The theory of evolution was proposed by Charles Darwin.It states that as time passes, organisms evolve to better adapt to their environments.This is closely related to natural selection, which is considered a driving force of evolution. How the fossil record supports this theoryThe fossil record provides essential data to support this claim.The data comes in the form of the comparison between fossils of two closely related organisms, separated by a matter of generations, that present changes in the genetic code that made them more apt for survival.Therefore, we can confirm that the most generally accepted form of conclusive evidence for evolution is the presence of fossils that show the genetic correlation between two organisms and the progression of evolution between them.
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. 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.
How many K are in 32 o C?
Answer:
273.15 Kelvins
Explanation:
Hope this helps !!!Need ASAP will give brainlist
Answer:
i think the answer will be C.
Explanation:
correct me if im wrong
loveya
Sound travels from a phone speaker to the ear of the person listening to the call. Sound waves are modeled by the image below. 1) What do the dots in the image represent? 2) How do sound waves travel through air to a person’s ear?
Answer:
Remember the black and red dots represented in the below animation are not molecules. They are just markers enabling us to visualize the local displacement of air particles and so, the rise and fall of pressure within the wave medium.
The air is made up of many tiny particles. When sound is created, the air particles vibrate and collide with each other, causing the vibrations to pass between air particles. The vibrating particles pass the sound through to a person's ear and vibrate the ear drum. Light travels much faster than sound through air.
Explanation:
whats a covalent bond ?
Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Answer:
A covalent bond is the “interatomic linkage that results from the sharing of an electron pair between two atoms.”
Explanation:
Hope this helps have a nice day
please explain me answer a b c d
Answer:
I don't know the answers of chemistry if you have an entrance question of maths so I can
[tex]\rule{2000pt}{1000000pt}[/tex]
how are homogeneous mixtures different from heterogeneous mixtures
Answer:
In Homogenous mixtures, the whole mixture is in the same phase whereas in Heterogeneous mixture, substances can be of two phases and layers may separate. ... Homogeneous mixture could be exemplified as a sugar solution or salt solution whereas Mixture of salt and sand could be used as an example of Heterogeneous mixture.
write the conjugate bases of the following acids ? H₂S , HCOOH ,HSO₃¯ , HSO¯₄ , HS¯, HNO₂ ,HCN,?
Answer:
HS(-)
HCOO(-)
SO3(2-)
SO4(2-)
S(2-)
NO2(-)
CN(-)
Explanation:
The parenthesis are the charges of the compounds. When an acid is introduced in a base, it dissociates its Hydrogens giving protons to the base. In this case, if you remove one hydrogen of a compound, you will reduce the charge of a compound since basically you're removing a positive charge from a compound. If you need to, I can explain how the thing of the charges work.
In fact, the definition of a conjugate base is a compound created when the original (an acid) compound dissacioate an atom of hydrogen (a proton) in a base.
what is the approximate pH of a solution labeled 0.050 M HCLO ?
Answer:
It would be around 4.4 in PH
Explanation:
I hope this helped.
What is the most soluble in water? iconic, covalent, metallic or nonmetallic
_265Hs--->_16O+_9Be=_____?
Answer:
265hs+24.464536b+16o
Explanation:
265hs+16o+9b(2.718282)
=265hs+16o+24.464536b
=265hs+24.464536b+16o
PLEASE HELP ME!!
The molar mass of BF3 is 67.81 g/mol. How many molecules of BF3 are there in 2 g? (1 point)
A) 1.776 x 1022
B) 8.881 x 1021
C) 1.204 x 1024
D) 4.084 x 1025
Answer:
A
Explanation:
We are given that the molar mass of boron triflouride BF₃ is 67.81 g/mol. We want to determine the number of molecules of BF₃ in 2 g of BF₃.
Recall that there are 6.02 × 10²³ molecules in any mole of a substance. In other words, there are 6.02 × 10²³ BF₃ molecules in a mole of BF₃. Starting with the initial value, multiply:
[tex]\displaystyle \begin{aligned} 2\text{ g BF$_3$}&\cdot \frac{1\text{ mol BF$_3$}}{67.81 \text{ g BF$_3$}} \cdot \frac{6.02\times 10^{23} \text{ molecules BF$_3$}}{1 \text{ mol BF$_3$}} \\ \\ &= 1.776 \times 10^{22} \text{ molecules BF$_3$}\end{aligned}[/tex]
Hence, our answer is A.
*Perhaps it rendered the values incorrectly, but since we started with only 2 g of BF₃, our resulting calculation should only contain one significant digit. Hence, the correct answer should be 2 × 10²² molecules of BF₃.
The molecules of BF₃ that are there in 2 g is 1.776 × 10²² molecules and the correct option is option A.
The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.
A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.
Given,
Molar mass of BF₃ = 67.81 g/mol
Mass = 2g
Moles = mass / molar mass
= 2 / 67.81
= 0.029 moles
1 mole = 6.023 × 10²³
0.029 moles = 6.023 × 10²³ × 0.029
= 1.776 × 10²² molecules
Thus, the ideal selection is option A.
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What is the role of starch in the titration reaction?
Answer:
Starch reacts with Iodine in the presence of Iodide ion to form an intensely colored blue complex, which is visible at very low concentrations of Iodine, making it a very good indicator in both direct and indirect lodometric titrations.
Explanation:
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