Answer:
Since elements in a group have the same number of valence electrons, they behave similarly in chemistry. An example would be the alkali metals (excepting hydrogen. Hydrogen is in this group only because it has one valence electron.
Explanation:
because it is
1. The strength with which an organic compound binds to an adsorbent depends on the strength of the following types of interactions: ion-dipole, dipole-dipole, hydrogen bonding, dipole induced dipole, and van der Waals forces. With silica gel, the dominant interactive forces between the adsorbent and the materials to be separated are_________________.
Answer:
Dipole-dipole interactions
Explanation:
Dipole-dipole interactions occur between two molecules with two polar end- a partially positive end and a partially negative end. The dipoles exists in these molecules due to the difference in the electronegativities of the atoms if the molecule. The positive end of a dipolar molecule will be attracted to the partially negative end of the neighboring molecule.
In the separation of molecules using silica gel as the adsorbent surface, the dominant interactive forces between the adsorbent and the materials to be separated are dipole-dipole interactions. The silica gel have polar SiOH groups on its surface which attracts polar molecules in the material to be separated. These polar molecules are strongly adsorbed to the silica gel surface whereas nonpolar or less polar molecules in the material to be separated are less strongly adsorbed, and thus, are eluted faster than the polar molecules.
Which best explains why the trend in noble gas boiling points increases down the group?A) increasing dispersion interactions B) increasing dipole-dipole interactions C) increasing ion-dipole interactions D) increasing hydrogen bonding interactions E) increasing ion-ion interactions
Answer:
A) increasing dispersion interactions
Explanation:
Polarizability allows gases containing atoms or nonpolar molecules (for example, to condense. In these gases, the most important kind of interaction produces dispersion forces, attractive forces that arise as a result of temporary dipoles induced in atoms or molecules.
Dispersion forces, which are also called London forces, usually increase with molar mass because molecules with larger molar mass tend to have more electrons, and dispersion forces increase in strength with the number of electrons. Furthermore, larger molar mass often means a bigger atom whose electron distribution is more easily disturbed because the outer electrons are less tightly held by the nuclei.
Because the noble gases are all nonpolar molecules, the only attractive intermolecular forces present are the dispersion forces.
The boiling point of the noble gas increases on moving down the group because of the increase in the dispersion force. Thus, option A is correct.
The noble gas has been consisted of the fully complete octet of the atom and has been less reactive in nature.
On moving down the group, there has been an increase in the number of shells of the atom with the increase in the atomic mass. The bigger molecules tend to have loosely bonded outermost electrons.
In noble gases, the force acting upon the molecule has been the Dispersion force. Since, the noble gas has a complete octet, the energy for removing the electrons and changing the state increase with the increase in the molecular mass.
The only force acting on the noble gases has been the dispersion force, Thus with an increase in the dispersion force, the boiling point increases. Thus, option A is correct.
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What mass of nitrogen is needed to fill an 855 L tank at STP?
Answer:
1068.8 g of N₂ are required.
We can also say, 1.07 kg of N₂
Explanation:
Let's apply the Ideal Gas Law equation to solve the problem:
Formula is P . V = n . R . T
At STP we know, that P is 1 atm and T is 273.15 K. So let's replace the formula:
1 atm . 855 L = n . 0.082 L.atm /mol.K . 273.15 K
(1atm . 855L) / (0.082 L.atm /mol.K . 273.15 K) = n
38.17 moles = n
Let's convert the moles to mass, nitrogen is a dyatomic gas → N₂
Molar mass N₂ = 28 g/mol
38.17 mol . 28 g/mol = 1068.8 g of N₂ are required.
AT STP the 1 moles of gas is equal to the 22.4 L of gas. The mass of the nitrogen gas in the 855 L tank at STP is 1068 g.
The mass of the Nitrogen gas can be calculate using the formula,
[tex]\bold {w = n \times m}\\[/tex]
Where,
w -mass = ?
n - number of moles = [tex]\bold {=\dfrac {855}{22.4} = 38.169\ moles }[/tex] at STP.
m - molar mass [tex]\bold {N_2}[/tex] =
Put the values in the formula,
[tex]\bold {w = 38.169 \times 28 = 1068.73\ g}[/tex]
Therefore, the mass of the nitrogen gas in the 855 L tank at STP is 1068 g.
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In which of the following compounds is the octet expanded to include 12 electrons?
PC13
H2S
SF6
PCIE
Answer: SF6
Sulfur hexafluoride or sulphur hexafluoride, is an inorganic, colorless, odorless, non-flammable, non-toxic but extremely potent greenhouse gas, and an excellent electrical insulator. SF₆ has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom.
Which part of the immune system is a physical barrier?
skin
tears
mucus
stomach acid
Answer:
Which part of the immune system is a physical barrier?
> Skin.
How can individuals in communities prevent the global spread of hepatitis C?
> By avoiding the blood of other people.
A)skin is a physical barrier.
What type of barrier is skin?The physical barrier is incorporating the stratum corneum, corneocytes, and lipid layers, as well as the nucleated epidermis.
The skin provides an effective barrier between the organism and the environment, preventing the invasion of pathogens and fending off chemical and physical assaults, as well as the unregulated loss of water and solutes.
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Given a solution of 5.0% by volume oleic acid in alcohol: Two drops (100 drops/cm3) are placed on a water surface and a continuous, circular film is formed 16.0 cm in diameter after all the alcohol has evaporated and the oil is distributed evenly on the surface. What would be the thickness of the layer of pure oil
Answer:
Thickness = 5.0 * 10^-6 to 1 significant figure
Explanation:
Volume of oleic acid added:
2 drops when there are 100 drops per cm³ means that each drop has a volume of;
2 * 0.01 = 0.02 cm³
A 5% v/v oleic acid in solution will contain:
5/100 * 0.02 = 0.001 cm³ of oleic acid .
Area of circular film on the water surface = πr²
where r, radius = 16 /2 = 8cm, π = 3.14
Area = 3.14 * 8²
Area = 201 cm²
Since volume = area * height or thickness
Thickness = volume/area
Thickness = 0.001 cm³ / 201 cm²
Thickness = 0.00000498 or 4.98 * 10^-6 cm
Thickness = 5.0 * 10^-6 to 1 significant figure
Draw the Lewis structure for (CH3)4NCl, a salt.
Answer:
See attached picture.
Explanation:
Hello,
In this case, for the given compound, since it is a salt, it contains a cation (positive charge) and an anion (negative charge), thus, since chlorine tends to gain electrons, it is negative whereas the nitrogen-containing side is positive, forming the anion and cation respectively. Moreover, for the drawing of its Lewis structure we must know that the chlorine is likely to interact via its seven valence electrons with nitrogen via its five valence electrons wherein four are bonded with four methyl radicals forming the tetramethylammonium chloride as shown on the attached picture.
We must realize that the nitrogen remain positively charged due to the presence of an extra bond with one methyl group (one carbon bonded to three hydrogens) which allow the formation of the salt.
Regards.
The Lewis structure for compound [tex](CH_3)_4NCl[/tex] is attached in the image below as an attachment.
Lewis structures are also called as electron dot structures and can be drawn if the molecular formula of a compound is known. It provides information regarding the nature of bond and the position of atoms .
They are also capable of exhibiting the lone pair if any present in a molecule or compound.Lewis defined a base to be an electron pair donor and an acid to be an electron pair acceptor.
Thus, the Lewis structure for compound [tex](CH_3)_4NCl[/tex] is attached in the image below as an attachment.
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QUESTION 10
A bottle of vitamin water contains 3500 mg of potassium in 591.5g of H 20 What is the concentration of potassium by mass percent?
085.5%
O 5.92%
O 0.59%
O 16.9%
Answer:
[tex]\% m/m=0.59\%[/tex]
Explanation:
Hello,
In this case, since the by mass percent is for potassium in this vitamin is:
[tex]\% m/m=\frac{m_K}{m_K+m_W}*100\%[/tex]
Thus, for 3500 mg of potassium that in grams are 3.5, the by mass percent turns out:
[tex]\% m/m=\frac{3.5g}{3.5g+591.5g}*100\%\\\\\% m/m=0.59\%[/tex]
Best regards.
what is the chemistery
Answer:
Explanation:
Chemistry is the science that studies the composition, structure and properties of matter and the changes it undergoes during chemical reactions and their relationship with energy
Explanation:
Chemistry is the branch of science concerned with the substances of which matter is composed, the investigation of their properties and reactions, and the use of such reactions to form new substances.
At 50 degree C pK_w = 13.26. What is the pH of pure water at this temperature?
a. 6.63
b. 7.00
c. 7.37
d. 13.26
Answer:
6.63
Explanation:
From the relationship;
pH = pKw/2
Pkw = 13.26
Then it follows that;
pH = 6.63
Hence if. pKw = 13.26, the pH = 6.63
Match the scientist with their scientific idea.
Substances combine or
break apart to create new,
different substances.
1. Democritus
2. Bernoulli
Gases are formed from tiny
particles so small you can't
see them. The particles are
spread out into a certain
area and move when
people walk through them.
3. Priestley
Matter was made of
different kinds of things.
Answer:
1. Democritus- Matter was made of
different kinds of things.
2. Bernoulli- Gases are formed from tiny particles so small you can't see them. The particles are spread out into a certain area and move when people walk through them.
3. Priestley- Substances combine or
break apart to create new different substances.
Explanation:
1. Democritus was a Greek philosopher regarded to be the "Father of Science". He discovered that all matter were composed of indestructible things he called ATOMOS. Hence, his idea was that Matter was made of different kinds of things (atoms).
2. David Bernoulli, a mathematician, was born in 1700. He contributed immensely to the kinetic molecular theory of gases. In his postulated theory, he gave the idea that gases are formed from tiny particles so small you can't see them. The particles are spread out into a certain area and move when people walk through them.
3. Priestley- Joseph Priestley, born in 1733, is widely known for his discovery of oxygen gas among other gases. His idea was that substances combine or
break apart to create new different substances.
What is impossible for a machine to do?
A. do a greater amount of work than the amount of work done on the machine
B. apply a force in a direction that is different than the direction of the force applied to the machine
C. move an object a greater distance than the distance that part of the machine was moved
D. apply a force that is less than the force that is applied to the machine
Answer:
CExplanation:
move an object a greater distance than the distance that part of the machine was moved
Answer:
a, sorry for late answer!!Explanation:
You have been given an orange liquid and told to describe its properties.
What methods would you use to observe, measure, and describe the
physical properties of this orange liquid without changing it?
Answer:
The correct answer would be - observing with the help of five senses.
Explanation:
To find and describe the physical properties of the given substance or the solution or liquid students can observe using their five senses. By looking at the liquid one can find its state and color, by smelling students can find the odor of the sample, by touching it one can observe and describe the texture.
Fluidity can also be measure by the touch if the solution is viscous or free-floating. By using a thermometer and using a graduated cylinder one can find the temperature at room temperature and the weight of substance respectively.
what is the coefficient of O2 when the equation is balanced?C4H8O2+O2
What are the differences between ionic and covalent (molecular) compounds?
Answer: Ionic compound are made by strong electrostatic interactions in the middle of ion , which will result in higher melting points and electrical conductivity when being compared to covalent compounds . covalent counds have bonds where the electrons are shared allying atoms .
Hoped I Helped-
Sleepy~
Whats the atomic radius of tin (Sn)
Explanation:
the atomic radius of ( Sn) is 225pm
1. How many elements are in the following Compound?
C8H10N,O2
Answer:
i believe it is 5
Explanation:
.......
What is the change in density if a sample goes from 3.21 g/L to 5.43 g/mL?
Answer:
[tex]\Delta \rho =2.22 g/mL[/tex]
Explanation:
Hello,
In this case, since a change in science is widely known to be considered as a subtraction between the the final and initial values of two measured variables and is represented via Δ, here the final density is 5.43 g/mL and the initial one was 3.21 g/mL, therefore, the change in density is:
[tex]\Delta \rho=\rho _f-\rho _i\\ \\\Delta \rho=5.43g/mL-3.21g/mL\\\\\Delta \rho =2.22 g/mL[/tex]
Best regards.
How many moles of HCl are present in 75.0 mL of a 0.200 M
solution?
Answer:
0.015 mol HCL
Explanation:
Molarity = moles solute/liters solution
Step 1: Define variables
M = 0.200
L = 75.0 mL
m = unknown, x
Step 2: Convert mL to L
1000 mL = 1 L
75.0 mL/1000 mL = 0.075 L
Step 3: Substitute
0.200 M = x mol/0.075 L
Step 4: Find x
x = 0.015 mol HCL
Group one elements, such as lithium, sodium, and
potassium, are known as
OA) alkali metals.
B)
halogens.
C) alkaline earth metals.
D) noble gasses.
Answer:
Alkali Metals
Explanation:
Because they are in group one, but Hydrogen is not an alkali metal.
Things that you learn through your senses during an experiment are
A. hypotheses
B. controls
C. observations
D. conclusion
Answer:
c- observations
hope this helps
Explanation:
How many mol of butan-1-ol are in 10.0 mL of butan-1-ol?
1) 0.165 mol
2) 0.109 mol
3) 0.943 mol
4) 0.258 mol
Answer:
2) 0.109 mol
Explanation:
The density of butan-1-ol is 0.8098g/mL. And its molar mass is: 74.121g/mol.
First, we need to convert volume of butan-1-ol to mass:
10.0mL * (0.8098g / mL) = 8.098g of butan-1-ol
Now, we need to convert these grams to moles using molar mass:
8.098g * (1mol / 74.121g) = 0.109 moles of butan-1-ol
Right answer is:
2) 0.109 moluppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 2.04 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 20.95 mL. What volume, in mL, of base was required for the titration?
Answer:
18.91 ml
Explanation:
Initial volume of base=2.04 ml
Final volume of base = 20.95 ml
Volume of base used= 20.95 - 2.04 = 18.91 ml
Note that the volume of base used is obtained as the difference between the final and initial volume of base, hence the answer given above.
which two quantities are used to predict gravitational force according to Newton's law of universal gravitation a. mass and speed b. mass and distance c. distance and velocity d. velocity and mass
Answer:
(b). Mass and distance.
Explanation:
The gravitational force between two objects is given by Newton's law of universal gravitation. The formula is as follows :
[tex]F=G\dfrac{m_1m_2}{r^2}[/tex]
Here,
G is universal gravitational constant
r is the distance between two objects
It is very clear that the gravitational force is directly proportional to the product of masses and inversely proportional to the square of the distance between them.
Hence, the two quantities are used to predict gravitational force according to Newton's law of universal gravitation are mass and distance.
Answer:mass and distance
Explanation:
it’s correct
An element has two isotopes. 90% of the isotopes have a mass number of 20 amu, while 10% have a mass number of 22 amu. Calculate the Average Atomic Mass of the element
Explanation:
aam= 90%•20amu+10%•22amu/100
aam= 2020/100
aam= 20.2
Taking into account the definition of atomic mass, isotopes and atomic mass of an element, the average mass of the element is 20.2.
First of all, you have to know that atoms are made up of protons and neutrons in a central nucleus, as well as an electronic cloud (the extra-nuclear zone), a place where there is a greater probability of finding electrons orbiting the nucleus of the atom.
Then, it is neccesary to know that the atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus.
The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element.
This is, isotopes are atoms whose atomic nuclei have the same number of protons but different numbers of neutrons.
Because the isotopes of an element have different atomic masses, the relative atomic mass or atomic weight is an average of the atomic masses of the different isotopes in a sample taking into account the relative abundance of each of them.
In this case, 90% of the isotopes have a mass number of 20 amu, while 10% have a mass number of 22 amu. Then, the average mass of the element can be calculated as:
20 amu×0.90 + 22 amu×0.10= 20.2
Finally, the average mass of the element is 20.2.
Learn more:
brainly.com/question/14403750?referrer=searchResults brainly.com/question/10043246?referrer=searchResults brainly.com/question/15553207?referrer=searchResultswhat is the ability to transfer thermal energy to something else
Answer:
.Heat energy can be transferred from one object to another. The transfer or flow due to the difference in temperature between the two objects is called heat.
Explanation:
The transfer of thermal energy is called heat. In this process, thermal energy moves through a substance. For example, an ice cube has heat energy and so does a glass of lemonade.
where is the fulcrum of this lever? circle and label its location on the diagram above
how do you balance the object on the measurement tray?
Answer:
Explanation:
1) A fulcrum is a pivot point that plays a central role (not necessarily located at the center) in a lever. The fulcrum of the attached picture has been circled (in blue).
2) The object placed on this lever's measurement tray is balanced by placing it at the center of the tray. This is the standard way of placing objects on any balance.
The fixed point on the rigid bar around which the machine (lever) can turn is called the fulcrum. It refers to the support that the lever rotates around. For instance, the midway or support is where the rod will pivot in the case of a common balance.
1) A fulcrum is a pivot point that plays a crucial (but not always essential) role in a lever. The accompanying image's fulcrum has been highlighted in blue with a circle.
2) By putting it in the middle of the measurement tray for this lever, the object is balanced. The norm for placing items on any balance is in this manner.
The pivotal point of the beam is known as the fulcrum. A load is applied at the other end of a lever when an effort is exerted on one end of the lever.
The fulcrum can be shown as follows:
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What type of cell is the typical human body cell
Answer:
Red blood cells
Explanation:
An average adult human has somewhere around 25 trillion red blood cells in their body.
Answer:
Heya! Maddie here! The answer is Red Blood Cells.
Explanation:
Hope this helps!
Peptides can be separated using an ion-exchange column based on their isoelectric (pl) values. At which pH values would two different peptides, one with a pl of 5.0 and the other with a pi of 9.4, bind to a caution- and anion-exchange column? Each peptide may be capable of binding to each column at more than one pH value. anion-exchange column at pH = 3.0__________pH = 7.1__________ pH = 10.1_____________ cation-exchange column at pH = 3.0____________ pH = 7.1___________pH = 10.1___________
Answer:b
Explanation:
2) 183 cg =
kg
5
.00183 kg
0.0183 kg
.183 kg
3) 0.25 kg =
g
Answer:
183 cg = 0.00183 kg
0.25 kg = 250 g
Explanation:
Use conversion factors. 1kg is equal to 1 x 10^5 cg (100000) and 1 kg is equal to 1 x 10^3 grams (1000 grams).
