Answer:
Carbon plays a unique role among the chemical elements. ... Due to its four valence electrons, carbon is the smallest element that is able to make covalent bonds to four different atoms in its neutral form.
How many moles are there in 3.9 grams of potassium
Answer:
0.0997485824191857
Explanation:
Potassium in 1 mol is 39.0983.
Divide 3.9 by 39.0983.
What is the molecular mass for a non-electrolyte if 35.0 g of it is dissolved in 45.0 grams of water and the solutions boiling point is 101.25oC? (The KB for H2O is .51°C/m)
The boiling point of water increases as the amount of impurities dissolved in it increases. For our purposes, we will consider the non-electrolyte to be the dissolved impurity. The change in the boiling point can be calculated using the equation:
[tex]\Delta T_b = i \times K_b \times m[/tex]
where [tex]\Delta T_b[/tex] is the change in boiling point, [tex]i[/tex] is the van ‘t Hoff factor (whose value denotes the number of particles each formula unit of the dissolved substance dissociates into in water), [tex]K_b[/tex] is the boiling point elevation constant, and [tex]m[/tex] is the molality (moles of solute/kilogram of solvent) of the solution.
Right off the bat, since we're dealing with a non-electrolyte, the dissolved substance can be assumed not to dissociate in water. So, our van ‘t Hoff factor, [tex]i[/tex], would be 1 (by contrast, the [tex]i[/tex] for an ionic compound like NaCl would be 2 since, in water, NaCl would dissociate into two particles: one Na⁺ ion and one Cl⁻ ion). We're also given our [tex]K_b[/tex], which is 0.51 °C/m.
Assuming the normal boiling point of pure water to be 100 °C (a defined value for sig fig purposes), the change in boiling point from having dissolved 35.0 g of the non-electrolyte can be obtained by subtracting 100 °C from the final—elevated—boiling point of 101.25 °C:
[tex]\Delta T_b = 101.25\text{ }^o\text{C} - 100\text{ }^o\text{C} = 1.25\text{ }^o\text{C}[/tex]
Now, recall what we're asked to determine: the molecular mass of the dissolved substance. There is one unknown left in the equation: the molality of the solution. Let's first solve for that:
[tex]m = \frac{\Delta T_b}{K_b} = \frac{1.25^\text{ o}\text{C}}{0.51^\text{ o}\text{C}/m} \\ m = 2.45 \text{ mol solute/kg water}.[/tex]
Notice that we didn't include the i since its value is 1.
Now, what would happen if we multiplied our molality by the mass of water we've been given? We would be left with the moles of solute. And what are we asked to find? The molecular mass, or the mass per mole. We can accomplish this in two steps. Remember to convert your mass of water to kilograms:
[tex]2.45 \text{ mol solute/kg water} \times 0.045 \text{ kg water} = 0.110 \text{ mol solute.}[/tex]
And, finally, we divide the mass of our solute by the number of moles of solute:
[tex]\frac{35.0 \text{ g solute}}{0.110 \text{ mol solute}} = 317.5 \text{ g/mol}[/tex]
Our answer to two significant figures (which is the number of sig figs to which our [tex]K_b[/tex] is given) would be 320 g/mol.
Write a summary paragraph explaining limiting and excess reactants and how you can tell which is which.
Will mark as Brainliest if it's correct and if it's not copied and pasted from the internet :)
3. Which element is the least reactive?
A. Na B. Ca C.P D. Ne
Answer:
Noble gases are the least reactive, so that is He, Ne, Ar, Kr, Xe, Rn, Og.
Explanation:
1Kr + 3 F2 → 1KrF6
2. How many moles of fluorine are required to
produce 3.0 grams of KrFo?
Answer: 0.045 moles of [tex]F_2[/tex] will be required to produce 3.0 grams of [tex]KrF_6[/tex].
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} KrF_6=\frac{3.0g}{198g/mol}=0.015moles[/tex]
The balanced chemical equation is:
[tex]Kr+3F_2\rightarrow KrF_6[/tex]
According to stoichiometry :
1 mole of [tex]KrF_6[/tex] is produced by = 3 moles of [tex]F_2[/tex]
Thus 0.015 moles of [tex]KrF_6[/tex] will be produced by=[tex]\frac{3}{1}\times 0.015=0.045moles[/tex] of [tex]F_2[/tex]
Thus 0.045 moles of [tex]F_2[/tex] will be required to produce 3.0 grams of [tex]KrF_6[/tex].
Part B
Do you think these fish are an example of natural selection among two populations of the same species? Explain your
answer.
B I
x
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JE 3
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Submit
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Answer:
The two fish are of the same species because they can mate with each other. Also, the characteristics of the blind cave fish enable them to live in caves. Eyes need energy. So, developing bodies with no eyes allowed these fish to function more efficiently.
Explanation:
plato answer
1. According to the equation, what mass of hydrogen fluoride is necessary to produce 2.3 g of sodium fluoride?
HF + NaNO3 -> HNO3 + NaF
Answer:
1.09 grams
Explanation:
According to the following chemical equation:
HF + NaNO₃ -> HNO₃ + NaF
1 mol of hydrogen fluoride (HF) produces 1 mol of sodium fluoride (NaF). Thus, we first convert from mol to grams by using the molar mass (MM) of each compound:
MM(HF)= (1 g/mol x 1 H) + (19 g/mol x 1 F) = 20 g/mol HF
1 mol HF x 19.9 g/mol HF = 20 g
MM(NaF) = (23 g/mol x 1 Na) + (19 g/mol x 1 F) = 42 g/mol NaF
1 mol NaF x 42 g/mol NaF = 42 g
Thus, from 20 g of HF are produced 42 g of NaF ⇒ 20 g HF/42 g NaF. We multiply this stoichiometric ratio by the mass of NaF produced to calculate the required mass of HF:
20 g HF/42 g NaF x 2.3 g NaF = 1.09 g HF
Therefore, 1.09 grams of HF are necessary to produce 2.3 g of NaF.
what is always made of the same combination of elements or compounds
What type of reaction is 2O3 ----> 3O2?
Answer:
Explanation:
It is a decomposition although it does not look like it. What is happening is that the O3 is giving up one oxygen, and the oxygen on the right is taking on in the form of a new molecule.
How many grams of water are in 8.16x10^22
Answer:
2.52 g of water
Explanation:
Recall that;
1 mole of water contains 6.02 * 10^23 molecules of water
x moles of water contains 8.16 * 10^22 molecules of water
x = 8.16 * 10^22 * 1/ 6.02 * 10^23
x = 1.4 * 10^-1 = 0.14 moles of water
Then;
1 mole of water = 18 g of water
0.14 moles of water = 0.14 * 18 /1 = 2.52 g of water
please help!! A solid has a melting point if 1710 C is soluble in water, and does not conduct electricity in the solid state. What is the most likely nature of the binding in this solid?
A) Molecular covalent B) Network Covalent C) Ionic D) Metallic
Answer:
d metallic
Explanation:
The domain level divides
organisms based on the
differences between
eukaryotes and
prokaryotes. Eukaryotes
have a nucleus in their
cells. Which BEST describes
prokaryotes?
A. Prokaryotes are nonliving things.
B. Prokaryotes do NOT have a nucleus.
C. Prokaryotes include all plant life.
D. Prokaryotes cannot reproduce.
Answer:
B. Prokaryotes do NOT have a nucleus.
how many moles are in 32.3g of calcium phosphate
Answer: the formula mass of calcium phosphate [Ca3(PO4)2] is 310.177 amu, so its molar mass is 310.177 g/mol. This is the mass of calcium phosphate that contains 6.022 × 1023 formula units.
Answer: 310.177
element with same number of valence electrons as iodine:
Fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) all have the same number of valence electrons.
What is valence electron ?
Valence is nothing but a number of electrons in an atom which may either lose or gain to attain the nearest noble gas or inert gas state of electronic configuration.
The valence electrons are contain more energy compared to the electrons present in inner orbits, so they are the part of chemical reaction.
The number of valence electrons of an atom helps to determine a specific chemical properties, like valence or valency, the formation of bonds with other elements, gives an idea of how readily the atoms can form bonds.
Some major characteristics of a valence electron include the valence electron exists only in the outermost electron shell, exist in the inner shell of a transition metal, the atom with the shell of valence electrons are chemically inert, either absorb or release energy in the form of a photon, determine electrical conductivity .
For more details valence electron, visit
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A 5.00 gram sample of water is heated so that its temperature increases from 10.0°C to 15.0°C. What is the
total amount of energy absorbed by the water?
Answer:
15.0°C
Explanation:
hope it helps
Heat Capacity
The heat capacity of a substance can be defined as the amount of heat required to change the temperature by a given amount the SI unit is joules per kelvin
The energy absorbed by the water is 105 joules
Given data:
mass of water = 5 grams
Change in temperature = 10 degrees from 15 degrees
The expression for the Quantity of heat is given by
Q = m x c x Δθ
Where m =mass
c = specific heat capacity and
Δθ = change in temperature
c = 4.2J/g/degrees
Q = 5 x 4.2 x (15 - 10)
Q = 5 x 4.2 x 5
Q = 105Joules
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Na + O2 → Na2O2
Can you guys help me !
Answer:
Explanation:
Assuming that you are asking for the full-balanced equations...
2Na + O2 = Na2O2
H2 + O2 = H2O2; This equation is already balanced, there is no need for change.
Please let me know if this is not the answer you are looking for and I will amend the answer.
An ionic bond involves two elements...
Answer:
a metal and a nonmetal element
Explanation:
What is the farthest distance the moon gets from Earth?
Answer:
When the Moon is the farthest away, it's 252,088 miles away. That's almost 32 Earths.
Explanation: The orbit is not a perfect circle.
Answer:
Explanation:
At perigee its closest approach the moon comes as close as 225,623 miles (363,104 kilometers).
At apogee the farthest away it gets the moon is 252,088 miles (405,696 km) from Earth.
How many atoms in 12 moles of oxygen
Answer:
7.23 x 10^24 atoms
Explanation:
Use Avogadro's number that states that there are 6.022 x 10^23 particles in one mole:
12 mol O x (6.022 x 10^23) atoms = 7.23 x 10^24 atoms
32 g of CH4 react with 128 g of O2, producing 88 g of CO2. How many grams of water are produced?
Answer:
88 g
Explanation:
32 g of CH4 react with 128 g of O2, producing 88 g of CO2.
what is a liquid? can a liquid change shape or volume
Answer:
A liquid is a substance that is wet and yes it can change shape and volume
Explanation:
What is the relationship between temperature and kinetic energy?
When all molecular motion stops, the temperature stop charging.
As molecules move more quickly, temperature increases.
When all molecular motion stops, the temperature starts to decrease.
As a molecules slow down, temperature starts to increase.
Answer:
As molecules move more quickly, temperature increases.
Explanation:
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Any material or object that allow the conduction (transfer) of electric charge or thermal energy is generally referred to as a conductor. Some examples of a conductor are metals, copper, aluminum, graphite, etc.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
Hence, the relationship between temperature and kinetic energy is that as molecules move more quickly, temperature increases due to the absorption of heat.
Can Someone Please help me answer this question? I will try to give brainliest.
Answer:
I believe the answer is y-axis
Explanation:
Sorry if it's not I just wanted to help you in return for helping me!!
Answer:
Y axis I think
Explanation:
If grasshoppers were removed from this food web which organism Would suffer the most birds or Baboon your answer please help thanks
Answer:
baboon po
Explanation:
basta yan anwer hope helpa
Answer:
birds for sure
Explanation:
cause baboons have another eating source
CO2 + H2O --> C2H2 + O2
Answer:
C2H2 + 5 O2 = 4 CO2 + 2 H2O
Add / Edited: 27.09.2014 / 25.01.2015
Evaluation of information: 5.0 out of 5 / number of votes: 2
Source: https://chemiday.com/en/reaction/3-1-0-339
Explanation:
what is the electrical charge of an atom
Earth is removed from the top to reveal the coal. Which type of coal mine does this describe? undersea subterranean drill strip
Answer:
Strip
Explanation:
Strip mining removes Earth in long strips from the top to reveal the coal. This earth to be removed is known as 'overburden'. The overburden from the first strip is referred to as out-of-pit dumping. Strip mining is a part of surface mining.
Strip mining destroys forests, landscapes, forests and wildlife habitats as trees and plants are removed from the mining area.
Therefore,
this describes the Strip coal mine.
Answer:
strip Mining.
Explanation:
Explain why electrons in the outer
energy levels are less stable than
those closer to the nucleus.
Answer:
Explanation:
The electrons in the outer shell can be stripped from their main atom more easy than the inner shell electrons.
16. Keesha performed a chemical reaction, and the products looked quite
different from the reactants. She knew the amount of matter had not
changed due to the law of conservation of mass. According to the law of
conservation of mass, what happens in a chemical reaction? *
Answer:
it's the third one
Explanation:
matter can't change, but mass can differ
A geologist finds an area with a lot of slate, a type of metamorphic rock, on the surface of the land. What might this indicate about Earth's history in this area?
Answer:
Explanation:
Two things that can be deduced by this finding would be that the location was most likely a very muddy area with lots of clay minerals, as well as having lots of crustal movements. This is because slate is created when crustal movement buries clay minerals and other materials in the crust of the Earth. This is later melted and squeezed together from the sheer heat that is applied being so far underground. Therefore, creating what we now know as Slate.