Answer:
1. 1.72 moles of potassium.
2. All of the answers are true
3. Are used up during a reaction
Explanation:
Recall that the number of moles is obtained from;
Number of moles= Mass of potassium/ molar mass of potassium
Mass of potassium= 67 g
Molar mass of potassium= 39 gmol-1
Number of moles of K= 67 g/ 39 gmol-1
Number of moles = 1.72 moles of potassium.
2. When we look at all the options, we will realize that all the options are true. The rate of reaction doubles for each 10°C rise in temperature, increasing reactant concentration increases particle collision and ultimately increases the rate of reaction. Rate of reaction deals with rate of disappearance of reactants or rate of appearance of products.
3. Catalysts remain unchanged in a chemical reaction because they do not actually participate in the reaction. Hence they are not used up in any chemical reaction.
How will you test for the gas which is liberated when hcl reacts with an active metal ?
Calculate the percent ionic, the percent covalent, and the bond length (in picometers) of a chemical bond between phosphorus and selenium.
Phosphorus—atomic radius: 109 pm; covalent radius: 106 pm; ionic radius: 212 pm.
Selenium—atomic radius: 122 pm; covalent radius: 116 pm; ionic radius: 198 pm.
98 percent ionic, 2 percent covalent, 410 pm
4 percent ionic, 96 percent covalent, 222 pm
2 percent ionic, 98 percent covalent, 222 pm
96 percent ionic, 4 percent covalent, 410 pm
Answer:
The correct option is;
4 percent ionic, 96 percent covalent, 222 pm
Explanation:
The parameters given are;
Phosphorus:
Atomic radius = 109 pm
Covalent radius = 106 pm
Ionic radius = 212 pm
Electronegativity of phosphorus = 2.19
Selenium:
Atomic radius = 122 pm
Covalent radius = 116 pm
Ionic radius = 198 pm
Electronegativity of selenium= 2.55
The percentage ionic character of the chemical bond between phosphorus and selenium is given by the relation;
Using Pauling's alternative electronegativity difference method, we have;
[tex]\% \, Ionic \ Character = \left [18\times (\bigtriangleup E.N.)^{1.4} \right ] \%[/tex]
Where:
Δ E.N. = Change in electronegativity = 2.55 - 2.19 = 0.36
Therefore;
[tex]\% \, Ionic \ Character = \left [18\times (0.36)^{1.4} \right ] \% = 4.3 \%[/tex]
Hence the percentage ionic character = 4.3% ≈ 4%
the percentage covalent character = (100 - 4.3)% = 95.7% ≈ 96%
The bond length for the covalent bond is found adding the covalent radii of both atoms as follows;
The bond length for the covalent bond = 106 pm + 116 pm = 222 pm.
The correct option is therefore, 4 percent ionic, 96 percent covalent, 222 pm.
An elements mass number is made up of the number of ____ in the nucleus.
protons and neutrons
electrons and neutrons
protons and electrons
atoms and molecules
Answer:
The answer is protons and nuetrons
Explanation:
The pressure inside of a sealed tube if you raise the temperature go ______..
Answer:
The pressure will increase due ot expnasion of gasses in a closed sealed tube tube .
Explanation:
Answer:
The pressure inside of a sealed tube will increase if the temperature is raised.
Explanation:
When the temperature of the gas inside the sealed tube is raised, the particles within that tube will start to become faster and faster. Because they are going faster they collide with the sides of the tube faster, therefore increasing the pressure inside the sealed tube.
Hope this helps!
can a substance be a lewis acid without being a bronsted-lowry acid?argue
Answer:
Yes
Explanation:
Yes, A substance can be a lewis acid without being a Bronsted-Lowery acid because there are some substances which cannot donate protons(Bronsted-Lowery acid) but can accept a pair of electron.
For Example:
Let us take the example of BF₃
BF₃ contains no proton so it is not a Bronsted Lowery Acid
However, BF₃ has an incomplete octet with 6 electrons. It needs an electron pair to complete its octet. It accepts a pair of electron to become a Lewis Acid
Answer:
Interesting question, and the answer is yes, a substance can be a Lewis acid but not a Bronsted-Lowrey acid. To see this, let’s take a look at the definitions of each.
Explanation:
Bronsted-Lowrey acid:
A compound that is a hydrogen ion (proton) donor. When dissolved in the solvent in question, these compounds lose a proton to the solution. The concentration of these protons in solution is referred to as acidity, and is measured on the pH scale.
Lewis acid:
A substance that is an electron pair receiver. In solution, free electron pairs will form bonds with the substance, either ionic or covalent. In this definition, a proton is itself an acid, rather than a part of an acid.
A key thing to note here is that, in the Bronsted-Lowrey definition, there must be a proton. That means, all Bronsted-Lowrey acids are of the form HXn→H++Xn− , showing the dissociation in solution. However, a Lewis acid needs only to have the ability to accept an electron pair, which means that H+ is a Lewis acid, instead of what makes a compound an acid. Additionally, that means that the number of compounds that qualify as a Lewis acid are expanded. A favorite example of mine is boron trifluoride, or BF3 . It is a common reagent in organic synthesis, it is a Lewis acid, but does not have any hydrogen, so it cannot be a Bronsted-Lowrey acid
A compound contains 34.5% calcium, 24.1% silicon and 41.4% oxygen by mass. What is its empirical formula?
[tex]empirical \: formula \\ = CaSiO3 \\ please \: see \: the \: attached \: picture \\ hope \: it \: helps[/tex]
9.0 L of a gas at 25 oC expands to a volume of 25.0 L. What is the resulting temperature in Kelvin?
Answer:
Explanation:
H
Where do you find the molar mass of an element
Answer:
Mass of a given chemical element or compound divided by the amount of substance.
(g/mol)
The forces between water molecules are stronger
than the forces between ethanol molecules. Which
liquid would probably be most difficult for an insect
to walk on? Explain your answer.
Answer:
An insect would have an easier time walking on the surface of water than on the surface of ethanol.
Water's stronger intermolecular forces lead to higher surface tension.
Higher surface tension allows water to support the insect.
Answer:
An insect would have an easier time walking on the surface of water than on the surface of ethanol.
Water's stronger intermolecular forces lead to higher surface tension.
Higher surface tension allows water to support the insect.
Explanation:
this is a multiple choice question. one of the answer from the option given is correct.Could you please help!!My sister needs help but she doesn't trust me '_' why am i even saying this, no one asked
6.What are the main
sources of water pollution?
a) Plastic, paper, metal
b) Snail in water
c) Agriculture, industry and community
C.
i cant explain why..................
Why does the ionization energy change when moving down a group of elements?
The number of valence electrons increases.
The nuclear positive charge increases.
The energy levels are increasing.
The attractive force decreases as the atom gets larger.
Answer:
D) The attractive force decreases as the atom gets larger.
Explanation:
i did the lesson and tried all 3, all 3 times, this was the last one and only choice left so it has to be.
Answer:
The attractive force decreases as the atom gets larger.
Explanation:
How marly electrons are in an atom of elemental
sodium?
Answer: 11 Electrons
Explanation:
We know that the atomic number of sodium is 11. This tells us that sodium has 11 protons and because it is neutral it has 11 electrons.
Answer:
The sodium atom is left with a full outermost electron shell with eight electrons, and the outermost shell of the other atom is full as well.
Explanation:
The sodium atom now has a positive electrical charge of plus 1, and the other atom has a negative charge of minus 1. The two opposite charges attract, and the two atoms now form the molecule of a compound.
Why you cannot add 0.3 moles of calcium fluoride directly to 1L of water to make a 0.3 M
solution ?
need help ASAP!
Answer:
Because it's not soluble in water, need to be heated acidic solution
Explanation:
Calcium Fluoride Formula: CaF2 Comprises of Ca2+ and F−
H2O = Water H+ O2- OH-
Insoluble in water
In order to dissolve a salt, you have to break apart the ions and hydrate them via a solvent.
Need to read
HSAB concept( Pearson acid-base concept) is an initialism for "hard and soft (Lewis) acids and bases"
So F- is a Halogen which is a Hard Base
And OH- is a Hard base as well
And H- is a soft base
So soft acids react best with soft bases and hard acids react best with hard bases.
Bases don't react with other bases.
Photosynthesis produces (4 points)
carbon dioxide and energy
carbon dioxide and oxygen
glucose and oxygen
glucose and carbon dioxide
(I'm pretty positive it's C, but correct me if I'm wrong)
Answer:
Glucose and oxygen is produced during photosyntheis
Explanation:
Carbon dioxide and water are required for photosyntheis producing oxygen and glucose
Answer:
C.Glucose and oxygen
What is a chemical solution and what are the names of its components?
Answer:
A chemical solution is defined as a homogeneous mixture of two or more substances. There are two components of chemical solution that include solute and solvent.
Solute is the component that get dissolved in another substance and solvent is the substance that dissolve solute.
For example: carbon dioxide in water. Where carbon-dioxide is solute and water is solvent.
You have nitrogen gas (N2) at a pressure of 0.5 atm, a volume of 25000 mL, and a temperature of 300 K, how many grams of nitrogen are present?
Answer:
About 7.109g
Explanation:
25000mL is the same as 25 liters.
[tex]PV=nRT \\\\0.5 (25)=n (0.0821) (300) \\\\n\approx 0.508[/tex]
Multiplying this by the molar mass of nitrogen, you get about 7.109 grams of nitrogen. Hope this helps!
I NEED HELP PLEASE, THANKS! :)
The mole is a counting number that allows scientists to describe how individual molecules and atoms react. If one mole of atoms or molecules is equal to 6.022 × 10^23 atoms or molecules, how many molecules are in a 23.45 g sample of copper (II) hydroxide, Cu(OH)2? Express your answer to the correct number of significant figures. (MM of Cu(OH)2 is 97.562 g/mol)
Answer:
[tex]\large \boxed{1.447 \times 10^{23}\text{ molecules Cu(OH)}_{2 }}[/tex]
Explanation:
1. Calculate the moles of copper(II) hydroxide
[tex]\text{Moles of Cu(OH)}_{2} = \text{23.45 g Cu(OH)}_{2} \times \dfrac{\text{1 mol Cu(OH)}_{2}}{\text{97.562 g Cu(OH)}_{2}} = \\\\\text{0.240 36 mol Cu(OH)}_{2}[/tex]
2. Calculate the molecules of copper(II) hydroxide
[tex]\text{No. of molecules} = \text{0.240 36 mol Cu(OH)}_{2} \times \dfrac{6.022 \times 10^{23}\text{ molecules Cu(OH)}_{2}}{\text{1 mol Cu(OH)}_{2}}\\\\= 1.447 \times 10^{23}\text{ molecules Cu(OH)}_{2}\\\text{The sample contains $\large \boxed{\mathbf{1.447 \times 10^{23}}\textbf{ molecules Cu(OH)}_{\mathbf{2}}}$}[/tex]
Answer:
Mass of Cu(OH)2 = 23.45 g
Molar mass of Cu(OH)2 = 97.562 g/mol
Since we know,
Moles = Mass/Molar mass
\Rightarrow Moles = (23.45 g)/(97.562 g/mol) = 0.2404 moles
Since 1 mole of substance contains = 6.022 × 1023 molecules
So 0.2404 moles will contain = 0.2404*(6.022 × 1023 molecules) = 1.448 × 1023 molecules
Explanation:
The pictures to the right, show two different models
of the atom. Type in the letter of your answer.
Which model best represents Dalton's atomic
theory?
Answer:
The pictures to the right, show two different models of the atom. Type in the letter of your answer.
Which model best represents Dalton’s atomic theory?
B
Which model best represents the modifications to the theory that Thomson’s results made necessary?
A
The model that represents Dalton's atomic model is the B model.
Dalton's Atomic TheoryDalton was a scientist who described how the atom is characterized, stating that the atom would be a massive and indestructible sphere, that is, it was not divided into subparticles (electrons, protons and neutrons).
Thus, model B is the most suitable according to Dalton's statements.
Learn more about atomic theories in: brainly.com/question/13157325
how can you tell from the name the types of bonds present in a hydrocarbon?
Answer:
Alkane
Alkene
Alkyne
Explanation:
Alkane=1 bond (Saturated hydrocarbon)
Alkene= 2 bonds (Unsaturated hydrocarbon)
Alkyne= triple bonds (Unsaturated hydrocarbon)
Formula of Alkane = CnH2n+2
Formula of Alkene = CnH2n
Formula of Alkyne = CnH2n-2
Which elements are diatomic?
Answer:The elements hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine and iodine are diatomic elements
Definition of diatomic elements:Diatomic elements are special as the atoms that form it do not like to be alone. That is, you will never find a nitrogen or fluorine atom, for example, hanging out solo. Rather, these atoms will always be paired together because they need to pool resources to have enough electrons.
Answer:
H2, O2, N2, F2, Cl2, Br2, I2
Explanation:
These occur naturally has molecules of 2 atoms.
They are all gases except Br2, liquid and iodine which is solid.
What would heating a sealed glass jar do?
O A. Increase the size of the gas molecules
B. Increase the number of gas molecules
C. Increase the pressure of the gas inside
D. Increase the volume of the gas inside
The right response is to raise the internal gas pressure. When a sealed glass jar is heated, the temperature of the gas within rises, causing the gas molecules to travel faster and collide with the jar's walls more often and with more force, increasing the gas's pressure.
What is gas molecule?Gas molecules are made up of atoms that are linked together. These interatomic connections function similarly to springs, connecting atoms of varying masses. This connection vibrates at a constant frequency known as the natural frequency. Atoms, molecules, and/or ions are all present in gases, liquids, and solids, but their behavior varies between the three phases. The graphic below depicts the tiny differences. A gas as seen via a microscope. A gas is a condition of stuff that does not have a set volume or form. Air, water vapor, and helium are examples of gases. A gas is a kind of stuff that does not have a defined volume or shape. To put it another way, a gas takes on the shape and volume of its container.
Here,
The correct answer is Increase the internal gas pressure as When a sealed glass jar is heated, the temperature of the gas within rises, forcing the gas molecules to travel faster and hit with the jar's walls more often and with more force, raising the gas's pressure.
To know more about gas molecule,
https://brainly.com/question/29848914
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Calcium carbonate, when heated, forms calcium oxide and carbon dioxide. 100grams of calcium carbonate will produce 56grams of calcium oxide. How many grams of carbon dioxide will it produce? Show working out
Answer:
It will produce 44 grams of carbon dioxide
Explanation:
Step 1: Data given
MAss of CaCO3 = 100 grams
Molar mass of CaCO3 = 100.09 g/mol
Mass of CaO produced = 56 grams
Molar mass of CaO = 56.08 g/mol
Step 2: The balanced equation
CaCO3 → CaO + CO2
Step 3: Calculate moles CaCO3
Moles CaCO3 = mass CaCO3 / molar mass CaCO3
Moles CaCO3 = 100 grams / 100.09 g/mol
Moles CaCO3 = 1.00 moles
Step 4: Calculate moles CaO
Moles CaO = 56 grams / 56.08 g/mol
Moles CaO = 1.00 moles
Step 5: Calculate moles CO2
For 1 mol CaCO3 we'll have 1 mol 1 mol CaO and 1 mol CO2
Step 6: Calculate mass CO2
Mass CO2 = moles CO2 * molar mass CO2
Mass CO2 = 1.00 moles * 44.0 g/mol
Mass CO2 = 44 grams
It will produce 44 grams of carbon dioxide
Please answer number 5 ASAP
Answer: Hello mister i dont now your question
Explanation:
which of these methods could are used to separate an insoluble solid and soluble solid
Answer:
To separate an insoluble solid from a soluble solid: Mixing the mixture with water, filtering out the insoluble solid, and then evaporating the water to isolate the soluble solid.
Explanation:
A weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has
what volume at -40.0 °C assuming pressure is held constant?
Answer:
17.1 Liters
Explanation:
It's a gas law question (more specifically a Charles's Law question). Formula is V1/T1 = V2/T2. You're given V1 and T1 and T2. However, in order to use the equation, temperature needs to be in Kelvins (by subtracting the degrees C from 273) for the numbers to work (among other reasons, the 0 degrees C will always give you an answer of zero or undefined). Placing all temps in kelvins makes the answers come out right. So 20L/273K = xL/233K gives you the answer when you cross-multiply.
Considering the Charles's law, a weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has 17.07 L at -40.0 °C, assuming pressure is held constant.
The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.
Charles's law is one of the gas laws. It relates the volume and the temperature of a certain quantity of ideal gas, kept at a constant pressure.
This law states that, at constant pressure, the volume of a gas is directly proportional to its temperature. In other words, for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases, and as the temperature decreases, the volume of the gas decreases.
Mathematically, Charles's law says that the quotient that exists between the volume and the temperature will always have the same value:
[tex]\frac{V}{T}=k[/tex]
Being an initial state 1 and a final state 2, it is true:
[tex]\frac{V1}{T1}=\frac{V2}{T2}[/tex]
In this case, you know:
V1= 20 LT1= 0 C=273 KV2= ?T2= -40 C= 233 KReplacing:
[tex]\frac{20 L}{273 K}=\frac{V2}{233 K}[/tex]
Solving:
[tex]V2=233 K x\frac{20 L}{273 K}[/tex]
V2=17.07 L
Finally, a weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has 17.07 L at -40.0 °C, assuming pressure is held constant.
Learn more:
https://brainly.com/question/4147359?referrer=searchResultsWhich statement describes a process involved in the evolution of Earth’s early atmosphere?
A.
Cyanobacteria transformed carbon dioxide in the atmosphere into oxygen during photosynthesis.
B.
Heavier gases escaped through Earth’s atmosphere, leaving only lighter gases such as oxygen behind.
C.
Volcanic eruptions produced enough oxygen to create Earth’s atmosphere.
D.
The amount of oxygen in the atmosphere declined due to respiration, or breathing.A sea breeze is a wind that blows from the sea toward land. Which statement best explains how air pressure influences sea breezes?
A.
Wind always blows from the sea toward land, regardless of differences in air pressure.
B.
The air above the land has a lower pressure than the air above the sea.
C.
The air above the sea has a lower pressure than the air above the land.
D.
The sea and the land are at equivalent air pressures, so waves cause the wind to move toward the land.
Answer:
D
Explanation:
a student balanced the chemical equation for the reaction of magnesium with oxygen by writing Mg + O2 ----> MgO2. What is wrong with this equation?
Answer:
Explanation:
Magnesium when it oxidizes has a valence of 2.
Oxygen, when it mixes with something, has a valence of - 2
So Mg and O2 will form something, but what? The answer is MgO
Mg + O2 ===> MgO
To balance this equation, you need 2 Magnesiums on the right and 2 Oxygens also on the right. The left will need a two Magnesiums.
The balanced equation will be
2Mg + O2 ====> 2MgO
the kidneys in human beings are a part of the system for
Pls help me with this will mark brainliest
Answer:
Pulmonary circulation moves blood between the heart and the lungs. The oxygenated blood then flows back to the heart. Systemic circulation moves blood between the heart and the rest of the body. It sends oxygenated blood out to cells and returns deoxygenated blood to the heart
Explanation:
The name given to the substance formed when a liquid is miscible in another liquid.
Answer:
Solute
Explanation: