Answer:
Electron cloud
Explanation:
If you were to scale the size of the atom up to have the nucleus be about the size of a basket ball, then the placement of the actual electrons (about the size of a large marble at this scale) throughout the cloud would be many yards away from the nucleus.
What is the solubility in moles/liter for calcium phosphate at 25°C given a Ksp value of 1.2 x 10^-29. Write using scientific notation and use 1 or 2 decimal places.
Answer:
Explanation:
Ca₃( PO₄)₂ = 3 Ca⁺² + 2 PO₄⁻³
x 3x 2 x
Let solubility be x mole per litre
solubility product = (3x )³ x ( 2x )²
= 108 x⁵ = 1.2 x 10⁻²⁹
x⁵ = .0111 x 10⁻²⁹ = .111 x 10⁻³⁰
x = .64 x 10⁻⁶ moles / litre
Which of the following statement best defines matter?
Answer:matter is anything has mass and take up space
Explanation:
Using the equations
2 Fe (s) + 3 Cl₂ (g) → 2 FeCl₃ (s) ∆H° = -800.0 kJ/mol
Si(s) + 2 Cl₂ (g) → SiCl₄ (s) ∆H° = -640.1 kJ/mol
Determine the enthalpy (in kJ/mol) for the reaction
3 SiCl₄ (s) + 4 Fe (s) → 4 FeCl₃ (s) + 3 Si (s)
The enthalpy : 320.3 kJ/mol
Further explanationThe change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
Based on the principle of Hess's Law,
the change in enthalpy of a reaction will be the same even though it is through several stages or ways
Reaction
2Fe (s) + 3Cl₂ (g) → 2FeCl₃ (s) ∆H° = -800.0 kJ/mol x 2
4Fe (s) + 6Cl₂ (g) → 4FeCl₃ (s) ∆H° = -1600.0 kJ/mol
Si(s) + 2 Cl₂ (g) → SiCl₄ (s) ∆H° = -640.1 kJ/mol
Reverse
SiCl₄ (s) → Si(s) + 2 Cl₂ (g) ∆H° = 640.1 kJ/mol x 3
3SiCl₄ (s) → 3Si(s) + 6Cl₂ (g) ∆H° = 1920.3 kJ/mol
------------------------------------------------------------------------ +
3 SiCl₄ (s) + 4 Fe (s) → 4 FeCl₃ (s) + 3 Si (s) ∆H° = 320.3 kJ/mol
The enthalpy for the formation of 4 moles of [tex]\rm FeCl_3[/tex] has been 320.3 kJ/mol.
The enthalpy of formation of 1 mole at standard temperature and pressure has been termed the standard enthalpy of formation.
The reaction enthalpy to be calculated has reactants of 3 moles of [tex]\rm SiCl_4[/tex], and 4 moles of Fe.
The enthalpy for the formation of [tex]\rm SiCl_4[/tex] has been -640.1 kJ/mol.
The enthalpy for the dissociation of [tex]\rm SiCl_4[/tex] has been the reverse of the formation reaction = +640.1 kJ/mol.
The enthalpy for the dissociation of 3 moles of [tex]\rm SiCl_4[/tex] has been = 3 [tex]\times[/tex] 640.1 kJ/mol.
The enthalpy for the dissociation of 3 moles of [tex]\rm SiCl_4[/tex] has been = 1920.3 kJ/mol.
The enthalpy for the formation of 2 moles of [tex]\rm FeCl_3[/tex] = -800 kJ/mol
The enthalpy for the formation of 4 moles of [tex]\rm FeCl_3[/tex] = -1600 kJ/mol.
The final reaction has 3 moles of [tex]\rm SiCl_4[/tex], and 4 moles of [tex]\rm FeCl_3[/tex].
Thus, the final enthalpy of reaction will be: 1920 kJ/mol + (-1600 kJ/mol)
The final enthalpy of reaction will be = 320.3 kJ/mol.
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describe the dual nature of electrons (give an example)
Answer:
In 1924, the French physicist, Louis de Broglie suggested that if light has electron, behaves both as a material particle and as a wave. According to this theory, small particles like electrons when in motion possess wave properties.
Explanation:
examples
This can be derived as follows according to Planck’s equation, E = hv = hc /λ ∴ v=c/λ(energy of the photon (on the basis of Einstein’s mass energy relationship) E = mc2
( If Bohr’s theory is associated with de-Broglie’s equation then wave length of an electron can be determined in bohr’s orbit and relate it with circumference and multiply with a whole number 2πr = nλ or λ = (2πr/2π) From de-Broglie equation, λ = (h/mv).
Aluminum has a density of 2.70 g/mL. Calculate the mass (in grams) of a piece of aluminum having a volume of 238 mL .
Answer:
mass in gram = 642.6 g
Explanation:
Given data:
Density of aluminum = 2.70 g/mL
Volume of aluminum = 238 mL
Mass in gram = ?
Solution:
Density:
Density is equal to the mass of substance divided by its volume. The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
d =m/v
d = density
m=mass
V=volume
Now we will put the values in formula.
2.70 g/mL = m/ 238 mL
m = 2.70 g/mL × 238 mL
m = 642.6 g
What does Gravity means
Please it’s due today need help please
Sulfite is similar to hydroxide in its behavior as a ligand: most sulfites are insoluble in water, but excess sulfite can result in the formation of a complex ion. Write the two equilibrium reactions of sulfite with the copper(II) ion that show this behavior.
Answer:
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
Explanation:
A ligand may be defined as a molecule or an ion or that binds to the central metal atom in order to form a more coordination complex. Sulfite is one such ligand and it behaves similarly as hydroxide as a ligand.
Now, according to the question, when we react copper with sulfite ion, it forms copper sulfite. The equation is
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
Now when excess of the sulfite ion is used in the reaction, we get a complex formation, which is shown by
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
The way the sulfite reacts is quite similar to hydroxide ion where they form a complex ion when hydroxide ion in excess is used in the reaction with metal cation.
what processes add methane (CH4) to the atmosphere
Answer:
Cultivated rice paddies
Drilling of natural deposits
Fossil fuel use
Burning of biomass
Landfills
Explanation:
The bulk of the methane released into the atmosphere are as a result of various human activities.
Cultivated rice paddies are a known source of methaneThe drilling of natural deposits and their exploration can release some methane into the atmosphereBurning of fossil fuel and biomass is a source of methane Landfills produces methane as organic materials begins to decay.A gram sample of a KCl and KClO3 mixture was found to contain 0.00875 mol of KClO3. What is the percent by mass of KClO3 in the original mixture?
Answer:
53.5%
Explanation:
Step 1: Given data
Mass of the sample: we will suppose it is 2.00 g to show the procedureMoles of KClO₃: 0.00875 molStep 2: Calculate the mass corresponding to 0.00875 moles of KClO₃
The molar mass of KClO₃ is 122.55 g/mol.
0.00875 mol × 122.55 g/mol. = 1.07 g
Step 3: Calculate the percent by mass of KClO₃ in the mixture
We will use the following expression.
%m/m = mass of KClO₃/mass of the sample × 100%
%m/m = 1.07 g/2.00 g × 100%
%m/m = 53.5%
The percent by mass of KClO3 in the original mixture is 53.5%.
Calculation of the percentage:Since
The mass of the sample should be 2.00 g
Moles of KClO₃: 0.00875 mol
The molar mass of KClO₃ is 122.55 g/mol.
Now the mass is
= 0.00875 mol × 122.55 g/mol.
= 1.07 g
Now the percentage should be
= mass of KClO₃/mass of the sample × 100%
= 1.07 g/2.00 g × 100%
= 53.5%
hence, The percent by mass of KClO3 in the original mixture is 53.5%.
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What branch of science studies The Periodic Table?
A.Biology
B.Earth Science
Chemistry
Atoms mover slower in the ____________. *
A.heat
B.cold
Atoms move faster in the __________. *
A.heat
B.cold
A nucleus is made of ________ and _________. *
A.protons and electrons
B.electrons and neutrons
C.protons and neutrons
Protons have what type of charge? *
A.neutral
B.negative
C.positive
Neutrons have what type of charge? *
A.neutral
B.negative
C.positive
Atoms have empty space. *
A.True
B.False
What is the center of an atom called? *
A.Neutron
B.Nitrogen
C.Nucleus
The atomic number represents the number of _______. *
A.protons
B.neutrons
C.electrons
What family of elements is most stable? *
A.metals
B.nonmetals
C.Nobel gasses
What scientist is credited with designing The Periodic Table? *
A.Albert Einstein
B.Isaac Newton
C.Dmitri Mendeleev
Atomic mass is found at the _______________.
A.top of the square
B.the middle of the square
C.the bottom of the square
The Periodic Table has elements that are liquids, gasses, and solids. *
A.True
B.False
With an atomic number of 1, which element is the lightest? *
A.Helium
B.Xenon
C.Hydrogen
D.Radon
Answers:
1. Chemistry
2. Cold
3. Heat
4. Protons and neutrons
5. Positive
6. Neutral
7. True
8. Nucleus
9. Protons
10. Nobel gasses
11. Dmitri Mendeleev
12. the bottom of the square
13. True
14. Helium
If a neutral atom has 49 protons, how many electrons does it have?
Compare and contrast the applications and benefits of circle graphs and bar charts. Explain
Answer:
A circle graph, or a pie chart, is used to visualize information and data. A circle graph is usually used to easily show the results of an investigation in a proportional manner. Bar graphs are used to compare things between different groups or to track changes over time. However, when trying to measure change over time, bar graphs are best when the changes are larger.
Explanation:
In short, bar graphs are better to keep track of data over long periods of time, and circle graphs are better when you are trying to visualize a specific set of data.
Circle graph can be also be called pie chart, which is more widely used. It is usually made up of a circle, divided into parts or pies. In the divided parts, it is used to differentiate between different data.
Bar charts on the other hand are like graphs having both x and y axis. It is used to represent data with respect to the height of the graph. Each data is divided into different smaller parts on the graph.
Example of what they look like is attached below.
First one is bar chart while the second is a circle graph
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In a closed system, the total energy before an energy transformation is _______ the total energy after it.
A.
less than
B.
equal to
C.
unrelated to
D.
greater than
In a closed system, the total energy before an energy transformation is greater than the total energy after it.
What is a closed system ?A closed system is a natural physical system that does not permit the movement of matter into or out of the system, while energy transfer is permitted in some situations, such as those found in physics, chemistry, or engineering.
A closed system is one that only allows the flow of energy; it forbids the exchange of matter. The heat can transfer when we boil water with a closed cover, but the matter cannot.
In a closed system, the overall energy is constant. The universe's overall energy is always changing. Mass may be used to store energy. In a closed system, energy may be transformed from one form to another.
Thus, option D is correct.
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If a reaction generated 3.5 g of H2O how many moles of water were formed?
Answer:
0.19 mol H₂O
General Formulas and Concepts:
Chem
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
Given: 3.5 g H₂O from RxN
Step 2: Define conversions
Molar Mass of H - 1.01 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol
Step 3: Convert
[tex]3.5 \ g \ H_2O(\frac{1 \ mol \ H_2O}{18.02 \ g \ H_2O} )[/tex] = 0.194229 mol H₂O
Step 4: Check
We are given 2 sig figs. Follow sig fig rules.
0.194229 mol H₂O ≈ 0.19 mol H₂O
If 0.0806 mol CaCl2 is dissolved in water to make a 0.490 M solution, what is the volume of the solution?
Answer:
0.16 L
Explanation:
From the question given above, the following data were obtained:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the volume of the solution as illustrated below:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity = mole /Volume
0.490 = 0.0806/volume
Cross multiply
0.490 × volume = 0.0806
Divide both side by 0.490
Volume = 0.0806 / 0.490
Volume of solution = 0.16 L
Thus, the volume of the solution is 0.16 L.
A solution is a mixture of solute in the solvent. The volume of the solution is 0.16 L.
What is a solution?A solution is a mixture of solute in the solvent.
An example of a solution is a mixture of salt in water.
Given,
Moles = 0.0806 mol [tex]\rm CaCl_2[/tex]
Molarity = 0.490 M
To find: the volume of the solution
[tex]Molarity = \dfrac{n}{V}[/tex]
Putting the values
[tex]0.490 M = \dfrac{ 0.0806}{V}\\\\0.490 M \times V = 0.0806\\\\Divide\; both\;side\; with\; 0.490\\\\V= \dfrac{ 0.0806}{0.490}=0.16 L[/tex]
Thus, the volume so the solution is 0.16 l.
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Liquid nitrogen is kept at a temperature of -320 degrees. When liquid nitrogen is heated it quickly boils and turns into a gas. Which pair of pictures represent the change caused by adding heat to liquid nitrogen?
So when something is boiling it is moving faster meaning the molecules are more spread out and not condense like a solid
So the answer is the 2nd set
The indicator phenolphthalein is added to the _____________.
a. Analyte
b. Water
c. Solute
d. Titrant
Answer:
A
Explanation:
I took the test
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of carbon tetrachloride would be produced by this reaction if of chlorine were consumed
Answer:
0.56 mL
Explanation:
Methane gas and chlorine gas react to form hydrogen chloride gas and carbon tetrachloride gas. What volume of carbon tetrachloride would be produced by this reaction if 1.1 mL of chlorine were consumed.
Step 1: Write the balanced equation
CH₄(g) + 2 Cl₂(g) → CCl₄(g) + 4 HCl (g)
Step 2: Calculate the moles corresponding to 1.1 mL of Cl₂
At standard temperature and pressure, 1 mole of a gas has a volume of 22.4 L.
1.1 × 10⁻³ L × 1 mol/22.4 L = 4.9 × 10⁻⁵ mol
Step 3: Calculate the moles of CCl₄ formed from 4.9 × 10⁻⁵ moles of Cl₂
The molar ratio of Cl₂ to CCl₄ is 2:1. The moles of CCl₄ are 1/2 × 4.9 × 10⁻⁵ mol = 2.5 × 10⁻⁵ mol.
Step 4: Calculate the volume corresponding to 2.5 × 10⁻⁵ moles of CCl₄
At standard temperature and pressure, 1 mole of a gas has a volume of 22.4 L.
2.5 × 10⁻⁵ mol × 22.4 L/mol = 5.6 × 10⁻⁴ L = 0.56 mL
Please help me please i will mark you brainliest. In the nucleus of an atom, there are 17 protons and 18 neutrons. What is the atomic number? What is the atomic mass? How many electrons are there? Be sure to answer all 3 questions.
Answer:
i can only help with 2 :( atimic mass is: 35.453 and number of electrons is:17
Explanation:
If you travel 7.5 km and walk for 1.5 h, what is your average speed?
Show your work?
C is the element symbol for which element?
a. Carbon
b. Cadmium
c. Celenium
d. Chlorine
Answer:
Carbon
Explanation:
How is filtration done?
What is the difference between residue and filtrate?
Answer:
residue is whatever remains after something else has been removed while filtrate is the liquid or solution that has passed through a filter, and which has been separated from the filtride.
filtration id done by placing a filter paper on the beaker or container then pour the filtride then let it settle and it will pass through and you will have the fitrate and residue
Explanation:
A) Earlier you were told that of all of the 14 solutes you will be studying, the only one that is not appreciably ionized in water is aqueous ammonia. What does this statement imply about the equilibrium point of the reaction involving aqueous ammonia/ammonium hydroxide?B) Use your results and conclusions from part (a) to explain why a complicated name like Aqueous ammonia/ammonium hydroxide is used for this solution?
Answer:
Throughout the overview section following portion, the description and according to particular circumstance is defined.
Explanation:
As per the question,
⇒ [tex]NH_3(aq)+H_2O\leftrightarrow NH_4+(aq)+OH-(aq)[/tex]
A weak basis seems to be NH3. It serves as a base since the aqueous solution or phase is protonated. But NH3 +, just becoming a weak base, is therefore deprotonated into form NH3, and therefore also 90% of ammonia becomes found throughout NH3 state in aqueous solution.⇒ [tex]NH_3+(aq) \leftrightarrow NH_3(aq)+H+(aq)[/tex]
However, it is also available in NH3 form throughout the aqueous solution much of the moment.
What factors affect the speed of a wave? Check all that apply. the amplitude of the wave the energy of the wave the temperature of the medium the type of wave the type of medium
Answer:
I believe its 1,2, and 5
Explanation:
C D E
temperature of medium
type of wave
type of medium
Determine the vapor pressure of a solution at 25°C that contains 76.6 g of glucose (C6H12O6 ) in 250.0 mL of water. The vapor pressure of pure water at 25°C is 23.8 torr
Answer:
[tex]23.093\ \text{torr}[/tex]
Explanation:
[tex]M_g[/tex] = Molar mass of glucose = 180.2 g/mol
[tex]M_w[/tex] = Molar mass of water = 18 g/mol
[tex]m_g[/tex] = Mass of glucose = 76.6 g
[tex]m_w[/tex] = Mass of water = [tex]250\times 1\ \text{g/mL}=250\text{g}[/tex]
[tex]P_0[/tex] = Vapor pressure of pure water at 25°C = 23.8 torr
The mole fraction of glucose is
[tex]x_g=\dfrac{\dfrac{m_g}{M_g}}{\dfrac{m_g}{M_g}+\dfrac{m_w}{M_w}}=\dfrac{\dfrac{76.6}{180.2}}{\dfrac{76.6}{180.2}+\dfrac{250}{18}}\\\Rightarrow x_g=0.0297[/tex]
Mole fraction of the solute would be
[tex]\dfrac{P_0-P}{P_0}=x_g\\\Rightarrow 0.0297=\dfrac{23.8-P}{23.8}\\\Rightarrow P=23.8-0.0297\times23.8\\\Rightarrow P=23.093\ \text{torr}[/tex]
The vapor pressure of the solution is [tex]23.093\ \text{torr}[/tex].
___ is a type of weathering caused by a chemical reaction with water.
A. Carbonation
B. Abrasion
C. Hydrolysis
D. Hydration
Option ( C ). Hydrolysis (/haɪˈdrɒlɪsɪs/; ancient Greek for "water" and "to dissolve") is a chemical reaction in which water molecules break one or more chemical bonds.)
What does the example of hydrolysis mean?
Hydrolysis is the process of breaking down compounds by adding water. Here is an example of hydrolysis:
Sodium acetate is a type of salt. When sodium acetate is mixed with water, the chemical bonds are broken and it breaks down into sodium ions and acetate ions.
What is function of hydrolysis?
Hydrolysis reactions break the bonds and release energy. Biopolymers are ingested and hydrolyzed in the gastrointestinal tract to form small molecules that can be absorbed by cells and further broken down to release energy.
Where does the hydrolysis take place?
Hydrolysis is the process by which compounds are broken down into simpler compounds and involves the chemical uptake of water. Almost all tissues contain enzymes that catalyze hydrolysis, but the highest concentration is in the liver.
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The freezing point of a solution the freezing point of the pure solvent
Answer:
This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur.
Explanation:
Answer:
Freezing Point Depression. The freezing point of a solution is less than the freezing point of the pure solvent. This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur
3 Which of the following best represents potential energy? *
A Air leaking rapidly from a car tire.
B A marble sitting at the top of a ramp.
C Heat radiating from a large forest fire.
D Water flowing through a rubber hose.
Answer:
Its B
Explanation:
help, Look at the model below. Explain what is correct and/or incorrect about the model based on scale, proportion, and quantity.
2. Find the ΔH for the reaction below, given the following reactions and subsequent ΔH
values:
2C2(g) + H2O(g) → C2H2(g) + ⁵/₂ O2(g)
C2H2(g) + 2H2(g) → C2H6(g) ΔH = –94.5 kJ
H2O(g) → H2(g) + ½ O2 (g) ΔH =71.2 kJ
C2H6(g) + ⁷/₂ O2(g) → 2 CO2(g) + 3 H2O(g) ΔH = –283 kJ