Answer:
Explanation:
Let the final volume be v .
from the formula
S₁ V₁ = S₂V₂
4 x 7 = .8 x V₂
V₂ = 35 mL
Final volume of the solution will be 35 mL .
SOMEONE PLEASE HELPPP
Calculate the sublimation pressure of the solid at the melting point of 400.00 K assuming that the enthalpy of sublimation is not a function of temperature.
This question is incomplete, the complete question is;
Tonksite is a solid at 300.00K. At 300.00 K its enthalpy of sublimation is 66.00 kJ/mol. The sublimation pressure at 300.00 K is 5.00 × 10⁻⁴ atm
Calculate the sublimation pressure of the solid at the melting point of 400.00 K assuming that the enthalpy of sublimation is not a function of temperature.
Answer: the sublimation pressure of the solid at the melting point is 0.3727 atm
Explanation:
Given that;
T1 = 300 K
T2 = 400 K
H_sub = 66 kJ/mol = 66000 J/mol
P1 = 5.00 × 10⁻⁴ atm
p2 = ?
now using the expression
log( p2 / 5.00 × 10⁻⁴ ) = (H_sub / R × 2.303 ) (( T2 - T1) / T1T2)
now we substitute of given values into the expression
log(p2/p1) = (66000 / 8.314 × 2.303 ) (( 400 - 300) / 300 × 400 )
p2 = 0.3727 atm
therefore the sublimation pressure of the solid at the melting point is 0.3727 atm
A student was performing a separation of a mixture of organic compounds. The final step of the process involved a filtration of the analyte from an aqueous solution. After drying the filtered solid for a very short period time, they took the melting point of the compound. The measured melting point range of the compound was 106 – 113.8 0C, while the literature melting point of the compound was 122.3 0C. The above scenario is a very common one in organic labs.
1. Do you think their sample was pure?
2. If not, then what do you think could be the source of error.
3. How do you think this error can be minimized?
Answer:
1) No
2) The solvent contaminated the analyte
3) The solvent should be evaporated properly before washing and drying the analyte
Explanation:
During separation of organic compounds, solvents are used. These solvents are able to contaminate the analyte and lead to a large difference in melting point of solids obtained.
However, the error can be minimized by evaporating the solvent before washing, drying and melting point determination of the solid.
Can someone help me with this chemistry I have attached?, just helping me understand these problems. Its moles and questions
calculate the equilibrium concentration for the nonionized bases and all ions in a solution that is 0.25M
Answer:
The equilibrium concentration of [CH₃NH₂] = 0.23965 M.
The equilibrium concentration of CH₃NH₃⁺ and OH⁻ = 0.01035 M respectively.
Explanation:
The first step is to write out the dissociation reaction. Therefore, the equation showing the dissociation is given as below;
CH₃NH₂ + H₂0 <--------------------------------------------------------> CH₃NH₃⁺ + OH⁻.
Kindly note that ''<----------->'' arrow shows that the reaction is an equilibrium reaction.
Therefore, at the start of the reaction [that is time, t =0], we have that the concentration of CH₃NH₂ = 0.25M, thus, the concentration of CH₃NH₃⁺ and OH⁻ is zero respectively at this time, t =0.
At equilibrium, the concentration of CH₃NH₂ = 0.25M - x, thus, the concentration of CH₃NH₃⁺ and OH⁻ is x respectively.
Therefore, kb = 4.47 × 10-4 = [CH₃NH₃⁺ ][OH⁻]/[CH₃NH₂]. Hence, slotting in the values into this equilibrium equation showing the relationship between kb and concentration of the species involved, we have that;
kb = 4.47 × 10⁻⁴ = x² /0.25 - x.
x² + 4.47 × 10⁻⁴x - 1.1175 × 10⁻⁴ = 0.
Solving this quadratic equation gives us the value of x as 0.01035 M.
Thus, the concentration of [CH₃NH₂] = 0.25 M - 0.01035 M = 0.23965 M
The equilibrium concentration of [CH₃NH₂] = 0.23965 M.
The equilibrium concentration of CH₃NH₃⁺ and OH⁻ = 0.01035 M respectively.
4. This is low wet land.
A. swamp
B. island
C. desert
D. peninsula
5. Japan is one of these.
A. island
B. peninsula
C. swamp
D. desert
Answer:
swap
Explanation: because it is a low wet land
Answer:
4. swamp
5. Island
Plz mark brainliest:)
Which of the following are decomposers?
O A. mice
O B. snakes
O C. fungi
OD. spiders
ASAP
What is the atomic mass of element X
Answer:
Which one of the table is element X?
Explanation:
I have no idea and help!!!!!!!!!!!!!!!!!!!!!!!!!
Label each of the following changes as a physical change or chemical change. Give evidence to support your answer.
A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas
Answer:
A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.
Explanation:
Hello.
In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:
[tex]2NO_2\rightarrow N_2+O_2[/tex]
As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.
Best regards.
How many moles of precipitate will be formed when 100.0 mL of 0.200 M NaBr is reacted with excess Pb(NO₃)₂ in the following chemical reaction?
2 NaBr (aq) + Pb(NO₃)₂ (aq) → PbBr₂ (s) + 2 NaNO₃ (aq)
Answer : The number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.
Explanation : Given,
Concentration of NaBr = 0.200 M
Volume of solution = 100.0 mL = 0.1 L (1 L = 1000 mL)
First we have to calculate the moles of NaBr.
[tex]\text{Moles of NaBr}=\text{Concentration of NaBr}\times \text{Volume of solution in L}[/tex]
[tex]\text{Moles of NaBr}=0.200M\times 0.1L=0.02mol[/tex]
Now we have to calculate the moles of precipitate, [tex]PbBr_2[/tex] formed.
The balanced chemical reaction is:
[tex]2NaBr(aq)+Pb(NO_3)_2(aq)\rightarrow PbBr_2(s)+2NaNO_3(aq)[/tex]
From the balanced chemical reaction we conclude that:
As, 2 moles of NaBr react to give 1 mole of [tex]PbBr_2[/tex]
So, 0.02 moles of NaBr react to give [tex]\frac{0.02}{2}=0.01[/tex] mole of [tex]PbBr_2[/tex]
Therefore, the number of moles of precipitate, [tex]PbBr_2[/tex] formed will be 0.01 moles.
The number of mole of the precipitate (i.e PbBr₂) formed when 100 mL of 0.2 M NaBr react with excess Pb(NO₃)₂ is 0.01 mole
We'll begin by calculating the number of mole of NaBr in 100 mL of 0.2 M NaBr solution. This can be obtained as follow:Volume = 100 mL = 100 / 1000 = 0.1 L
Molarity of NaBr = 0.2 M
Mole of NaBr =?Mole = Molarity x Volume
Mole of NaBr = 0.2 × 0.1
Mole of NaBr = 0.02 mole Finally, we shall determine the number of mole of the precipitate (i.e PbBr₂) produced from the reaction. This can be obtained as follow:2NaBr(aq) + Pb(NO₃)₂(aq) → PbBr₂(s) + 2NaNO₃ (aq)
From the balanced equation above,
2 moles of NaBr reacted to produce 1 mole of PbBr₂.
Therefore,
0.02 mole of NaBr will react to produce = [tex]\frac{0.02}{2} \\\\[/tex] = 0.01 mole of PbBr₂.
Thus, the number of mole of the precipitate (i.e PbBr₂) produced from the reaction is 0.01 mole
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The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the
А.
electron
B
proton
neutron
D
atom
Answer:
The answer is D - Atom
The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the atom.
What is an atom?
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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calculate the amount of water produced by the combustion of 16 gram of methane
Answer: Since, the given weight of methane is 16 g, hence the water produced by the combustion of 16 g of methane is 36 g.
Explanation: Have a blessed day!
The smallest form of matter that still retains the properties of an element
Answer:
atom
Explanation:
the atom is the smallest form.
Which of the following is NOT a strong electrolyte?
:
Answers:
Na2SO4
KI
CaCl2
LiOH
C6H1206
Answer:
C6H1206
Explanation:
C6H12O6 is a monomer of carbohydrates also known as glucose, so it is not an electrolyte at all.
What are two weather factors that are directly influenced by ocean currents
O Air density and humidity
O Air pressure and temperature
O Temperature and humidity
O Precipitation and air pressure
Explanation:
Preciptation and air pressure
Answer:
It is Temperature and humidity. C
Explanation:
I took the test and it said it was C
Hereditary information is passed on from:
O nucleus to nucleus
O cell to cell
O cell to nucleus
O nucleus to cell
Answer:
D - Nucleus to Cell
Explanation:
Hope it helps!!
:D
The energy associated with the motion and position of an object is called a.kinetic energy
b.potential energy
c.gravitational potential energy d.mechanical energy
Answer: The answer is D.
Explanation:
The form of energy associated with the motion, position, or shape of an object is called mechanical energy. An object's mechanical energy is a combination of its potential energy and its kinetic energy. The basketball has both potential energy and kinetic energy.
Hope this helps!
________ and ________ fibres are obtained from animals
Answer:
Explanation:
Silk and wool
Answer:
silk and wool fibers are obtained from animals
Explanation:
good luck :)
How many atoms of Chlorine are in 1.00 mol of Chlorine gas?
6.022 x 10∧23
3.01 x 10∧23
6.022 x 10∧24
Answer:
6.02 × 10²³ atoms Cl₂
Explanation:
Avagadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
Step 1: Define
1.00 mol Cl₂ (g)
Step 2: Use Dimensional Analysis
[tex]1.00 \hspace{3} mol \hspace{3} Cl_2(\frac{6.02(10)^23 \hspace{3} atoms \hspace{3} Cl_2}{1 \hspace{3} mol \hspace{3} Cl_2} )[/tex] = 6.02 × 10²³ atoms Cl₂
What is magma?
solid rock with a fine texture
cooled rock with large crystals
molten rock below Earth’s surface
flowing rock above Earth’s surface
Answer:
C. molten rock below Earth’s surface
Explanation:
Which statement describes how this rock was likely formed?
slow cooling of magma beneath the surface of Earth
rapid cooling of magma beneath the surface of Earth
slow cooling of lava on the surface of Earth
rapid cooling of lava on the surface of Earth
I will mark Brainlyest
Answer:
A
Explanation:
Slow cooling of magma beneath the surface of earth
To solve this we must be knowing each and every concept related to rock and its formation. Therefore, the correct option is option A among all the given options.
What is rock?Rock is a naturally occurring mineral aggregate that is cohesive and composed of one or even more minerals. These aggregates often take the shape of recognisable and mappable volumes and are the fundamental building block of the solid Earth.
Mineral crystals as well as the sorts of rocks that serve as their hosts cycle through many forms as geologic materials. Temperature, weight, time, and variations in the climate in the Earth's crust and on its surface all play a role in the process. Slow cooling of magma beneath the surface of Earth is the statement that best describes the formation of rock.
Therefore, the correct option is option A.
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a change of matter is a physical change
True or False
Answer:
true
Explanation:
hope it helps
Answer:
I'm pretty sure it's true
Explanation:
20 characters
A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is a stainless-steel cylinder that measures 41.0cm wide and 49.2cm high. The maximum safe pressure inside the vessel has been measured to be 3.70MPa. For a certain reaction the vessel may contain up to 2.50kg of dinitrogen difluoride gas.
Required:
Calculate the maximum safe operating temperature the engineer should recommend for this reaction. Write your answer in degrees Celsius. Be sure your answer has the correct number of significant digits.
Answer:
[tex]T=2.78x10^3 \°C[/tex]
Explanation:
Hello,
In this case, considering that the safe temperature may be computed via the ideal gas law as we now the pressure, mass and volume via the dimensions:
[tex]V=\pi r^2 h=\pi *(41.0cm)^2*49.2cm=2.60x10^5cm^3*\frac{1L}{1000cm^3} =260L[/tex]
The pressure in atm is:
[tex]P=3.70MPa*\frac{1x10^6Pa}{1MPa} \frac{1atm}{101325Pa} =36.5atm[/tex]
And the moles considering the mass and molar mass (66 g/mol) of dinitrogen difluoride (N₂F₂):
[tex]n_{N_2F_2}=2.50kg*\frac{1000g}{1kg}*\frac{1mol}{66g} =37.9mol[/tex]
In sich a way, by applying the ideal gas equation, which is not the best assumption but could work as an approximation due to the high temperature, the temperature, with three significant figures, will be:
[tex]T=\frac{PV}{nR}=\frac{36.5Pa*260L}{37.9mol*0.082\frac{atm*L}{mol*K} }\\ \\T=3053.6K-273.15\\\\T=2.78x10^3 \°C[/tex]
Best regards.
The solubility of silver(I)phosphate at a given temperature is 2.43 g/L. Calculate the Ksp at this temperature. After you calculate the Kspvalue, take the negative log and enter the (pKsp) value with 2 decimal places.
Answer:
Kps = 3.07 x 10⁻⁸
pKsp= 7.51
Explanation:
First, we calculate the molar solubility of silver(I)phosphate (Ag₃PO₄) from the solubility in g/L by using its molar mass (418.6 g/mol):
2.43 g/L x 1 mol/418.6 g = 5.8 x 10⁻³ mol/L= s
Now, we have to write the ICE chart for the aqueous equilibrium of Ag₃PO₄ as follows:
Ag₃PO₄(g) ⇄ 3 Ag⁺(aq) + PO₄³⁻
I 0 0
C +3s +s
E 3s s
Ksp = [Ag⁺]³[PO₄³⁻]= (3s)³s= 27s⁴
Since s=5.8 x 10⁻³ mol/L, we calculate Ksp:
Ksp= 27(5.8 x 10⁻³ mol/L)⁴= 3.07 x 10⁻⁸
The pKsp value is:
pKsp= - log Ksp = -log (3.07 x 10⁻⁸) = 7.51
How are salinity, temperature and circulation related?
Answer:
Salinity, along with temperature, determines the density of seawater, and hence its vertical flow patterns in thermohaline circulation. 2. Salinity records the physical processes affecting a water mass when it was last at the surface. Hope this helps!
Explanation:
1. Determine the electron-domain geometry and molecular geometry for each of the following.
a. SBr2
b. PI4+
c. IBr2−
2. The following three compounds all have the same general formula, XF4. Compare the electron-domain geometries of these three compounds and explain what characteristic(s) of the central atom causes differences in geometry.
a. SiF4:
b. SeF4:
c. XeF4:
Answer:
SBr2: Electron geometry-tetrahedral; molecular geometry-trigonal pyramidal
PI4+: Electron geometry-tetrahedral; molecular geometry-tetrahedral
IBr2−: Electron geometry- Trigonal bipyramidal ; molecular geometry- linear
Explanation:
In SBr2, the molecule is of the structure type AX2E2 hence it is based on a tetrahedron but have two lone pairs of electrons hence the molecular geometry is trigonal pyramidal.
PI4+ has four electron domains and all of them are bond pairs hence both electron geometry and molecular geometry are both tetrahedral.
IBr2- is of the structure type AX2E3 hence it is based on a trigonal bipyramd and has a linear molecular geometry.
2)
SiF4 has a tetrahedral molecular and electron domain geometry because the central atom(Si) has no lone pairs.
SeF4 has a trigonal bipyramidal electron geometry with the structure AX4E. Its molecular geometry is See-saw since it has one lone pair of electrons that causes a deviation from its ideal trigonal bypyramidal geometry.
XeF4 has an octahedral electron domain geometry and the molecule is AX4E2. The two lone pairs are positioned above and below the plane of a square hence the molecule is square planar.
A sample of an ideal gas has a volume of 2.23 L at 289 K and 1.05 atm. Calculate the pressure when the volume is 1.08 L and the temperature is 304 K. P= atm
Answer:
2.28 atm
Explanation:
V₁ = 2.33L, V₂ = 1.08L
T₁ = 289K, T₂ = 304K
P₁ = 1.05 atm, P₂ = ?
Where V₁ and V₂ are initial and final volume respectively
T₁ and T₂ are initial and final temperature respectively
P₁ and P₂ are initial and final pressure respectively
The formula to be used here is the general gas equation:
P₁V₁/T₁=P₂V₂/T₂
1.05 × 2.23/289 = P₂ × 1.08/304
P₂ × 1.08 × 289 = 1.05 × 2.23 × 304
P₂ = (1.05 × 2.23 ×304) ÷ (1.08 × 289)
P₂ = 711.82 ÷ 312.12
P₂ = 2.28 atm
how many grams of oxygen are there in 66.2 g of nitrous acid
Answer:
15.9994 grams
You can view more details on each measurement unit: molecular weight of Oxygen or grams The molecular formula for Oxygen is O. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Oxygen, or 15.9994 grams.
Explanation:
Answer:
First you need to know the Chemical formula for Nitrous acid which is HNO₂
Explanation:
Select the term that matches each definition:
a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
b) The mass of a salt in grams that will dissolve in 100 mL of water.
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
e) The maximum number of moles of a salt that will dissolve in 1 L of solution.
*** Answer options for all questions: ***
- Solubility
- Molar Solubility
- Solubility product constant
- Common ion effect
- Saturated Solution
Answer: a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion : Common ion effect
b) The mass of a salt in grams that will dissolve in 100 mL of water: Solubility
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved: Saturated solution
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation : Solubility product constant
e) The maximum number of moles of a salt that will dissolve in 1 L of solution : Molar solubility
Explanation:
Solubility is expressed usually as the mass of solute per 100 grams or 100 ml of solvent.
Molar solubility of a solid is expressed as the concentration of the dissolved solid in a saturated solution.
Solubility product constant is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as [tex]K_{sp}[/tex]
The common-ion effect is the decrease in solubility of a sparingly soluble salt by the addition to the solution of a soluble compound with an ion in common with the precipitate.
Saturated solution is defined as the solution in which no more solute particles can be dissolved in the solvent.
Match the following terms and definitions.
1. major ecological grouping of plants and animals
food chain
biome
environmental factor
decomposers
2. bacteria and fungi that break down dead matter
a state of change in which the end result is equal or
3.
balanced
the basic relationships that show how a community of plants,
animals, and bacteria live and grow and how these living
4. things are dependent on each other as well as the Sun, soil,
and other nonliving parts of their environment; a cycle of
relationships
line of plants and animals that shows the order in which
5.
organisms are eaten
a condition or conditions of the nonliving surroundings, such
6.
as light, temperature, water, and so on
ecosystem
dynamic equilibrium
Answer:
major ecological grouping of plants and animals
food chain
*biome*
bacteria and fungi that break down dead matter
*decomposers*
a state of change in which the end result is equal or
balanced
*dynamic equilibrium*
the basic relationships that show how a community of plants,
animals, and bacteria live and grow and how these living
*ecosystem*
things are dependent on each other as well as the Sun, soil,
and other nonliving parts of their environment; a cycle of
relationships
line of plants and animals that shows the order in which
*Food chain*
organisms are eaten
a condition or conditions of the nonliving surroundings, such
*environmental factor*
Explanation: