The enthalpy of precipitation of calcium fluoride is -13.974 kJ/mol.
In order to solve this, first we need to write the balanced chemical reaction equation of the reaction in question:
CaCl₂(aq) + 2KF(aq) → CaF₂(s) + 2KCl(aq)
In order to calculate the enthalpy of precipitation (ΔH), we need the amount of heat released (Q) and the number of moles of CaF₂ (n):
ΔH = Q/n
To calculate the number of moles, we can use the molarity (c = 1.00 M) of the calcium chloride solution and its volume (V = 25 mL = 0.025 L):
c = n/V ⇒ n = c*V
n = 1.00 M * 0.025 L = 0.025 mol
We calculate the amount of heat released (Q) using the following equation:
Q = (t₁ - t₂) * C * m
t₁ - initial temperature (25.0 ⁰C)
t₂ - final temperature (26.7 ⁰C)
C - specific heat capacity (4.184 J/⁰Cg)
m - the mass of the solution
We need the mass of the solution, which we can calculate using the density (d = 1.00 g/mL) and the volume (V = 25 mL + 25 mL = 50 mL) of the solution:
d = m/V ⇒ m = d*V
m = 1.00 g/mL * 50 mL = 50 g
Q = (25.0 ⁰C - 26.7 ⁰C) * 4.184 J/°Cg * 50 g
Q = -349.4 J
ΔH = -349.4 J / 0.025 mol
ΔH = -13974 J/mol = -13.974 kJ/mol
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If earth’s atmosphere was composed entirely of nitrogen and oxygen, would the globally averaged surface air temperature increase or decrease compared to our current globally averaged surface air temperature?.
The globally averaged surface air temperature would decrease if the atmosphere were composed entirely of nitrogen and oxygen. The main greenhouse gases in the atmosphere are water vapor, carbon dioxide, and methane.
These gases allow sunlight to pass through the atmosphere and then trap some of the heat that radiates back from the Earth's surface. Nitrogen and oxygen are not greenhouse gases, so they would not trap heat in the atmosphere.The global average surface air temperature would decrease because nitrogen and oxygen are both transparent to incoming solar radiation, meaning that less heat would be trapped at the surface of the Earth. Additionally, the greenhouse effect would be weaker without other greenhouse gases like water vapor and carbon dioxide, further cooling the planet.
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under certain conditions, the substance bromine trifluoride can be broken down to form bromine and fluorine. if 23.1 grams of bromine trifluoride react to form 13.5 grams of bromine, how many grams of fluorine must simultaneously be formed
Bromine Trifluoride is a colourless to grayish-yellow fuming liquid with a strong odour. It has a strong reaction to water. It is a fluorinating agent as well as an electrolytic solvent.
Bromine trifluoride was first described in 1906 by Paul Lebeau, who obtained it by reacting bromine with fluorine at 20 °C: Br 2 + 3 F 2 2 BrF. Bromine trifluoride is formed by disproportioning bromine monofluoride: 3 BrF BrF 3 + Br
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Bromine Trifluoride is a colourless to grayish-yellow fuming liquid with a strong odour. It has a strong reaction to water. It is a fluorinating agent as well as an electrolytic solvent.
Bromine trifluoride was first described in 1906 by Paul Lebeau, who obtained it by reacting bromine with fluorine at 20 °C: Br 2 + 3 F 2 2 BrF. Bromine trifluoride is formed by disproportioning bromine monofluoride: 3 BrF BrF 3 + Br
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Which two solutions would be the BEST choice for their experiment?
Solutions 1 and 3 because they are a strong acid and a strong base.
Solutions 1 and 4 because they are a strong acid and a weak acid.
Solutions 3 and 4 because they are a strong base and a weak acid.
Solutions 2 and 3 because they are a weak base and a strong base.
Solutions 1 and 3 because they are strong acids and a strong base. Option A.
Strong acids and strong bases are completely ionized in an aqueous solution. Weak acids and weak bases also ionize, but only partially and the reaction is reversible. So you know if an acid or base is strong or weak. A simple way to determine strength is to add the acid or base to water. A higher reactivity means a stronger acid or base.
One of the simplest tests to determine whether a solution is an acid or base is the litmus paper test. To do this, dip a special strip of paper so-called litmus paper into the solution and observe the color of the paper. Litmus paper turns red in acidic solutions and blue in basic solutions. Sodium hydroxide is the strongest base because it completely dissociates to form sodium and hydroxide ions. These hydroxide ions are further treated with hydrogen ions by an acid to completely ionize the hydrogen ions.
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Which protozoan is a ciliate?
A. Paramecium
B. Giardia
C. Amoeba
D. Plasmodium
Plant reproduction. Answer as much as possible, thanks!
Answer:
Plant Reproduction
When plants reproduce asexually, they use mitosis to produce offspring that are genetically identical to the parent plant. The advantage of asexual reproduction is that it allows successful organisms to reproduce quickly. ...
When plants reproduce sexually, they use meiosis to produce haploid cells that have half the genetic information of the parent (one of every chromosome)
Explanation:
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A chemist sets up an experiment as follows: she puts bromine gas in a flask that is attached to an airless chamber. Describe what the chemist will observe when she opens the tap connecting the chamber to the flask. Explain your answer.
If the bromine gas in flask is attached to an airless chamber it liquefies and when the tap opens the bromine liquid comes outside.
What is bromine?Bromine is an element in 17th group of periodic table and it is a halogen exists in gaseous state.
When we apply sufficient pressure to a gas in a container the gas molecules starts condensing and then forms changes to its liquid state.
Therefore, in the airless flask where the pressure is higher the bromine gas starts to liquify and thus the tap pour the bromine liquid.
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divide the molar mass of the compound by the empirical formula mass. the result should be a whole number or very close to a whole number. multiply all the subscripts in the empirical formula by the whole number found in step 2. the result is the molecular formula.
The given statement is true. If we divide the molar mass of the compound by the empirical formula mass, the result should be a whole number or very close to a whole number. multiply all the subscripts in the empirical formula by the whole number found in step 2. the result is the molecular formula.
If we write the above statement in the equation or formula then we will get
[tex]\frac{Empirical formula mass}{ Molecular mass}[/tex] = n
Where 'n' is always a whole number
Now, let's understand the above statement with the help of an example.
If we take glucose, a monosaccharide sugar, having molecular formula C₆H₁₂O₆.
The molar mass of glucose is 300 g/mole. Its empirical formula mass is 180 g/mol.
Now by diving them, we will get a whole number
180 / 30 = 6 ( A whole number)
The empirical formula of glucose is CH₂O. If we multiply all the subscripts in the empirical formula (CH₂O) by 6, the result is the molecular formula i.e C₆H₁₂O₆.
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The planet Venus is surrounded by a thick layer of gases. In fact, the atmospheric pressure on Venus is over 90 times greater than the atmospheric pressure on Earth. Which statements are true about boiling water on Venus? Choose the two statements that apply.
The two statements that apply about boiling water on Venus are:
The tempurature will remain constant while it boilsWater will boil at a higher tempurature on Venus than on EarthWhat impact does pressure have on boiling point?
Because the boiling point is the point at which the vapour pressure equals or exceeds the atmospheric pressure, the amount of energy needed to boil a liquid increases as pressure increases.
Explanation:
According to the definition given earlier, anything reaches its boiling point when its vapour pressure reaches or exceeds that of the atmosphere. More and more particles have the energy to transition into the gas phase as temperature rises. As a result, the liquid boils as the vapour pressure rises to equal or higher than atmospheric pressure.
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Question:
The planet Venus is surrounded by a thick layer of gases. In fact, the atmospheric pressure on Venus is over 90 times greater than the atmospheric pressure on Earth. Which statements are true about boiling water on Venus? Choose the two (2) statements that apply.
A. The temperature of water will remain constant while it boils.
B. Water will boil at a higher temperature on Venus than on Earth.
C. Water will boil at a lower temperature on Venus than on Earth.
D. The temperature of water will increase as it boils.
the addition of 0.3800 l of 1.150 m kcl to a solution containing ag and pb2 ions is just enough to precipitate all of the ions as agcl and pbcl2. the total mass of the resulting precipitate is 61.90 g. find the masses of pbcl2 and agcl in the precipitate.
The mass of PbCl2 and AgCl is respectively 23.82 grams and 38.08 grams.
Solution -
Molarity = moles of solute / liters of solution
Moles of Cl- from KCl = molarity × volume in liter = 1.150 * 0.380 = 0.437
Let mass of AgCl = x grams
Moles of AgCl = x/143.32
So moles of Cl- from AgCl = x/143.32
Moles of PbCl2 = (61.90 - x) / 278.106
So moles of Cl- from PbCl2 = 2 × (61.90-x) / 278.106 = (61.90-x) / 139.053
Now,
(x/143.32) + (61.90-x) / 139.053 = 0.437
139.053x + 8871.508 - 143.32x = 8709.0062
- 4.267x = -162.5018
x = 38.08
Thus,
Mass of AgCl = x = 38.08 grams
Mass of PbCl2 = 61.9 - 38.08 = 23.82 grams
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A scientist has a “mystery element” that she wants to identify by using its properties. These properties include its freezing point. She collected data about the element’s freezing point and displayed it on this graph.
The line shows a decreasing slope from 1650 C until a little below 1500 C from time 1 to 15 minutes. At a little below 1500 C, the line flattens until 25 minutes. After 1500 C, the slope decreases until 35 minutes.
Examine the graph. Explain what physical states are represented by each graph region, and describe how the behavior of the particles changes over time.
The physical states represented by each graph region are;
between 1650 C until a little below 1500 C is solid statebelow 1500°C is liquid stateAs time proceeds, the particles become less mobile and more ordered in structure.
What is a change of state?A change of state refers to the processes by which matter changes from one physical state to another.
A change of state of matter occurs when heat is added or removed from a substance.
The stages of matter are:
solidliquid, andgasThe processes of change of state include;
freezing - when a liquid changes to solidmelting - when a solid changes to liquidevaporation - when a liquid changes to gascondensation - when a gas changes to liquidFor pure substances, a change of state occurs at a definite temperature.
This property is used to determine the purity of substances.
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calculate molar solubilities, concentrations of constituent ions, and solubilities in grams/liter for the following compounds at 25°c. i. barium phosphate (ksp
The solubility product, Ksp of barium phosphate is helpful to calculate the molar solubility and concentration of ions.
The equilibrium constant for a solid material dissolved in an aqueous solution is the solubility product constant, Ksp. It denotes the concentration at which a substance dissolves in solution. A material's Ksp value indicates how soluble it is - larger the Ksp value, the more soluble it is. Solubility equilibrium is a sort of dynamic equilibrium that occurs when a chemical substance in solid form is in chemical equilibrium with that compound's solution. The solid may dissolve unmodified, by dissociation, or through chemical reactivity with another solution element, such as acid or alkali. The solubility product is determined by the molar concentrations of the ions in saturated solutions, whereas the ionic product is determined by any solution.
Reaction:
[tex]Ba_3(PO_4)_2 \rightleftharpoons 3Ba^{2+} + 2PO_4^{3-}[/tex]
The solubility product of barium phosphate, Ksp = 1.3 x [tex]10^{-29}[/tex]
The expression of solubility product for barium phosphate is given as:
Ksp = [tex](3S)^3[/tex] x [tex](2S)^2[/tex] = 108 [tex]S^5[/tex]
1.3 x [tex]10^{-29}[/tex] x [tex](2S)^2[/tex] = 108 [tex]S^5[/tex]
[tex]S^5[/tex] = 1.3 x [tex]10^{-29}[/tex] / 108
S = 6.5479 x [tex]10^{-7}[/tex]M
Concentration of barium ions = [tex][Ba^{2+}][/tex] = 3 x 6.5479 x [tex]10^{-7}[/tex] = 1.9643 x [tex]10^{-6}[/tex]M
Concentration of phosphate ions = [tex][PO_4^{3-}][/tex] = 2 x 6.5479 x [tex]10^{-7}[/tex] = 1.3096 x [tex]10^{-6}[/tex]M
Molar solubility of [tex][Ba_3(PO_4)_2] \frac{[Ba^{2+}]}{3}[/tex] = 1/3 x 1.9643 x [tex]10^{-6}[/tex] = 6.5479 x [tex]10^{-7}[/tex]M
Solubility product of [tex]Ba_3(PO_4)_2[/tex] = 6.5479 x [tex]10^{-7}[/tex] x 601 = 0.0003935g/L
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The correct number of atoms of each element present in the formula (NH 4) is
STEP-BY-STEP EXPLANATION:
Given the below compound
Calculate the mass in AMU of a sample that contains 25 potassium atoms
Answer:
1.52x10^-21 grams/atom K
Explanation:
The molar mass of potassium (K) is 39.1 g/mole. One mole = 6.02x10^23 atoms of K.
(25 K atoms)*(39 g/mole)(1 mole/6.023x10^23 atoms) = 1.52x10^-21 grams/atom K
What do these two changes have in common? dew appearing on grass in the morning water freezing into ice Select all that apply.
The similarities which exist between a freezing water and a morning dew on a plant surface is that:
Both conserve massBoth are changes of stateThe correct answer choices are options b and d.
How is freezing of water a change of state of matter?Matter means any thing or substance that has mass and occupies space. There are four different phases of matter including the solid, liquid, gas and plasma.
When a matter changes from one form or state to another, a change of state is said to have taken place. For instance when we place a water ( liquid ) into a freezer such that it turns to ice, this is known as what we call freezing. Here, the water is the liquid and the ice formed is the solid.
So we say freezing means the changing of liquid to solid.
So therefore, it can be deduced from above that there is a change of state of matter when water is freezed into ice and when dews appears of leaves.
Complete question:
What do these two changes have in common? dew appearing on grass in the morning water freezing into ice Select all that apply.
a. Both are chemical changes.
b. Both conserve mass.
c. Both are only physical changes.
d. Both are changes of state.
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Which compound contains covalent bonds?
1. AlN
2. Ca3N2
3. NaCl
4. HCl
HCl compund contains covalent bond.
When 2 atoms exchange one or a lot of pairs of electrons, a covalent bond is formed.
A chemical bond is formed once the distinction between the leptonegativities of 2 atoms is just too tiny for associate electron transfer to occur and manufacture ions.
Let's determine which choice contains covalent bonding.
1. Al-N bonds exhibit some ionic properties in addition to being partially covalent. structure, 1.633, which is most likely influenced by the ionic properties of Al-N bonds [3].
2. Ca and N have electronegativities of 1.0 and 3.0, respectively. Therefore, the difference in electronegativity between Ca and N is (3.0-1.0) or 2.0. Thus, an ionic link exists between Ca and N. Ca3N2 C a 3 N 2 is hence an ionic compound.
3. Since covalent compounds are created by the exchange of electrons, NaCl is not a covalent compound; rather, it is an ionic compound.
4. Because the difference in electronegativity between hydrogen and chloride is less than 2.0, HCl is a covalent compound.
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An 8. 6 mol sample of NO2 is in a 5. 1 L container. What is the pressure of this gas in atmospheres at 33 K? R= 0. 08206 L•atm / (mol•K)
8.6 mole sample of NO₂ in a 5. 1 L container has 4.6 atmospheric pressure at 33 K.
Given, number of moles of No₂(n) = 8.6 mole
Volume (V) = 5.1 liters
Temperature (T) = 33K
R= 0. 08206 L•atm / (mol•K)
Using ideal gas equation ,
PV=nRT
P (5.1L) = (8.6mol) (0.08206L•atm/(mol•K)) (33K)
P (5.1) = 8.6 × 0.08206 × 33
P (5.1) = 23.3
P = 23.3 ÷ 5.1
P = 4.6 atm
Hence, the pressure of the given gas is 4.6 atmosphere (atm).
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flowback waste water is disposed of in a process called deep well injection which plumps large quantities of waste water down into porous sandstone and limestone rock formations underground. what potential problems could result from this?
The potential problems associated with a deep well injection is that it can result in polluting underground water.
If there are many wells nearby, injecting wastewater into subsurface rock strata can be problematic. Consider porous sandstone, which contains minute openings. Water under high pressure, such as wastewater from fracking, can penetrate the sandstone and travel with underground water.
An injection well is employed to inject fluid underground into porous geologic formations. These subterranean structures might be anything from a modest soil layer to thick sandstone or limestone. Water, wastewater, brine (salt water), and water that has been combined with chemicals are all examples of injected fluids.
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What happens to Rutherfordium when it decomposes and loses two
neutrons?
Rutherfordium when decomposes and loses two neutrons, both these rutherfordium isotopes produce neutrons as they undergo their nuclear decay into nobelium.
Rutherfordium's reactivity with the halogens is unclear because so little of it has ever been produced. One would anticipate that it will behave similarly to zirconium and hafnium, which are just above rutherfordium in the periodic table (two places above). After the rutherfordium decays, the distinctive nobelium decay energy and half-life were also seen. Atoms have been created rather infrequently. It is solely employed at this time for research.
The biological function of rutherfordium is unknown. When Rutherfordium, the 104th element on the periodic table, was first artificially created in the 1960s, it sparked a decades-long international debate. The main point of contention was who should get to name the new element. Traditionally, the person who discovers an element is given the privilege of naming it, but this becomes complex when two parties have conflicting claims of discovery.
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a scuba diver exhales 2.05 l of air while swimming at a depth of 98.70 m where the sum of atmospheric pressure and water pressure is 10.54 atm. by the time this exhaled air rises to the surface, where the pressure is 1.00 atm, what is its volume?
The final volume of the air assuming constant temperature is 21.607 Liters using Boyle's gas law.
What is the Boyle's gas law equation?The empirical relation states that under constant temperature, the pressure (p) of a given amount of gas changes inversely with its volume (v); that is, pv = k.
Given,
Initial volume = 2.05 Liters.
Height = 98.70 meters
Final pressure = 1.00 atm.
Initial pressure =10.54atm.
PV = k
P₁V₁=P₂V₂
Substituting the given parameters into the formula,
10.54 × 2.05 = 1 × V₂
V₂ = 21.607
Final volume = 21.607 Liters.
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10.0 trillion DNA molecules is equal to how many moles of DNA?
1.66 × 10–11 moles
6.02 × 1010 moles
6.02 × 1036 moles
1.66 × 1010 moles
10.0 trillion DNA molecules are equal to option a. 1.66 × 10–11 moles.
Deoxyribonucleic acid is a polymer composed of polynucleotide chains that coil around every different to shape a double helix sporting genetic instructions for the improvement, functioning, increase, and reproduction of all known organisms and many viruses. DNA and ribonucleic acid are nucleic acids.
DNA is fabricated from chemical constructing blocks known as nucleotides. those building blocks are the product of three components: a phosphate institution, a sugar institution, and one of four styles of nitrogen bases. To shape a strand of DNA, nucleotides are connected into chains, with the phosphate and sugar corporations alternating.
calculation:-
1 trillion = 10¹² DNA molecules
6.022 × 10²³ molecule = 1 mole
10¹² DNA molecules = 1 / 6.022 × 10²³ × 10¹²
= 1.66 × 10–11 moles
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heat capacity is a measure of the heat required to . group of answer choices raise the temperature of one gram of a substance by one degree celsius raise the temperature of one ounce of a substance by one degree fahrenheit bring a liquid to change phase raise the amount of heat a liquid will absorb before evaporating
Answer:
raise the temperature of one gram of a substance by one degree Celsius
Explanation:
Heat capacity is a physical property of matter, which is defined as the amount of heat to be supplied to something to produce a unit change in its temperature. Heat capacity is also called thermal capacity.
Which of the following is NOT a true statement?
Two or more atoms held together with bonds make up a molecule..
O Pure Substances are made of only one type of atom.
O At least two types of atoms are required to make a compound.
Mixtures can be made of two elements, two compounds, or an element and a
compound.
Two or more atoms held together with bonds make up a molecule is not the true statement
Bonds arise from the electrostatic forces between positively charged atomic nuclei and negatively charged electrons and covalent bond is defined as a chemical bond that includes the sharing of electron pair between atoms and the pair of electrons are know as bonding pairs and the stable balance of attractive and repulsive forces between atoms
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a reaction occurring in a calorimeter absorbs 850.0 j of energy. the initial temperature of 200.0 g of water is 24.5 °c. do you expect the temperature of the water to increase or decrease? explain?
The temperature of the system in equilibrium is 25.51⁰ C.
The equilibrium temperature of the system depends on the heat released from both gold and water. The total heat received by the system will equal to total heat released by objects. It should follow
Q released = Q received
The heat can be defined by
Q = m . c . ΔT
where Q is heat, m is mass, c is the specific heat constant and ΔT is the change in temperature.
The given parameters are
m = 200 g = 0.2 kg
T1 = 24.5⁰ C
c = 4200 J/kg⁰ C
Q received = 850 J
Lets assume that the value of equilibrium temperature is T. Hence,
Q released = Q received
m . c . ΔT = 850
0.2 . 4200 . ΔT = 850
ΔT = 1.01
T - T1 = 1.01
T - 24.5 = 1.01
T = 25.51⁰ C
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3. In the metric unit nanometer, "nano" is the base unit.
a. TRUE
b. FALSE
Answer:
False
Explanation:
The base unit is "meter."
Nanometer is equal to one billionth of a meter.
preparation and characterization of a copper phosphotungstate/titanium dioxide (cu-h3pw12o40/tio2) composite and the photocatalytic oxidation of high-concentration ammonia nitrogen
Try this? I'm not sure if i understood the question correctly
A composite photocatalyst of copper phosphotungstate/titanium dioxide (Cu-H3PW12O40/TiO2) : prepared by sol-gel hydrothermal synthesis.The composite catalyst was characterized by X-ray diffraction (XRD), UV–vis-diffuse reflectance spectroscopy (UV-VIS-DRS), Fourier converted infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS)、scanning electron microscopy (SEM) and power dispersive X-ray spectroscopy (EDS). The photocatalytic oxidation of a high-concentration NH4+/NH3 occured under ultraviolet (UV)light. The composite catalyst exhibited higher photocatalytic activity than that of TiO2. When 300 mg·L−1, the initial pH was 11, the catalyst concentration was 1.5 g·L−1, the loading level of Cu-H3PW12O40 was 40%, the aeration rate was 1.5 L·min−1, and lastly the removal rateof NH4+/NH3 by the composite photocatalyst could reach >80%. Very little NO2− and NO3− were produced, and N2 was the main product.
what volume, in ml, of concentrated 16 m nitric acid would you need to use in order to prepare 500.0 ml of a 0.250 m hno3(aq) solution? (formula mass of hno3
The volume of concentrated 16 m nitric acid required is 7.81ml
Concentration of HNO3= 16M
We need to find the volume of HNO3. V=?
Concentration of required solution= 0.250M
Volume of required solution= 500M
So to solve this problem, we have to use the Molarity equation
m1v1=m2v2
So now we have to substitute the given values in the molarity equation
After doing that we get:
16M x V1 = 0.250M X 500M
V1= 0.250 X 500M/ 16M
Therefore V1= 7.81ML
Hence, the volume of concentrated 16 m nitric acid required is 7.81ml in order to prepare 500.0 ml of a 0.250 m hno3(aq) solution.
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how many molecules are in 80 grams of Bromine
Answer:
[tex]6.029 \times 10^{23} molecules[/tex]
Copper(II) sulfate crystals, CuSO4.5H₂O, can be made by heating copper(II) oxide with dilute
sulfuric acid and then crystallising the solution formed.
a
Calculate the maximum mass of crystals that could be made from 4.00 g of
copper(II)oxide using an excess of sulfuric acid.
CuO(s) + H₂SO4(aq) → CuSO4(aq) + H₂O(1)
CuSO4(aq) + 5H₂O(l) → CuSO4.5H₂O(s)
8.05 g of CuSO₄ is the highest mass of crystals.
a) CuO(solid) + H₂SO₄(aqueous) → CuSO₄(aqueous) + H₂O(liquid)
Molecular weight,
CuO = 79 g
Molar weight of CuSO₄ = 159 g,
79 g of CuO reacted with H₂SO₄ 159 g to form CuSO₄.
∴ 4 g of CuO
= 159/79 × 4
= 8.05 g of CuSO₄
b) Percentage yield and Theoretical yield :
The Theoretical yield:
CuSO₄ of 159.6 g → CuSO₄.5H₂O of 249.5 g
8.05 g = 249.5 × 8.05 ÷ 159.6 = 12.58 g
And the percentage yield = Weight of the product ÷ Theoretical yield × 100
= 11.25 ÷ 12.58 × 100
= 89.42%
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Which of the following is NOT an example of matter?
O All of these are examples of matter
O air
O gold
O apple juice
O a rose bush
Answer: All of these are examples of matter
Explanation:
Matter is any substance that has mass and takes up space by having volume. All examples have mass (including air) and take up space, so the answer is, "All of these are examples of matter."
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The ΔE for the transition of an electron from n= 7 to n=4 is 9.159 × 10⁻²⁰ J and the frequency is 1.373 × 10¹⁴ S⁻¹.
A spectral line is a darkish or vibrant line in any other case uniform and non-stop spectrum, because of an excess or deficiency of photons in a slim frequency variety, compared with the close by frequencies.
A spectral line is a darkish or shiny line in any other case uniform and continuous spectrum, as a consequence of emission or absorption of light in a slim frequency variety, in comparison with the close by frequencies. Spectral lines are regularly used to perceive atoms and molecules.
ΔE = E final - E initial = -13.6 × Z² (1/n final² -1/n initial²) eV/atom
= +13.6 × 1² (1/7² - 1/4²)
= 13.6 × ( 1/49 - 1/16)
= 13.9 × ( 16 - 49) / 49 × 16
= - 0.57244 eV/atom
= 0.57244 × 1.6 × 10⁻¹⁹ J
= 0.9159 × 10⁻¹⁹ J
= 9.159 × 10⁻²⁰ J
Frequency(ν):-
ΔE = hν
ν = ΔE/h
= 9.159 × 10⁻²⁰ J / 6.626 × 10⁻³⁴
= 1.373 × 10¹⁴ S⁻¹ ( four significant figure)
Learn more about spectral lines here:-https://brainly.com/question/14587536
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