The colour of Variamine blue salt B, a redox indicator changes from yellow to colourless at the endpoint of the complexometric titration indicating alkalinity.
Complexometric titration (also known as chelatometry) is a type of volumetric analysis in which the creation of a coloured complex is utilized to determine the titration's end point. Complexometric titrations are extremely useful for estimating the concentration of a metal ion mixture in solution. EDTA, or ethylenediaminetetraacetic acid, is a frequent indicator for complexometric titration because it may function as a ligand, binding to coordination centers, which are generally metals, to produce colourful complexes. Organic dyes are the most commonly used indicators in complexometric titrations because they generate a colourful complex with the metal ion being titrated. EDTA replaces the indicator during the reaction to create a more stable complex with metal, and when the reaction is through, the colour changes.
The alkalinity of solution is indicated by a colour change from yellow to colourless in the complexometric titration using Variamine blue salt B as the indicator.
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2) How many moles of silicon are in a 56.18 g sample?
what will be the equilibrium temperature when a 229 g block of copper at 290 ∘c is placed in a 136 g aluminum calorimeter cup containing 835 g of water at 12.6 ∘c ?
The equilibrium temperature will be 19.3 °C. We can calculate this using the specific heat capacities of all materials involved (copper, aluminum, and water).
We can calculate the equilibrium temperature by comparing the amount of heat (Q) released by the block of copper and the amount of heat absorbed by aluminum and water.
Q = (t₁ - t₂) * c * m
t₂ - starting temperature
t₁ - final temperature (X)
c - specific heat capacity (0.389 J/g°C for copper, 0.903 J/g°C, 4.186 J/g°C for water)
m - mass of the substance
Q(released) = (290 C - X) * 0.389 J/g°C * 229 g
Q(released) = 25833.49 J - 89.081 J/°C * X
Q(absorbed) = (X - 12.6 °C) * (0.903 J/g°C * 136 g + 4.186 J/g°C * 835 g)
Q(absorbed) = (X - 12.6 °C) * 3618.118 J/°C
Q(absorbed) = 3618.118 J/°C * X - 45588.2868 J
We know that the amount of heat released is equal to the amount of fear absorbed, so we will use that:
25833.49 J - 89.081 J/°C * X = 3618.118 J/°C * X - 45588.2868 J
71421.7768 J = 3707.199 J/°C * X
X = 71421.7768 J / 3707.199 J/°C
X = 19.3 °C
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PLEASE HELP !!!! What would be the mass of AB and A2B3 if the atomic mass of A is 2 units, and the atomic mass of B is 3 units
Answer:
1. 5
2. 13
Explanation:
1. AB = 2 + 3 = 5
2 A2B2 = 2(2) + 3(3) = 4 + 9 = 13
Ammonia gas decomposes when heated.
15
2NH₂(g) → N₂(g) + 3H₂(g)
In an experiment, a sample of 500 cm³ of ammonia was heated and 20% decomposed.
The total volume of gas present at the end of the experiment, in cm³, was
D A 200
00= 100 cm
B
400
C
600
D 1000
The total volume of gas present at the end of the experiment in cm³ was 600. Option C.
In this chemical reaction, 2 molecules of ammonia NH3 are decomposed or decomposed into 1 molecule of nitrogen N2 and 3 molecules of hydrogen H2. Laboratory glass tubing is used in many laboratories and industrial workplaces to connect other glassware and equipment and to transport or dispense chemicals, solvents, liquids, gases, and other products.
Laboratory glass tubes are typically manufactured from borosilicate glass for the most demanding applications. Ammonia gas which has a lower molecular weight than hydrogen chloride diffuses faster and travels a longer distance in the tube. As a result, a white ring of ammonium chloride forms much closer to the hydrochloric acid end of the tube.
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Question 14 (3 points)If 20g of aluminum is used to replace calcium chloride in a single displacementreaction, how many grams of calcium will be produced? The 20g of aluminum is thelimiting reactant.
Answer
The grams of calcium produced will be 44.44 grams
Explanation
The equation for the reaction is:
3CaCl₂ + 2Al → 2AlCl₃ + 3Ca
From the equation; 2 mol Al = 3 mol Ca
1 mole of Al = 27 g/mol
1 mole of Ca = 40 g/mol
Therefore, the mass of Ca produced when 20 g of Al react is:
[tex]\begin{gathered} 2mol\times27g\text{/}mol\text{ }Al=3mol\times40g\text{/}mol\text{ }Ca \\ \\ 20g\text{ }Al=x \\ \\ x=\frac{20g\text{ }Al}{2mol\times27g\text{/}mol\text{ }Al}\times3mol\times40g\text{/}mol\text{ }Ca \\ \\ x=\frac{20g}{54g}\times120g\text{ }Ca \\ \\ x=44.44\text{ }grams\text{ }Ca \end{gathered}[/tex]Thus, the grams of calcium produced will be 44.44 grams
how can i tell what compounds have higher ionic character?
The compound would have higher ionic character if the difference in electronegativity between the atoms is higher.
Electronegativity is a property that explains the tendency of an atom to attract more electrons from other compounds to itself which would result in bond formation. If the attraction or electronegativity is higher, it results in ionic bond between the atoms. This is called ionic character.
We can also say that the ionic character would be high if the covalent character is less in a compound.
Thus, higher electronegativity between shared electrons between atoms and less covalent character in a compound would help us identify the compounds with higher ionic character.
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ammonium carbamate, nh4co2nh2, decomposes as follows: nh4co2nh2(s) δ 2nh3(g) 1 co2(g) starting with only the solid, it is found that at 40°c the total gas pressure (nh3 and co2) is 0.363 atm. calculate the equilibrium constant kp.
The equilibrium constant is equal to 7.09 * 10⁻³ atm³.
The expression for the equilibrium constant (Kp) for this reaction will look like this:
Kp = (pNH₃)²pCO₂
pNH₃ - partial pressure of NH₃
pCO₂ - partial pressure of CO₂
Because ammonium carbamate is solid, its concentration and pressure cannot change (they are constant), so there is no need to include it in the expression. We know that all the gas present in the mixture is formed by the decomposition of ammonium carbamate. We also know that for every two moles of ammonia formed, 1 mole of carbon dioxide is also formed.
Because partial pressure is proportional to the molar ratio, we can establish that:
pNH₃ = 2 * pCO₂
pNH₃ + pCO₂ = 0.363 atm
2 * pCO₂ + pCO₂ = 0.363 atm
3 * pCO₂ = 0.363 atm
pCO₂ = 0.363 atm / 3
pCO₂ = 0.121 atm
pNH₃ = 2 * 0.121 atm
pNH₃ = 0.242 atm
We can now plug these values into the expression for the equilibrium constant:
Kp = (0.242 atm)² * 0.121 atm = 7.09 * 10⁻³ atm³
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The diagram below shows some subatomic particles.
An outer circle, labeled X, surrounds three smaller circles; one of these is labeled Quark. The three inner circles are connected by a line from each circle to a point at the center of the large circle; the three lines resemble the letter Y.
Which of these statements best identifies the particle that is labeled with an X?
It is either a nucleus or a proton.
It is either a proton or a neutron.
It is either a neutron or an electron.
It is either an electron or a nucleus.
Answer:
c
Explanation:
Answer:
C
Explanation:
How would this model be like after being separated chemically?
A separation method known as chemical extraction depends on the difference between an element's solubility in an organic solvent and an aqueous solution.
What exactly are organic solvents?Organic solvents are chemicals with a carbon structure that can dissolve or disperse one or more other compounds. Organic solvents have the potential to be neurotoxins, genital poisons, and carcinogens. The organic solvents benzene, carbon tetrachloride, and trichloroethylene are carcinogenic. The boiling point of organic solvents is low – Organic solvents are known to have very low boiling points.
Is oil a type of organic solvent?Vegetable oil is analysed and weighed for use as an organic solvent for wastewater treatment in liquid membrane systems.e vegetable oil as a more sustainable organic solvent is highlighted.
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Tungsten filament is the element found in light bulbs. Which
subatomic particles surrounding the nucleus of tungsten are responsible for the
continuous spectrum observed?
Electrons subatomic particles surrounding the nucleus of tungsten are responsible for the continuous spectrum observed.
What are 3 the subatomic particles?These particles are commonly referred to as subatomic particles since they are the building blocks of atoms. There are protons, neutrons, and electrons, three types of subatomic particles. Protons and electrons, two of the subatomic particles, each have an electrical charge of one or the other.
How do subatomic particles function?Two crucial functions for subatomic particles in the construction of matter. They serve as both the universe's fundamental building blocks and the glue that connects them. Although the atoms that play these various jobs belong to two separate categories, they do have some things in common, most notably size.
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Which of the following has the largest radius?
A. N a^ +
B. K ^ +
C. Na
D. K
K (Potassium) has the largest radius
Atomic radius – Distance between the nucleus of an atom to its outermost orbit.
In the periodic table, as we go down the group the atomic radius increases. This is because the energy level increases as we go down the group.
Na has 11 electrons. It would have 3 shells – 2,8,1
K has 19 electrons. It would have 4 shells – 2,8,8,1
Na⁺ and K⁺ are ions with the loss of electrons of the atom Na and K respectively.
Na⁺ and K⁺ would have lost one electron resulting in 2 and 3 shells respectively. Thus, they are smaller than Na and K respectively.
Na and K belongs to period 3 and 4 down the group. So, K in 4th period would have more energy levels compares to Na. Thus, K (Potassium) would have the largest atomic radius with 4 shells.
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HELP ASAP! Will mark brainliest for correct answer
The density data for a
substance was collected in
the table to the right. The
substance is known to have a
density of 7.4 g/mL. What is
the percent error for the data?
A. about 12%
B. about 0.12%
C. about 14%
D. about 0.14%
A. The percentage error in the measurement of the density is about 12%.
What is error in measurement?The error in any measurement is the difference between the actual measurement of the substance and the estimated measurement of the substance.
The percentage error is obtained by dividing the error in the measurement by actual measurement and multiply the result by 100%.
The average density measurement = 6.5 g/mL
error = actual measurement - estimated measurement
error = 7.4 g/mL - 6.5 g/mL
error = 0.9 g/mL
percentage error = (0.9 / 7.4) x 100%
percentage error = 12.16 %
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Answer: A
Explanation:
a chemist recrystallizes 10 g of a solid and isolates 7 g as the first crop and 1 g as the second crop. what is the percent recovery in the first crop? what is the total percent recovery?
Percent recovery in the first crop is 70%
Total percent recovery is 80%
Percent recovery is defined as amount recovered divided by the total possible amount recovered
First part:
Amount recovered=7g
Total amount recoverable=10g
Percent recovery=7/10=.7=70%
Percent recovery in the first crop is 70%
Second part:
Amount recovered=(7+1)g=8g
Total amount Recoverable=10g
Percent recovery=8/10=.8=80%
Total percent recovery is 80%
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What most accurately explains whether liquid water or ice has a higher density, and why?
Hydrogen bond is a type of intermolecular force, a strong bond that is formed due to a dipole-dipole attraction, and it will occur when Hydrogen atom bonds with strongly electronegative atoms, like F, O or N. According to this explanation, let's analyze the options:
A) Hydrogen bond will not occur between two hydrogen atoms, because there is no dipole being formed between them
B) It is not a covalent bond, since it is an interaction between molecules and not atoms, and another reason is that H bonds are strong in terms of dipoles, and covalent bondings will not have that electronegative difference
C) Water is a polar molecule, and that would be a reason for why we have hydrogen bonds
D) Since hydrogen bonds are based on a strong difference in electronegativity, it is considered to be a strong interaction
E) As I wrote in the explanation, yes this interaction between H and O will represent a hydrogen bond
F) Yes! When we talk about hydrogen bonds, we are talking about interaction between molecules and not atoms
Correct:
C
E
F
label each of the following product pairs as optically active or inactive. a. 50% r enantiomer and 50% s enantiomer b. a pair of diastereomers c. a meso compound d. 40% r enantiomer and 60% s enantiomer e. just the r enantiomer f. a racemic mixture
The optical activity of the given enantiomer pairs is inactive, active, inactive, active, active, and inactive respectively.
Enantiomers have similar physical and chemical characteristics, making it difficult to identify and separate them. A chiral compound's right- and left-handed enantiomers cause different perturbations in plane-polarized light. It has been called optical activity and is specific to chiral compounds.
Optically active substances rotate the plane of polarized light. A stereoisomeric pair has two identical but sign-opposite enantiomers, each of which is optically active. Because they are scientifically established constants that describe and distinguish pure enantiomers, specific rotations are helpful.
a) 50% r enantiomer and 50% s enantiomer – Optically inactive because the plane-polarized light is moved in an equal but opposing direction by both the r and s enantiomers.
b) A pair of diastereomers – Optically active because these compounds have the same molecular formula but also have non-superimposable non-mirror images.
c) A meso compound – Optically inactive as they do not have enantiomers, because the mirror image of a meso compound is itself.
d) 40% r enantiomer and 60% s enantiomer – Optically active since the s enantiomer is in excess (60 – 40 = 20%).
e) Just the r enantiomer – Optically active because of the light's plane of polarization rotating.
f) A racemic mixture – Optically inactive because each component's rotatory impact completely balances out the other.
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What are the astronomer qualifications
Minimum qualifications of Astronomer 4 year degree to get a postgraduate qualification like a master of physics.
2 or 3 A levels, or similar, in math and physics; 5 GCSEs at grades 9 to 4 (A* to C), or equivalent; and a degree in a field that is useful for postgraduate study.
Math and physics expertise, analytical thinking abilities, science knowledge, great verbal communication skills, the capacity to take initiative, and the capacity to think coherently utilizing logic and reasoning are all desirable. To be extremely knowledgeable about computer applications and systems.
A scientist who concentrates their research on a particular issue or area outside the purview of Earth is called an astronomer in the science of astronomy. In either observational or theoretical astronomy, they observe celestial bodies like stars, planets, moons, comets, and galaxies.
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How is it possible that when you combine Na (sodium) an explosive metal, and Cl (chlorine) a poisonous gas it creates NaCl (salt) that we put on our food?
Answer:
They share an outer electron.
Explanation:
For complementary reasons, sodium and chlorine are both highly reactive. Sodium has a single electron in its outermost, third shell, and chlorine has one electron less than eight in its outermost, fourth shell. They form a strongly bound molecule by sharing that outer electron.
What can cause pollution in each of the three categories?
the reaction 2no(g) br2(g) 2nobr(g) has a kp value of 109 at a particular temperature. if the equilibrium partial pressure of br2 is 0.108 atm and the equilibrium partial pressure of nobr is 0.482 atm, what is the equilibrium partial pressure of no?
The equilibrium pressure of the NO is given by 0.14 atm
What is the equilibrium constant?We define the equilibrium constant as the value that shows the extent to which the reactant is converted to product. If the value of the equilibrium constant have been calculated to be large then most of the reactants have been converted to products.
We can write;
K = [NOBr]/[NO]^2 [Br2]
We now need to make the equilibrium concentration of the NO the subject of the formula as follows;
K[NO]^2 [Br2] = [NOBr]
[NO] = [NOBr]/K [Br2]
[NO] = √0.482^2/109 * 0.108
[NO] = √0.232/11.77
= 0.14 atm
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Calculate the number of atoms in 24.83g calcium phosphate.
Avogadro's Number:
Avogadro's number, which is equal to 6.02214076 x [tex]10^{23}[/tex] , is the quantity of units in one mole of any material. Hence, 1 mole of calcium phosphate,[tex]Ca_{3} (PO_{4}) _{2}[/tex] will contain 6.02214076 x [tex]10^{23}[/tex] atoms.
The molar mass of calcium phosphate is 310.18 g/mol,
Then, number of moles in 24.83g of calcium phosphate = [tex]\frac{mass}{molar mass}[/tex]
= [tex]\frac{24.83}{310.18}[/tex]
= 0.08 mole
Then, 0.08 mole of [tex]Ca_{3} (PO_{4}) _{2}[/tex] will contain,
= 0.08 moles x 6.02214076 x [tex]10^{23}[/tex] atoms
= 0.4818 x [tex]10^{23}[/tex] atoms = 4.818 x [tex]10^{22}[/tex] atoms.
Hence, 0.08 mole of calcium phosphate will contain 4.818 x [tex]10^{22}[/tex] atoms.
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how many milliliters of 3.00 m h2so4 are required to react with 4.35 g of a solid mixture containing 23.2 % (w:w) ba(no3)2? (i.e. in the original sample, there are 23.2 g of barium nitrate per 100 g of total sample) (5 pts)
1.29 milliliters of 3.00 m [tex]H_{2}[/tex] [tex]SO_{4}[/tex] (Sulfuric acid) are required to react with 4.35 g of a solid mixture containing 23.2 % (w/w) [tex]Ba(NO_{3)2[/tex]
Equation of the reaction:
[tex]H_2[/tex]S[tex]O_{4}[/tex](aq) + Ba(N[tex]O_{3}[/tex][tex])_{2}[/tex](aq) --> BaS[tex]O_{4}[/tex] + 2HN[tex]O_{3}[/tex](aq)
Mass of [tex]Ba(NO_{3)3[/tex] = wt% * mass of the solid
= 23.2 x 4.35 / 100
= 1.01 g
Number of moles of [tex]Ba(NO_{3)2[/tex] = Mass / Molar Mass
Molar mass of [tex]Ba(NO_{3})2[/tex] = 137 + (14 + (16 * 3))*2
= 261 g/mol
= 1.01 / 261
= 0.00387
Since the chemical reaction occurs between one mole of Ba(NO3)2 and one mole of [tex]H_{2[/tex] [tex]SO_{4}[/tex]. Therefore, number of moles of [tex]H_{2}[/tex] [tex]SO_{4}[/tex] = 0.00387 moles. The formula is
Volume = number of moles/molar concentration
= 0.00387/3
= 0.00129 L
V2 = 1.29 mL
Hence, 1.29 milliliters of 3.00 m [tex]H_{2}[/tex] [tex]SO_{4}[/tex] (Sulfuric acid) are required to react with 4.35 g of a solid mixture containing 23.2 % (w/w) Ba(NO3)2.
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The complete question is:
How many milliliters of 3.00 m H2SO4 are required to react with 4.35 g of a solid mixture containing 23.2 % (w:w) Ba(NO3)2? (i.e. in the original sample, there are 23.2 g of barium nitrate per 100 g of total sample).
suppose 7.1 kg of chloroform at 21.4°c is poured into 9 kg of propylene glycol at 36.4°c. calculate the final equilibrium temperature, neglecting any energy processes associated with mixing, given cprop
32.66℃ is found to be the final equilibrium temperature of the system.
The movement of energy from a higher temperature to a lower temperature is referred to as heat. The system (or combination of systems) is considered to be in thermal equilibrium when these temperatures stabilize and heat stops flowing, and this temperature is known as the equilibrium temperature.
The temperature of the water at which the total of all heat fluxes through the sea surface is zero is known as the equilibrium temperature.
Because the Keq is temperature sensitive, the value of the equilibrium temperature has altered in this scenario. That is why equilibria alter with temperature changes.
If the temperature is raised, the point of equilibrium will shift in such a way that the temperature will fall again. It will do this by promoting the process that absorbs heat.
Given:
Cprop, [tex]c_{pr}[/tex] = 2500 J/(kg⋅K)
Cchloroform, [tex]c_{ch}[/tex] = 1050 J/(kg⋅K)
To find:
Final equilibrium temperature, [tex]T_f[/tex] = ?
Formula:
Heat gained by chloroform = Heat lost by propylene glycol
[tex]m_{ch} c_{ch} ( T_f -T_{ch}) = m_{pr} c_{pr} (T_{pr} - T_f)[/tex]
Calculations:
[tex]T_f[/tex] – 21.4 / 36.4 – [tex]T_f[/tex] = [tex]m_{pr}c_{pr} / m_{ch} c_{ch}[/tex] = 9 x 2500 / 7.1 x 1050
[tex]T_f[/tex] – 21.4 / 36.4 – [tex]T_f[/tex] = 22500 / 7455
[tex]T_f[/tex] – 21.4 / 36.4 – [tex]T_f[/tex] = 3.01
[tex]T_f[/tex] – 21.4 = 3.01 x (36.4 – [tex]T_f[/tex])
[tex]T_f[/tex] – 21.4 = 109.564 – 3.01 [tex]T_f[/tex]
[tex]T_f[/tex] + 3.01 [tex]T_f[/tex] = 109.564 + 21.4
4.01 [tex]T_f[/tex] = 130.964
[tex]T_f[/tex] = 130.964 / 4.01
[tex]T_f[/tex] = 32.66℃
Result:
The final equilibrium temperature is found to be 32.66℃
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Which statement best describes why a chemical change is different from a physical change?
A. A chemical change is used to identify characteristics of a substance, and a physical change identifies the behavior of a substance when in a reaction.
B. A chemical change is used by scientists to create new substances, and a physical change happens naturally.
C. A chemical change results in a different state of matter, and a physical change results in a new substance being formed.
D. A chemical change results in a new substance being formed; whereas, a physical change will result in a different state of matter.
a 0.561 m solution of an unknown electrolyte depresses the freezing point of water by 2.93 c. what is the van't hoff factor for this electrolyte? the freezing point depression constant, kfp, for water is -1.86 c/m
The value of van't Hoff factor for the electrolyte is i = 0.28
Molarity of solution = 5.61 m
The temperature which depresses the freezing point of water = 2.93 °C
The freezing point depression constant, kfp, for water = 1.86 °C kg[tex]mol^{-1}[/tex]
To find the van't Hoff factor, let's use the following formula.
ΔTf = kf × molality × i
Here ΔTf = depression fo freezing point
kf = freezing point depression constant
i = Van't Hoff's factor
Now substitute the values in the above formula.
2.93 = 1.86 x 5.61 x i
i = 2.93 / 1.86 x 5.61
i = 2.93 / 1.043 = 0.28
Hence, the value of van't Hoff factor is 0.28
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The complete question is:
A 05.61 m solution of unknown electrolyte depresses the freezing point of water by 2.93 °C. What is van't Hoff factor for this electrolyte? The freezing point depression constant (Kf) for water is 1.86 °C kg[tex]mol^{-1}[/tex].
How did lithium get verified as a new element? (PLS HELP!)
Answer:
The element was discovered on Earth in 1817 by Johan August Arfvedson (1792-1841) in Stockholm when he investigated petalite, one of the first lithium minerals to be discovered. (It was observed to give an intense crimson flame when sprinkled on to a fire.)
a new whiskey flavoring is said to contain two major compounds: 2-butanone and 2- propanol. your lab partner proposes to separate these two compounds by fractional distillation. do you think this is a good idea? if not, propose an alternative method of separation based on what we have learned in this course.
It is not a good idea to separate a mixture of 2-butanone and 2- propanol by fractional distalltion. However, they should be seaparted by extractive distillation.
What is fractional distillation?Fractional distillation is a separation technique in which two immiscible liquids are separated by means of distillation based on differences in their boiling points.
The liquid with the lowest boiling point distills over first, before the one with the higher boiling poinr.
However, to separate two miscible liquids by fractional distillation, their boiling points must be far apart.
The boiling point of 2-butanone is 79.64 °C
The boiling point of 2- propanol is 82.5 °C
Therefore, they can not be separated by fractional distillation.
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Look up the density of water (CRC Handbook 6-6). Is it necessary to use the density of water in calculations for the %error?
Answer:
The density is 33.4
Explanation:
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You are asked to prepare a pH=3.00 buffer solution starting from 1.35 L of a 1.00 M solution of hydrofluoric acid (HF) and an excess of sodium fluoride (NaF)
What is the pH of the hydrofluoric acid solution prior to adding sodium fluoride?
How many grams of sodium fluoride should be added to prepare the buffer solution? Neglect the small volume change that occurs when the sodium fluoride is added.
Answer:
a) 1.58
Explanation:
= 0.681 M Need grams of NaF
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The pH of the hydrofluoric acid solution prior to adding sodium fluoride - = 1.606 and the amount of sodium fluoride should be added to prepare the buffer solution - 35.75g or 36 g.
a) Weak acid such as hydrofluoric acid is not entirely dissociate. The capacity of dissociation of the compound will be given by it's acid dissociation constant ka
HF <==> H+ + F-
I 1.0 0 0
C -x +x +x
E 1.0-x x x
I = initial conc. C = Change in conc. E = Conc. at equilibrium
Ka = (Ka for HF is 6.3 x 10-4 constant)
= 6.3 x 10-4 =
= 6.3 x 10-4 (1.0- x ) =
Solve for x using quadratic equation method. Neglecting negative value as concentration is always positive value
x = -0.0254 and x = 0.0248 = [H+]
pH = - log []
pH = - log 0.0248
= 1.606 ( pH of HF before adding NaF)
b) Given:
pH = 3.00
[HF] = 1.00 M
[F-] - ?
Solution:
a buffer follows the Henderson-Hasselbach equation:
pH = pKa + log
3.00 = 3.167 + log
log = -0.167
[] = (0.681) ([HF])
= (0.681) (1.00)
= 0.681 M
NaF --> + [NaF]
= 0.681 M Need grams of NaF
The amount of would be =
=
= 35.75g NaF
Thus, the pH of the hydrofluoric acid solution prior to adding sodium fluoride - = 1.606 and the amount of sodium fluoride should be added to prepare the buffer solution - 35.75g or 36 g.
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Anyone good there at chemistry? Please help me with this problem
Answer:
19.5°C (nearest tenth)
Explanation:
When a gas is trapped inside a container whose volume cannot change, the pressure is directly proportional to the Kelvin temperature.
Gay Lussac's Law
[tex]\sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
where:
P₁ is the initial pressure.T₁ is the initial temperature.P₂ is the final pressure.T₂ is the final temperature.Temperature must be in kelvins (K).
To convert Celsius to kelvins, add 273.15.
Given values:
P₁ = 4.882 atmP₂ = 4.690 atmT₂ = 8 C = 8 + 273.15 = 281.15 KSubstitute the given values into the equation and solve for T₁:
[tex]\implies \sf \dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
[tex]\implies \sf \dfrac{4.882}{T_1}=\dfrac{4.690}{281.15}[/tex]
[tex]\sf \implies \sf T_1=\dfrac{4.882 \cdot 281.15}{4.690}[/tex]
[tex]\sf \implies \sf T_1=\dfrac{1372.5743}{4.690}[/tex]
[tex]\sf \implies T_1=292.6597655...\:K[/tex]
To convert kelvins to Celsius, subtract 273.15:
[tex]\sf \implies T_1=292.6597655...-273.15=19.5097...^{\circ}C[/tex]
[tex]\sf \implies T_1=19.5^{\circ}C\;(nearest\;tenth)[/tex]
Therefore, the temperature of the previous day was 19.5°C (nearest tenth).
Clarify the chemical reaction, and then write a balanced formula chemical equation
NaF
The balanced chemical equation for the formation of sodium fluoride, NaF is given below:
2 Na (s) + F₂ (g) ----> 2 NaF (s)
What kind of reaction is the formation of sodium fluoride?The formation of sodium fluoride, NaF is an example of a synthesis reaction.
In a synthesis reaction, two or more elements or compounds react together to form a single compound.
The formation of sodium fluoride is given in the chemical equation below:
2 Na (s) + F₂ (g) ----> 2 NaF (s)
The reaction is a highly exothermic reaction. The compound formed, NaF is an ionic compound.
During the reaction, two moles of sodium atoms lose an electron each to fluorine gas atom which readily accepts the electrons to fluoride ions.
electrostatic forces of attraction between the oppositely-charges ions keep the compound in a crystal lattice form.
Learn more about synthesis reactions at: https://brainly.com/question/26313963
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