Answer:
percent ionization = 50.01%; pH = 4.75
Explanation:
To solve this question we must write the acetic acid equilibrium (Where HX will be acetic acid and X⁻ the sodium acetate):
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
Where equilibrium constant, Ka, is defined as:
Ka = 1.76x10⁻⁵ = [H⁺] [X⁻] / [HX]
Where the concentration of each ion is:
[H⁺] = X
[X⁻] = 0.10M + X
[HX] = 0.10M - X
Replacing in Ka expression:
1.76x10⁻⁵ = [X] [0.10-X] / [0.10+X]
1.76x10⁻⁶ + 1.76x10⁻⁵X = 0.10X - X²
X² - 0.0999824 X + 1.76×10⁻⁶ = 0
X ≈ 0.1M → False solution. Decreases a lot the concentration of HX
X = 0.0000176M → Right solution.
The concentration of each ion is:
[H⁺] = 0.0000176062M
[X⁻] = 0.10M + 0.0000176M = 0.1000176M
[HX] = 0.10M - 0.0000176M = 0.0999824M
Percent ionization:
[X-] / [X-] + [HX] * 100 =
0.1000176M / 0.2M =
50.01%And pH = -log [H+]
pH = 4.75As you can see, [H+]≈ Ka
What is the molarity of a solution made by adding :1.565 moles of PbN03 to 500 mL
Answer:
This question is a bit vague. We're not told if 500ml is the volume of the solution and additional info is not given to calculate the volume of pbNo3 being added.
If you solve with 500ml as the volume of solution ... You'll have the answer below.
Molarity=moles of solutes/Volume of solvent(in litres)
moles of solute given=1.565moles
Volume = 500ml. There's 1000ml to a litre. Dividing by 1000ml to convert to Litres... You have 0.5L
Molarity = 1.565/0.5
=3.13M
Help help help :/
Please
A 1.757-g sample of a / alloy was dissolved in acid and diluted to exactly 250.0 mL in a volumetric flask. A 50.00-mL aliquot of the diluted solution was brought to a pH of 10.0 with an / buffer; the subsequent titration involved both cations and required 28.89 mL of 0.06950 M EDTA. A second 50.00-mL aliquot was brought to a pH of 10.0 with an / buffer, which also served to mask the ; 19.07 mL of the EDTA solution were needed to titrate the . Calculate the percent and in the sample.
Answer:
78.14% Pb²⁺ and 21.86% of Cd²⁺
Explanation:
The first titration involves the reaction of both Pb²⁺ and Cd²⁺
In the second titration, as the buffer is HCN/NaCN, the Cd²⁺ precipitates as Cd(CN)₂ and the only ion that reacts is Pb²⁺
In the first titration:
Moles EDTA = Moles Pb²⁺ and Cd²⁺:
28.89mL = 0.02889L * (0.06950moles / L) = 2.008x10⁻³ moles in the aliquot. In the sample:
2.008x10⁻³ moles * (250.0mL / 50.0mL) =
0.01004 moles = Pb²⁺ + Cd²⁺ (1)
In the second titration:
19.07mL = 0.01907L * (0.06950mol / L) = 1.325x10⁻³ moles Pb²⁺ in the aliquot. In the sample:
1.325x10⁻³ moles Pb²⁺ * (250.0mL / 50.0mL) =
6.626x10⁻³ moles Pb²⁺
That means the moles of Cd²⁺ are:
0.01004 moles = Cd²⁺ + 6.626x10⁻³ moles Cd²⁺
3.413x10⁻³ moles Cd²⁺
The mass of each ion is:
Cd²⁺ -Molar mass: 112.411g/mol-:
3.413x10⁻³ moles Cd²⁺ * (112.411g / mol) =
0.384g of Cd²⁺
Pb²⁺ -Molar mass: 207.2g/mol-:
6.626x10⁻³ moles Pb²⁺ * (207.2g / mol) =
1.373g of Pb²⁺
The percent mass of each ion is:
1.373g Pb²⁺ / 1.757g = 78.14% Pb²⁺
And:
0.384g of Cd²⁺ / 1.757g * 100 = 21.86% of Cd²⁺
water from a town is suspected to contain chloride ions but not sulphate ions . describe how the presence of the chloride ions in the water can be shown
Answer:
See Explanation
Explanation:
The presence of chloride ions in water can be established by adding dilute trioxonitrate V acid to a sample of the water in drops followed by aqueous silver trioxonitrate V.
If a white precipitate is formed, which is soluble in excess aqueous ammonia solution, then the presence of chloride ion in the water sample is ultimately confirmed.
Which trend is observed as the first four elements in Group 17 on the Periodic Table are considered in order of increasing atomic number?
1. Electronegativity decreases
2. First ionization energy increases
3. The number of valence electrons increases
4. The number of electron shells decreases
How many grams of KI are needed to prepare 2,000. grams of an aqueous solution
containing 25 parts per million (ppm) of solute?
Answer:
[tex]m_{solute}=0.05g[/tex]
Explanation:
Hello there!
In this case, according to the equation for the calculation of the parts per million:
[tex]ppm=\frac{m_{solute}}{m_{solution}} *1x10^6[/tex]
It is possible to solve for the mass of KI (solute) as shown below:
[tex]m_{solute}=\frac{ppm*m_{solution}}{1x10^6}[/tex]
Thus, we plug in to obtain:
[tex]m_{solute}=\frac{25*2,000g}{1x10^6} \\\\m_{solute}=0.05g[/tex]
Best regards!
The phenomenon that causes air masses and water to bend or curve is the ______________.
PLZ I NEED HELP ILL GIVE BRAINLIEST
Answer:
The Coriolis effect
Explanation:
The Coriolis effect is the effect that makes tornados, water spouts, and are often seen in storms. They make water curve and rotate as well as the wind And current.
What can be different between products and reactants in a balanced equation?
a) The total mass of products and reactants
b) The total moles of each element present in the reactants and in the products.
c) The number of molecules in the reactants and in the products
Answer:
b) The total moles of each element present in the reactants and in the products.
Explanation:
Hello there!
In this case, since the law of conservation of mass is used to realize that the mass, atoms and molecules of all the species involved in a chemical reaction must be the same at both reactants and products, we can see that a and c stand for those that must be equal; thus, we infer that the moles can be different as they stand for the amount of substance which is related to the mass via molar masses. Therefore, the answer would be b) The total moles of each element present in the reactants and in the products.
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explain why we see the pattern between predator and prey
Answer:
The food chain starts as prey to a preditor and then when the preditor dies the prey eat the preditor
Explanation:
Just that
A sample of hydrogen takes up 34.0 dm3 of space when it is under 500.0 kPa of pressure. When the pressure is changed to 340.0 kPa, what is the new volume? dm3 H2
Answer:
50 dm³
Explanation:
Assuming constant temperature, we can solve this problem using Boyle's law, which states:
P₁V₁=P₂V₂Where in this case:
P₁ = 500.0 kPaV₁ = 34.0 dm³P₂ = 340.0 kPaV₂ = ?We input the data:
500.0 kPa * 34.0 dm³ = 340.0 kPa * V₂And solve for V₂:
V₂ = 50.0 dm³Thus the answer is 50.0 dm³ H₂.
one drawback of x-ray scattering experinment.
Answer:
Rutherford passed beams of alpha particles through a thin gold foil to observe the atom and noted how the alpha particles scattered from the foil.
Observations of Rutherford's alpha ray scattering experiment:
1.Most of the α-particles passed straight through the gold foil without any deviation.
2. Some of the α-particles were deflected by the foil by some angles.
3.Interestingly one out of every 12,000 alpha particles appeared to rebound
Conclusion of Rutherford's scattering experiment:
1.Most of the space inside the atom is empty because most of the α-particles passed through the gold foil without getting deflected.
2. Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.
3. A very small fraction of α-particles were deflected by very large angles, indicating that all the positive charge and mass of the gold atom were concentrated in a very small volume within the atom.
How are u ??Hopefully u will satisfy with my answer of ur question..!!Mark on brainleast please..!!Have a nice day ahead dear..!!How does increasing and decreasing the temperature affect the kinetic energy of molecules? How does this impact heat
transfer?
Answer: As the temperature of a molecular system increases, the kinetic energy of molecules also increase. Also as the temperature of a molecular system decreases, the kinetic energy of the molecules will also decrease.
Explanation:
James Clerk Maxwell developed the kinetic-molecular theory (KMT) of gases. In this theoey, five assumptions concerning an ideal gas was made. One of the them was that," the average kinetic energy of the gas molecules is proportional to the temperature of the gas". This simply means that a s the temperature of a molecular system increases, the kinetic energy of molecules also increase. Also as the temperature of a molecular system decreases, the kinetic energy of the molecules will also decrease.
Also another scientist known as Rudolf Clausius incorporated energy into the kinetic theory. He proposed that heat is a form of energy that affects the temperature of matter by changing the motion of molecules in matter.
Heat is defined as the flow of energy which is caused by difference in temperature.
In conclusion, when the temperature of a system is increased, the collision of the molecules with one another and the walls of their container increases as more molecules gain more heat energy at higher temperature. While as the temperature of the system decreases, the collision of the molecules will also decrease as molecules lose heat energy at lower temperature.
Answer:
Temperature increases the average kinetic energy of the atoms as well as molecules increases because when the temperature increases the collision between the atom and molecules increases and particles may collide with one another.
because it may associate with the thermal energy when thermal energy increases because of the motion of the gas particle and may initiate the kinetic energy of the gas.
when the temperature goes increasing the movement of the particle is at a very high rate, especially in gas and then solids, and especially this must be increased when the endothermic reaction is involved this must proceed such a reaction that the temperature results in to increase in the average kinetic energy.
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Determine whether each described process is endothermic or exothermic.
a. Ice melts into liquid water
b. A process with a calculated positive q.
c. Wood burns in a fireplace.
d. A process with a calculated negative q.
e. Acid and base are mixed, making test tube feel hot.
f. Solid dissolves into solution, making ice pack feel cold
Answer:
Ice melts into liquid water- endothermic
A process with a calculated positive q - endothermic
Wood burns in a fireplace - exothermic
A process with a calculated negative q - exothermic
Acid and base are mixed, making test tube feel hot - exothermic
Solid dissolves into solution, making ice pack feel cold - endothermic
Explanation:
An endothermic process is one in which heat is absorbed from the surroundings. The absorption of heat means that heat is removed from the surroundings hence the surroundings feel cool. When heat is absorbed, q is positive.
An exothermic process is one in which heat is released to the surroundings. The evolution of heat means that heat is released into the surroundings hence the surroundings feel hot . When heat is evolved, q is negative.
A solution has a pH of 9.5. Is the solution an acid or a base?
Answer:
The solution is Basic
a sample of 0.0084 mol of HCl is dissolved in water to make a 1500 mL solution. calculate the molar it’s of the HCl solution, The H3O, and the pH
Answer:
pH = 2.25
Explanation:
pH is a measurement in chemistry defined as the -log [H₃O⁺]. Molarity [], is defined as the ratio between moles of solute (HCl) and the liters of solution
To solve this question we must find the molarity of the H₃O⁺ knowing: [HCl] = [H₃O⁺]
[HCl]:
0.0084moles / 1.500L
= 0.0056M = [HCl] = [H₃O⁺]
pH = -log [H₃O⁺] = -log [0.0056M]
pH = 2.25A solution prepared by dissolving 0.0084 moles of HCl in 1500 mL of solution has a molar concentration of HCl of 5.6 × 10⁻³ M, a molar concentration of H₃O⁺ of 5.6 × 10⁻³ M and a pH of 2.3.
A solution is prepared by dissolving 0.0084 moles of HCl in 1500 mL of solution. The molarity of HCl is:
[tex][HCl] = \frac{0.0084mol}{1.5L} = 5.6 \times 10^{-3} M[/tex]
HCl is a strong acid according to the following equation.
HCl(aq) + H₂O(l) ⇒ Cl⁻(aq) + H₃O⁺(aq)
Thus, the concentration of H₃O⁺ will be equal to the initial concentration of HCl, 5.6 × 10⁻³ M.
Finally, we will calculate the pH of the solution using its definition.
[tex]pH = -log [H_3O^{+} ] = -log (5.6 \times 10^{-3} ) = 2.3[/tex]
A solution prepared by dissolving 0.0084 moles of HCl in 1500 mL of solution has a molar concentration of HCl of 5.6 × 10⁻³ M, a molar concentration of H₃O⁺ of 5.6 × 10⁻³ M and a pH of 2.3.
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15 The Following statement describes which body system? It also produces blood cells, and stores calcium. It regulates endocrine as well. This specific system uses all bones & joints in your body. A. The Lymphatic System B.The Muscular System C.The Reproductive System D.The Skeletal System
what is the volume in liters at 422K if n and P does not change?
Answer:
0.75 L
Explanation:
V1/T1 = V2/T2
V1 = 0.520 L
T1 = 18 C = 291 K (make sure to convert to Kelvin by adding 273 to the Celsius temperature)
V2 = ?
T2 = 422 K
Solve the equation for V2
V2 = V1T2/T1
V2 = (0.520 L)(422 K) / (291 K) = 0.754 L ≈ 0.75 L (since it says to only give two significant figures)
The half-life of I-37 is 8.07 days. If 25 grams are left after 40.35 days, how many grams were in the original sample?
Answer:
800 g
Explanation:
We can express the decay of I-37 using the formula:
Final Mass = Initial Mass * [tex]0.5^{\frac{Time}{Half-Life} }[/tex]We input the data:
25 g = Initial Mass * [tex]0.5^{(\frac{40.35}{8.07})}[/tex]And solve for Initial Mass:
25 g = Initial Mass * [tex]0.5^{5}[/tex]25 g = Initial Mass * 0.03125Initial Mass = 800 gMeaning that out 800 grams of I-37, only 25 will remain after 40.35 days.
Which of the following is TRUE about most gases?
1) They expand to completely fill their container.
2) They cannot be compressed.
3) All of their particles are the same size.
4) They have a fixed volume.
5) Their particles are very close together.
Explanation:
I think it is the first option
Answer:
1) They expand to completely fill their container. :)
Explanation:
How was the position of planet Uranus predicted?
Upon studying the orbit of Uranus more closely, astronomers realized its orbit was being affected by the presence of another very large mass - so the hunt was on for another large planet. He sent his prediction to the Astronomer Royal, Sir George Airy, who passed it on to an 'observer'.
más inteligente o gracias por favor :)) <33 / brainliest or a thank you please :)) <33
The position of Uranus was predicted by determining the position of a larger mass ( Neptune ) exerting a gravitational push on Uranus
Uranus is the 7th planet in the galaxy it was initially discovered with the aid of a telescope by an astronomer whom initially thought it was a star.
The position of Uranus was predicted when an astronomer ( John Couch Adams ) and his colleague predicted the gravitational effect on Uranus from another larger mass ( Neptune ). they discovered the position of the larger mass affecting the orbit of Uranus and the position of this larger mass ( Neptune ) was used to predict the position of Uranus in the galaxy.
Hence we can conclude that the position of Uranus was predicted by determining the position of a larger mass ( Neptune ) exerting a gravitational push on Uranus
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During the reaction of 2,4-dinitrofluorobenzene with methoxide in methanol it was observed that it occurs at a significantly higher rate than the same reaction of 3,4-dinitrofluorobenzene. Explain the observation with a detailed mechanism and convincing structural arguments.
Answer:
Explanation:
your not so smart
If I contain 2 moles of gas in a container with a volume of 30 liters and at a temperature of 337 K, what is the pressure inside the container?
Answer:
1.84
Explanation: just input the value into the formula pv=nrt
p*30=2*0.08206*337 then divide both sides by 30 and get 1.84
0.500 mole of copper(II) sulfate contains
moles of O.
Answer:
2 mol
Explanation:
There are 4 mols of O per one sulfate so since there is only one sulfate you simply times 4 by .5 to get the number of mol
Tectonic plates interact with each other and can create landforms. TRUE/FALSE
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Answer: True
I hope this helped!
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Answer:
true
Explanation:
how many mass extension of ocean animals have there been in the last 400-500million years
Answer:
Explanation:
Around 439 million years ago, 86% of life on Earth was wiped out. Scientists believe two major events resulted in this extinction: glaciation and falling sea levels. Some theories suggest that the Earth was covered in such a vast quantity of plants that they removed too much carbon dioxide from the air which drastically reduced the temperature. Falling sea levels were possibly a result of the Appalachian mountain range forming. The majority of the animal life lived in the ocean. Trilobites, brachiopods, and graptolites died off in large numbers but interestingly, this did not lead to any major species changes during the next era.
Deep water currents are formed partly due to the amount of _________________ in the water.
Answer:
Density differences
Explanation:
The water transports cool masses of air and hot air, the transports is driven by the amount of changes of Temperature and Salinity (ThermoHaline)
c) If 21.0 g of potassium reacts with 62.5 g of barium nitride, what mass of potassium nitride will be produced?
Explanation:
21.0 g of potassium reacts with 62.5 g of barium nitride, what mass of potassium nitride will be produced
Compounds consist of two or more elements. Which of the following properties must each of the elements in a compound
have?
A. solubility
B. conductivity
c. high density
D. chemical reactivity
When 86.5 g of calcium chlorate decomposes into calcium chloride and oxygen, how many grams of oxygen are produced? Ca(ClO3)2 → CaCl2 + O2
Answer:
40.1 g
Explanation:
The balanced equation is:
Ca(ClO₃)₂ → CaCl₂ + 3O₂First we convert 86.5 g of calcium chlorate into moles, using its molar mass:
86.5 g Ca(ClO₃)₂ ÷ 206.98 g/mol = 0.418 mol Ca(ClO₃)₂Then we convert Ca(ClO₃)₂ moles into O₂ moles, using the stoichiometric coefficients of the balanced reaction:
0.418 mol Ca(ClO₃)₂ * [tex]\frac{3molO_2}{1molCa(ClO_3)_2}[/tex] = 1.254 mol O₂Finally we convert O₂ moles into grams:
1.25 mol O₂ * 32 g/mol = 40.1 g O₂number of atoms per unit cell in face centred cube is
Answer: 4 atoms is the answer. I hope it helped you.
Explanation: