(a) The molar solubility of Mg(OH)2 in water is 1.75 x 10^-11 M, and the pH of a saturated Mg(OH)2 solution is 10.40. (b) The molar solubility of Mg(OH)2 in a solution buffered at pH 5.5 is higher than in pure water.
(a) To determine the molar solubility of Mg(OH)2 in water, we can use the solubility product constant (Ksp) expression:
Ksp = [Mg2+][OH-]^2
Since Mg(OH)2 dissociates into one Mg2+ ion and two OH- ions, the equilibrium expression becomes:
Ksp = [Mg2+][OH-]^2 = (s)(2s)^2 = 4s^3
Given that the Ksp of Mg(OH)2 is 1.8 x 10^-11, we can solve for 's' (molar solubility):
1.8 x 10^-11 = 4s^3
s^3 = 4.5 x 10^-12
s ≈ 1.75 x 10^-4 M
To calculate the pH of a saturated Mg(OH)2 solution, we need to consider the equilibrium of the hydroxide ions (OH-) in water:
OH- (aq) ⇌ H+ (aq) + OH- (aq)
Since Mg(OH)2 is a strong base, it completely dissociates in water to produce OH- ions. Thus, the concentration of OH- in the saturated solution is equal to the molar solubility:
[OH-] = 1.75 x 10^-4 M
Using the equation for the dissociation of water:
Kw = [H+][OH-] = 1.0 x 10^-14
We can substitute the value of [OH-] and solve for [H+]:
1.0 x 10^-14 = [H+][1.75 x 10^-4]
[H+] ≈ 5.71 x 10^-11 M
Taking the negative logarithm of [H+], we can find the pH:
pH ≈ -log10(5.71 x 10^-11) ≈ 10.40
(b) To determine the molar solubility of Mg(OH)2 in a solution buffered at pH 5.5, we need to consider the effect of the common ion (OH-) provided by the buffer. The presence of OH- ions will shift the equilibrium and reduce the solubility of Mg(OH)2 compared to pure water.
The exact calculation of molar solubility in a buffered solution would require additional information about the buffer composition and its equilibrium constants. Without that information, a direct comparison of molar solubility cannot be made.
The molar solubility of Mg(OH)2 is higher in pure water compared to a solution buffered at pH 5.5. In pure water, the molar solubility is approximately 1.75 x 10^-4 M, while in the buffered solution, the solubility is expected to be lower due to the presence of OH- ions provided by the buffer. The exact molar solubility in the buffered solution would require further information about the buffer system.
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HELP ASAP plz!:) I’ll give brainliest
Answer:
it is closer to the south pole
Explanation:
The shark and remora have a relationship that benefits the remora but neither helps nor harms the shark. What type of relationship is this?
commensalism
or
predation
or
mutualism
or
parasitism
Answer:
commensalism
Explanation:
It's not parasitism as the shark is not harmed in the relationship
please help me i need this good grade
The heat capacity of aluminum is 0.900 J/gºC. a. How much energy is needed to raise the temperature of an 8.50 x 102g block of aluminum from 22.8°C to 94.6°C?
Recall the heat capacity equation:
q = mc∆T
We're given mass, specific heat capacity, as well as the change in temperature. All we need to do is plug the numbers into the variables and we'll have our answer!
Although this question doesn't try to trick you, more often than not questions regarding energy change will attempt to throw you off with specific heat capacity. It's extremely important to note the units of the specific heat capacity and ensure that the numbers you use are in those units. As an example, the specific heat capacity might be given to you in J/mol*K - in this case, you'd have to do some unit conversions with your given data in order to fit all the numbers. In this question, we're given the specific heat capacity in J/gºC, so we don't need to change anything since all of our data is already in these units.
Anyways, back to the actual question:
q = mc∆T
q = (8.50 * [tex]10^{2}[/tex]) * (0.900) * (94.6 - 22.8)
q = 54927 (J)
Remeber to include significant figures:
54927 = 5.49 * 10^4 (J)
The required energy is 5.49 * [tex]10^{4}[/tex] Joules, or 5.49 * [tex]10^{1}[/tex] kJ
Let me know if you need any of my work to be explained!
- Breezeツ
HELP ME WOTH QUESTION BELOW PLEASE
tip
this is just a tip not the true answer but try to add the given number
Which organisms are decomposers?
Select all correct answers.
mushrooms
snake
bacteria
grass
mold
Answer:
mushrooms bacteria mold
Explanation:
calculate the linear atomic density in atoms per millimeter for the following directions in bcc tantalum, which has a lattice constant of 0.33026nm: (a) [100], (b) [110], (c) [111]
The linear atomic density in atoms per millimeter can be calculated for different crystallographic directions in bcc tantalum, which has a lattice constant of 0.33026 nm. The linear atomic density for the [100], [110], and [111] directions can be determined by dividing the number of atoms along the direction by the length of the direction.
The linear atomic density in atoms per millimeter can be calculated by dividing the number of atoms along a specific crystallographic direction by the length of that direction. In bcc (body-centered cubic) crystals, there are specific arrangements of atoms along different crystallographic directions.
(a) For the [100] direction, there is one atom per unit cell. The length of the [100] direction can be determined using the lattice constant, which is 0.33026 nm. Therefore, the linear atomic density for the [100] direction is 1 atom / (0.33026 nm) = 3.027 atoms/nm or 30.27 atoms/mm.
(b) For the [110] direction, there are two atoms per unit cell. The length of the [110] direction can be calculated by multiplying the lattice constant by the square root of 2. Therefore, the linear atomic density for the [110] direction is 2 atoms / (0.33026 nm √2) = 6.054 atoms/nm or 60.54 atoms/mm.
(c) For the [111] direction, there are three atoms per unit cell. The length of the [111] direction can be calculated by multiplying the lattice constant by the square root of 3. Therefore, the linear atomic density for the [111] direction is 3 atoms / (0.33026 nm √3) = 9.090 atoms/nm or 90.90 atoms/mm.
Thus, the linear atomic density in atoms per millimeter for the [100], [110], and [111] directions in bcc tantalum are approximately 30.27 atoms/mm, 60.54 atoms/mm, and 90.90 atoms/mm, respectively.
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A boy is skating down the street, hits a curb, and files off the board. Why did this happened? Can y’all plz help me it’s due today!
Answer:
to much sause
Explanation:
What does the word Microbial mean?
Answer:
relating to or characteristic of a microorganism, especially a bacterium causing disease or fermentation.
Explanation:
ex: "skin is a major source of microbial contamination during a surgical procedure"
◕‿↼ Hey There!
Answer → Microbial means, relating to or characteristic of a microorganism, especially a bacterium causing disease or fermentation.
✨Hope This Helps!✨
An unknown piece of metal absorbs 1350 J of heat as 55.0 g of the metal heats up from 20.0 oC to 47.0 oC
Answer:
[tex]C=0.91\frac{J}{g\°C}[/tex]
Explanation:
Hello there!
In this case, according to the given information, it is possible to recall the equation to calculate the heat, Q, in these calorimetry problems as shown below:
[tex]Q=mC(T_f-T_i)[/tex]
Thus, given the absorbed heat, mass and temperatures, we can easily calculate the specific heat of the metal as shown below:
[tex]C=\frac{Q}{m(T_f-T_i)}[/tex]
Then, by plugging in we obtain:
[tex]C=\frac{1350J}{55.0g(47.0\°C-20.0\°C)} \\\\C=0.91\frac{J}{g\°C}[/tex]
Best regards!
Determine the number of moles of Krypton contained in a 3.25 liter gas tank at 5.80 bar and 25.5 °C. If the gas were Oxygen instead of Krypton, how will the answer change? Explain.
There are approximately 0.689 moles of krypton in the gas tank.
To determine the number of moles of krypton in the gas tank, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure (in bar)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0831 L·bar/(mol·K))
T = temperature (in Kelvin)
Given:
Pressure (P) = 5.80 bar
Volume (V) = 3.25 liters
Temperature (T) = 25.5 °C = 25.5 + 273.15 = 298.65 K
Using the ideal gas law equation, we can solve for the number of moles (n):
n = PV / RT
n = (5.80 bar * 3.25 L) / (0.0831 L·bar/(mol·K) * 298.65 K)
n ≈ 0.689 moles
Therefore, there are approximately 0.689 moles of krypton in the gas tank.
If the gas in the tank were oxygen instead of krypton, the answer would change because the molar mass of oxygen is different from that of krypton. The ideal gas law equation remains the same, but the value of n (number of moles) would be different since it depends on the molar mass of the gas. Oxygen has a molar mass of approximately 32 g/mol, while krypton has a molar mass of approximately 84 g/mol. So, the number of moles of oxygen in the gas tank would be different and can be calculated using the same ideal gas law equation, but substituting the molar mass of oxygen instead of krypton.
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What is the relationship between the valence electrons of an atom and the chemical bonds the atom can form?
Answer:
Valence electrons are outer shell electrons with an atom and can participate in the formation of chemical bonds. In single covalent bonds, typically both atoms in the bond contribute one valence electron in order to form a shared pair. The ground state of an atom is the lowest energy state of the atom.
A drought hits the habitat of a semi-aquatic bird population. All ponds dry up, and fish populations decline. There are two groups of birds in the population that differ in leg length and diet. Long-legged birds eat fish, while short-legged birds eat insects. The drought has little effect on insect populations.
Answer:
The population of the long-legged birds decreases.
Explanation:
The population of the short-legged birds increases whereas the population of long-legged birds decreases due to availability of food in that environment. The long-legged birds feed on fish whose population decreases due to drought conditions so the population of long-legged birds also decreases while on the other hand, the population of short-legged birds increases or remain the same because they feed on the insects and the insects are available in large amount and less affected by the drought conditions.
A solution is made by mixing 140. g of water and 91. g of methanol (CH3OH) Calculate the mole fraction of water in this solution. Be sure your answer has the correct number of significant digits.
The mole fraction of water in the solution is 0.62.
To calculate the mole fraction of water in the solution, we need to determine the moles of water and methanol present.
Mass of water = 140 g
Mass of methanol = 91 g
Molar mass of water (H2O) = 18.015 g/mol
Molar mass of methanol (CH3OH) = 32.04 g/mol
Step 1: Calculate the number of moles of water and methanol.
Moles of water = Mass of water / Molar mass of water
Moles of water = 140 g / 18.015 g/mol ≈ 7.773 mol
Moles of methanol = Mass of methanol / Molar mass of methanol
Moles of methanol = 91 g / 32.04 g/mol ≈ 2.840 mol
Step 2: Calculate the total moles of the solution.
Total moles = Moles of water + Moles of methanol
Total moles = 7.773 mol + 2.840 mol = 10.613 mol
Step 3: Calculate the mole fraction of water.
Mole fraction of water = Moles of water / Total moles
Mole fraction of water = 7.773 mol / 10.613 mol ≈ 0.732
The mole fraction of water in the solution is approximately 0.732.
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most modern catalytic converters in automobiles have a surface with a platinum-rhodium catalyst. for which of the following reactions is this catalyst used
The platinum-rhodium catalyst used in most modern catalytic converters in automobiles is primarily employed for the oxidation of harmful pollutants. It facilitates the conversion of carbon monoxide (CO) and unburned hydrocarbons (HC) into carbon dioxide (CO2) and water (H2O).
The platinum-rhodium catalyst in catalytic converters is specifically designed to promote the oxidation reactions of carbon monoxide (CO) and unburned hydrocarbons (HC). These reactions are crucial for reducing the emission of harmful pollutants from automobile exhaust gases.
Carbon monoxide (CO) is a toxic gas produced during incomplete combustion. The platinum-rhodium catalyst assists in the oxidation of CO, converting it into carbon dioxide (CO2). This reaction is represented by the equation:
2 CO + O2 → 2 CO2
Unburned hydrocarbons (HC) are volatile organic compounds (VOCs) that contribute to smog formation. The platinum-rhodium catalyst aids in their oxidation, transforming them into carbon dioxide (CO2) and water (H2O). The general reaction can be expressed as:
HC + O2 → CO2 + H2O
The platinum-rhodium catalyst is essential in facilitating these oxidation reactions, promoting more complete combustion of harmful pollutants and reducing their negative environmental impact.
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Why might changes to an environment cause an organism’s population to decrease?
6. Calculate the molecular mass of acetylsalicylic acid (HOOC-C6H4-OOCCH3).
The molecular mass of acetylsalicylic acid (HOOC-C6H4-OOCCH3) is 180.157 g/mol.What is molecular mass Molecular mass is the sum of the masses of all the atoms in a molecule. The unit of molecular mass is grams per mole the are (g/mol).Acetylsalicylic acid molecular
mass calculation In acetylsalicylic acid, HOOC-C6H4-OOCCH3, add the mass of each atom:Oxygen (O) = 2 x 16.00 g/mol = 32.00 g/ (C) = 9 x 12.01 g/mol = 108.09 g/mol Hydrogen (H) = 8 x 1.01 g/mol = 8.08 g/molAdd the masses of all the atoms to calculate the molecular mass:32.00 g/mol + 108.09 g/mol + 8.08 g/mol = 148.17 g/molThe molecular mass of acetylsalicylic acid is 180.157 g/mol (approximately)
Molecular mass is the mass of a molecule measured in atomic mass units (amu). The molecular mass is the sum of the atomic masses of all the atoms present in the molecule.The molecular mass formula can be written as: Molecular mass = (mass of first element × number of atoms) + (mass of second element × number of atoms) + ...The molecular mass of acetylsalicylic acid (HOOC-C6H4-OOCCH3) can be calculated by adding the mass of each atom. Here's how to calculate the molecular mass of acetylsalicylic acid:Oxygen (O) = 2 x 16.00 g/mol = 32.00 g/molCarbon (C) = 9 x 12.01 g/mol = 108.09 g/molHydrogen (H) = 8 x 1.01 g/mol = 8.08 g/molAdd the masses of all the atoms to calculate the molecular mass:32.00 g/mol + 108.09 g/mol + 8.08 g/mol = 148.17 g/molThe molecular mass of acetylsalicylic acid is 180.157 g/mol (approximately) the formula to calculate molecular mass.
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how many moles of oh−(aq) (hydroxide ions)are present in the balanced redox reaction?
A chemical equation must balance according to the rule of conservation of mass. According to the rule, mass cannot be generated or removed during a chemical process. The number of moles of hydroxide ions in the given balanced equation is 2.
A chemical equation is said to be balanced if the quantity of each type of atom in the reaction is the same on both the reactant and product sides. In a balanced chemical equation, the mass and charge are both equal.
The numbers which are used to balance the given chemical equation are known as the coefficients.
Here the balanced equation is:
2NO₃⁻(aq) + 3ClO⁻(aq) + H₂O(l) → 2NO(g) + 3ClO₂⁻(aq) + 2OH⁻(aq)
The moles of OH⁻ required is 2.
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Explain how the copper could be in the lake sample near the picnic area but not have been detected by this test.
Answer:
May be the instrument is incorrect or may be error in it.
Explanation:
The copper have not been detected by this test because the test may be not for the detection of copper, may be it is used for identification of another minerals. If there is copper in the lake sample but can't be detected in the test so it means that the instrument which is used for detection is not the right one or having error in that instrument. Every mineral has a specific type of instrument that detect its presence, if we use incorrect instrument for the mineral then we can't detect the presence of that specific mineral.
Choose all the nucleophiles.
Choose one or more:
CH3SNa
NaNH2
H3O+
CH3OH
CH3CH2CH3
NH4+
OH-
(CH3)3CLi
Answer:
CH3CH2CH3
(CH3)3CLi
CH3SNa
Explanation:
the formula equation of Acetylene + oxygen ----> carbon dioxide + water
Answer:
The final balanced equation is : 2C2H2+5O2→4CO2+2H2O.
Waves made by the breeze were very different than wave created by speedboat. describe the difference
Answer:
The amplitude of the speedboat waves were larger then the Breeze waves. The frequency of the speedboats waves were lower than the breeze waves. the speedboat waves had more of an effect on the boat, which tells us the speedboat waves had more energy.
Explanation:
plz can i get brainliest:)
Answer:
speedboat waves artificail and waves by breezes natural
Explanation:
Balance the chemical equation for the following redox reaction under acidic aqueous conditions with the smallest whole-number coefficients possible using the half-reaction method. On which side does H2O(l) appear, and what is its coefficient?
MnO4^-(aq)+NH3(aq)---->Mn^2+(aq)+NO2(g)
Water ([tex]H_{2}O[/tex]) appears on the product side with a coefficient of 8. To balance the given redox reaction, we can use the half-reaction method. Let's begin by balancing the reduction half-reaction and the oxidation half-reaction separately.
Reduction half-reaction: [tex]MnO_{4}^{-aq}[/tex] + [tex]8H^{+aq}[/tex] + [tex]5e^{-}[/tex] → [tex]Mn^{2+}[/tex](aq) + [tex]4H_{2}O[/tex](l)
Oxidation half-reaction: [tex]NH_{3}[/tex](aq) → [tex]NO_{2}[/tex](g) + [tex]3H^{+}[/tex](aq) + [tex]2e^{-}[/tex]
Next, we need to balance the number of electrons transferred in both half-reactions. To do this, we multiply the oxidation half-reaction by 5 and the reduction half-reaction by 2:
[tex]2NH_{3}[/tex](aq) → [tex]2NO_{2}[/tex](g) + [tex]6H^{+}[/tex](aq) + [tex]4e^{-}[/tex]
[tex]2MnO_{4}^-[/tex](aq) + [tex]16H^{+}[/tex]+(aq) + [tex]10e^{-}[/tex] → [tex]2Mn^{2+}[/tex](aq) + [tex]8H_{2}O[/tex](l)
Now, we can combine the two half-reactions and cancel out the common species:
[tex]2MnO_{4}^-[/tex](aq) + [tex]16H^{+}[/tex](aq) + [tex]10NH_{3}[/tex](aq) → [tex]2Mn^{2+}[/tex](aq) + [tex]2NO_{2}[/tex](g) + [tex]8H_{2}O[/tex](l)
From the balanced equation, we can see that water ([tex]H_{2}O[/tex]) appears on the product side with a coefficient of 8.
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hi trying this again :D What are ALWAYS the products of the complete combustion of a hydrocarbon? Check all that apply.
- oxygen
- water
- carbon dioxide
- hydrogen
- sulfur trioxide
it should be carbon dioxide and water
Determinar el volumen de una solución en mililitros cuya concentración es 0,3 M en ácido sulfúrico y que contiene 1,5 moles del ácido
Answer:
V = 5000 mL
Explanation:
¡Hola!
En este caso, dado que la molaridad de una solution se calcula al dividir las moles por el volume de solución en litros, es posible calcular el volumen cuando se dividen las moles por la molaridad, tal y como se muestra a continuación:
[tex]M=\frac{n}{V}\\\\V=\frac{n}{M}[/tex]
Así, podemos reemplazar la molaridad y moles dadas para obtener:
[tex]V=\frac{1.5mol}{0.3mol/L}=5L[/tex]
Que en mililitros sería:
[tex]V=5L*\frac{1000mL}{1L}\\\\V=5000mL[/tex]
¡Saludos!
Calcular una solución que contiene 250 g de cloruro de calcio en 1500 mL de solución y tiene una decidad de 1,2gr/ml
Answer:
13.89% p/p
Explanation:
El porcentaje peso a peso de una solución (%p/p) es definido como cien veces la relación entre la masa del soluto (En este caso, cloruro de calcio) y la masa de la solución. La ecuación es:
%p/p = Masa cloruro de calcio (250g)/ Masa solución * 100
Para hallar la masa de la solución debemos usar el volumen y la densidad de este:
1500mL * (1,2g / mL) = 1800g
Así, el %p/p será:
250g / 1800g * 100
13.89% p/pWhat are cathode rays
Answer:
a beam of electrons emitted from the cathode of a high-vacuum tube.
Explanation:
Cathode rays (also known as electron beam or e-beam) are electron waves that can be used in vacuum tubes.
Calculate the number of grams of solute in 500.0 mL of 0.179 M KOH. A) 5.02 g B) 1.60 g C) 5.02 x103 g D) 157 g
The mass (in grams) of solute in 500 mL of 0.179 M potassium hydroxide, KOH solution is 5.02 grams (option A)
How do i determine the mass of KOH?First, we shall obtain the mole of KOH in the solution. Details below:
Volume = 500 mL = 500 / 1000 = 0.5 LMolarity = 0.179 MMole of KOH =?Mole of solute = molarity × volume
Mole of KOH = 0.179 × 0.5
Mole of KOH = 0.0895 mole
Finally, we shall determine the mass of solute, KOH in the solution. Details below:
Mole of KOH = 0.0895 moleMolar mass of KOH = 56.1 g/molMass of KOH = ?Mass = Mole × molar mass
Mass of KOH = 0.0895 × 56
Mass of KOH = 5.02 grams
Therefore, the mass of KOH present in the solution is 5.02 grams (option A)
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Which would be the best starting question to determine
the composition of the Outer Core and the Inner Core?
A) Are the Outer Core and the Inner Core composed of
large amounts of iron?
B) How much rock do the Outer Core and the Inner Core
contain?
C) How deep in the Earth are the Outer Core and the
Inner Core?
D) Are the Outer Core and the Inner Core composed of
large amounts of metal?
how many equivalents of mg 2 are present in a solution that contains 2.75 mol of mg 2?
There are 5.50 equivalents of Mg^2+ present in a solution containing 2.75 mol of Mg^2+.
The concept of equivalents is used to quantify the number of reactive entities or charges present in a solution. In the case of Mg^2+, each Mg^2+ ion carries two positive charges, so it is necessary to determine the number of moles of Mg^2+ and then convert it to equivalents.
Given:
Number of moles of Mg^2+ = 2.75 mol
To calculate the equivalents, we use the relationship that one mole of Mg^2+ is equal to 2 equivalents of Mg^2+ (since each Mg^2+ ion carries two positive charges):
Equivalents of Mg^2+ = Number of moles of Mg^2+ * 2
Equivalents of Mg^2+ = 2.75 mol * 2
Equivalents of Mg^2+ = 5.50 equivalents
Therefore, in a solution containing 2.75 mol of Mg^2+, there are 5.50 equivalents of Mg^2+ present.
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