Elemental silicon is oxidized by O₂ to give a compound which dissolves in molten Na₂CO₃. when this solution is treated with aqueous hydrochloric acid, a precipitate forms. silica gel is the precipitate.
The compound formed by the oxidation of elemental silicon with O₂ is silicon dioxide (SiO₂), which can dissolve in molten Na₂CO₃ to form sodium silicate (Na₂SiO₃).
When this solution is treated with aqueous hydrochloric acid (HCl), the sodium silicate reacts with the HCl to form a precipitate of silica gel (SiO₂·nH₂O). This reaction is known as the gelatinization of sodium silicate. The sodium chloride (NaCl) formed by the reaction remains in solution.
The silica gel precipitate is often used as a desiccant or drying agent due to its high surface area and ability to adsorb water molecules.
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The pressure of a gas is 1.2 atm at 300k. calculate the pressure at 250k if the gas is in a rigid container.
The pressure of a gas is 1.2 atm at 300k. the pressure at 250k if the gas is in a rigid container is 1.0 atm.
To solve this problem, we can use the combined gas law, which states that:
(P1 * V1) / (T1) = (P2 * V2) / (T2)
where P1 is the initial pressure, V1 is the initial volume (which is constant since the gas is in a rigid container), T1 is the initial temperature, P2 is the final pressure (what we're trying to find), V2 is the final volume (also constant), and T2 is the final temperature.
We can rearrange the equation to solve for P2:
P2 = (P1 * V1 * T2) / (V2 * T1)
Plugging in the given values, we get:
P2 = (1.2 atm * V1 * 250K) / (V2 * 300K)
Since the container is rigid, V1 = V2, so we can cancel those terms:
P2 = (1.2 atm * 250K) / 300K
Simplifying:
P2 = 1.0 atm
Therefore, the pressure of the gas at 250K in a rigid container is 1.0 atm.
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how many grams of SO2 can be produced if 2.5 molecules of o2 are used.
Answer:
320.3 grams of SO2 can be produced
Explanation:
In order to calculate the amount of SO2 produced, we first need to write a balanced chemical equation for the reaction between O2 and sulfur:
2 SO2 + O2 -> 2 SO3
From the equation, we can see that 1 molecule of O2 reacts with 2 molecules of SO2 to produce 2 molecules of SO3.
Therefore, we need to convert the number of O2 molecules to the number of SO2 molecules in order to calculate the amount of SO2 produced.
1 molecule of O2 reacts with 2 molecules of SO2, so:
2.5 molecules of O2 * (2 molecules of SO2 / 1 molecule of O2) = 5 molecules of SO2
Now that we have the number of SO2 molecules produced, we can calculate the mass of SO2 using its molar mass. The molar mass of SO2 is approximately 64.06 g/mol.
5 molecules of SO2 * (64.06 g/mol) = 320.3 grams of SO2
Therefore, if 2.5 molecules of O2 react with sulfur to form SO2, then 320.3 grams of SO2 can be produced.
A 72. 4 mL solution of Cu(OH) is neutralized by 47. 8 mL of a 0. 56 M H2(C204) solution. What is the concentration of the Cu(OH)?
The concentration of Cu(OH) is 0.185 M.
To find the concentration of Cu(OH), we need to use the balanced chemical equation for the neutralization reaction:
Cu(OH)₂ + 2 H₂(C₂₀₄) → Cu(C₂₀₄) )₂ + 4H2O
From the equation, we can see that 2 moles of H₂(C₂₀₄) react with 1 mole of Cu(OH)₂.
Therefore, we can use the following equation to calculate the moles of Cu(OH)₂:
moles of Cu(OH)₂ = moles of H₂(C₂₀₄) / 2
To find the moles of H₂(C₂₀₄) , we can use the concentration and volume of the H₂(C₂₀₄) solution:
moles of H₂(C₂₀₄) = concentration of H₂(C₂₀₄) x volume of H₂(C₂₀₄) (in liters)
We need to convert the volume of the H₂(C₂₀₄) solution from milliliters to liters:
volume of H₂(C₂₀₄) = 47.8 mL = 0.0478 L
Substituting the given values, we get:
moles of H₂(C₂₀₄) = 0.56 M x 0.0478 L = 0.026768 moles
Now we can calculate the moles of Cu(OH)₂:
moles of Cu(OH)₂ = 0.026768 moles / 2 = 0.013384 moles
To find the concentration of Cu(OH), we need to divide the moles of Cu(OH)₂ by the volume of the Cu(OH) solution in liters:
concentration of Cu(OH) = moles of Cu(OH)₂ / volume of Cu(OH) (in liters)
We need to convert the volume of the Cu(OH) solution from milliliters to liters:
volume of Cu(OH) = 72.4 mL = 0.0724 L
Substituting the calculated values, we get:
concentration of Cu(OH) = 0.013384 moles / 0.0724 L = 0.185 M
Therefore, the concentration of Cu(OH) is 0.185 M.
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Carbon disulfide is produced by the reaction listed below:
[tex]5C+2SO_{2}[/tex]--->[tex]CS_2+4CO[/tex]
If you started the reaction with 5. 44 moles of [tex]SO_2[/tex]and excess carbon, what amount, in moles, of [tex]CS_2[/tex] will be produced?
Enter your numerical answer with the correct number of significant figures
Enter your numerical answer with the correct number of significant figures: 5.24 moles.
What is moles?Moles are small mammals that are known for their distinctive black or brown fur and their burrowing habits. They belong to the family Talpidae and are found in many parts of the world including North America, Europe, and some parts of Asia. Moles have small eyes and ears, short legs, and a long, cylindrical body. They typically measure around 3 to 5 inches in length and weigh around 1 to 4 ounces. They feed mostly on earthworms and other small invertebrates, and their diet is supplemented by insects, eggs, and other small animals. Moles have specialized claws and feet which allow them to dig quickly and efficiently.
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A person uses 500kcal of energy to run a race. convert the energy used for the race to the following energy units:
joules(j)
kilojoules (kj)
1 calorie= 4.184 joules
Answer: Look at the image I attached - I drew what you should write.
According to the general procedure of Experiment A2b, 213 mg of (E)-stilbene (180. 25 g/mol) was reacted with 435 mg of pyridinium bromide perbromide (319. 82 g/mol) to afford 342 mg of meso-stilbene dibromide (340. 05 g/mol) as a white solid. Calculate the percent yield for this reaction. Enter your answer as digits only (no units), using the proper number of significant figures
The percent yield of the reaction is 80%.
To calculate the percent yield, we need to use the following formula:
Percent yield = (actual yield / theoretical yield) x 100The actual yield of the reaction is 342 mg.
To calculate the theoretical yield, we need to first calculate the number of moles of (E)-stilbene and pyridinium bromide perbromide used in the reaction:
Number of moles of (E)-stilbene
= 213 mg / 180.25 g/mol = 0.001182 molNumber of moles of pyridinium bromide perbromide
= 435 mg / 319.82 g/mol = 0.001361 molTheoretical yield of meso-stilbene dibromide = number of moles of (E)-stilbene x 2 = 0.002364 mol x 340.05 g/mol = 803 mg
Now we can substitute the values into the formula:
Percent yield = (342 mg / 803 mg) x 100 = 80%Therefore, the percent yield of the reaction is 80%.
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Calculate the volume of an hcp unit cell in terms of its a and c lattice parameters. also show that the apf for there hcp crystal structure is 0.74
The a and c lattice parameters can be used to calculate the volume of a hcp unit cell i.e. [tex]\( V = \frac{3}{2} \sqrt{3} a^2 c \)[/tex], and the atomic packing factor for the hcp crystal structure is 0.74, which represents the percentage of space occupied by atoms in the unit cell.
In a hexagonal close-packed (hcp) unit cell, there are six atoms located at the corners of a regular hexagon, and a seventh atom at the center of the hexagon. The unit cell has a height of c and a base with sides of length a. The volume of the unit cell can be calculated as:
[tex]\( V = \frac{3}{2} \sqrt{3} a^2 c \)[/tex]
To show that the atomic packing factor (APF) for an hcp crystal structure is 0.74, we need to calculate the total volume occupied by the atoms in the unit cell and divide it by the total volume of the unit cell.
The volume of one atom can be approximated as a sphere with a radius of a/2, so its volume is [tex]\( \frac{4}{3} \pi \left(\frac{a}{2}\right)^3 = \frac{4}{3} \pi \frac{a^3}{8} \)[/tex]. There are two types of atoms in an hcp unit cell: the six atoms at the corners of the hexagon and the central atom. So the total volume of atoms in the unit cell is:
[tex]\( V_{\text{atom}} = \frac{6}{8} \cdot \frac{4}{3} \pi a^3 + \frac{4}{3} \pi a^3 \)[/tex]
= [tex]\(\frac{2 \sqrt{3} \pi a^3}{3}\)[/tex]
The total volume of the unit cell is just [tex]\(a^2 \cdot c \cdot \sqrt{3} / 2\)[/tex]. So the APF is:
[tex]\( \text{APF} = \frac{V_{\text{atom}}}{V_{\text{cell}}} \)[/tex]
= [tex]\(\frac{2 \sqrt{3} \pi a^3}{3 (a^2 c \sqrt{3} / 2)}\)[/tex]
=[tex]\(\frac{2\pi a}{\sqrt{3}c}\)[/tex]
≈ 0.74
Therefore, the volume of an hcp unit cell can be expressed as [tex]\( \frac{3}{2} \sqrt{3} a^2 c \)[/tex], and the APF for an hcp crystal structure is approximately 0.74.
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If the reaction above had 110.88g of CS2 and 3.12 mol of NaOH determine the mass (in grams) produced of Na2CS3 in the reaction.
3CS2+6NaOH—>2Na2CS3+NaOH+3H2O
Answer Asap pls
186.48 g of [tex]Na_2CS_3[/tex] were generated throughout the reaction.
The balanced chemical equation is:
[tex]3CS_2[/tex] + 6NaOH → [tex]2Na_2CS_3[/tex] + NaOH + [tex]3H_2O[/tex]
The molar mass of [tex]CS_2[/tex] is 76.14 g/mol, and the molar mass of [tex]2Na_2CS_3[/tex] is 192.23 g/mol.
To find the limiting reactant, we need to calculate the number of moles of each reactant. Using the given mass of [tex]CS_2[/tex]:
110.88 g [tex]CS_2[/tex] / 76.14 g/mol = 1.456 mol [tex]CS_2[/tex]
Using the given number of moles of [tex]NaOH[/tex]:
3.12 mol [tex]NaOH[/tex]
We can see that [tex]CS_2[/tex] is the limiting reactant, since it has fewer moles than [tex]NaOH[/tex]. Therefore, we will use the amount of [tex]CS_2[/tex] to calculate the amount of [tex]Na_2CS_3[/tex] produced.
From the balanced equation, we can see that 3 mol of [tex]CS_2[/tex] produces 2 mol of [tex]Na_2CS_3[/tex]. So, 1.456 mol of [tex]CS_2[/tex] will produce:
(2 mol [tex]Na_2CS_3[/tex] / 3 mol [tex]CS_2[/tex]) * 1.456 mol [tex]CS_2[/tex] = 0.971 mol [tex]Na_2CS_3[/tex]
Now, we can use the molar mass of [tex]Na_2CS_3[/tex] to calculate the mass produced:
0.971 mol [tex]Na_2CS_3[/tex] * 192.23 g/mol = 186.48 g [tex]Na_2CS_3[/tex]
Therefore, the mass of [tex]Na_2CS_3[/tex] produced in the reaction is 186.48 g.
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What is the weight of nacl in a 0.500 l bottle of 2.00 m nacl
The weight of NaCl in a 0.500 L bottle of 2.00 M NaCl solution is 58.44 grams.
To calculate the weight of NaCl in a 0.500 L bottle of 2.00 M NaCl solution, we need to use the formula:
Mass = Moles x Molar mass
First, let's calculate the number of moles of NaCl in the solution:
Moles = Molarity x Volume
Moles = 2.00 mol/L x 0.500 L
Moles = 1.00 mol
The molar mass of NaCl is 58.44 g/mol, so we can now calculate the mass of NaCl in the solution:
Mass = moles x molar mass
Mass = 1.00 mol x 58.44 g/mol
Mass = 58.44 g
Therefore, the weight of NaCl in a 0.500 L bottle of 2.00 M NaCl solution is 58.44 grams.
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the commonly used rules of thumb used by chemists to make buffers are: a) the two components in the buffer should have about the same concentrations. b) a combination of a weak acid with its salt should be used for a buffer with a ph below 7, while a weak base/salt mixture should be used for a buffer with a ph above 7. c) for acidic buffers, the pka of the weak acid should be close to the ph of the desired buffer. in basic buffers however, the pka of the conjugate acid should be close to the desired ph.
The commonly used rules of thumb used by chemists to make buffers are:
The two components in the buffer should have about the same concentrations.A combination of a weak acid with its salt should be used for a buffer with a pH below 7, while a weak base/salt mixture should be used for a buffer with a pH above 7.For acidic buffers, the pKa of the weak acid should be close to the pH of the desired buffer. In basic buffers, however, the pKa of the conjugate acid should be close to the desired pH.Buffers are solutions that resist changes in pH when small amounts of acid or base are added to them. They are commonly used in many chemical and biological applications. The rules of thumb mentioned above provide guidelines for making effective buffers. Rule a) ensures that there is an adequate amount of buffering capacity in the solution. Rule b) is based on the fact that weak acids have a pH-dependent dissociation constant, and therefore, the pH of a buffer made from a weak acid will be close to the pKa of the weak acid.
Similarly, the pH of a buffer made from a weak base will be close to the pKa of the conjugate acid. Rule c) ensures that the buffering capacity of the solution is optimized by selecting the appropriate pKa value. Overall, these rules of thumb help chemists to design effective buffers that can maintain a stable pH over a range of conditions.
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What is the oxidized form of the most common electron carrier that is needed for both glycolysis and the citric acid cycle
NAD+ is the most common electron carrier needed for both glycolysis and the citric acid cycle. It is a coenzyme and is involved in redox reactions.
It is an oxidized form of NADH, which is the reduced form. During the oxidation of organic molecules, NAD+ will accept electrons and become NADH. During the reduction of organic molecules, NADH will give electrons and become NAD+.
During glycolysis, NAD+ is used to accept electrons from the oxidation of glucose, creating NADH and releasing energy for the ATP production. During the citric acid cycle, NAD+ accepts electrons from the oxidation of acetyl CoA, creating NADH and releasing energy for the ATP production. The NADH produced in both glycolysis and the citric acid cycle can be used in the electron transport chain to produce ATP.
In summary, NAD+ is an oxidized form of NADH and it is essential in both glycolysis and the citric acid cycle to produce energy in the form of ATP.
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Two students in a chemistry lab start a particular lab with 1. 23 g of aluminum. They react it with excess sulfuric acid to produce aluminum sulfate. If they produce 3. 00 g of aluminum sulfate what is their percent yield
The percent yield for the reaction of 1.23 g of aluminum with excess sulfuric acid to produce 3.00 g of aluminum sulfate is 38.46%.
To find the percent yield for the reaction of aluminum with sulfuric acid to produce aluminum sulfate, you need to follow these steps:
1. Write the balanced chemical equation for the reaction:
2 Al + 3 H₂SO₄ → Al₂(SO₄)₃ + 3 H₂
2. Calculate the molar mass of aluminum (Al) and aluminum sulfate (Al₂(SO₄)₃):
Al: 26.98 g/mol
Al₂(SO₄)₃: (2 × 26.98) + (3 × [4 × 16.00 + 32.07]) = 53.96 + 342.15 = 342.15 g/mol
3. Determine the moles of aluminum used in the reaction:
moles of Al = mass of Al / molar mass of Al = 1.23 g / 26.98 g/mol = 0.0456 mol
4. Calculate the theoretical yield of aluminum sulfate based on the moles of aluminum:
moles of Al₂(SO₄)₃ = 0.0456 mol Al × (1 mol Al₂(SO₄)₃ / 2 mol Al) = 0.0228 mol Al₂(SO₄)₃
mass of Al₂(SO₄)₃ = moles of Al₂(SO₄)₃ × molar mass of Al₂(SO₄)₃ = 0.0228 mol × 342.15 g/mol = 7.80 g (theoretical yield)
5. Calculate the percent yield:
percent yield = (actual yield / theoretical yield) × 100% = (3.00 g / 7.80 g) × 100% = 38.46%
So, the percent yield for the reaction of 1.23 g of aluminum with excess sulfuric acid to produce 3.00 g of aluminum sulfate is 38.46%.
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Hydrogen peroxide is a compound that contains two hydrogen atoms and two oxygen atoms. Which formula represents hydrogen peroxide?.
Answer: H2O2
Explanation: The formula that represents hydrogen peroxide is H2O2
2HI (g) ⇋ H2 (g) I2 (g) kc = 64 if the equilibrium concentrations of H2 and I2 at 400°c are found to be [H2] = 4.2 x 10^-4 m and [i2] = 1.9 x 10^-3 m, what is the equilibrium concentration of HI?a. The concentrations of HI and I2 will increase as the system is approaching equilibrium.b. The concentrations of H2 and I2 will increase as the system is approaching equilibrium.c. The system is at equilibrium.d. The concentrations of H2 and HI will decrease as the system is approaching equilibriume. The concentration of HI will increase as the system is approaching equilibrium.
The correct answer is e. The concentrations of H2 and HI will decrease as the system is approaching equilibrium.
the equilibrium concentration of HI is 1.18 x 10^-4 M.
The correct answer is e. The concentrations of H2 and HI will decrease as the system is approaching equilibrium.
This is because the equilibrium constant, Kc, for the reaction is 64, which is a relatively large value. This suggests that the forward reaction (2HI → H2 + I2) is favored at equilibrium, meaning that the concentration of HI will decrease as the system approaches equilibrium.
To calculate the equilibrium concentration of HI, we can use the equilibrium constant expression:
Kc = [H2][I2]/[HI]^2
Substituting the given values, we get:
64 = (4.2 x 10^-4)(1.9 x 10^-3)/[HI]^2
Solving for [HI], we get:
[HI] = sqrt((4.2 x 10^-4)(1.9 x 10^-3)/64) = 1.18 x 10^-4 M
Therefore, the equilibrium concentration of HI is 1.18 x 10^-4 M.
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In the electrowinning process, a Metallurgical/Chemical Engineer uses an Infrared (IR) camera to detect metallurgical short-circuits (hot spots) over the anodes and cathodes. Given that the mass of an electron is 9. 109× 1031 and Rydberg’s constant is 1. 090×107 −1 , determine the energy (in MJ) applied when 5 mol of IR photons having a wavelength of 32 nm is used in the copper electrolysis process
In the electrowinning process, the energy applied using 5 mol of IR photons with a wavelength of 32 nm is 1.863 MJ.
1. Convert wavelength to energy using the equation: E = (hc)/λ, where h is Planck's constant (6.626×10⁻³⁴ Js), c is the speed of light (3×10⁸ m/s), and λ is the wavelength (32 nm = 32×10⁻⁹ m).
2. Calculate the energy of one IR photon: E = (6.626×10⁻³⁴ Js × 3×10⁸ m/s) / (32×10⁻⁹ m) = 6.184×10⁻¹⁹ J.
3. Determine the energy for 5 moles of IR photons: Total energy = 6.184×10⁻¹⁹ J × 5 × 6.022×10²³ photons/mol = 1.863×10⁶ J.
4. Convert energy to megajoules: 1.863×10⁶ J = 1.863 MJ.
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HELPP!!!
If 15. 6 mL of 0. 010 M aqueous HCl is required to titrate 25. 0 mL of an aqueous solution of
NaOH to the equivalence point, what is the Concentration of the NaOH solution?
The concentration of the NaOH solution is approximately 0.00624 M.
To find the concentration of the NaOH solution, you can use the titration formula:
M1V1 = M2V2
where M1 is the concentration of HCl (0.010 M), V1 is the volume of HCl (15.6 mL), M2 is the concentration of NaOH (unknown), and V2 is the volume of NaOH (25.0 mL).
0.010 M * 15.6 mL = M2 * 25.0 mL
Now, solve for M2:
M2 = (0.010 M * 15.6 mL) / 25.0 mL
M2 ≈ 0.00624 M
So, the concentration of the NaOH solution is approximately 0.00624 M.
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Problems - Using Equation Editor SHOW all calculations!!! 1. The stannous fluoride in a 10. 00 g sample of toothpaste was extracted and then precipitated with lanthanum nitrate solution. 0. 105 g of precipitate was collected. What is the mass of SnF2 present in the toothpaste sample? What is the mass percentage of stannous fluoride in the 10. 00 g sample of toothpaste? The percentage of SnF2 listed on the box was 1. 50%. What does this say about our percent yield of the extraction/recovery process?
The calculation of the mass of SnF₂ present in the toothpaste sample determined it to be 0.105 g. The mass percentage of stannous fluoride in the toothpaste sample was found to be 1.05%. The percent yield of the extraction/recovery process, comparing the recovered mass of SnF₂ to the expected mass based on the percentage listed on the box, was calculated to be 70.0%. This indicates a moderate level of efficiency in the extraction/recovery process.
To solve this problem, we need to use stoichiometry and the concept of percent yield.
1. Calculation of the mass of SnF₂ present in the toothpaste sample:
Let's assume that all the SnF₂ in the toothpaste sample was extracted and precipitated.
The balanced chemical equation for the reaction between stannous fluoride and lanthanum nitrate is:
SnF₂ + 2La(NO₃)3 → La₂(SnF₆) + 6NO₃
According to the equation, 1 mole of SnF₂ reacts with 2 moles of La(NO₃)₃ to form 1 mole of La2(SnF6).
The molar mass of SnF2 is 156.69 g/mol.
Therefore, the number of moles of SnF₂ in the toothpaste sample is:
n(SnF₂) = (0.105 g)/(156.69 g/mol) = 0.0006701 mol
Since the stoichiometric ratio of SnF₂ to La₂(SnF₆) is 1:1, the number of moles of La₂(SnF₆) formed is also 0.0006701 mol.
The mass of SnF2 present in the toothpaste sample is:
m(SnF₂) = n(SnF₂) × M(SnF₂) = 0.0006701 mol × 156.69 g/mol = 0.105 g
Therefore, the mass of SnF₂ present in the toothpaste sample is 0.105 g.
2. Calculation of the mass percentage of stannous fluoride in the toothpaste sample:
The mass percentage of SnF₂ in the toothpaste sample is:
% mass = (mass of SnF₂ / mass of toothpaste sample) × 100%
The mass of the toothpaste sample is given as 10.00 g.
Therefore, the mass percentage of SnF₂ in the toothpaste sample is:
% mass = (0.105 g / 10.00 g) × 100% = 1.05%
Therefore, the mass percentage of stannous fluoride in the toothpaste sample is 1.05%.
3. Analysis of the percent yield of the extraction/recovery process:
The percentage of SnF₂ listed on the box was 1.50%.
The percent yield of the extraction/recovery process is calculated as:
% yield = (mass of SnF₂ recovered / expected mass of SnF₂) × 100%
The expected mass of SnF₂ in the toothpaste sample, based on the percentage listed on the box, is:
mass of SnF₂ expected = (1.50% / 100%) × 10.00 g = 0.150 g
Therefore, the percent yield of the extraction/recovery process is:
% yield = (0.105 g / 0.150 g) × 100% = 70.0%
This means that the efficiency of the extraction/recovery process was 70.0%, which is not very high. It could be due to various factors such as incomplete extraction or loss of SnF₂ during the precipitation process.
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0. 18 g of a
divalent metal was completely dissolved in 250 cc of acid
solution containing 4. 9 g H2SO4 per liter. 50 cc of the
residual acid solution required 20 cc of N/10 alkali for
complete neutralization. Calculate the atomic weight of
metal.
39.
Ans: 36
The atomic weight of the metal is 36 g/mol.
To solve this problem, we need to use the concept of equivalent weight. The equivalent weight of a divalent metal is equal to its atomic weight divided by its valency, which in this case is 2.
First, let's calculate the number of equivalents of H2SO4 present in the solution.
4.9 g of H2SO4 per liter of solution means that there are 4.9/98 = 0.05 moles of H2SO4 per liter.
So in 250 cc (or 0.25 liters) of solution, there are 0.05 x 0.25 = 0.0125 moles of H2SO4.
Since H2SO4 is a diprotic acid, each mole of H2SO4 can donate 2 equivalents of H+. Therefore, the total number of equivalents of H+ present in the solution is 2 x 0.0125 = 0.025.
Now let's calculate the number of equivalents of alkali (which we know is N/10 or 0.1 N) required to neutralize 50 cc of the solution.
20 cc of N/10 alkali is equal to 0.002 equivalents of alkali (since N/10 alkali has a normality of 0.1, which means it can donate 0.1 equivalents of OH- per liter of solution).
Since the acid and alkali react in a 1:1 ratio, this means that there are also 0.002 equivalents of H+ in 50 cc of the solution.
Therefore, the initial number of equivalents of H+ in the solution must have been 0.025 + 0.002 = 0.027.
Now we can use this information to calculate the number of equivalents of metal present in the solution.
Since the metal is divalent, it will donate 2 equivalents of metal ions for every 1 equivalent of H+ that it reacts with.
Therefore, the number of equivalents of metal present in the solution is 0.027/2 = 0.0135.
Finally, we can calculate the atomic weight of the metal using the formula:
Atomic weight = Equivalent weight x Valency
In this case, the equivalent weight is equal to the atomic weight divided by 2 (since the metal is divalent).
So:
Atomic weight = Equivalent weight x 2
Atomic weight = (0.018 g / 0.0135 equivalents) x 2
Atomic weight = 36 g/mol
Therefore, the atomic weight of the metal is 36 g/mol.
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A sample of 140 g of an unstable isotope goes through 4 half-lives. how much of the parent isotope will be left at that time?
After four half-lives, 12.5 grams of the parent isotope will be left in a sample that originally contained 140 grams of an unstable isotope.
The amount of the parent isotope remaining after a certain number of half-lives can be calculated using the formula:
Remaining amount = Initial amount x (1/2)^(number of half-lives)
For this problem, the initial amount of the unstable isotope is 140 g, and it goes through 4 half-lives.
One half-life is the time it takes for half of the original sample to decay, and the number of half-lives is equal to the total time elapsed divided by the length of one half-life.
If we know the half-life of the isotope, we can find the total time elapsed. Let's assume the half-life of the isotope is 10 days.
After 10 days, half of the initial sample will remain:
Remaining amount = 140 g x (1/2)¹ = 70 g
After another 10 days (20 days total), half of the remaining sample will decay:
Remaining amount = 70 g x (1/2)¹ = 35 g
After another 10 days (30 days total), half of the remaining sample will decay again:
Remaining amount = 35 g x (1/2)¹ = 17.5 g
After another 10 days (40 days total), half of the remaining sample will decay once more:
Remaining amount = 17.5 g x (1/2)¹ = 8.75 g
Therefore, after 4 half-lives (40 days), there will be approximately 8.75 g of the parent isotope remaining.
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You are in a car traveling 60 mph. the car stopped suddenly and you are thrown forward but are stopped by the seat belt. why are you thrown forward?
Answer:
when u stop at great speed in a vechial your body is in still in motion
Explanation:
consider 5 sequential reactions where the product of each reaction is the reactant of the next and the 5 percent yields are 80%, 90%, 65%, 76% and 30%. if you begin with 100 molecules of the first limiting reagent, what is the maximum number of product molecules you can form at the end of the final reaction? \textbf{hint:} remember that you cannot have parts of a molecule!
Starting with 100 molecules of the first limiting reagent, the maximum number of product molecules that can be formed at the end of the final reaction, given the yields of each reaction, is 11 molecules.
Let's call the starting number of molecules of the first limiting reagent "A". Then, the number of molecules of each reactant and product after each reaction can be represented as follows,
Reaction 1: A → B (80% yield)
Starting molecules of A = 100
Molecules of B produced = 80
Reaction 2: B → C (90% yield)
Starting molecules of B = 80
Molecules of C produced = 72
Reaction 3: C → D (65% yield)
Starting molecules of C = 72
Molecules of D produced = 46.8 (rounded to 47)
Reaction 4: D → E (76% yield)
Starting molecules of D = 47
Molecules of E produced = 35.72 (rounded to 36)
Reaction 5: E → F (30% yield)
Starting molecules of E = 36
Molecules of F produced = 10.8 (rounded to 11)
Therefore, the maximum number of product molecules that can be formed at the end of the final reaction is 11, rounded to the nearest whole number.
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A 634. 5 g sample of helium absorbs 125. 7 calories of heat. The specific heat capacity of helium is 1. 241 cal/(g·°C). By how much did the temperature of this sample change, in degrees Celsius?
The temperature of the helium sample changed by approximately 0.0314 degrees Celsius.
To calculate the temperature change of the helium sample, we can use the formula:
q = mcΔT
where q is the heat absorbed (125.7 calories), m is the mass of the sample (634.5 g), c is the specific heat capacity of helium (1.241 cal/(g·°C)), and ΔT is the temperature change in degrees Celsius. We need to find ΔT.
Rearranging the formula to solve for ΔT, we get:
ΔT = q / (mc)
Now, plug in the given values:
ΔT = 125.7 cal / (634.5 g × 1.241 cal/(g·°C))
ΔT ≈ 0.0314 °C
Therefore, the temperature of the helium sample changed by approximately 0.0314 degrees Celsius.
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what happens to stars that are 8 times the sun's mass
Answer:
They forge heavy elements in their cores, explode as supernovas, and expel these elements into space.
Explanation:
How much energy is needed to change 475. 0 grams of liquid water at 40. 0°C to steam at 100. 0°C?
The total energy needed to convert the 475.0 grams of water at 40.0°C to steam at 100.0°C is 1,068,637.5 Joules.
The energy needed to change 475.0 grams of liquid water at 40.0°C to steam at 100.0°C is known as the latent heat of vaporization.
This amount of energy is required to overcome the forces that keep the molecules of water in a liquid state. In other words, it is the energy needed to break the bonds that keep the molecules of water in a liquid state.
To calculate the total energy needed, the latent heat of vaporization is multiplied by the mass of water. Therefore, the total energy needed to convert the 475.0 grams of water at 40.0°C to steam at 100.0°C is 1,068,637.5 Joules.
This energy needs to be supplied in the form of heat for the water to change from liquid to steam.
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What is the ability to do work or produce heat?
Answer: Energy
Explanation:
Energy is the ability to do work or produce heat.
How much heat is released when a 27. 7 g sample of ethylene glycol (C = 2. 42 J/gºC) at 42. 76°C is cooled to
32. 5°C
When a 27. 7 g sample of ethylene glycol (C = 2. 42 J/gºC) at 42. 76°C is cooled to 32. 5°C the amount of heat released is 685.87 joule.
To calculate the heat released when a 27.7 g sample of ethylene glycol is cooled from 42.76°C to 32.5°C, you can use the formula:
q = mcΔT
where q represents the heat released, m is the mass (27.7 g), c is the specific heat capacity (2.42 J/gºC), and ΔT is the change in temperature (42.76°C - 32.5°C).
ΔT = 42.76°C - 32.5°C = 10.26°C
Now plug in the values into the formula:
q = (27.7 g) × (2.42 J/gºC) × (10.26°C) = 685.87 J
So, 685.87 Joules of heat are released when the 27.7 g sample of ethylene glycol is cooled from 42.76°C to 32.5°C.
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Using an experimentally determined value (1. 8×10−10) of Ksp, determine the value for the reaction quotient 'Q' if Ag2CrO4 will precipitate when 5. 00 mL of 0. 0040 M AgNO3 are added to 4. 00 mL of 0. 0024 M K2CrO4
The solubility product constant (Ksp) for Ag2CrO4 is given by the following equation:
Ag2CrO4(s) ⇌ 2Ag+(aq) + CrO4^(2-)(aq)
The expression for Ksp is:
Ksp = [Ag+]^2[CrO4^(2-)]
where [Ag+] and [CrO4^(2-)] are the concentrations of the silver ion and chromate ion in the equilibrium mixture, respectively.
To determine the value of Q, the reaction quotient, we need to determine the concentrations of Ag+ and CrO4^(2-) in the mixture of 5.00 mL of 0.0040 M AgNO3 and 4.00 mL of 0.0024 M K2CrO4. To do this, we need to make some assumptions:
1. The volumes of the two solutions are additive, so the total volume is 9.00 mL.
2. The AgNO3 and K2CrO4 solutions react completely to form Ag2CrO4.
First, we need to determine the moles of Ag+ and CrO4^(2-) in each solution:
For the AgNO3 solution:
moles of Ag+ = (0.0040 M) x (0.00500 L) = 2.0 x 10^-5 mol
For the K2CrO4 solution:
moles of CrO4^(2-) = (0.0024 M) x (0.00400 L) = 9.6 x 10^-6 mol
Since the AgNO3 and K2CrO4 react in a 1:1 ratio to form Ag2CrO4, the limiting reactant is K2CrO4. Therefore, all of the CrO4^(2-) is used up in the reaction, and the concentration of CrO4^(2-) in the equilibrium mixture is zero.
The concentration of Ag+ in the equilibrium mixture is:
[Ag+] = moles of Ag+ / total volume of mixture
[Ag+] = (2.0 x 10^-5 mol) / (9.00 x 10^-6 L)
[Ag+] = 2.22 M
Now, we can calculate the value of Q:
Q = [Ag+]^2[CrO4^(2-)] = (2.22 M)^2(0 M) = 0
Since Q is equal to zero and Ksp is greater than zero (1.8 x 10^-10), the reaction is not at equilibrium and Ag2CrO4 will precipitate from the solution.
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wade could tell it was the night before trash pickup. The garbage can stank! What was it about summer that made the trash smell so bad, but the odor wasn't as bad during the winter months? construct an explanation that details the role particle energy plays in smell.
Answer:
Rameshwaram Gandhamadan mountain
What is the concentration of hydrochloric acid, HCL(aq) that gives a solution with a pH of 3.69?
To solve this problem, we need to use the pH formula:
pH = -log[H+]
where [H+] represents the concentration of hydrogen ions in moles per liter (M).
To find [H+], we can rearrange the formula:
[H+] = 10^(-pH)
Substituting pH = 3.69, we get:
[H+] = 10^(-3.69) = 2.21 × 10^(-4) M
Since hydrochloric acid is a strong acid, it completely dissociates in water to give hydrogen ions and chloride ions:
HCl(aq) → H+(aq) + Cl-(aq)
Therefore, the concentration of hydrochloric acid required to give a solution with a pH of 3.69 is also 2.21 × 10^(-4) M.
The other station has a solution of sodium bicarbonate (formula: nahco₃) and citric acid (formula: hoc(co2h)(ch2co2h)2).
na2hco3 (aq) + h3c3h5o7(aq) → na3c3h5o7(aq) + h2co3 (aq)
type of reaction? ___________________________________
the carbonic acid produced in this reaction keeps reacting to produce water and carbon dioxide
h2co3 (aq) → h2o(l) + co2(g)
type of reaction? decomposition
iii. notice the symbols inside the parentheses after the formula of the compounds. what do they mean?
s
l
g
aq
The type of reaction for the given equation is a double displacement reaction, where the sodium bicarbonate and citric acid react to form sodium citrate and carbonic acid. The carbonic acid then undergoes a decomposition reaction to produce water and carbon dioxide. This type of reaction is called a decomposition reaction.
The symbols inside the parentheses after the formula of the compounds represent the chemical structure of the molecule. In the case of citric acid, the parentheses indicate the presence of three carboxylic acid functional groups, which are responsible for its acidity.
The presence of these groups also allows for the reaction with sodium bicarbonate to occur, forming sodium citrate and carbonic acid. Overall, this reaction demonstrates the principles of acid-base chemistry and the importance of understanding chemical structures in predicting reactions.
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