The mass of [tex]\(\text{As-76}\)[/tex] remaining after 538 minutes is approximately [tex]\( 270.38 \text{ g} \).[/tex]
To determine the remaining mass of [tex]\(\text{As-76}\)[/tex] after 538 minutes given its half-life of 26.0 hours, we can use the concept of radioactive decay.
First, convert the given time from minutes to hours:
[tex]\[ 538 \text{ minutes} \times \frac{1 \text{ hour}}{60 \text{ minutes}} = 8.97 \text{ hours} \][/tex]
Next, we use the formula for radioactive decay:
[tex]\[ N(t) = N_0 \left( \frac{1}{2} \right)^{\frac{t}{t_{1/2}}} \][/tex]
Plug in the values:
[tex]\( N_0 = 344 \text{ g} \)[/tex][tex]\( t = 8.97 \text{ hours} \)[/tex][tex]\( t_{1/2} = 26.0 \text{ hours} \)[/tex]Calculate the fraction of the substance remaining after 8.97 hours:
[tex]\[ N(t) = 344 \left( \frac{1}{2} \right)^{\frac{8.97}{26.0}} \][/tex]
First, compute the exponent:
[tex]\[ \frac{8.97}{26.0} \approx 0.344 \][/tex]
Now calculate the remaining mass:
[tex]\[ N(t) = 344 \left( \frac{1}{2} \right)^{0.344} \][/tex]
[tex]\[ N(t) = 344 \times 0.786 \][/tex]
[tex]\[ N(t) \approx 270.38 \text{ g} \][/tex]
So, the mass of [tex]\(\text{As-76}\)[/tex] remaining after 538 minutes is approximately [tex]\( 270.38 \text{ g} \).[/tex]
If there are 25 marbles in a box and 9 of them are blue, what percent of the marbles are a color than blue?
There are 25 marbles in a box and 9 of the marbles are blue. What percent of the marbles are a color other than blue.
First, we need to understand what the problem is asking us to do. If we know that there are 9 marbles in the box that are blue and there are 25 marbles that are in the box altogether, we can subtract 9 from 25 and we get a difference of 16. Now we know that we need to find the percent of the marbles that are not blue.
16 ÷ 25 = 0.64
0.64 × 100 = 64%
Therefore, 64% of the marbles are a different color than blue and 36% of the marbles are blue.
Phosphorus has three unpaired electrons and hydrogen has one unpaired electron this means that_____ equivalents of hydrogen can react with ______ equivalents of phosphorus.
Three equivalents of hydrogen can react with one equivalent of phosphorus to form compounds like phosphine, where each hydrogen atom forms a bond with one of the unpaired electrons of phosphorus.
Phosphorus typically has three unpaired electrons and hydrogen has one unpaired electron, which means that three equivalents of hydrogen can react with one equivalent of phosphorus. For instance, in the formation of phosphine, PH₃, three hydrogen atoms will combine with one phosphorus atom, each hydrogen providing one electron to form a single bond with phosphorus. Since phosphorus has three unpaired electrons available, it is able to form three single bonds with three hydrogen atoms, resulting in the phosphine compound.
In the reaction Na2CO3 + 2HCl → 2NaCl + CO2 + H2O, how many grams of CO2 are produced when 7.5 moles of HCl is fully reacted?
165.04 grams of CO2 will be produced when 7.5 moles of HCl is fully reacted with Na2CO3 according to the balanced chemical equation provided, using stoichiometry and the molar mass of CO2.
Calculating the Mass of CO2
To find out how many grams of CO2 are produced when 7.5 moles of HCl is fully reacted, we will use the given balanced chemical equation and stoichiometry. The balanced equation is Na2CO3 + 2HCl
ightarrow 2NaCl + CO2 + H2O. According to the stoichiometry of the equation, 2 moles of HCl will produce 1 mole of CO2. Since we have 7.5 moles of HCl, this would react to produce 7.5 / 2 = 3.75 moles of CO2.
The molar mass of CO2 is 44.01 g/mol. So to convert moles of CO2 to grams, we multiply the number of moles by the molar mass: 3.75 moles imes 44.01 g/mol = 165.0375 grams of CO2. Therefore, 165.04 grams of CO2 (rounded to two decimal places) will be produced when 7.5 moles of HCl is fully reacted.
Why is it reasonable to assume the specific heats of naoh and hcl solutions are the same as water?
It's reasonable to assume the specific heats of NaOH and HCL solutions are the same as water because these solutions are largely water, and the solutes blend into the solution without significantly altering its inherent properties. This assumption is commonly made in calorimetry experiments. However, this is an approximation, and exact values may deviate for solutions with high concentrations.
Explanation:It's reasonable to assume the specific heats of NaOH and HCL solutions are similar to that of water because they are largely composed of water. When HCL and NaOH (both of which are solutes) are added to water, they dissociate and blend into the solution without significantly altering the water's inherent properties, like specific heat.
We rely on this assumption when conducting calorimetry experiments. Here, we trap heat in a calorimeter to eliminate any heat transfer between the reaction solution (rxn soln) and the external environment. We then use the specific heat of water to help calculate the heat either absorbed or released during the reaction.
Examples for this assumption include calculations where the enthalpy change of reactions involving HCL and NaOH are measured, or where their mass or heat capacity are considered and observed to result similarly as with water. However, it's also important to note that this is an approximation, and exact values may deviate for solutions with higher concentrations.
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A sample of hydrated sodium thiosulfate has a mass of 6.584 g. After it is heated, it has a mass of 4.194 g. What is the percentage by mass of water in the hydrate?
36.30%
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acetylene (C2H2) burns in pure oxygen with a very hot flame. The products of this reaction are carbon dioxide and water. How much oxygen is required to react with 52.0 g of acetylene?
Answer:
160.0 g
Explanation:
Since O2 has an amu of 32 and it has a coefficent of five in the balanced equation you would do 32 x 5 = 160.0g
Approximately 4.995 moles of oxygen (O2) are required to react with 52.0 g of acetylene (C2H2).
Explanation:To determine how much oxygen is required to react with 52.0 g of acetylene (C2H2), we need to consider the balanced chemical equation and use stoichiometry.
The balanced equation for the reaction between acetylene and oxygen is 2 C2H2 + 5 O2 → 4 CO2 + 2 H2O.
From the balanced equation, we can see that 2 moles of acetylene react with 5 moles of oxygen to produce 4 moles of carbon dioxide and 2 moles of water.
First, we need to convert the given mass of acetylene (52.0 g) to moles. Using the molar mass of acetylene (26.02 g/mol), we find that 52.0 g of acetylene is equal to 1.998 moles.
Next, we use the mole ratio from the balanced equation to determine the moles of oxygen required. The ratio of acetylene to oxygen is 2:5, so for every 2 moles of acetylene, we need 5 moles of oxygen.
Using the mole ratio:
(1.998 moles C2H2) x (5 moles O2 / 2 moles C2H2) = 4.995 moles O2
Therefore, approximately 4.995 moles of oxygen (O2) are required to react with 52.0 g of acetylene (C2H2).
If the solubility of AgNO3 is 63.7g/100 mL water and you have 5.77 g dissolved in 10 mL of water is your solution unsaturated, saturated, or super saturated? Explain and describe how this solution would look.
Calculate the pH if the pOH is 2.8
If the pOH of a solution is 2.8, you subtract it from 14 to find the pH, resulting in a pH of 11.2.
To calculate the pH from a given pOH, we can use the relationship that the sum of the pH and pOH is equal to 14 at 25 °C (298 K). If the pOH is 2.8, then we can find the pH by subtracting the pOH from 14:
pH = 14 - pOH
pH = 14 - 2.8
pH = 11.2
Therefore, if the pOH of a solution is 2.8, the pH is 11.2.
How many moles of oxygen are needed to completely react with 9.5 grams of sodium
Answer: 0.103 moles of oxygen
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 Liters at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given volume}}{\text {Molar volume}}[/tex]
[tex]\text{Number of moles of sodium}=\frac{9.5g}{23g/mol}=0.413moles[/tex]
[tex]4Na+O_2\rightarrow 2Na_2O[/tex]
According to stoichiometry:
4 moles of [tex]Na[/tex] combine completely with 1 mole of [tex]O_2[/tex] to give 2 moles of [tex]Na_2O[/tex]
Thus 0.413 moles of [tex]Na[/tex] will combine completely with=[tex]\frac{1}{4}\times 0.413=0.103[/tex] moles of [tex]O_2[/tex]
Thus 0.103 moles of oxygen are needed to completely react with 9.5 grams of sodium
When a colorless aqueous solution of lead nitrate is combined with a colorless aqueous solution of sodium iodide a bright yellow precipitate is formed. what is the chemical formula for the precipitate?
The chemical formula of the bright yellow precipitate is PbI₂ (lead iodide).
What is the balanced chemical equation?A chemical equation is the representation of a chemical reaction which consists of reactants participating, formed products, and an arrow indicating the direction of the chemical reaction.
The equation that has the number of atoms of substances equal on either side of the chemical equation is known as a balanced chemical equation.
The law of conservation of mass has to be followed by a balanced chemical equation, according to which, the total mass of the elements on the reactant side must be equal to the total mass of elements on the product side.
The chemical equation of the reaction of lead nitrate and an aqueous solution of sodium iodide:
[tex]Pb(NO_3)_2(aq) + 2NaI \longrightarrow 2NaNO_3(aq) + PbI_2 (s)[/tex]
The bright yellow precipitate formed in the above chemical reaction has the chemical formula PbI₂.
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Compare bond lengths in butane and t butylcyclohexane
Answer:
The lengths of the C-C bonds increases with the decrease in the resistance of said bond, for example, a triple bond has a shorter length than in the case of a single bond. Butane has the single bonds and the CC bond is hybridized with sp3 hybridization, however in the butylcyclohexane structure the CC bond is also sp3 and the angle is 120°, however the angle shown is equal to 109.5°, so there is a certain angular tension and it is very unstable with respect to butane
Explanation:
Find the missing part of this equation
What is the molality of a 13.82% by mass glucose solution? the molar mass of c6h12o6 is 180.16 g/mol?
Answer:
The molality is [tex]0.8901m[/tex]
Explanation:
Let's start defining the molality.
[tex]Molality=\frac{MolSolute}{KgOfSolvent}[/tex]
We also know that in terms of masses :
[tex]SoluteMass+SolventMass=SolutionMass[/tex] (I)
Finally, we define the mass percent as :
[tex]MassPercent=\frac{MassOfSolute}{MassOfSolution}.(100)[/tex]
Using the data of the mass percent we find that :
[tex]13.82=\frac{MassOfSolute}{MassOfSolution}.(100)[/tex]
[tex]\frac{MassOfSolute}{MassOfSolution}=0.1382[/tex] ⇒ [tex]MassOfSolution=\frac{MassOfSolute}{0.1382}[/tex] (II)
We know that the molar mass of glucose is [tex]180.16\frac{g}{mol}[/tex]
Therefore, if we use the mass of 1 mole of glucose ([tex]180.16g[/tex]) in (II) ⇒
[tex]MassOfSolution=\frac{180.16g}{0.1382}[/tex]
[tex]MassOfSolution=1303.618g[/tex]
Now, if we use the equation (I) :
[tex]180.16g+SolventMass=1303.618g[/tex]
[tex]SolventMass=1123.458g[/tex]
[tex]1Kg=1000g[/tex] ⇒ [tex]SolventMass=1.1234Kg[/tex]
We find that 1 mole of glucose ([tex]180.16g[/tex] of glucose) are combined with [tex]1.1234Kg[/tex] of solvent to obtain [tex]1303.618g[/tex] of solution which is a 13.82% by mass glucose solution.
If we want to find the molality, we can replaced all the data in the equation of molality :
[tex]Molality=\frac{(1Mol)OfGlucose}{(1.1234Kg)OfSolvent}[/tex]
[tex]Molality=0.8901m[/tex]
We use 1 mol of glucose in the equation (which corresponds to 180.16 g of glucose)
The letter ''m'' is the unit of molality.
Calculate the mass of water produced when 1.92 g of butane reacts with excess oxygen.
The addition of 435.2 j of heat is required to raise the temperature of 3.4 g of olive oil from 21?c to 85?c. what is the specific heat of the olive oil?
The specific heat of olive oil is 2 J/g °C'
From the question,
We are to determine the specific heat of olive oil
From the formula
Q = mcΔT
Where Q is the quantity of heat
m is the mass of substance
c is the specific heat of substance
ΔT is the change in temperature
From the given information
Q = 435.2 J
m = 3.4 g
ΔT = 85 °C - 21 °C = 64 °C
Putting the above parameters into the formula, we get
435.2 = 3.4 × c × 64
435.2 = 217.6c
∴ c = 435.2 ÷ 217.6
c = 2 J/g °C
Hence, the specific heat of olive oil is 2 J/g °C
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Use the specific heat of water to determine how much heat is required to raise the temperature of 50.0g of water from 35oc to 55oc.
Answer:
There is 4184 Joule of energy required
Explanation:
Step 1: Data given
Mass of water = 50.0 grams
Initial temperature of water = 35.0 °C
Final temperature = 55.0 °C
Specific heat of water = 4.184 J/g°C
Step 2: Calculate the heat
Q = m*c*ΔT
⇒ Q = the heat transfer (in Joules)
⇒ m = the mass of water = 50.0 grams
⇒ c = the specific heat of water = 4.184 J/g°C
⇒ ΔT = The change of temperature of the water = T2 - T1 = 55.0°C - 35.0 °C = 20.0 °C
Q = 50.0g * 4.184 J/g°C * 20.0 °C
Q = 4184 J
There is 4184 Joule of energy required
Why is butane in the lighter a liquid yet the butane in the buret is a gas?
A gas cylinder contains exactly 15 moles of oxygen gas (O2). How many molecules of oxygen are in the cylinder? 4.01 × 1022 molecules 6.02 × 1023 molecules 9.03 × 1024 molecules 2.89 × 1026 molecules
Answer:
answer in picture It's B
Explanation:
55 kg of liquefied natural gas (lng) are stored in a rigid, sealed 0.17 m3 vessel. in this problem, model lng as 100% methane. due to a failure in the cooling/insulation system, the temperature increases to 200 k, which is above the critical temperature; thus, the natural gas will no longer be in the liquid phase.
The pressure in the vessel after the temperature increase is approximately 33.65 MPa.
We are given a scenario where liquefied natural gas (LNG) stored in a rigid, sealed vessel experiences a temperature increase beyond its critical point, causing it to transition from a liquid to a gas phase. We need to find the final pressure in the vessel using the ideal gas law.
2. Modeling the system:
We treat the LNG as pure methane ([tex]CH_4[/tex]) for simplification.
We assume the system behaves like an ideal gas, meaning it follows the ideal gas law.
3. Setting up the equation:
The ideal gas law relates pressure (P), volume (V), number of moles (n), gas constant (R), and temperature (T) through the equation:
PV = nRT
4. Identifying known and unknown values:
V: 0.17 m³ (volume of the vessel)
R: 8.314 J/(mol·K) (universal gas constant)
T: 200 K (final temperature)
P: Unknown (pressure we need to solve for)
5. Converting mass of LNG to moles:
Molar mass of methane ([tex]CH_4[/tex]): 16.04 g/mol
Mass of LNG (m): 55 kg = 55,000 g
Number of moles (n):
n = m / molar mass
n = 55,000 g / 16.04 g/mol
n ≈ 3433 mol
6. Solving for pressure:
Plug the known values into the ideal gas law and solve for P:
P = (n * R * T) / V
P = (3433 mol * 8.314 J/(mol·K) * 200 K) / 0.17 m³
P ≈ 33,647,247 Pa
7. Converting units and expressing final answer:
Convert pressure from Pascal (Pa) to Megapascal (MPa):
P = 33,647,247 Pa * (1 MPa / 1,000,000 Pa)
P ≈ 33.65 MPa
The question probable may be:
55 kg of liquefied natural gas (lng) are stored in a rigid, sealed 0.17 m3 vessel. in this problem, model lng as 100% methane. due to a failure in the cooling/insulation system, the temperature increases to 200 k, which is above the critical temperature; thus, the natural gas will no longer be in the liquid phase. What would be pressure in the vessel after the temperature increase
The generic metal a forms an insoluble salt ab(s) and a complex ac5(aq). the equilibrium concentrations in a solution of ac5 were found to be [a] = 0.100 m, [c] = 0.0110 m, and [ac5] = 0.100 m. determine the formation constant, kf, of ac5.
Assuming that the reaction from A and C to AC5 is only one-step (or an elementary reaction) with a balanced chemical reaction of:
A + 5 C ---> AC5
Therefore the formation constant can be easily calculated using the following formula for formation constant:
Kf = product of products concentrations / product of reactants concentration
Kf = [AC5] / [A] [C]^5
---> Any coefficient from the balanced chemical reaction becomes a power in the formula
Substituting the given values into the equation:
Kf = 0.100 M / (0.100 M) (0.0110 M)^5
Kf = 6,209,213,231
or in simpler terms
Kf = 6.21 * 10^9 (ANSWER)
Which statement best describes the properties of metals?
A) they are shiny and bend without breaking
B) they are dull and are good electrical insulators
C) they conduct electricity well and are brittle
D) they can be flattened and do not conduct heat well
The correct option is A.
Metals have certain characteristics properties, they include the following: they are ductile, malleable, shiny, hard, lustrous, flexible and they are good conductor of heat and electricity. The malleability of metals refers to their ability to withstand bending and hammering without breaking. Metals are not dull, neither are they brittle, those are the properties of non metals.
Answer : The correct statement is, (A) they are shiny and bend without breaking
Explanation :
Metals : Metals are the elements that easily loose electrons and forms cations.
The properties of the metals :
Generally all the metals are hard except sodium and potassium are soft.They are malleable that means it can be molded into different shapes.They are ductile that means it can be molded into thin wire.They are good conductor of heat and electricity.Non-metals : Non-metals are the elements that easily gain electrons to form an anion.
The properties of the non-metals :
They are non-malleable that means it can not be molded into different shapes.They are non-ductile that means it can not be molded into thin wire.They are poor conductor of heat and electricity.They are brittle in nature.Hence, the best statement is, (A) they are shiny and bend without breaking
What is the mass loss of the nucleus, in u, upon emission of this gamma ray? -g?
What gas was produced by the decomposition of hydrogen peroxide? what happened when the smoldering toothpick came into contact with the gas? b boldi italicsu underline bulleted list numbered list superscript subscript?
calculate the density of a rectangular solid, which has a mass of 25.71g. It is 2.30cm long, 4.01cm wide, and 1.82cm high
Pressure and volume are inversely related. When the pressure on a gas is doubled, what happens to the volume
Answer: Volume decreases to half of original volume
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
[tex]{P_1V_1}={P_2V_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = p
[tex]P_2[/tex] = final pressure of gas = 2p
[tex]V_1[/tex] = initial volume of gas = v
[tex]V_2[/tex] = final volume of gas = ?
Now put all the given values in the above equation, we get the final pressure of gas.
[tex]{p\times v}=2p\times V_2[/tex]
[tex]V_2=\frac{v}{2}[/tex]
Therefore, the final volume of the gas will become half of initial volume.
What would indicate that a physical change takes place when copper is drawn into wire
Explanation:
A physical change is defined as a change that does not bring any difference in chemical composition of a substance.
For example, shape, size, mass, volume, density, etc of a substance are all physical properties.
So, when copper is drawn into wire then there will occur change in its shape but there will not be any change in its chemical composition.
Whereas when a change in chemical composition of a substance occurs then it is known as a chemical change.
Hence, we can conclude that change in the shape of copper when it is drawn into wire indicates a physical change.
Determine the expression for the equilibrium constant, kc, for the reaction by identifying which terms will be in the numerator and denominator: kc=numeratordenominator=?? place the terms into the appropriate bin.
The kc is a representation of how fast the reaction proceeds to their products when it has achieved equilibrium. The activation energy for the forward and the one for the reverse reaction are similar because they attained chemical equilibrium. A chemical equilibrium happens when both of the reactant and products achieve the same concentration. An example is the process of melting and freezing. Melting and freezing for a given substance occurs at the same temperature. Because the temperature at which the solid starts to melt is also the temperature at which the liquid starts to freeze. They are at chemical equilibrium.
A fixed amount of gas occupies a volume of 7.25 l at a pressure of 4.52 atm. what will be the volume occupied if the pressure is decreased to 1.21 atm at constant temperature?
The volume occupied if the pressure is decreased to 1.21 atm at constant temperature is 27.08 L
Data obtained from the questionInitial volume (V₁) = 7.25 LInitial pressure (P₁) = 4.52 atmTemperature = ConstantNew pressure (P₂) = 1.21 atmNew Volume (V₂) =? How to determine the new volumeThe new volume of the gas can be obtained by using the Boyle's law equation as illustrated below:
P₁V₁ = P₂V₂
4.52 × 7.25 = 1.21 × V₂
Divide both sides by 1.21
V₂ = (4.52 × 7.25) / 1.21
V₂ = 27.08 L
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Determine the number of 3s electrons in na.
Calculate the vapor pressure of a solution containing 27.2 g of glycerin (c3h8o3) in 132 ml of water at 30.0 ?c. the vapor pressure of pure water at this temperature is 31.8 torr. assume that glycerin is not volatile and dissolves molecularly (i.e., it is not ionic) and use a density of 1.00 g/ml for the water.
Final answer:
To find the vapor pressure of the glycerin solution, calculate the moles of glycerin and water, determine the mole fraction of water, and apply Raoult's law using the vapor pressure of pure water at the specified temperature.
Explanation:
To calculate the vapor pressure of the solution containing glycerin in water, we will use Raoult's law, which states that the vapor pressure of a solution is directly proportional to the mole fraction of the solvent. The first step is to calculate the number of moles of glycerin (C3H8O3) by using its molar mass (92.09 g/mol), and then calculate the number of moles of water using its given density (1.00 g/mL) to convert the volume to mass and then to moles with its molar mass (18.015 g/mol).
Once we have both amounts in moles, we can calculate the mole fraction of water and apply Raoult's law to find the new vapor pressure of the solution, knowing the vapor pressure of pure water at the given temperature (30.0 °C) is 30.6 Torr.