Answer:
The answer is "17200 years".
Explanation:
Given:
[tex]A = 20 \ \frac{counts}{minute}\\\\A_{o} = 160\ \frac{counts}{minute}[/tex]
Let the half-life of carbon-14, is beta emitter, is [tex]T = 5730\ years[/tex]
Constant decay [tex]\ w = \frac{0.693}{ T}[/tex]
[tex]= 1.209 \times 10^{-4} \ \frac{1}{year}\\[/tex]
The artifact age [tex]t= ?[/tex]
[tex]A = A_{o} e^{-wt} \\\\e^{-wt} = \frac{A}{A_{o}}\\\\-wt = \ln \frac{A}{A_{o}}\\\\= -2.079\\\\t = 1.7199 \times 10^{4} \ years\\\\\sim \ 17200\ years\\[/tex]
Study this chemical reaction: 2Fe(s) 3Pb(NO3)2(aq) 3Pb(s) 2Fe(NO3)3(aq) Then, write balanced half-reactions describing the oxidation and reduction that happen in this reaction.
Answer:
Explanation:
2Fe(s) + 3Pb(NO₃)₂(aq) = 3Pb(s) + 2Fe(NO₃)₃(aq)
Half ionic reactions
2Fe(s) = 2Fe⁺³ + 6e
3Pb⁺² + 6e = 3 Pb(s)
In the first reaction Fe is oxidised to Fe⁺³ because its oxidation number increases from zero to + 3 .
In the second reaction , Pb⁺² is reduced to Pb (s) because its oxidation number is reduced from + 2 to zero.
NEED HELP ASAP!!!! PLEASE DONT COMMENT IF YOU DONT KNOW. I WIILL REPORT YOU.
Answer:
is C the Ch because is look 99% the answer pls don't report if I'm wrong it took me a long time to answer it
Consider the reaction: CaCO3(s)CaO(s) CO2(g) Using standard absolute entropies at 298K, calculate the entropy change for the system when 1.58 moles of CaCO3(s) react at standard conditions.
Answer:
the entropy change for the system when 1.58 moles of CaCO3(s) react at standard conditions is 253.748 J/K
Explanation:
Given the data in the question;
CaCO₃(s) → CaO(s) + CO₂(g)
1.58 moles 1.58 moles 1.58 moles
Since 1 mole of CaCO₃ gives 1 mole of CaO and 1 mole of CO₂
Thus, 1.58 mole of CaCO₃ gives 1.58 moles of CaO and 1.58 moles of CO₂.
Now,
At 298 K, standard entropy values are;
ΔS° ( CaCO₃ ) = 92.9 J/mol.K
ΔS° ( CaO ) = 39.8 J/mol.K
ΔS° ( CO₂ ) = 213.7 J/mol.K
So,
ΔS°[tex]_{system[/tex] = ∑ΔS°( product ) - ∑ΔS°( reactant )
ΔS°[tex]_{system[/tex] = [ ΔS°(CaO) + ΔS°( CO₂ ) ] - ΔS°( CaCO₃ )
we substitute
ΔS°[tex]_{system[/tex] = [ 39.8 J/mol.K + 213.7 J/mol.K ] - 92.9 J/mol.K
ΔS°[tex]_{system[/tex] = 160.6 J/mol.K
i.e, for 1 mol CaCO₃, ΔS°[tex]_{system[/tex] = 160.6 J/mol.K
Now, for 1.58 mol CaCO₃,
ΔS°[tex]_{system[/tex] = 1.58 mol × 160.6 J/mol.K
ΔS°[tex]_{system[/tex] = 253.748 J/K
Therefore, the entropy change for the system when 1.58 moles of CaCO3(s) react at standard conditions is 253.748 J/K
For the reaction of oxygen and nitrogen to form nitric oxide, consider the following thermodynamic data :
ΔH∘rxn 180.5kJ/mol
ΔS∘rxn 24.80J/(mol⋅K)
Required:
a. Calculate the temperature in kelvins above which this reaction is spontaneous
b. Calculate the equilibrium constant for the following reaction at room temperature, 25°C
Answer:
a. 7278 K
b. Kc = 4.542 × 10⁻³¹
Explanation:
a.
The reaction is spontaneous when ΔG° < 0. We can calculate ΔG° using the following expression.
ΔG° = ΔH° - T × ΔS°
Then, the reaction will be spontaneous when,
ΔH° - T × ΔS° < 0
T > ΔH°/ΔS
T > (180.5 × 10³ J/mol)/(24.80J/mol⋅K)
T > 7278 K
b.
First, we will calculate ΔG° at 25 °C (298 K)
ΔG° = ΔH° - T × ΔS°
ΔG° = (180.5 × 10³ J/mol) - 298 K × (24.80J/mol⋅K) = 1.731 × 10⁵ J/mol
Then, we will calculate the equilibrium constant (Kc) using the following expression.
ΔG° = - R × T × ln Kc
-ΔG°/R × T = ln Kc
-(1.731 × 10⁵ J/mol)/(8.314 J/mol.K) × 298 K = ln Kc
Kc = 4.542 × 10⁻³¹
The article source and supplementary information compare p-toluenesulfonic acid and Amberlyst-15 as catalysts that can be used to synthesis Methyl Diantilis. In a paragraph please summarize and explain the differences between these two catalysts. This summary should include both differences of chemical principles and laboratory practicality.
Answer:
Following are the solution to these questions:
Explanation:
P-toluene sulfonic acid variations between Amberlyst-15
Acid p-Toluenesulfonic (PTSA)
Organic acid SimpleAquaPTSA will be removed after a reaction from a difficult workflowHard to recycleEnvironmental pollution conditionsComposite single unitToxicAmberlyst 15
Acid PolymerSolidComfortably separated by simple filtration after the reaction.Easily recycle and reuseNot environmentally damagingion exchange resin based on polystyrene.NontoxicP-toluene and Amberlyst-15 do have the same catalytic effect in the reaction as the mechanism is defined in the attached file. The Amberlyst 15 is always considered as best, given the better future for Amberlyst 15.
What does the red line in the diagram below represent?
A. The equilibrium position
B. The difference in energy between the reactants and products
C. The potential energy of the reactants
D. The activation energy
Answer:
The activation energy
Explanation:
The activation energy is the energy hump that lies between reactants and products. It is the energy barrier that reactants must cross before they are converted into products.
Based on the collision theory, only particles that possess the activation energy are able to collide in such a way that leads to reaction.
Collision of particles having an energy content less than the activation energy of the reaction merely leads to elastic collision between such particles.
An intravenous solution was prepared by add-in 13.252 g of dextrose (C6H12O6) and 0.686 g of sodium chloride to a 250.0 mL volumetric flask and diluting to the calibration mark with water. What is the molarity of each component of the solution
Explanation:
Molarity(M) of a solution is defined as the number of moles of solute(n) present in one liter of solution(V).
[tex]M=\frac{n}{V}[/tex]
The number of moles(n) can be calculated as shown below:
[tex]n=\frac{mass of solute}{molar mass of solute}[/tex]
Molar mass of dextrose is 198.17 g/mol
Molar mass of NaCl is 58.5 g/mol.
Volume of the solution =250.0mL=0.250 L
The number of moels of dextrose([tex]n_{d}[/tex]) is:
[tex]n_{d} =\frac{13.252g}{198.17g/mol} \\=0.0669mol[/tex]
The number of moles of NaCl is:
[tex]n_{NaCl} =\frac{0.686 g}{58.5g/mol} \\\\=0.01177 mol[/tex]
Thus, the molarity of dextrose is:
[tex]M_d=\frac{n_d}{0.250 L} \\=0.0669mol/0.250L\\=0.268 M[/tex]
The molarity of NaCl is:
[tex]M_Na_Cl=\frac{n_d}{0.250 L} \\\\=0.0118mol/0.250L\\\\=0.0472 M[/tex]
Answer:
The molarity of dextrose is 0.268 M.
The molarity of NaCl is 0.0472 M.
Flag A solution of the weak acid, HF, and a solution of the strong acid, HCl, have the same pH. Which solution will require the most sodium hydroxide, NaOH, to neutralize
Answer:
C) Both will require the same amount because the concentrations are equal.
Explanation:
The pH of a solution is defined as:
pH = -log [H+]
This H+ is the ion that reacts with OH- (From NaOH) as follows:
H+ + OH- → H2O
When all H+ reacts, we can say the solution was neutralized.
Now, as both, the solution with the weak acid and the solution with strong acid have the same pH, we can say that their [H+] is the same. Assuming the volume of both solutions is the same:
Both will require the same amount because the concentrations are equal.
How we get this answer?? I need the way with rules?
Answer:
Do you know the formula¿?
What is the concentration of a 1:15 dilution of a 3.0 M solution of nacl
Answer:
0.20M NaCl is the concentration of the NaCl dilution
Explanation:
A dilution consist on the addition of more solvent in a solution in order to decrease their concentration.
In this problem, the 3.0M NaCl solution is decreasing their concentration 15 times. That is:
3.0M NaCl / 15 =
0.20M NaCl is the concentration of the NaCl dilutionEnzyme catalyzing breakdown of atp to adp
Answer:
ATP hydrolase
Explanation:
Enzymes are biological catalysts which perform diverse functions in the body. Enzymes are specific in their mode of action because an enzyme fits into its substrate as a key fits into a lock.
The particular enzyme that catalyzes the breakdown of ATP to ADP is ATP hydrolase. The phosphate released by the action of this enzyme is used in the phosphorylation of other compounds thereby making them more reactive.
Balance the following chemical equation by
providing the correct coefficients.
C3H8 + O2 + CO2 + H2O
A 2.8.4.2
B 1.5.3.4
Answer:
C3H8 + 502+3CO2 + 4H20
Explanation:
In order to get this answer you would have to would balance out the carbons on the products side by multiplying CO2 by 3. The new equation will be
C3H8 + 02 ----> 3CO2 + H20
Now, that the carbons are balanced, we will look at the hydrogens. We can multiply the number of waters on the product side by 4, to make 4 H20 molecules. This gives both sides of the equation 8 hydrogens. Next we can check our oxygens. There will be 10 oxygens on the products side and 2 on the reactants so to balance these out, we multiply the 02 on the reactants side by 5.
1. Why is it necessary to equalize the pressure(i.e, have the water level the same in each tube) before taking a volume reading?
2. Why is it important to use water that has been pre-saturated with CO2 in the gas burettes?
3.If your antacid sample had been contaminated by moisture, what effect(if any )would you expect this to have on your result
4.Explain why an'antacid is called as such,what is the role of the NAHCO3 or CACO3 in reactions?
Answer:
If you contact water with a gas at a certain temperature and (partial) pressure, the concentration of the gas in the water will reach an equilibrium ('saturation') according to Henry's law.
Explanation:
This means: if you increase the pressure (e.g. by keeping the vial closed), the CO2 concentration will increase. So it simply depends what concentration you need for your assay: 'CO2-saturated' water at low pressure or 'CO2-saturated' water at high pressure.
g When copper(II) chloride and sodium carbonate solutions are combined, solid copper(II) carbonate precipitates, leaving a solution of sodium chloride. Write the conventional equation, total ionic equation, and net ionic equation for this reaction. (Use the lowest possible coefficients. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank.)
Answer:
When copper(II) chloride and sodium carbonate solutions are combined, solid copper(II) carbonate precipitates, leaving a solution of sodium chloride. Write the conventional equation, total ionic equation, and net ionic equation for this reaction.
Explanation:
The word equation for the reaction is:
Copper (II) chloride(aq) + sodium carbonate (aq) ->sodium chloride (aq) + copper carbonate(s)
The balanced chemical equation of the reaction is:
[tex]CuCl_2(aq)+Na_2CO_3(aq)->2NaCl(aq)+CuCO_3(s)[/tex]
The complete ionic equation is:
[tex]Cu^2+(aq)+2Cl^-(aq)+2Na^+(aq)+CO_3^2^-(aq)->2Cl^-(aq)+2Na^+(aq)+CuCO_3(s)\\[/tex]
The net ionic equation is obtained from the complete ionic equation after removing the spectator ions:
[tex]Cu^2^+(aq)+CO_3^2^-(aq)->CuCO_3(s)[/tex]
I place 3 moles of N2 and 4 moles of O2 in a 35 L container at ta temperature of 25 degree Celsius, what will the pressure (in atm) of the resulting mixture of gases be?
Answer:
The pressure of the resulting mixture of gases will be 4.89 atm.
Explanation:
An ideal gas is a theoretical gas that is considered to be composed of randomly moving point particles that do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:
P*V = n*R*T
where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas. The universal constant of ideal gases R has the same value for all gaseous substances. The numerical value of R will depend on the units in which the other properties are worked.
In this case:
P= ?V= 35 Ln= 3 moles of N₂ + 4 moles of O₂= 7 molesR= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 25 C= 298 K (being 0 C= 273 K)Replacing:
P* 35 L= 7 moles* 0.082 [tex]\frac{atm*L}{mol*K}[/tex] * 298 K
Solving:
[tex]P=\frac{ 7 moles* 0.082 \frac{atm*L}{mol*K} * 298 K}{35 L}[/tex]
P= 4.89 atm
The pressure of the resulting mixture of gases will be 4.89 atm.
The pressure (in atm) of the resulting mixture of the gases is 4.89 atm
From the question given above, the following data were obtained:
Mole of N₂ = 3 moles
Mole of O₂ = 4 moles
Total mole = 3 + 4 = 7 moles
Volume (V) = 35 L
Temperature (T) = 25 °C = 25 + 273 = 298 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure of mixture (P) =?The pressure of the resulting mixture of the gases can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
P × 35 = 7 × 0.0821 × 298
P × 35 = 171.2606
Divide both side by 35
P = 171.2606 / 35
P = 4.89 atmTherefore, the pressure of the resulting mixture of the gases 4.89 atm
Learn more: https://brainly.com/question/21912477
Why did Rutherford choose alpha particles in his experiment?
Select True or False: All intermolecular forces must be overcome in order for a substance to undergo a phase change from a liquid to a gas
Answer:
True
Explanation:
In order for a liquid to boil it must undergo transformation in its structural composition that are arranged by intermolecular. Such as changes will need more energy to overcome and changes in phases form solid to liquid to gas.Predict the Normality of H2SO4 if 75 ml of 96.6 % pure H2SO4 added to 425 ml water. The density of H2SO4 is 1.83 g/cm3?
Explanation:
Normality is one of the concentration terms.
It is expressed as:
[tex]N=\frac{mass of the substance}{equivalent mass}* \frac{1}{volume of solution in L.}[/tex]
The volume of the solution is 425 mL.
Mass of sulfuric acid given is:
[tex]mass=volume * purity* density\\ = 75 mL * 0.966 * 1.83 g/mL\\\\=132.5 grams\\[/tex]
The equivalent mass of sulfuric acid is 49.0g/equivalents
Hence, the normality of the given solution is:
[tex]N=\frac{132.5g}{49.0g/equi.} *\frac{1000}{425mL} \\Normality=6.36N[/tex]
Answer is: 6.36N.
If 225 cal of heat is added to 15.0 g of 2-propanol at room temperature, 25ºC, the alcohol will reach a final temperature of ________ ºC. The specific heat of 2-propanol is 0.612 cal/(g•ºC).
Explanation:
I have no idea about this
why beta carbon hydrogen is easily replaced
Answer:
γ−Hydrogen is easily replacable during bromination reaction in presence of light , because Allylic substitution is being preferred.
Explanation:
that's all
γ−Hydrogen is easily replacable during bromination reaction in presence of light , because Allylic substitution is being preferred.
1. When 6.0 grams of zinc are dropped into excess hydrochloric acid, how many grams of zinc chloride will be produced?
2. When 45.0 grams of copper (II) carbonate are decomposed with heat, how many grams of carbon dioxide will be produced? (Teachers note: Other product is copper (II) oxide.)
Please explain as well if possible! Thanks.
Explanation:
here are the answers for your questions
I basically converted the given grams to moles, and then multiplied that by the product-to-reactant ratio in the equation, and then convert that to grams
Answer:
Explanation:
1.
The reaction can be represented by the equation: Zn + 2 HCl -> ZnCl2 + H2
From the equation, molar ratio of Zn and ZnCl2 is 1:1.
Molar mass of Zn = 65.38
Molar mass of ZnCl2 = 65.38 + 35.45*2 = 136.28
So 6.0 grams of Zn will produce 6 / 65.38 * 136.28 = 12.5 grams
2.
As the only other product is copper (II) oxide, the reaction can be represented by the equation: CuCO3 -> CuO + CO2
From the equation, molar ratio of CuCO3 and CuO is 1:1.
Molar mass of CuCO3 = 123.55
Molar mass of CuO = 79.55
So 45.0 grams of CuCO3 will produce 45 / 123.55 * 79.55 = 28.96 grams
What is the oxidation state of nitrogen in N ?
Answer:
+5
Explanation:
The diagram above shows the hydrides of groups 14, 15, 16, and 17 elements. Why does H20, HF, and NH3 have much higher boiling points than the rest of the molecules in their groups?
Answer:
Hydrogen Bonding
Explanation:
Hydrogen Bonding occurs when a hydrogen atom is bonded to N, O, and F atoms.
The molecules H₂O, HF, and NH₃ all experience hydrogen bonding, which is a relatively strong IMF, causing the molecules to have stronger attraction to each other. Having a stronger attraction between molecules results in more energy required to separate them, thus these molecules will have a higher boiling point than the rest of the molecules in their group.
When the plutonium bomb was tested in New Mexico in 1945, approximately 1 gram of matter was converted into energy. Suppose another bomb is tested, and 8.7 grams of matter are converted into energy. How many joules of energy are released by the explosion
Answer:
See explanation
Explanation:
Given Einstein's theory of relativity, we have that;
E= mc^2
m= mass of the substance
c= speed of light
For one gram of the substance,
E= 1 ×10^-3 × (3 × 10^8)^2
E = 9 × 10^13 J
For 8.7 g of matter;
E = 8.7 × 10^-3× (3 × 10^8)
E= 7.83 ×10^ 14 J
To conduct the synthesis of iodosalicylamide, Edward used 1.07 g of salicylamide (MW: 137.14 g/mol) and 1.68 g of sodium iodide (MW:149.89 g/mol). Assuming the reaction yield is 100%, how many grams of iodosalicylamide (MW:263.03 g/mol) would be formed
Answer:
2.05 g
Explanation:
Number of moles of salicylamide = 1.07g/137.14 g/mol = 0.0078 moles
Number of moles of NaI = 1.68 g/149.89 g/mol = 0.011 moles
Since the reaction is in a ratio of 1:1, salicylamide is the limiting reactant and 0.0078 moles of iodosalicylamide is formed.
Hence, theoretical yield of iodosalicylamide = 0.0078 moles × 263.03 g/mol = 2.05 g
Since there is 100% yield, actual yield = theoretical yield = 2.05 g
What is the concentration (M) of Ch3OH a solution prepared by dissolving of CH3OH sufficient water to give exactly 230 of solution?
Answer:
1.59 M
Explanation:
What is the concentration (M) of CH₃OH a solution prepared by dissolving 11.7 g of CH₃OH sufficient water to give exactly 230 mL of solution?
Step 1: Given data
Mass of CH₃OH: 11.7 gVolume of solution: 230 mL (0.230 L)Step 2: Calculate the moles corresponding to 11.7 g of CH₃OH
The molar mass of CH₃OH is 32.04 g/mol.
11.7 g × 1 mol/32.04 g = 0.365 mol
Step 3: Calculate the molarity of the solution
M = moles of solute / liters of solution
M = 0.365 mol / 0.230 L = 1.59 M
Name the following molecule
Answer:
It is a Biological Molecule
Aoagive reason fluorine is a gas iodine is a solid
Answer:
because electron molecule in floirine are tightly held to the nuclei dispersion force are relatively weak and in iodine they are strong
Write the separation scheme for the isolation of triphenylmethanol from the reaction mixture once the reaction is complete. The separation begins after the addition of HCl and water to the reaction and includes the column chromatography procedure to further purify crude triphenylmethanol isolated in the day 1 procedure.
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Categorize the following reaction as an acid-base neutralization, precipitation, combination, decomposition, combustion, displacement, or disproportionation reaction.
Ba(C2H3O2)2(aq) + Na2CO3(aq) → BaCO3(s) + 2 NaC2H3O2(aq)
Answer:
Precipitation
Explanation:
Let's consider the balanced chemical equation between barium acetate and sodium carbonate to form barium carbonate and sodium acetate.
Ba(C₂H₃O₂)₂(aq) + Na₂CO₃(aq) → BaCO₃(s) + 2 NaC₂H₃O₂(aq)
Both products and reactants are salts. But, among the products, barium carbonate is solid. This allows us to classify it as a precipitation reaction.
