Answer:
6.05%
Explanation:
From the question given above, the following data were obtained:
Decay constant (K) = 0.0561 /yr
Time (t) = 50 years
We can obtain the percentage of tritium remaining after 50 years by using the following formula:
Log (N₀/N) = kt /2.303
NOTE:
N₀ is the original amount.
N is the amount remaining.
K is the decay constant.
t is the time
Log (N₀/N) = (0.0561 × 50) /2.303
Log (N₀/N) = 2.805/2.303
Log (N₀/N) = 1.218
Take the anti log of 1.218
(N₀/N) = anti log (1.218)
(N₀/N) = 1.218
N₀/N = 16.52
Invert and multiply by 100 to obtain the percentage.
N/N₀ = 1/16.52 × 100
N/N₀ = 6.05%
Thus, the percentage of tritium remaining after 50 years is 6.05%
Answer:
6.08% remains after 50 years
Explanation:
The radioactive decay follows the equation:
Ln[A] = -kt + Ln [A]₀
Where [A] is concentration of reactant after time t, [A]₀ is its initial concentration, k is rate constant and t is time.
Assuming its Initial concentration is 100%
Time is 50 yr
k is 0.056 yr⁻¹
And [A] is our incognite
Ln[A] = -0.056 yr⁻¹*50yr + Ln [100%]
ln[A] = 1.805
[A] =
6.08% remains after 50 years
The balanced equation for the combustion of Hydrogen is:
2 H2 + O2 → 2H2O
How many moles of H2O will be formed from the complete reaction of 0.750 moles of O2?
0.375 mol
1.50 mol
2.67 mol
0.750 mol
Answer:
1.5 moles H₂O
General Formulas and Concepts:
Chemistry - Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
RxN: 2H₂ + O₂ → 2H₂O
Given: 0.750 moles O₂
Step 2: Stoich
[tex]0.750 \ mol \ O_2(\frac{2 \ mol \ H_2O}{1 \ mol \ O_2} )[/tex] = 1.5 moles H₂O
Step 3: Check
We are given 3 sig figs.
Since our answer is 2 sig figs, we don't need to round.
Suppose the Cu ions are produced by the reaction of 0.94 g of copper turnings with excess nitric acid. How many moles of Cu are produced?
Answer:
0.0148 moles
Explanation:
Solid copper is oxidized with HNO₃:
Cu + 4HNO₃ → Cu²⁺ + 2 NO₃⁻ + 2H₂O + 2NO₂
Where 1 mole of Cu produce 1 mole of Cu²⁺ when nitric acid is in excess.
Moles of Cu that react (Molar mass Cu = 63.546g/mol):
0.94g * (1mol / 63.546g) = 0.0148 moles of Cu
And moles of Cu²⁺ produced are also:
0.0148 molesCalculate the volume in milliliters of 1.57 M potassium hydroxide that contains 10.3 g of solute.
Answer:
[tex]V = 0.117 \ L[/tex]
General Formulas and Concepts:
Chem
Reading a Periodic TableWriting compounds and polyatomic ionsMolarity = moles of solute / liters of solutionExplanation:
Step 1: Define
1.57 M KOH (potassium hydroxide)
10.3 g KOH
Step 2: Define conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol
Step 3: Convert
[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH
Step 4: Solve for Volume
Substitute: [tex]1.57 \ M=\frac{0.183568 \ mol}{x \ L}[/tex]Move x: [tex]x1.57 \ M=0.183568 \ mol[/tex]Isolate x: [tex]x=\frac{0.183568 \ mol}{1.57 \ M}[/tex]Evaluate: [tex]x=0.116922 \ L[/tex]Step 5: Check
We are given 3 sig figs. Follow sig fig rules.
[tex]0.116922 \ L \approx 0.117 \ L[/tex]
Calculate the root mean square (rms) average speed of the atoms in a sample of krypton gas at 0.14 atm and -16 0C.
Answer:
8.52 m/s
Explanation:
Step 1: Given data
Molar mass of krypton (M): 83.80 g/molPressure of the sample (P): 0.14 atmTemperature of the sample (T): -16 °CStep 2: Convert "T" to the Kelvin scale
When working with gases, we need to consider the absolute temperature. We will convert from Celsius to Kelvin using the following expression.
K = °C + 273.15 = -16 + 273.15 = 257 K
Step 3: Calculate the root mean square speed of the gas
The root mean square speed measures the average speed of particles in a gas. We will calculate it using the following expression.
[tex]v_{rms} = \sqrt{\frac{3 \times R \times T}{M} } = \sqrt{\frac{3 \times 8.314 J/mol.K \times 257 K}{88.30 g/mol} } = 8.52 m/s[/tex]
Chem Muti Choice. Tell me the correct answer.
Answer:
my gues is red not a 100% but its in the 700s
Explanation:
Calculate the following quantity: volume of 1.58 M calcium chloride that must be diluted with water
to prepare 994 mL of a 6.20 x 10^-2 M chloride ion solution.
100. g of ice at 0 is added to 300.0 g of water at 60C. Assuming no transfer of heat to
the surroundings, what is the temperature of the liquid water after all the ice has
melted?
The final temperature of the liquid water after all the ice has melted is equal to 25°C.
What is the specific heat capacity?The specific heat capacity can be described as the quantity of heat needed to raise the temperature in one unit (1kg) of substance by one-degree Celcius.
The formula to show the relationship between the specific heat capacity and heat absorbed or lost is:
Q = mCΔT
Given, the amount of ice, m = 100g
The amount of water, M = 300g
The specific heat capacity of the water, C = 1 cal /g°C
The heat of fusion of ice, C = 80 cal/g
Heat given by water = Heat taken by ice + Heat taken by water formed from ice
300 × 1 ×(60 - T) = 100 × 80 + 100 × 1 ×T
18000 - 300 T = 8000 + 100 T
400 T = 10000
T = 25°C
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I have 2 samples of solid chalk (aka calcium carbonate). Sample A has a total mass of 4.12 g and Sample B has a total mass of 19.37 g. What is the difference between the samples?
A) Sample B has more calcium carbonate molecules
B) Sample B has a larger ratio of carbon, oxygen, and calcium atoms
C) Sample B has more calcium ion than carbonate ions
D) Sample B must have some impurity
Answer:
A) Sample B has more calcium carbonate molecules
Explanation:
M = Molar mass of calcium carbonate = 100.0869 g/mol
[tex]N_A[/tex] = Avogadro's number = [tex]6.022\times 10^{23}\ \text{mol}^{-1}[/tex]
For the 4.12 g sample
Moles of a substance is given by
[tex]n=\dfrac{m}{M}\\\Rightarrow n=\dfrac{4.12}{100.0869}\\\Rightarrow n=0.0411\ \text{mol}[/tex]
Number of molecules is given by
[tex]nN_A=0.0411\times 6.022\times 10^{23}=2.48\times 10^{22}\ \text{molecules}[/tex]
For the 19.37 g sample
[tex]n=\dfrac{19.37}{100.0869}\\\Rightarrow n=0.193\ \text{mol}[/tex]
Number of molecules is given by
[tex]nN_A=0.193\times 6.022\times 10^{23}=1.16\times 10^{23}\ \text{molecules}[/tex]
[tex]1.16\times 10^{23}\ \text{molecules}>2.48\times 10^{22}\ \text{molecules}[/tex]
So, sample B has more calcium carbonate molecules.
The ratio of the elements of carbon, oxygen, calcium atoms, ions, has to be same in both the samples otherwise the samples cannot be considered as calcium carbonate. Same is applicable for impurities. If there are impurites then the sample cannot be considered as calcium carbonate.
Which compound most likely has Atoms Held together by ionic bonds?
A. Magnesium sulfide, MgS
B. Hydrogen peroxide, H2O2
C. Ammonia, NH3
D. Carbon monoxide, CO
Answer:
MgS Magnesium sulfide
Calculate Kb for a 0.1 M solution of cyanide ion, given that Ka for hydrocyanic acid is 6.2 x 10â10.a) 8.4 x 10â9b) 7.87 x 10â3c) 1.34 x 10â3d) 1.8 x 105e) 7.87 x 10â6f) 1.61 x 10â5g) 7.4 x 10â8
Answer:
Kb = 1.6 × 10⁻⁵
Explanation:
Step 1: Given data
Acid dissociation constant of hydrocyanic acid (Ka): 6.2 × 10⁻¹⁰
Concentration of cyanide ion (Cb): 0.1 M
Step 2: Calculate the basic dissociation constant (Kb) of cyanide ion
We have the Ka of HCN. We can calculate the Kb of its conjugate base using the following expression.
Ka × Kb = Kw = 1.0 × 10⁻¹⁴
Kb = 1.0 × 10⁻¹⁴/Ka
Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰
Kb = 1.6 × 10⁻⁵
The Kb for a 0.1 M solution of cyanide ion is :
- 1.6 × 10⁻⁵
Base dissociation constantGiven:
Acid dissociation constant of hydrocyanic acid (Ka)= 6.2 × 10⁻¹⁰
Concentration of cyanide ion (Cb)= 0.1 M
Base dissociation constant (kb)=?
Ka × Kb = Kw = 1.0 × 10⁻¹⁴
Kb = 1.0 × 10⁻¹⁴/Ka
Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰
Kb = 1.6 × 10⁻⁵
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fireworks convert chemical energy into what kind of energy
Answer:
Kinetic energy
Explanation:
Fireworks convert chemical energy into kinetic energy to send them flying upward. Hope it is correct!
Calculate the concentration (M) of arsenic acid (H3AsO4) in a solution if 25.00 mL of that solution required 35.21 mL of 0.1894 M KOH for neutralization.
Answer:
[tex]M_{acid}=0.08892M[/tex]
Explanation:
Hello!
In this case, since the reaction between arsenic acid and potassium hydroxide is:
[tex]H_3AsO_4+3KOH\rightarrow K_3AsO_4+3H_2O[/tex]
Thus, since the mole ratio between the acid and the base is 1:3, at the equivalence point we can write:
[tex]3n_{acid}=n_{base}[/tex]
That in terms of molarities and volumes is:
[tex]3M_{acid}V_{acid}=M_{base}V_{base}[/tex]
Thus, the concentration of the arsenic acid is:
[tex]M_{acid}=\frac{M_{base}V_{base}}{3V_{acid}}=\frac{0.1894M*35.21mL}{3*25.00mL} \\\\M_{acid}=0.08892M[/tex]
Best regards!
The concentration (M) of arsenic acid in a solution of 25.00 mL is 0.088M.
How we calculate the molarity?Molarity of any solution will be calculated as:
M = n/V, where
V = volume
n is the moles and it will be calculated as:
n = W/M, where
W = given mass
M = molar mass
Given chemical reaction is:
H₃AsO₄ + 3KOH → K₃AsO₄ + 3H₂O
Moles of 35.21 mL of 0.1894 M KOH will be calculated as:
n = (0.1894)(0.035) = 0.0066 moles
From the stoichiometry of the reaction it is clear that:
1 mole of H₃AsO₄ = react with 3 moles of KOH
0.0066 moles of KOH = react with 1/3×0.0066= 0.0022 moles of H₃AsO₄
Now we calculate the molarity of H₃AsO₄ in 25mL of solution as:
M = 0.0022/0.025 = 0.088 M
Hence, required molarity is 0.088 M.
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How many valence electrons are found in P3- ?
Answer:
5 valence elctrons
Explanation:
the outer most orbitals, 3s2 and 3p3 contains 5 electrons, thus valences electrons for P is 5
Which of the following are fair conductors and are always solid at room temperature?
1.Metals
2.Nonmetals
3.Metalloids
4.Ions
Answer:
Metalloids and ions
Explanation:
Mercury is not solid at room temperature. (Metals)
Many nonmetals aren't good at conducting electricity. Oxygen for example. (Nonmetals)
Metalloids are always solid at room temp and are fair conductors. (Metalloids)
Ions are same as metalloids. (Ions)
PLS GIVE BRAINLIEST
A student performs an experiment in which 5.0 g of potassium chloride, KCI, are dissolved into 100.0 mL of distilled water. The student records the
temperature both before and after dissolving the KCl into the water, as shown in the data table below. Use this data to answer the question that follows.
Initial Temperature, °C Final Temperature, °C
21.8°C
16.4°C
Which statement below is a correct conclusion based on these results ?
The temperature of the water decreases and so the reaction is exothermic
The temperature of the water increases and so the reaction is exothermic
The temperature of the water decreases and so the reaction is endothermic
The temperature of the water increases and so the reaction is endothermic
Answer:
The temperature of the water decreases and so the reaction is endothermic
Explanation:
This option is correct because when the 5.0g potassium chloride (KCl) was added to the 100.0ml distilled water, the KCl made the water absorb heat coming from it which made the water decrease in temperature thereby causing an endothermic reaction.
An endothermic reaction actually takes place when the temperature of a system which is isolated decreases. The surroundings of a non-isolated system actually gains heat. While in an exothermic reaction, the temperature of a system increases due to the release or evolution of heat. This heat is released into the surroundings.
Which lists the elements in order from least conductive to most conductive?
Answer:
Answer. Answer: Nitrogen (N), antimony (Sb), bismuth (Bi) is the order from least conductive to most conductive.
Answer:
nitrogen (N), antimony (Sb), bismuth (Bi)
If you start with 34.0 grams of silver (I) nitrate, how many grams of solid silver would be
produced?
Answer:
6.36 g AgCl
Hope this helps!
What is the mass of the oxygen in one mole of calcium phosphate
Answer:
16.00 g/mol
Explanation:
Answer:
16.00 g/mol
Explination:
1 mol of calcium phosphate contains 8 moles of oxygen. From this, we can compute for the amount of oxygen in grams using the molar mass of oxygen, which is 16.00 g/mol.
Calculate the molarity of a solution that contains 183.51 grams of lead (II) bromide in 500.0 mL of the solution
Answer: 1M
Explanation:
Molarity = mols/L
moles of lead bromide: 183.51/ 367.0 = 0.5 mol
500 ml/ 1000 mL = .5L
.5 mol / .5 L = 1 mol/L = 1M
the average kinetic energy of the gas molecule is greatest in which container
Answer:
Explanation:
average kinetic energy of a gas molecule really only depends on the temperature, so which ever container is at the highest temperature is the answer
In comparison to other fundamental states of matter, plasma has the highest kinetic energy. This is due to the fact that particles in a plasma travel more quickly than those in a corresponding solid, liquid, or gas.
What is kinetic energy ?
The energy that an object has as a result of motion is known as kinetic energy. It is described as the effort required to move a mass-determined body from rest to the indicated velocity. The body holds onto the kinetic energy it acquired during its acceleration until its speed changes.
The reason why molecules in gases have the largest kinetic energy is because they have more space between one another, experience less intermolecular force, and travel at a faster rate, which results in higher energy.
The temperature has a direct impact on the average kinetic energy of the particles inside a container.
Thus, In comparison to other fundamental states of matter, plasma has the highest kinetic energy.
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raw material for fusion
Answer:
Deuterium and Lithium.
Explanation:
I searched it up on google.
An igneous intrusion show that a magma body emerged in a stratigraphic section. This magma body is _____ than the rocks around it.
A) older
B) the same age
C) newer
Answer:
Younger/newer
Explanation:
Stratagraphic means an intrusion or fault is younger than the layer it affects.
PLZ HELP ME NO WRONG ANSWERS
Answer:
okay I will help you just message me johnpatrick on messenger
How many neutrons does the isotope of hydrogen called
deuterium have?
a. four
b. three
C. one
d. two
What is the mole fraction of water in a solution that contains 8.0 mol of ethanol (C2H5OH) and 1.6 mol of water?
Answer:
the mole fraction of water in a solution is 0.17
Explanation:
The computation of the mole fraction of water in a solution is shown below:
Given that
Ethanol be 8.0 mol
And, the water be 1.6 mol
Based on the above information, the mole fraction of water in a solution is
= Water ÷ (Water + ethanol)
= 1.6 mol ÷ (1.6 mol + 8.0 mol)
= 1.6 mol ÷ 9.6 mol
= 0.17
Hence, the mole fraction of water in a solution is 0.17
Washing machines use a large amount of water. A student suggested that old pairs of stained jeans which have to be washed more frequently should be replaced by new pairs of jeans to conserve water. Which of these statements best describes the suggestion made by the student? Question 9 options: It is not practical because an old pair of jeans needs less water to be washed than a new pair of jeans. It is practical because a huge amount of water can be conserved by this method. It is practical because it is easy to implement. It is not practical because it takes a huge amount of water to produce a new pair of jeans.
Answer:
C |||| It is not practical because it takes a huge amount of water to produce a new pair of jeans
Explanation:
If you're doing flvs then it's C.
Answer:
C!
Explanation:
i got it right on the test UwU
How many grams of CO2 are produced by the combustion of 344 g of a mixture that is 33.6% CH4 and 66.4% C3H8 by mass
Answer:
1,002.936 g
Explanation:
The combustion equation of each will be;
CH4 + 2O2 = CO2 + H2O
C3H8 + 5O2 = 3CO2 + 4H2O
We are told the mixture is 344g.
Thus;
For CH4 combustion;
Amount of CH4 = 0.336 × 344 = 115.584g
Molar mass of CH4 is 16 g/mol
Number of moles of CH4 is;
n = 115.584g/(16 g/mol)
n = 7.224 moles
n(CO2) = n(CH4) = 7.224 moles
For C3H8 combustion;
Amount of C3H8 = 0.664 × 344 = 228.416 g
Molar mass of C3H8 = 44 g/mol
Thus;
Number of moles of C3H8 = 228.416 g/(44 g/mol) = 5.19 mol
n(CO2) = 3n(C3H8) = 3 × 5.19 = 15.57 moles
Total moles of CO2 = 7.224 moles + 15.57 moles = 22.794 mol
Molar mass of CO2 = 44 g/mol
Thus amount of CO2 by mass = 22.794 mol × 44 g/mol = 1,002.936 g
At equilibrium, the value of [H ] in a 0.240M solution of an unknown acid is 0.00417M . Determine the degree of ionization and the Ka of this acid.
Answer:
[tex]ionization=1.74\%[/tex]
Explanation:
Hello!
In this case, since the degree of ionization of an acid is computed in terms of the concentration of hydrogen ions and the initial concentration of the acid:
[tex]ionization=\frac{[H^+]}{[HA]} *100\%[/tex]
Because the ionization reaction is represented by:
[tex]HA\rightleftharpoons H^++A^-[/tex]
Therefore, the degree or percent ionization turns out:
[tex]ionization=\frac{0.00417M}{0.240M} *100\%\\\\ionization=1.74\%[/tex]
Best regards!
according to the conveyor belt mode of ocean circulation, what happens when water reaches the poles
Answer: Some salt is trapped between ice crystals, but most are left behind in the unfrozen seawater.
Explanation:
Answer: The salinity of the water increases
Explanation: Hope this helps!
A sample of neon gas occupies 5.5 liters at 20°C and 650 mmHg. What is the expected volume of the gas at S.T.P.
Answer:
V₂ = 4.4 L
Explanation:
Given data:
Initial volume = 5.5 L
Initial pressure = 650 mmHg (650/760 =0.86 atm)
Initial temperature = 20 °C (20 +273 = 293 K)
Final temperature = 273 K
Final volume = ?
Final pressure = 1 atm
Solution:
Formula:
P₁V₁/T₁ = P₂V₂/T₂
V₂ = P₁V₁T₂/T₁ P₂
V₂ = 0.86 atm× 5.5 L × 273 K / 293 k × 1 atm
V₂ = 1291.29 atm.K.L / 293 k.atm
V₂ = 4.4 L