Cesium- is radioactive and has a half life of years. Calculate the activity of a sample of cesium-. Give your answer in becquerels and in curies. Round your answer to significant digits.
The question is incomplete, the complete question is;
Cesium-137 is radioactive and has a half life of 30. years. Calculate the activity of a 6.8 mg sample of cesium-137. Give your answer in becquerels and in curies. Round your answer to 2 significant digits Bq Ci
Answer:
See explanation
Explanation:
The formula for activity is;
R= 0.693N/t1/2
N= 6.02 ×10^23 mol × 6.8 ×10^-3g/137 g/mol = 3 × 10^19
Substituting into the formula;
R= 0.693 × 3 × 10^19/30 years
R= 6.93 ×10^17 y^-1
In Bq;
6.93 ×10^17 y^-1 × 1.00y/3.16 ×10^7 seconds
= 2.19 ×10^10 Bq
In Ci;
2.19 ×10^10 Bq/3.7 ×10^10 Bq/Ci
= 0.59 Ci
A solution is made by mixing 34.5 g of sugar with 75.0 g of water. What is the mass percent of sugar in this solution?
Please explain and show work.
the mass percent of sugar in this solution is 46%.
Answer:
Solution given:
mass of solute=34.5g
mass of solvent=75g
mass percent=[tex]\frac{mass\:of\:solute}{mass\:of \:solvent}*100\%[/tex]
=[tex]\bold{\frac{34.5}{75.0}*100\%=46\%}[/tex]
We know that,
[tex]mass \: solute = \frac{mass \: of \: solute}{mass \: of \: solvent} [/tex]×100
[tex] \frac{34.5}{75.0} = 0.46[/tex]
hope it helps..
Calculate the numerical value of the equilibrium constant, Kc, for the reaction below if the equilibrium concentrations for CO, H2 , CH4 and H2O are 0.989 M, 0.993 M, 1.078 M and 0.878 M, respectively. (calculate your answer to three sig figs)
CO(g) + 3 H2(g) ⇌ CH4(g) + H2O(g)
Kc = [CH4]×[H2O] / [CO]×[H2]^3
Kc = 1.078×0.878 / (0.989×0.933^3)
Kc = 0.977
The numerical value of the equilibrium constant, Kc, for the given reaction is found to be 0.977.
What is Equilibrium constant?The Equilibrium constant may be defined as the numerical value that significantly indicated the correlation between the amounts of products and reactants present at equilibrium in a reversible chemical reaction at a definite temperature.
According to the question, the reaction is as follows:
[tex]CO +3H_2[/tex] ↔ [tex]CH_4+ H_2O[/tex].
The equilibrium concentrations are 0.989 M, 0.993 M, 1.078 M and 0.878 M, respectively.
Now, the equilibrium constant is calculated by the following formula:
Kc = [CH4]×[H2O] / [CO]×[tex][H_2]^3[/tex]= 1.078×0.878 / (0.989×0.93[tex]3^3[/tex]).
= 0.9464/(0.989 × 0.8121)
= 0.977.
Therefore, the numerical value of the equilibrium constant, Kc, for the given reaction is found to be 0.977.
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PLEASE HELP
iv. A total of 132.33g C3H8 is burned in 384.00 g O2. Use the following questions to determine the amounts of products formed.
• Determine if one of the reactants is a limiting reagent.
• How many grams of CO2 and H2O will be produced? (2 points)
b. If the furnace is not properly adjusted, the products of combustion can include other gases, such as CO and unburned hydrocarbons. If only 269.34 g of CO2 were formed in the above reaction, what would the percent yield be? (2 points)
Answer:
See explanation
Explanation:
The equation of the reaction is;
C3H8 + 5O2 ----> 3CO2 + 4H2O
Number of moles of C3H8 = 132.33g/44g/mol = 3 moles
1 mole of C3H8 yields 3 moles of CO2
3 moles of C3H8 yields 3 × 3/1 = 9 moles of CO2
Number of moles of oxygen = 384.00 g/32 g/mol = 12 moles
5 moles of oxygen yields 3 moles of CO2
12 moles of oxygen yields 12 × 3/5 = 7.2 moles of CO2
Hence C3H8 is the limiting reactant.
Mass of CO2 produced = 9 moles of CO2 × 44 g/mol = 396 g of CO2
1 moles of C3H8 yields 4 moles of water
3 moles of C3H8 yields 3 × 4/1 = 12 moles of water
Mass of water = 12 moles of water × 18 g/mol = 216 g of water
b) Actual yield = 269.34 g
Theoretical yield = 396 g
% yield = actual yield/theoretical yield × 100/1
% yield = 269.34 g /396 g × 100
% yield = 68%
Sodium acetate is produced by the reaction of baking soda and vinegar. The resultant solution is then heated until it becomes saturated and allowed to cool. As a result, the solution has become supercooled. Upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes. Its molar enthalpy of fusion is 35.9 kJ/mol. How much thermal energy would be released by 276.0 g of sodium acetate trihydrate (molar mass
Answer: The thermal energy that would be released by 276.0g of sodium acetate trihydrate is 71.8kJ.
Explanation:
Supercooling is the process of lowering the temperature a liquid below its freezing point, without it becoming solid. A liquid below its freezing point will crystallize in the presence of a seed crystal because it serves as a structure for formation of crystals. From the question,
The given mass of sodium acetate trihydrate
(CH3COONa.3H2O)= 276.0g
Molar mass of sodium acetate
trihydrate= 136.08g/mol
Thermal heat of fusion of sodium acetate
trihydrate = 35.9 kJ/mol
From the given mass the number of moles present= 276.0/ 136.08
= 2.0moles
Therefore the heat (thermal) energy of the given mass of sodium acetate
trihydrate = 2.0 × 35.9
= 71.8kJ
Therefore, upon addition of a small seed crystal, the solution temperature increases as sodium acetate trihydrate crystallizes.
A quantity of ideal gas requires 800 kJ to raise the temperature of the gas by 10.0 K when the gas is maintained at constant volume. The same quantity of gas requires 900 kJ to raise the temperature of the gas by 10.0 K when the gas is maintained at constant pressure. What is the adiabatic gas constant of this gas
Answer:
[tex]\gamma=1.125[/tex]
Explanation:
From the question we are told that:
Initial Heat [tex]Q_1=800kJ[/tex]
initial Temperature [tex]T_1=10.0K[/tex]
Final Heat [tex]Q_2=800kJ[/tex]
Final Temperature [tex]T_2=10.0K[/tex]
Generally the equation for Adiabatic constant is mathematically given by
[tex]\gamma=\frac{Cp}{Cv}[/tex]
Since
Equation for Heat [tex]dQ=nCdT[/tex]
Where
[tex]n_1=n_2\\\\T_1=T_2[/tex]
Therefore
[tex]Q_1=Cv\\\\Cv=800[/tex]
And
[tex]Cp=900[/tex]
Therefore
[tex]\gamma=\frac{900}{800}\\\\\gamma=\frac{9}{8}[/tex]
[tex]\gamma=1.125[/tex]
using the balanced equation below how many grams of lead(||) sulfate would be produced from the complete reaction of 23.6 g lead (|V) oxide
Answer:
59.8 g of PbSO₄.
Explanation:
The balanced equation for the reaction is given below:
Pb + PbO₂ + 2H₂SO₄ —> 2PbSO₄ + 2H₂O
Next, we shall determine the mass of PbO₂ that reacted and the mass of PbSO₄ produced from the balanced equation. This can be obtained as follow:
Molar mass of PbO₂ = 207 + (16×2)
= 207 + 32
= 239 g/mol
Mass of PbO₂ from the balanced equation = 1 × 239 = 239 g
Molar mass of PbSO₄ = 207 + 32 + (16×4)
= 207 + 32 + 64
= 303 g/mol
Mass of PbSO₄ from the balanced equation = 2 × 303 = 606 g
SUMMARY:
From the balanced equation above,
239 g of PbO₂ reacted to produce 606 g of PbSO₄.
Finally, we shall determine the mass of PbSO₄ that will be produced by the reaction of 23.6 g of PbO₂. This can be obtained as follow:
From the balanced equation above,
239 g of PbO₂ reacted to produce 606 g of PbSO₄.
Therefore, 23.6 g of PbO₂ will react to produce = (23.6 × 606) / 239 = 59.8 g of PbSO₄.
Thus, 59.8 g of PbSO₄ were obtained from the reaction.
I NEED A ANSWER FOR THIS QUESTION, ASAP
Write a balanced half-reaction for the oxidation of manganese ion (mn2 ) to solid manganese dioxide (mno2) in acidic aqueous solution. Be sure to add physical state symbols where appropriate.
Answer:
Mn2+(aq) + 2H2O(l) ⇒ MnO2(s) + 4H+(aq) + 2e-
Explanation:
Step 1: Data given
The oxidation number of manganese ion (Mn2+ ) is +2
The oxidation number of manganese dioxide is +(MnO2)4
This means the oxidation number from Mn will go from +2 to +4, since it's increased, this is an oxidation reaction
Mn2+(aq) ⇒ MnO2(s)
We have to balance both sides. Mn is already the same. But on the right side we have O atoms. T obalance both sides we have to add O atoms to the left side. This by adding 2x H2O
Mn2+(aq) + 2H2O(l) ⇒ MnO2(s)
Now the amount of O atoms is balanced, but we have H- atoms at the left side. To balance we have to add 4 H atoms to the right side
Mn2+(aq) + 2H2O(l) ⇒ MnO2(s) + 4H+(aq)
Now the amount of atoms is balanced at both sides. We also have to check if the charge on both sides is the same.
Since the left side has a charge of +2, and right has a charge of +4, we have to add 2 electrons to balance this.
Mn2+(aq) + 2H2O(l) ⇒ MnO2(s) + 4H+(aq) + 2e-
Dylan has a coworker who is always showing up late and then not finishing his work on time . It's frustrating the other members of the team . What can he do that might help the situation ? a ) Complain about the coworker to other team members b ) Ask his coworker if he understands his job responsibilities c ) Tell his boss that the coworker is slacking off d ) Complete his coworker's work for him
PLEASE HELP ASAP
A total of 132.33g C3H8 is burned in 384.00 g O2. Use the following questions to determine the amounts of products formed.
• How many grams of CO2 and H2O will be produced? (2 points)
b. If the furnace is not properly adjusted, the products of combustion can include other gases, such as CO and unburned hydrocarbons. If only 269.34 g of CO2 were formed in the above reaction, what would the percent yield be? (2 points)
Answer:
See explanation
Explanation:
We must first write the equation of the reaction as follows;
C3H8 + 5O2 ----> 3CO2 + 4H2O
Now;
We obtain the number of moles of C3H8 = 132.33g/44g/mol = 3 moles
So;
1 mole of C3H8 yields 3 moles of CO2
3 moles of C3H8 yields 3 × 3/1 = 9 moles of CO2
We obtain the number of moles of oxygen = 384.00 g/32 g/mol = 12 moles
So;
5 moles of oxygen yields 3 moles of CO2
12 moles of oxygen yields 12 × 3/5 = 7.2 moles of CO2
We can now decide on the limiting reactant to be C3H8
Therefore;
Mass of CO2 produced = 9 moles of CO2 × 44 g/mol = 396 g of CO2
Again;
1 moles of C3H8 yields 4 moles of water
3 moles of C3H8 yields 3 × 4/1 = 12 moles of water
Hence;
Mass of water = 12 moles of water × 18 g/mol = 216 g of water
In order to obtain the percentage yield from the reaction, we have;
b) Actual yield = 269.34 g
Theoretical yield = 396 g
Therefore;
% yield = actual yield/theoretical yield × 100/1
Substituting values
% yield = 269.34 g /396 g × 100
% yield = 68%
The number of organic compounds that have been reported in 2019 is more than 10 million. This is due to carbon's ability to bond to other carbon molecules, called
electron affinity.
ionic bonding.
catenation.
electronegativity.
Answer:
catenation
Explanation:
Carbon atoms have four electrons to share in bonding environments to get to the ideal octet. To do this, it bonds with other carbon molecules, called catenation. Catenation is the ability of an atom to bond and share electrons with other atoms of its kind.
Write the balanced equation for the hydration of CuSO4CuSO4. Indicate the physical states using the abbreviations (ss), (ll), or (gg) for solid, liquid, or gas, respectively. Use (aqaq) to indicate the aqueous phase. Indicate appropriate charges on negative and positive ions if they are formed.
Answer:
CuSO4(s) + 5H2O(l) ----> CuSO4.5H2O(s)
Explanation:
Hydration is the process by which anhydrous CuSO4 acquires molecules of water of crystalization to form the pentahydrate.
The water of crystalization becomes attached go the crystals of the CuSO4 to form the hydrated salt.
Beginning with solid anhydrous CuSO4 we have;
CuSO4(s) + 5H2O(l) ----> CuSO4.5H2O(s)
What trends were seen in medeleevs periodic table
Answer:
groups are based on how many electrons to become stable
Explanation:
I don’t know what Ksp and Kf are stand for?
Answer:
Sorry but I know only what ksf stand for
Explanation:
Ksf stand for solubility product constant
Answer:
ksp stands for solubility product constant .
kf stands for molal freezing point depression constant ..
Explanation:
KSP = The solubility product constant, Ksp, is the equilibrium constant for a solid substance dissolving in an aqueous solution. It represents the level at which a solute dissolves in solution. The more soluble a substance is, the higher the Ksp value it has .
KF = Kf is a constant for a given solvent. Kf is called the molal freezing point depression constant and represents how many degrees the freezing point of the solvent will change when 1.00 mole of a nonvolatile nonionizing (nondissociating) solute dissolves in one kilogram of solvent.
For each reaction, write the chemical formulae of the oxidized reactants.
a. ZnCl2 (aq) + 2Na(s) → Zn(s) + 2NaCl(aq)
b. Al(s) + FeBrz (aq) → AlBrz (aq) + Fe(s)
c. FeSO4 (aq) + Zn (s) → Fe(s) + ZnSO4(aq)
Answer:
a. Na(s); b. Al(s); c. Zn(s)
Explanation:
Let's consider the following redox reactions.
a. ZnCl₂ (aq) + 2 Na(s) → Zn(s) + 2 NaCl(aq)
Na is oxidized because its oxidation number increases from 0 to +1 (in NaCl) whereas Zn is reduced because its oxidation number decreases from 2+ (in ZnCl₂) to 0.
b. Al(s) + FeBr₃ (aq) → AlBr₃ (aq) + Fe(s)
Al is oxidized because its oxidation number increases from 0 to +3 (in AlBr₃) whereas Fe is reduced because its oxidation number decreases from 3+ (in FeBr₃) to 0.
c. FeSO₄ (aq) + Zn(s) → Fe(s) + ZnSO₄(aq)
Zn is oxidized because its oxidation number increases from 0 to +2 (in ZnSO₄) whereas Fe is reduced because its oxidation number decreases from 2+ (in FeSO₄) to 0.
Could someone please help me out???
Answer:
Time is 2.2 seconds.
Explanation:
Time:
[tex]{ \boxed{ \bf{time = \frac{distance}{speed} }}}[/tex]
Substitute into the formula:
speed = 715 km/h = 198.61 m/s
[tex]{ \tt{time = \frac{435}{198.61} }} \\ { \tt{time = 2.2 \: seconds}}[/tex]
Oxygen and hydrogen are compressed into two cubical boxes of the same
size at a temperature of 28 K. What do these gases have in common
according to the kinetic theory?
Explanation:
Following are the kinetic theory of gases postulates:
1) Space-volume to molecules ratio is negligible.
2)There is no force of attraction between the molecules at normal temperature and pressure. The force of attraction between the molecules build when the temperature decreases and the pressure increases.
3) There is large space between the molecules resulting in continuous motion.
4) The free movement of molecules results in collision which is perfectly elastic.
5) The molecules have kinetic energy due to random movement. But the average kinetic energy of these molecules differs with temperature.
6) Molecules exert pressure on the walls of the container.
How many electrons will one atom of element with 6 protons and 9 neutrons .
Answer:
The atomic mass of this element would be 12 amu
Explanation:
The subatomic particles provide several bits of information about a given element.
The number of protons is equal to the atomic number of the element. For this element having 6 protons makes the atomic number 6 and makes the element Carbon.
The number of protons plus the number of neutrons equals the atomic mass of the element based upon atomic mass units (amus)
For this element 6 protons and 6 neutrons combine to make an atomic mass of 12 amus.
Lastly, the values of protons and electrons tell whether the atom is an ion or neutral. When protons equal electrons the atom is neutral. When protons are greater than neutrons the atom is a positive charge or cation. When the protons are less than the electrons the atom is a negative charge or anion. For this example the Carbon atom has 6 protons and 6 electrons making it neutral.
Chlorine radicals perform the first propagation step:
a. in comparison to bromine radicals.
b. radicals form easily in the presence of chlorine radicals.
c. Subsequently, the resulting radicals can react with bromine in a second propagation step to yield monobrominated products.
Answer:
b. radicals form easily in the presence of chlorine radicals.
Explanation:
Chlorine radicals perform the first propagation step: because "radicals form easily in the presence of chlorine radicals."
This is because the first propagation step consumes a CHLORINE RADICAL while the second propagation step regenerates a CHLORINE RADICAL. In this way, a chain reaction occurs, whereby one CHLORINE RADICAL can ultimately cause thousands of molecules of methane to be converted into chloromethane with C12 present.
Hence, in this case, the correct answer is that "radicals form easily in the presence of chlorine radicals."
5.32 picometers is the same as
A.5.32 x 10^-12 meters
B.5.32 x 10^12 meters
C.5.32 x 10^9 meters
D.5.32 x 10^2 meters
What information does the first quantum number of an electron give?
A. The sublevel that the electron is in
B. The specific orbital the electron is in
C. The energy level the electron is in
D. The spin that the specific electron has
Answer:
с
Explanation:
the first quantum number of an electron gives the information about the energy level the electron is in
The information first quantum number of an electron give is the energy level the electron is in.
What are quantum numbers?Quantum numbers is a set of symbols which gives idea about the position of electron present inside an atom.
First quantum number is denoted by symbol 'n' which gives idea about the number of shell or energy level in which electron is present.The sublevel that the electron is in is the second quantum number denoted by symbol 'l'.The specific orbital in which electron is present is denoted by symbol 'm' and it is the third quantum number.The spin that the specific electron has is the forth quantum number and denoted by symbol 's'.Hence first quantum number of electron gives ideal about the energy level.
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Evaluate the validity of the following statement: Spontaneous processes are ones that occur quickly and have a low activation energy. A) False. Spontaneous processes always require an input of energy to overcome the activation energy, but always react quickly. B) False. Spontaneous processes can occur slowly, but always have a low activation energy. C) False. Spontaneous reactions can react slowly and can have a high activation energy. D) False. Spontaneous processes always react slowly and always have a high activation energy. E) True.
Answer:
Spontaneous processes are ones that occur quickly and have a low activation energy. - False -
Spontaneous processes always require an input of energy to overcome the activation energy, but always react quickly - False
Spontaneous processes can occur slowly, but always have a low activation- false
Spontaneous reactions can react slowly and can have a high activation energy - True
Spontaneous processes always react slowly and always have a high activation energy- False
Explanation:
A spontaneous reaction is reaction that proceeds on its own without us having to do a thing at all!
A spontaneous reaction may be fast or slow depending on the activation energy of the reaction. A spontaneous reaction having a high activation energy will be slow. However, if the spontaneous reaction has a low activation energy then it will be fast.
We have to note here that a spontaneous reaction proceeds without a prolonged input energy. Sometimes energy may be supplied to the reaction at the beginning for instance in the case of the combustion of hydrocarbons.
So, spontaneous processes are not necessarily fast. Some of them may have a very high activation energy such as in the rusting of iron hence they are slow.
The decomposition of ammonia is: 2 NH3(g) ⇌ N2(g) + 3 H2(g). If Kp is 1.5 × 103 at 400°C, what is the partial pressure of ammonia at equilibrium when N2 is 0.20 atm and H2 is 0.15 atm?
Answer:
"[tex]6.7\times 10^{-4} \ atm[/tex]" is the right answer.
Explanation:
Given:
Partial pressure of [tex]N_2[/tex],
= 0.20 atm
Partial pressure of [tex]H_2[/tex],
= 0.15 atm
[tex]K_p = 1.5\times 10^3[/tex] at [tex]400^{\circ} C[/tex]
As we know,
⇒ [tex]K_p = \frac{pN_2\times pH_2^3}{pNH_3^2}[/tex]
By putting the values, we get
[tex]1.5\times 10^3=\frac{0.20\times (0.15)^3}{pNH_3^2}[/tex]
[tex]pNH_3^2 = \frac{0.000675}{1.5\times 10^3}[/tex]
[tex]=6.7\times 10^{-4} \ atm[/tex]
In the reoxidation of QH2 by purified ubiquinone-cytochrome c reductase (Complex III) from heart muscle, the overall stoichiometry of the reaction requires 2 mol of cytochrome c per mole of QH2 because:
Answer: Options related to your question is missing below are the missing options
a. cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor.
b. cytochrome c is a two-electron acceptor, whereas QH2 is a one-electron donor.
c. cytochrome c is water soluble and operates between the inner and outer mitochondrial membranes
d. heart muscle has a high rate of oxidative metabolism, and therefore requires twice as much cytochrome c as QH2 for electron transfer to proceed normally.
e. two molecules of cytochrome c must first combine physically before they are catalytically active.
answer:
cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor. ( A )
Explanation:
The overall stoichiometry of the reaction requires 2 mol of cytochrome per mole of QH2 because a cytochrome is simply a one-electron acceptor while QH2 is not a one-electron donor ( i.e. it is a two-electron donor )
An electron donor in a reaction is considered a reducing agent because it donates its electrons to another compound thereby self oxidizing itself in the process.
A 13.4 mL sample of CO2 gas was collected in an experiment.
What is this volume in liters (L)? Use significant figures, do NOT include the units.
Explanation:
here's the answer to your question
When water reaches the metastable state, the phase of water will be?
Answer:
water, when the metastable state is reached, is cooled below the zero temperature. It freezes abruptly. this is called metastable. They are not at equilibrium per se; as at negative temperatures the only equilibrium state of water is ice.
Explanation:
Identify the compound that possesses a permanent dipole. Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices acetone, (CH3)2CO cyclohexane, C6H12 pentane, C5H12 methane, CH4.
Answer:
acetone, (CH3)2CO cyclohexane are the compound that possesses a permanent dipole
Explanation:
Permanent dipole describes the partial charge separation that can occur within a molecule along with the bond dat form between 2 different atoms
What type of oxide is each of the following? NO2, CO, Fe2O3, Al2O3, P20,
Nitrogen Dioxide
Carbon Monoxide
Iron (II) Oxide
Aluminum Oxide
DiPhosphorus Monoxide
crassify the given quantities into scalar quantity and vetor quantity
Answer:
where is the quantities?