Answer:
The correct answer is - A. 12.5 gram.
Explanation:
Given:
The initial amount of sample = 400 gram
the half-life cycle = 3 days
after 15 days remain value = ?
Solution:
The number of half-lives in 15 days = 15/3
= 5 half-lives
the remaining amount of sample after one half-life 3 days = 400/2 = 200
the remaining amount of sample after 2nd half-life or 6 days= 200/2 = 100
the remaining amount of sample after 3rd half-life or 9 days= 100/2 = 50
the remaining amount of sample after 4th half-life or 12 days= 50/2 = 25
the remaining amount of sample after 5th half-life or 15 days= 25/2 = 12.5 gram
Thus, the correct answer is = 12.5 g.
One way to remove the pollutant nitrogen monoxide, NO, from mobile diesel exhaust is by reacting it with ammonia, NH, as seen in the balanced reaction below. What mass, in grams, of NH, is required to remove 57.0 grams of NO from the air? 4 NH3 + 6 NO → 5 N, + 6H2O
Answer:
[tex]m_{NH_3}=21.6gNH_3[/tex]
Explanation:
Hello there!
In this case, in agreement to the given chemical reaction, it is possible for us to calculate the mass of NH3 required to remove 57.0 g NO via the stoichiometry based off the 4:6 mole ratio between them:
[tex]m_{NH_3}=57.0g NO*\frac{1molNO}{30.01gNO}*\frac{4molNH_3}{6molNO} *\frac{17.03gNH_3}{1molNH_3} \\\\m_{NH_3}=21.6gNH_3[/tex]
Best regards!
A metal forms two oxides X and Y when contains 28.9% and 21.0% oxygen respectively.
a) calculate the ratio by mass of metal in the two oxides
b) what chemical law does it illustrate
Please help no Link please
If I had 3.50 x 10 24molecules of Cl2 gas, how many grams is this?
Answer:
412 g Cl₂
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 3.50 × 10²⁴ molecules Cl₂
[Solve] grams Cl₂
Step 2: Identify Conversions
Avogadro's Number
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of Cl₂ - 2(35.45) = 70.9 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 3.50 \cdot 10^{24} \ molecules \ Cl_2(\frac{1 \ mol \ Cl_2}{6.022 \cdot 10^{23} \ molecules \ Cl_2})(\frac{70.9 \ g \ Cl_2}{1 \ mol \ Cl_2})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 412.072 \ g \ Cl_2[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
412.072 g Cl₂ ≈ 412 g Cl₂
Which of the following factors would affect weather?
When warm air meets cool air, the warm air rises, cools off, and falls as rain.
Air moves as wind from an area of high pressure to an area of low pressure.
Air stays awhile over a surface area with uniform humidity and temperature.
All of the above
Answer: Hewo, there!
All of the above wold be my answer
Explanation:
Although many factors combine to influence weather, the four main ones are solar radiation, the amount of which changes with Earth's tilt, orbital distance from the sun and latitude, temperature, air pressure and the abundance of water.
Hope this helps you!!
Have a great day
What happens to the entropy when a solution is made?
A. The entropy increases.
B. The entropy decreases.
C. The entropy goes to zero.
D. The entropy is unaffected.
Answer:
The entropy increases
Explanation:
Just took the quiz
Which of the following is the weakest of the intermolecular forces?
A.Hydrogen bonds
B. Dipole-dipole interactions
C. Dipole-hydrogen interactions
D. London dispersion force
Answer:c
Explanation:yes
Thorium-236 has a half life of 10.0 minutes. If I have 250 grams of Thorium-236, How many half lives will have taken place after 50.0 minutes?
from your findings what conclusions and recommendations can you make on the issue of human rights violations to Government and communities
Explanation:
Recommendations:
1.To make strict rules and regulations against those who violates rights
2.To mobilize police actively to stop such incidents
3.To raise public awareness to prevent human rights violation
Which of the following has the largest mass of carbon per gram?
H₂CO₃
CH₃CO₂H
CH₃OH
CH₃CH₂OH
Answer:
ch3
Explanation:
If 1.00 g of KCl is completely dissolved in 24.5 g of water, what is the percent composition (by mass) of the solution that is formed?
Answer:
3.92%
Explanation:
The solution that is formed is of KCl in water. This means that the percent composition by mass is given by the formula:
Mass of KCl / Mass of Solution * 100%We now calculate the mass of solution:
Mass of Solution = Mass of KCl + Mass of Water = 1.00 g + 24.5 gMass of Solution = 25.5 gFinally we calculate the percent composition:
1.00 g / 25.5 g * 100% = 3.92%Which gland would most likely have an issue with maintaining the breakdown of food?
the thyroid
the thymus
the pancreas
the ovaries
Answer:
OKAY EVERYONE STOP SAYING PANCREAS THATS WRONG
Explanation:
It is actually thyroid
What is the mass of 4.76 moles of Na3Po4?
SHOW WORK PLEASE - NO LINKS OR FILES(I will not open them)
( btw if your user is Alexgrelli do not answer , I have already reported your account )
Answer:
780 g
Explanation:
Step 1: Given data
Moles of sodium phosphate: 4.76 moles
Step 2: Calculate the mass corresponding to 4.76 moles of sodium phosphate
To convert moles to mass, we need a conversion factor. In this case, we will use the molar mass of sodium phosphate, which is 163.94 g/mol.
4.76 mol × 163.94 g/mol = 780 g
In the oxidation of ethane: 2 C2H6 + 7 02 → 4 CO2 + 6 H2O how many
liters of O2 are required to react with 90 grams of ethane?
Answer:
10.5 L of O₂.
Explanation:
We'll begin by calculating the number of mole in 90 g of C₂H₆. This can be obtained as follow:
Molar mass of C₂H₆ = (12×2) + (6×1)
= 24 + 6
= 30 g/mol
Mass of C₂H₆ = 90 g
Mole of C₂H₆ =?
Mole = mass / molar mass
Mole of C₂H₆ = 90 / 30
Mole of C₂H₆ = 3 moles.
Finally, we shall determine the volume of O₂ required. This is illustrated:
2C₂H₆ + 7O₂ —> 4CO₂ + 6H₂O
From the balanced equation above, we can say that:
2 L of C₂H₆ required 7 L of O₂.
Therefore, 3 L of C₂H₆ will require
= (3 × 7)/ 2 = 10.5 L of O₂.
Thus, 10.5 L of O₂ is required for the reaction.
What is the correct definition of temperature
Answer:
i'm pretty sure its the last answer and if not its the 2nd one
Jerry is trying to classify cells by their physical characteristics. He discovers a multicellular organism containing cells that have a nucleus and a cell wall as well as the ability to conduct photosynthesis. Into which of the three domains would this organism most likely fit? A. Archaea B. bacteria C. Eukarya D. Viral
Domains eukarya would this organism most likely fit.
The domain eukarya comprised of eukaryotes or organisms whose cells contain true nucleus.
What is a domain?It is the largest of all groups in the classification of life. There are three domains:-
Archaea domainBacteria domainEukarya domainWhat is Eukarya?It is the domain of organism called eukaryotes. These are the organism who have a well defined nucleus and membrane bound organelles.
Hence, C) option is correct.
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Using your freshly made 5M stock aqueous solution of NaCl and your 10% aqueous stock of SDS, you find a prepackaged bottle of 1M Tris-Hcl (aqueous solution) along with a 95% solution of liquid NP-40 in a bottle. Using these stock reagents calculate the amount needed for the following final concentrations for each reagent as well as the final volume of water needed to obtain:
Total Final volume of 500 mL
Final Concentrations:
150 mM NaCl
50 mM Tris-HCl
1% NP-40 .
1% SDS
Answer:
1. Volume of stock required = 15 mL
Volume of water required = 485 mL
2. Volume of stock required = 5 mL
Volume of water required = 495 mL
3. Volume of stock required = 5.30 mL
Volume of water required = 494.70 mL
4. Volume of stock required = 50 mL
Volume of water required = 450 mL
Explanation:
Using the dilution formula C₁V₁ = C₂V₂
Where C₁ = initial concentration; C₂ = final concentration; V₁ = initial volume; V₂ = final volume
1. C₁ = 5 M NaCl, C₂ = 150 mM NaCl = 0.15 M NaCl
V₁ = ?; V₂ = 500 mL
V₁ = C₂V₂/C₁
V₁ = 0.15 × 500/ 5 = 15 mL
Volume of stock required = 15 mL
Volume of water required = 500 mL - 15 mL
Volume of water required = 485 mL
2. C₁ = 1 M Tris-HCl, C₂ = 50 mM Tris-HCl = 0.05 M Tris-HCl
V₁ = ?; V₂ = 500 mL
V₁ = C₂V₂/C₁
V₁ = 0.05 × 500/ 5 = 5 mL
Volume of stock required = 5 mL
Volume of water required = 500 mL - 5 mL
Volume of water required = 495 mL
3. C₁ = 95% NP-40, C₂ = 1% NP-40
V₁ = ?; V₂ = 500 mL
V₁ = C₂V₂/C₁
V₁ = 1 × 500/ 95 = 5.30 mL
Volume of stock required = 5.30 mL
Volume of water required = 500 mL - 5.30 mL
Volume of water required = 494.70 mL
4. C₁ = 1% SDS, C₂ = 10% SDS
V₁ = ?; V₂ = 500 mL
V₁ = C₂V₂/C₁
V₁ = 1 × 500/ 10 = 50 mL
Volume of stock required = 50 mL
Volume of water required = 500 mL - 50 mL
Volume of water required = 450 mL
how to get a girl
need to get a girl
Answer:
pretty easy
Explanation:
step 1: Approach her
step 2: Ask her for something (make it look like you're lost even when you aren't)
step 3: engage in a conversation with her
step 4: you talk for hours and she give you her number
step 5: you wake up from your dream
step 6: wait you woke up
step 7: go back to dreaming again.
Answer: Girls are tough. Girls are....attitude, we all know its true.
Explanation
Best thing to start is shush when shes talking.
A reaction occurs in which carbon combines with sulfur to form carbon
disulfide. Is this a chemical reaction or a nuclear reaction, and how do you
know?
A. This is a nuclear reaction, because mass was conserved.
B. This is a chemical reaction, because only the electrons were
rearranged.
C. This is a nuclear reaction, because there was a change in the
atoms' nuclei.
D. This is a chemical reaction, because mass was not conserved.
The reaction in which carbon combines with sulfur to form carbon
disulfide. Is
B. This is a chemical reaction, because only the electrons were rearranged.What is a chemical reaction?In a chemical reaction, bonds between molecules of the reactant are broken and new bonds between molecules of the product are established to create a new substance.
Chemical reactions occur all around us, including in our body's digestion of food and the creation of the sunlight's light. Understanding physical and chemical changes is crucial before starting any chemical reactions.
Sulfur and carbon combine to form carbon disulfide in an endothermic reaction that absorbs 92 kJ/mol of heat.
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What was the independent variable in Mendel's pea plant experiment?
A.The temperature
B.Cross-pollination
C.Type of plant
D.Characteristic of the offspring
Why is it important to make sure that the endpoint is noted accurately in titration?
You are performing an acid-base neutralization reaction in the laboratory to determine the concentration of an unknown base. You are supposed to titrate it with a monoprotic acid, but your lab partner accidentally fills your buret with sulfuric acid, a diprotic acid, with the same concentration as the acid called for in the experiment. How will the volume of diprotic acid compare to the volume of monoprotic acid you would have used
Answer:
Volume is reduced to half
Explanation:
Acid base titration are commonly used reactions in a lab, and are ofter used to get pH or different kind of solutions.
The neutralization of an acid base reaction is reached, when the solution (having added an indicator previously) changes its original color. chemically speaking, this occurs when the number of moles of the acid and the base are balanced and equal. In other words the following:
n₁ = n₂ (1)
This expression can also be expressed in function of concentration and volume:
M₁V₁ = M₂V₂ (2)
From here, solving for V₁:
V₁ = M₂V₂ / M₁
Now, this expression is true only when we have the same kind of substance that can lose or gain the same number of hydrogens.
Lets suppose that we have as base NaOH (Monoprotic base) and HCl (monoprotic acid), the titration reaction would be:
NaOH + HCl --------> NaCl + H₂O
As both of the species are monoprotic, the number of moles are the same when they reach the equilibrium, so, expression (2) can be used, and calculate volume or concentrations.
However, in this case, a partner made a mistake and use a diprotic acid, in this case, H₂SO₄, In this case, things chance because H₂SO₄ is diprotic, meaning that we need to dissociate two hydrogens in equilibrium, therefore, expression (2) would be something like this.
Acid: 1; Base: 2
H₂SO₄ + 2NaOH ------> Na₂SO₄ + H₂O
nH₂SO₄ = n₁ = 1
nNaOH = n₂ = 2
n₁/n₂ = 1/2
2n₁ = n₂ (3)
Writting this, in function of concentration and volume, it would be:
2M₁V₁ = M₂V₂ (4)
From here, if we solve for the volume of the acid (V₁):
V₁ = M₂V₂ / 2M₁
Therefore, according to this expression, we can see that the volume required of the acid would be half the volume required of the monoprotic acid. For example, if we need 50 mL of Chloridic acid to reach the equivalence point with NaOH, then, with H₂SO₄ it will only need 25 mL. This, of course, assuming that concentrations are the same, and volume of the base used, the same.
Hope this helps
please help i don’t know this:(
Answer:
29.5 days
Explanation:
orginally 27.3 days but 29.5 days is also correct
For the gaseous reaction below, the Kc value is 3.67. What is the Kp value at the same temperature? CO2 + H2 = CO + H20
Answer:
3.67
Explanation:
Step 1: Write the balanced equation
CO₂(g) + H₂(g) = CO(g) + H₂O(g)
Step 2: Calculate the value of the pressure equilibrium constant (Kp)
The concentration equilibrium constant (Kc) is 3.67.
We can calculate the value of the pressure equilibrium constant using the following expression.
[tex]Kp = Kc \times (R \times T)^{\Delta n(g)}[/tex]
where,
R: ideal gas constant
T: absolute temperature
Δn(g): moles of gaseous products - moles of gaseous reactants
Δn(g) = 2 mol - 2 mol = 0
Then,
Kp = Kc × (R × T)⁰ = Kc = 3.67
WILL GIVE BRAINLIEST!!!
Answer:
The answer is B
Explanation:
The answer is B because representative particles can only be atoms.
what characteristics of a metallic bond explains some of the properties of metals
Answer:
See Explanation
Explanation:
Metallic bonds involve attraction between electrons and positively charged metal ions. The metals are ionized and electrons form a sea of valence electrons. These loosely bound electrons surround the nuclei of the metals.
The presence of this sea of electrons explains the fact that metals conduct electricity and heat due to the free valence electrons.
Due to the nature of the bonding between metal atoms,metals are malleable and ductile.
Due to the strong electrostatic interaction between metal ions and electrons, the metallic bond is very strong and is very difficult to break thereby accounting for the greater strength of metals as the size of the metallic ion decreases.
14. A sample of carbon dioxide occupies a 2.54 dm² container at STP. What is the volume of the gas at a
pressure of 150.0 kPa and a temperature of 26.0°C?
0.180 dm
c. 2.24 dm3
b. 1.88 dm
d. 4.65 dm3
By using combined gas law , volume will be 1.88 [tex]dm^{3}[/tex].
What is combined gas law?
The combined gas law contains the laws of Charles, Boyle, and Gay-Lussac. When you know the pressure, volume, and temperature of a system and need to modify one of these, you can apply this law to compute the resulting unknown.
Combined gas law is expressed as:
[tex]$\frac{P_{1} V_{1}}{T_{1}}=\frac{P_{2} V_{2}}{T_{2}}$[/tex]
Calculation of volume by using combined gas law
It is given that, [tex]V_{1}[/tex] = 254[tex]dm^{3}[/tex], at STP P = 101.3 kPa and T = 273 K
Now, put the value of given data in above equation.
[tex]V_{2}[/tex] = (254[tex]dm^{3}[/tex]) (101.3 kPa) (26+273) /(150 kPa) (273)
[tex]V_{2}[/tex] = 1.88 [tex]dm^{3}[/tex].
By using combined gas law volume will be 1.88 [tex]dm^{3}[/tex].
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Answer the above pic
i bet no one can solve this correctly with steps
Answer:
solution given:
log k=4-[tex] \frac{200}{t} [/tex]
so,
On comparison
∆S°/R = 4
∆ S° = 4R
mousam brother is correct
hope it helps you have a good day
which solution has a higher percent ionization of the acid , a .10 M solution of HC2H3O2 (aw) or a .010 M solution of HC2H3O2(aq)
Answer:
0.0010 M of HC2H302(aq)
While playing hockey in gym class, Timmy is trying to send a plastic puck across the floor and into the goal. Which of the following best describes the forces acting on the plastic puck as it travels across the floor and into to the goal? A.-electromagnetic and gravity. B-.gravity and friction. C.-mechanical force and friction. D-.magnetism and friction
NO LINKS.....pls!
Answer:
The answer is gravity and friction.
Explanation:
When NH3(g) reacts with O2(g) to form N2O(g) and H2O(l) , 342 kJ of energy are evolved for each mole of NH3(g) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation. Note that the answer box for the energy term is case sensitive. Use the SMALLEST INTEGER coefficients possible and put the energy term (including the units) in the last box on the appropriate side of the equation. If a box is not needed, leave it blank.
Answer:
2 NH₃(g) + 2 O₂(g) ⇒ N₂O(g) + 3 H₂O(l) ΔH° = -684 kJ
Explanation:
Let's consider the unbalanced equation that occurs when NH₃(g) reacts with O₂(g) to form N₂O(g) and H₂O(l).
NH₃(g) + O₂(g) ⇒ N₂O(g) + H₂O(l)
We will begin balancing N atoms by multiplying NH₃(g) by 2.
2 NH₃(g) + O₂(g) ⇒ N₂O(g) + H₂O(l)
Then, we will balance H atoms by multiplying H₂O(l) by 3.
2 NH₃(g) + O₂(g) ⇒ N₂O(g) + 3 H₂O(l)
Finally, we will get the balanced equation by multiplying O₂(g) by 2.
2 NH₃(g) + 2 O₂(g) ⇒ N₂O(g) + 3 H₂O(l)
Since 342 kJ of energy are evolved for each mole of NH₃(g), and there are 2 moles of NH₃(g) in the balanced equation, the heat evolved will be2 × 342 kJ = 684 kJ. By convention, when heat is evolved, it takes a negative sign. The balanced thermochemical equation is:
2 NH₃(g) + 2 O₂(g) ⇒ N₂O(g) + 3 H₂O(l) ΔH° = -684 kJ