Answer:
ΔS = nR(In (Vf/Vi))
Explanation:
We are told the temperature has the same value and therefore it's constant.
Formula for change in entropy isothermally is;
ΔS = nR(In (V2/V1))
V2 is final volume and V1 is initial volume.
We are told that the volume changes from Vi to Vf.
Thus, V2 = Vf and V1 = Vi
Hence;
ΔS = nR(In (Vf/Vi))
If a radioactive substance has a half-life of 9 days what fraction of its original mass would remain after 27 days? *
Answer:
1/8
Explanation:
If the substance has a half-life of 9 days, that means that after 9 days, half of it will be left. So, after 18 days, one-fourth will be left. And after 27 days, 1/8 would be left. It's kind of like an exponential function, if that helps.
If a radioactive substance has a half-life of 9 days, the fraction of its original mass that would remain after 27 years will be 1/8.
What is half-life?Half-life is the time when a radioactive substance is decayed half.
If the radioactive substance has a half-life of 9 day. It means it will be decayed half after 9 days. The radioactive substance will be 1/4 decayed in 18 days. The substance will be 1/8 decayed in 27 days.
Thus, the correct option is 1/8 days.
Learn more about half-life
https://brainly.com/question/23117643
#SPJ2
a mixture of of sand,salt and sawdust was stirred into water and the mixture was allowed to stand.
a)how might you collect "pure" sawdust?
b)what is the sediment which forms?
c)the clear liquid was poured off and divided into 2 parts.one part was evaporated,and the other was distilled.
i)what substance would be collected by distillation?
ii)what would be collected by evaporation?
iii)what difference in properties allows the separation in both evaporation and distillation?
Answer:
A) To get the pure sawdust u can filter it..
B) The muddy sagment that will form .
C) The clear liquid can divide into 3 layers on the top there will be pure water in middle there will be muddy or dark layer of water and in lower layer there will be the stones or heavy particles of water .
True or False: Bromine is a gas at – 60 °C
Answer:
False
Explanation:
teeth to Bachile can be see more than once
Come as the chemical mantragen has the valence electrons each hydrogen has one walence electron, and chionner
Campie eles are for this went compound
.
NH H-
CI
ou
Determine the oxidation number of sulfur in S203 ( with steps)
Answer:
The oxidation number of sulphur in is +2
Explanation:
S2O3 2-
2 (S) + 3(O)=-2
2 (S) + 3(-2)=-2
2 (S) + (-6) =-2
2 S = +4
S= +2
This is the chemical formula for acetic acid (the chemical that gives the sharp taste to vinegar): An analytical chemist has determined by measurements that there are moles of oxygen in a sample of acetic acid. How many moles of hydrogen are in the sample
Answer:
0.11 mol
Explanation:
This is the chemical formula for acetic acid (the chemical that gives the sharp taste to vinegar): CH₃CO₂H. An analytical chemist has determined by measurements that there are 0.054 moles of oxygen in a sample of acetic acid. How many moles of hydrogen are in the sample?
Step 1: Given data
Formula of acetic acid: CH₃CO₂HMoles of oxygen in the sample of acetic acid: 0.054 molesStep 2: Establish the appropriate molar ratio
According to the chemical formula of acetic acid, the molar ratio of H to O is 4:2.
Step 3: Calculate the moles of atoms of hydrogen
We will use the theoretical molar ratio for acetic acid.
0.054 mol O × (4 mol H/2 mol O) = 0.11 mol H
Which sphere forms Earth's outermost layer?
Atmosphere
Biosphere
Cryosphere
Hydrosphere
Answer: I believe the answer is A.
Explanation: Well, the lithosphere is rocks and earth, the hydrosphere makes up all the water on Earth, the biosphere is us, (living things,) and the atmosphere is the air that surrounds us and our planet. So if you go in order, it's basically lithosphere, hydrosphere, biosphere, and then atmosphere.
Answer:
Atmosphere
Explanation:
I took test
How many atoms is 9.8 moles of calcium
Answer:
How many grams is in 10.00 moles of calcium (Ca)? The number of atoms can also be calculated using Avogadro's Constant (6.02214179×1023) / one mole of substance.
Explanation:
Hope this helps
What is the molarity of a HCl solution that
contains 6.27 g of HCl in 163 mL of solution?
Answer in units of M.
Answer:
M = 1.04 M
Explanation:
Given data
Molarity of solution = ?
Mass of HCl = 6.27 g
Volume of solution = 163 mL (163 mL× 1L /1000 mL = 0.163 L)
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of HCl:
Number of moles = mass/molar mass
Number of moles = 6.27 g / 36.5 g/mol
Number of moles = 0.17 mol
Molarity:
M = 0.17 mol/ 0.163 L
M = 1.04 M
Answer:
4.6
Explanation:
4. Which type of molecule forms a bilayer within a cell membrane?
Answer:
The answer is Phospholipids.
Explanation:
A phospholipid bilayer. Phospholipids spontaneously form stable bilayers, with their polar head groups exposed to water and their hydrophobic tails buried in the interior of the membrane.
I really hope this helps!! Have an amazing day!! :)
Perform the following
mathematical operation, and
report the answer to the correct
number of significant figures.
1.987/3.46 = [?]
Answer:
.574
Explanation:
smallest number of digits in the expression was 3, so the final answer should have 3 sig figs
What do you think is responsible for the color produced in the flame, the metal atom or what is attached to the metal atom?
Hint: The metal atom comes first in the formula and the name of the compound.
Answer:
metal Atom
Explanation:
every transition metal atom are responsible for the flame color. Some metal are also confirmed by flame test.
Jasmine and her partner want to test to see if there is a relationship between how much of her solar panel is exposed to sunlight and how fast her solar car will move. She uses a piece of paper to cover the solar panel different amounts of her solar panel. The chart below shows the data she collected.
What is the independent or manipulated variable for this experiment?
The average of the trials
The speed in centimeters per second
The size of the solar panel
The amount of solar panel covered
Answer:
The amount of solar panel covered
Explanation:
The variable that is the independent one is the one that Jasmine is changing. In this case, it is the amount of solar panel covered, via a piece of paper.
Answer:
D: The amount of solar panel covered
Explanation:
The skeletal structure in line‑angle (line‑bond) mode of 2‑isopropyltoluene is shown. Identify the number of hydrogen atoms bound to each carbon atom in the structure.
Answer:
Fourteen hydrogen atoms are bounded in total to the carbon atoms in the structure
Explanation:
The boxes that show "one" indicate that there is only one hydrogen atom bonded to that particular carbon atom while those that show "zero" shows there are no hydrogen atoms bonded to that particular carbon atom. Those that show "three" indicate that there are three hydrogen atoms bonded to that particular carbon.
There are 10 carbon atoms in the structure.
NOTE that each of these carbon atoms must be surrounded with four bonds; which was how the number of hydrogen atoms (numbers in the boxes) weree determined.
solve the equation: 3)15.000 cm²= x dm ²
BRAINLIEST!!!!
Answer:
x = 150 dm
Explanation:
10 cm = 1 dm
100 cm² = 1 dm²
15,000 cm² = 150 dm²
Answer:
csc = (60)
cos = (390)
−4 = cot (−45)
Explanation:
make me braienst please?
when a neutral atom gains or loses electrons, it becomes charged and is called ain)!______________
List two different reasons ants work together
True or False: Water is a liquid at – 5 °C.
Answer:
False
Explanation:
Answer:
False
Explanation:
Water's freezing point is at 0 degrees celsius
One method used commercially to peel potatoes is to soak them in a solution of NaOH for a short time and then remove them from the NaOH. The peel will have separated from the potato and so it can then easily be sprayed off to yield beautifully peeled potatoes! The NaOH solution however, must be analyzed periodically to make sure its concentration is adequate for the reaction In one such analysis, 45.7 mL of 0.500 M H2SO4 is required to react completely with a 20.0 mL sample of the NaOH solution. The products of the reaction are Na2SO4 and water. What is the concentration of the starting NaOH solution?a. 1.14 M b. 2.28 M c. 0.438 M d. 0.500 M e. 0.571M
Answer:
b. 2.28 M
Explanation:
The reaction of neutralization of NaOH with H2SO4 is:
2NaOH + H2SO4 → Na2SO4 + 2H2O
Where 2 moles of NaOH react per mole of H2SO4
To solve the concentration of NaOH we need to find the moles of H2SO4. Using the chemical equation we can find the moles of NaOH that react and with the volume the molar concentration as follows:
Moles H2SO4:
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles H2SO4
Moles NaOH:
0.02285 moles H2SO4 * (2moles NaOH / 1 mol H2SO4) = 0.0457moles NaOH
Molarity NaOH:
0.0457moles NaOH / 0.020L =
2.28M
Right option:
b. 2.28 MThe concentration of the starting NaOH solution is:
b. 2.28 M
Neutralization reaction:
The reaction of neutralization of NaOH with H₂SO₄ is:
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
Calculation for concentration of NaOH:We need to find the moles of H₂SO₄. Using the chemical equation we can find the moles of NaOH.
Moles of H₂SO₄:
45.7mL = 0.0457L * (0.500mol/L) = 0.02285 moles of H₂SO₄
Moles of NaOH:
0.02285 moles H₂SO₄ * (2moles NaOH / 1 mol H₂SO₄) = 0.0457moles NaOH
Molarity of NaOH:
0.0457moles NaOH / 0.020L =2.28M
Thus, the concentration of the starting NaOH solution is: 2.28 M.
Find more information about Molarity here:
brainly.com/question/17138838
Assuming the graphs are constructed to the same scale, which seismograph shows the shortest S-P time?
Answer:
a
Explanation:
Which two photos show electric force in action?
DA.
Answer:
its c and d i just took the test
Explanation:
Electric force is degenerated when papers are attracted onto the comb and when the nails attached to the stone. In both cases a static electricity is generated. Thus, option A and C are correct.
What is static electricity ?When a material is rubbed the electrons gets delocalized and the material gets a negative charge. For instance when comb is rubbed through hair it acquires a negative charge and this when comes in contact with a paper, the paper will attracts on the comb.
The random charges of the paper gets aligned temporarily into two poles by the attraction of electrons from the comb. Thus the positive pole of the comb gets attached to the comb and there creates a static electricity.
The the conducting nails when scratched on the stone a static electricity generates whereas in the case of a bar magnet no electric field is comes in action when it attracts the nails to the magnetic field. Thus, photos A and C are correct.
To find more on static electricity, refer here:
https://brainly.com/question/12791045
#SPJ5
how does philosophy look at man
Answer:
The philosophical view of man implies that we are moral as well as intelligence beings. It provides the framework to discover the nature of human excellence embodied by the perennial virtues towards which all men of good will tend.
Answer?? Hurry!!! Comment dadt
Answer:
The particles in the water are always moving
Explanation:
How many moles are in 2.3 x10^25 atoms of phosphorus
Answer:
38.21 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{2.3 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 38.20598...[/tex]
We have the final answer as
38.21 molesHope this helps you
When chlorobenzene reacts with Mg in ether followed by CO2 and neutralization with dilute HCl, __________ will be formed.
a. p-chlorobenzoic acid
b. p-deuterobenzoic acid
c. benzoic acid
d. benzene
e. No correct response
Answer:
c. benzoic acid
Explanation:
The given reaction is an example of a Grignard reaction:
When chlorobenzene (C₆H₅Cl) reacts with Mg in ether, an intermediate is formed (C₆H₅MgCl).
Said intermediate then reacts with CO₂ producing a benzoic acid salt (C₆H₅CO₂X), this salt is then neutralized with dilute HCl producing benzoic acid (C₆H₅CO₂H).
help me plzz in chemistry
a) f2 loses electrons and is oxidised. li gains electrons and is reduced
c)sn2+ loses electrons and is oxidised.Al gains electrons and is reduced
b)br2 loses electrons and is oxidised. I- in KI gains electrons and is reduced
11. Silver ions can be precipitated from aqueous solutions by the addition of aqueous chloride:
KCl(aq) + AgNO3(aq) → AgCl(s) + KNO3(aq)
Silver chloride is virtually insoluble in water so that the reaction appears to go to completion. How many grams of solid KCl must be added to 25.0 mL of 0.125 M AgNO3 solution to completely precipitate the silver?
Answer:
0.2330 grams of solid KCl
Explanation:
In order to find KCl in grams, we need to convert from moles to moles to grams..
However, we are given the volume and the molarity, so first we will use that to convert to moles of AgNO3 (silver nitrate) and then use that to convert to moles of KCl and finally to grams of KCl..
-----------------------------------------------------------------------------------------------------------------
Step 1 -> We need to convert milliliters to liters
(25.0 ml)([tex]\frac{1 L}{1000 mL}[/tex]) = 0.025 L
Step 2 -> Convert from liters and molarity to just moles of AgNO3
(0.025 L)(0.125 [tex]\frac{moles AgNO_{3} }{1 ln soln}[/tex]) = 0.003125 moles [tex]AgNO_{3}[/tex]
**Liters cancel out, so just multiply across...
Step 3 -> Now that we have moles of AgNO3, we will convert to moles of KCl
We will do this using the balanced equation
We see that in the balanced equation, for every mol of AgNO3 that reacts, one mol of KCl will react too. So we will set the dimensional analysis up like the following:
(0.003125 moles AgNO3) * [tex]\frac{1 mol KCl}{1 mol AgNO3}= 0.00312 mol KCl[/tex]
Step 4-> So now that we have moles of KCl, we will just convert to grams
We will do this using the molar mass (atomic mass) of KCl to convert to grams
0.00312 mol KCl * [tex]\frac{74.5513 grams KCl}{1 mol KCl} = 0.2329728125 grams of KCl[/tex]
This can be rounded to 0.2330 grams of KCl
giving brainliest answer it
Answer:
B as its not specific enough
For the chemical reaction:
N2 (g)
+
H2(g)=
NH3 (g)
Calculate the volume of NH; that will form from 200 dm cubed of N2 at STP. (N = 14; H - 1)
[At STP. 1 mole of any gas occupies volume of 22 A dm cubed
Answer:
Volume of ammonia produced = 398.7 dm³
Explanation:
Given data:
Volume of N₂ = 200 dm³
Pressure and temperature = standard
Volume of ammonia produced = ?
Solution:
Chemical equation:
N₂ + 3H₂ → 2NH₃
Number of moles of N₂:
PV = nRT
1 atm× 200 L = n× 0.0821 atm.L/mol.K × 273 K
n = 200 atm.L /22.41 atm.L/mol
n = 8.9 mol
Now we will compare the moles of ammonia and nitrogen.
N₂ : NH₃
1 : 2
8.9 : 2/1×8.9 = 17.8 mol
Volume of ammonia:
1 mole of any gas occupy 22.4 dm³ volume
17.8 mol ×22.4 dm³/1 mol = 398.7 dm³
27. The compound having only primary hydrogen atoms is ( ).
(A) isobutene
(B) 2,3-dimethylbutene
(C) cyclohexane
(D) propyne
Answer:
The correct answer is - (a) isobutene.
Explanation:
A 1° or primary hydrogen atom is one that is bonded to a 1° carbon atom; a 2° hydrogen atom is one that is connected to a 2° carbon atom; In isobutene only among all the all option having only primary hydrogen atoms. rest have secondary or teritary hydrogen atoms in them
C1∘H3≡CH: (only 1∘ hydrogen atoms)