Answer:
There are several ways of expressing the concentration of a solution.
Explanation:
Concentration is the proportion of a substance in a mixture. There are several ways of expressing them, each with their own usefulness. What's incredibly useful is with a little math and conversion factors, these can all be interconverted.
Molarity (M) - amount (mol) of solute / volume (L) of solutionPros: Very common in labs, makes conversions easy. Cons: Effected by temperature (liquid expands with heat so unit volume of hot solution has less solute than cold solution) and mixing (volumes are not always additive (for instance, 50 mL of water and 50 mL of ethanol is not exactly 100 mL of mixture due to solvent-solvent interactions).Molality (m) - amount (mol) of solute / mass (kg) of solventPros: Preferred when temperature and density could change; molal is based on masses, not volume so molality does not change with temperature. Masses, unlike volumes sometimes, are always additive.Cons: When dealing with moles in reactions conversions are harder.Parts by mass a.k.a mass % (% w/w) - mass of solute / mass of solutionPros: Good indication of how pure a substance is; and good for very small concentrations such as toxin or pollutant levels in a biological or environmental setting, respectively.Cons: Not the most useful for reaction stoichiometry.Parts by volume a.k.a volume % (%v/v) - volume of solute / volume of solutionPros: Very good and common for measuring main ingredients in things, such as alcohol in hand sanitizer, hydrogen peroxide in those brown bottles you see, and how much alcohol in wine bottles.Cons: Again, not the easiest to use for reaction stoichiometry.Mole fraction (X) - amount (mol) of solute/ amount (mol) of solute + amount (mol) of solvent Pros: N/ACons: N/AMass per volume percentage - mass of solute / volume of solutionPros: Common for measuring main ingredients in medicine, such as how much of it is in an aqueous solution (example: benzocaine)Cons: Difficult to use with stoichiometry.Parts per million and parts per billion (ppm or ppb) - mass of substance / mass of sample * 10^6 or 10^9Pros: Excellent for expressing concentrations of very trace components such as a toxin or pollutant in blood, for example. Cons: Not very useful for large quantities of things.Note: to find the percent of some of these, such as for mass percent or volume percent, multiply the result by 100.
Additionally, with some practice you can answer a question such as, "The label on a 0.750-L bottle of Italian chianti says "11.5% alcohol by volume." How many liters of alcohol does the wine contain?". etc...
I really hope this helps! Take care.
In the reaction shown below, cobalt ...
Co(s) + Ni (C2H302)2(aq) → Co(C2H302)2(aq) + Ni(s)
A) gains electrons and is reduced
B) loses electrons and is oxidised
C) loses electrons and is reduced
D) gains electrons and is oxidised
B) loses electrons and is oxidised
Its oxidation number is 0 in Co(s) and +2 in Co(C2H302)2(aq), hence it gets oxidised
In the reaction as mentioned below:-
[tex]Co(s) + Ni(C2H302)2aq -- > Co(C2H3O2)2aq + Ni(s)[/tex]
As shown in reaction cobalt losses elections so the reaction is oxidised. Thus, option b is correct.
What is oxidation?Oxidation is a type of reaction in which loss of electrons and gain of protons is takes place during a reaction by molecules, atom or ion. Oxidation takes place when the oxidation state of a molecule, atoms or ion is increased.
The opposite reaction is called as reduction in which gains of electron and loss of protons is takes place . In reduction reaction the oxidation state of molecules, atoms or ion is decreased.
Oxygen has been added to a compound as an older method of oxidation. Although oxygen is typically added to a compound in compliance with the loss of electrons requirements and the oxidation state increase.
Therefore, we can say that in the reaction
[tex]Co(s) + Ni(C2H302)2aq -- > Co(C2H3O2)2aq + Ni(s)[/tex]
As shown in reaction cobalt losses elections so the reaction is oxidised. Thus, option b is correct.
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Elemental phosphorus reacts with chlorine gas according to the equation
P4(s)+6Cl2(g)→4PCl3(l)
A reaction mixture initially contains 45.57 g P4 and 130.2 g Cl2.
Once the reaction has reached completion, what mass (in g) of the excess reactant is left?
(Express the mass in grams to three significant figures.)
Mass (in g) of the excess reactant (P₄) left = 7.626 g
Further explanationGiven
Reaction
P4(s)+6Cl2(g)→4PCl3(l)
45.57 g P4 and 130.2 g Cl2
Required
mass (in g) of the excess reactant left
Solution
mol P₄ (MW=124 g/mol) :
45.57 : 124 = 0.3675
mol Cl₂(MW=71 g/mol) :
130.2 : 71 = 1.834
mol : coefficient of reactant : P₄ : Cl₂ :
= 0.3675/1 : 1.834/6
= 0.3675 : 0.306
Cl₂ as limiting reactant(smaller ratio)
Reacted mol of P₄ (as an excess reactant):
=1/6 x 1.834
= 0.306
Unreacted mol of P₄ :
= 0.3675 - 0.306
= 0.0615
Mass of P₄(left) :
= 0.0615 x 124
= 7.626 g
The data below shows the change in concentration of dinitrogen pentoxide over time, at 330 K, according to the following process.
2N2O5(g) = 4NO2(g) + O2
[N2O5] Time (s)
0.100 0.00
0.066 200.00
0.044 400.00
a) Find the rate of disappearance of N2O5 from t=0 s to t=200s
b) Find the rate of appearance of NO2 from t=0 s to t =200s
Answer: a) [tex]1.7\times 10^{-4}[/tex]
b) [tex]3.4\times 10^{-4}[/tex]
Explanation:
The reaction is :
[tex]2N_2O_5(g)\rightarrow 4NO_2(g)+O_2(g)[/tex]
Rate = Rate of disappearance of [tex]N_2O_5[/tex] = Rate of appearance of [tex]NO_2[/tex]
Rate = [tex]-\frac{d[N_2O_5]}{2dt}[/tex] = [tex]\frac{d[NO_2]}{4dt}[/tex]
Rate of disappearance of [tex]N_2O_5[/tex] = [tex]\frac{\text {change in concentration}}{time}[/tex] = [tex]\frac{0.100-0.066}{200-0}=1.7\times 10^{-4}[/tex]
a) Rate of disappearance of [tex]N_2O_5[/tex] = [tex]-\frac{d[N_2O_5]}{2dt}[/tex]
Rate of appearance of [tex]NO_2[/tex] = [tex]\frac{d[NO_2]}{4dt}[/tex]
b) Rate of appearance of [tex]NO_2[/tex] = [tex]\frac{d[NO_2]}{dt}=2\times 1.7\times 10^{-4}}=3.4\times 10^{-4}[/tex]
A) Find the rate of disappearance of [tex]N_2O_5[/tex] from t = 0 s to t = 200s
[tex]Rate = \frac{1}{2}(\frac{-\delta N_2O_5}{\delta t})\\\\Rate = -\frac{1}{2}(\frac{0.066 - 0.100}{200 - 0})\\\\Rate = 8.5*10^{-5}[/tex]
B) Find the rate of appearance of [tex]NO_2[/tex] from t = 0 s to t = 200s
According to rate law,
[tex]\frac{1}{2}(\frac{-\delta N_2O_5}{\delta t}) = \frac{1}{4}(\frac{\delta NO_2}{\delta t})\\\\8.5*10^{-5} = \frac{1}{4}(\frac{\delta NO_2}{\delta t})\\\\\frac{\delta NO_2}{\delta t} = 4 * 8.5*10^{-5}\\\\Rate = 3.4*10^{-4}[/tex]
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Which type of species distribution pattern might require collaboration between different countries for effective preservation?
Answer:
migratory distribution
Explanation: The pattern of migratory distribution of species may require collaboration between different countries for effective preservation. This is because species migration can make them enter different territories, which will need to provide an effective level of preservation for species survival
(2)
3.
How would you calculate the change in entropy when the pressure of a perfect gas is
changed isothermally from P; to Pr
How would you calculate the change in entropy when the pressure of a perfect gas is changed isothermally from P_i to P_f
Answer:
ΔS = nRIn(P_i/P_f)
Explanation:
Formula for entropy change is;
ΔS = nC_p•In(T_f/T_i) + nRIn(P_i/P_f)
Since the pressure of the perfect gas is changed isothermally, it means that temperature remains the same and as such T_f = T_i
Thus, we now have;
ΔS = nC_p•In(1) + nRIn(P_i/P_f)
In(1) = 0
Thus;
ΔS = nRIn(P_i/P_f)
Atoms have _______ different subatomic particles.
A. 7
B. 5
C. 3
D. None of the above
Answer:
C. 3
Explanation:
I hope my answer will be useful
Which of the following is not a natural
way water is stored in the water cycle?
A Stream
B. Pond
C. Iceberg
D. Cup
Answer:
cup...................
275L/sec to mL/hour with work
If the pressure, volume, and temperature of a gas are known, which can most likely be found by using the ideal gas law?
a.the molar amount of the gas
b.the partial pressure of the gas
c.the standard temperature and pressure
d.the molar mass
Answer:
the moral amount of the gas.
why do liquids fill the bottom of a container
Answer:
Liquids take the shape of their containers because they are stuck together enough to not go flying off like gases but not so tightly that they stay in a stiff shape like solids do.
Explanation:
Hope this helps you! ^^
How many electrons must nitrogen gain to become like it’s closest noble gas, Neon?
Answer:
3
Explanation:
A solid substance formed from a solution is a(n)
a. reactant
b. equation
C. compound
d. precipitate
A solid substance formed from a solution is a(n).
Answer:D. Precipitate
#CARRYONLEARNING #STUDYWELLA solid substance formed from a solution is a(n)
Choosing:a. reactant
b. equation
C. compound
d. precipitate
Answer:D. Precipitate
#READINGHELPSWITHLEARNING #CARRYONLEARNING #STUDYWELL3. The endpoint of a titration involving the reaction of MnO4- to Mn2+ can be detected
by the ... *
A) useofa pH probe.
B) use of redor blue litmus.
C)pink colour of the Mn+2.
D)addition of an indicator like methyl orange.
The solution of manganese ion, Mn2+ is colorless. This way, the reaction involves a colour change from pink to transparent.
There is no option with this information.
So, the best answer is (A)
Answer:
C)pink colour of the Mn+2.
Explanation:
First of all, a titration involving the change from MnO4- to Mn2+ is a redox reaction.
This redox reaction does not need an indicator because the MnO4- has a deep violet colour while Mn2+ has a light pink colour.
Hence, the change from MnO4- to Mn2+ is signaled by the appearance of the light pink colour of Mn2+ at end point.
Write electron configuration
1s
2s
2p
3s
3p
4s
3d
4p
5s
4d
Answer:
Here:
Explanation:
Determine the number of electrons in the atom from its atomic number. (See Below.)
Add electrons to the sublevels in the correct order of filling.
Add two electrons to each s sublevel, 6 to each p sublevel, 10 to each d sublevel, and 14 to each f sublevel.
To check your complete electron configuration, look to see whether the location of the last electron added corresponds to the element’s position on the periodic table.
Predicting the Order of Filling of the Orbitals
There are three ways to predict the order of filling of the orbitals. Probably the least reliable method is to memorize the following list (even though it shows the order of filling of all the orbitals necessary for describing the ground state electron configurations of all of the known elements).
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p
Instead of relying on memorization, you can use the memory aid shown below to remind you of the correct order of filling of the sublevels. The following steps explain how to write it and use it yourself.
Write the possible sublevels for each energy level in organized rows and columns like the image below. To do this, you need to remember that there is one sublevel on the first principal energy level, two on the second, three on the third, etc. Every principal energy level has an s orbital. The second principal energy and all higher energy levels have a p sublevel. The d sublevels start on the third principal energy level, the f sublevels start on the fourth principal energy level, etc.
Draw arrows like those you see below .
Starting with the top arrow, follow the arrows one by one in the direction they point, listing the sublevels as you pass through them.
The sublevels that are not needed for describing the known elements are enclosed in parentheses below .
Image of the memory aid that allows you to determine the order of filling for the sublevels
We can also use the block organization of the periodic table, as shown below, to remind us of the order in which sublevels are filled. To do this, we move through the elements in the order of increasing atomic number, listing new sublevels as we come to them. The type of sublevel (s, p, d, or f ) is determined from the block in which the atomic number is found. The number for the principal energy level (for example, the 3 in 3p) is determined from the row in which the element is found and the knowledge that the s sublevels start on the first principal energy level, the p sublevels start on the second principal energy level, the d sublevels start on the third principal energy level, and the f sublevels start on the fourth principal energy level.
We know that the first two electrons added to an atom go to the 1s sublevel.
Atomic numbers 3 and 4 are in the second row of the s block (look for them in the bottom half of in image below), signifying that the 3rd and 4th electrons are in the 2s sublevel.
Atomic numbers 5 through 10 are in the first row of the p block, and the p sublevels start on the second energy level. Therefore, the 5th through 10th electrons go into the 2p sublevel.
Atomic numbers 11 and 12 are in the third row of the s block, so the 11th and 12th electrons go into the 3s sublevel.
Because atomic numbers 13 through 18 are in the p block, we know they go into a p sublevel. Because the p sublevels begin on the second principal energy level and atomic numbers 13 through l8 are in the second row of the p block, the 13th through 18th electrons must go into the 3p sublevel.
The position of atomic numbers 19 and 20 in the fourth row of the s block and the position of atomic numbers 21 through 30 in the first row of the d block show that the 4s sublevel fills before the 3d sublevel.
Moving through the periodic table in this fashion produces the following order of sublevels up through 6s:
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s
Notice that atomic numbers 57 through 70 on the periodic table below are in the 4f portion of the table. It is a common mistake to forget that the 4f sublevel is filled after the 6s sublevel and before the 5d sublevel. In order to make the overall shape of the table more compact and convenient to display, scientists have adopted the convention of removing the elements with atomic number 57 through 70 and 89 through 102 (the latter being the 5f portion of the table) from their natural position between the s and d blocks and placing them at the bottom of the table. Electrons go into the 5f sublevel after the 7s sublevel and before the 6d sublevel. The second periodic table below shows how the blocks on the periodic table would fit together if the inner transition metals—the f block—were left in their natural position.
50POINTS!
Using the ideal gas law (PV=nRT) solve for the missing. Variable. R= 0.08206atm*L/mol*k
If 22.9L of an ideal gas was collected at STP. How many moles of the gas were present?
A. 1.02 moles
B. 5.99 moles
C. 3.05 moles
D. 2.74 moles
Answer:
A. 1.02 moles .
Explanation:
Hello!
In this case, given the ideal gas equation, as we need to solve for moles, we divide both sides by RT to get:
[tex]n=\frac{PV}{RT}[/tex]
Thus, by plugging in the pressure and temperature at STP (1.00 atm and 273.15 K respectively) we obtain:
[tex]n=\frac{1.00atm*22.9L}{0.08206\frac{atm*L}{mol*K}*273.15K}\\\\n=1.02mol[/tex]
Therefore, the correct answer is A. 1.02 moles
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how long does crushed candy dissolve in a warm water
Answer:
Because of reaction between solid and liquid
Answer:
shouldn't take that long i would say from 30 to 40 minutes bc its melting in warm water its turning from a solid to a liquid.
Explanation:
What can you do differently for
the last half of the year in science? Whether it is
improving study skills, turning work in on time
Answer:
I would say, what helps me is really paying attention in class and asking questions, also making sure you study for upcoming test's and quizzes and completely assingments on time
Explanation:
How did Wilma contribute to change in America
Answer:
She overcame her disabilities to compete in the 1956 Summer Olympic Games, and in 1960, she became the first American woman to win three gold medals in track and field at a single Olympics. Later in life, she formed the Wilma Rudolph Foundation to promote amateur athletics.
Explanation:
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Explain the difference between atom and element
Answer:
an atom is the smallest part of an element that has the properties of that element
it can't be broken further into smaller substances
an element is the simplest chemical
it consists of one type of atoms
so you can consider atoms as the building block of an element
Based on the molecular formula, determine whether each of the following is an alkane, alkene, or alkyne. (Assume that the hydrocarbons are noncyclical and there is no more than one multiple bond.)
a. C3H6
b. C6H12
c. H8H18
d. C7H12
Answer:
C₃H₆ is an alkene
C₆H₁₂ is an alkene
C₈H₁₈ is an alkane
C₇H₁₂ is an alkyne
Explanation:
To determine which of the compound is alkane, alkene, or alkyne,we shall use the general formula of alkane, alkene, and alkyne. This is illustrated below:
General formula for alkane => CₙH₂ₙ₊₂
General formula for alkene => CₙH₂ₙ
General formula for alkyne => CₙH₂ₙ₋₂
For C₃H₆:
n = 3
Alkane => CₙH₂ₙ₊₂ => C₃H₂₍₃₎₊₂ => C₃H₈
Alkene => CₙH₂ₙ => C₃H₂₍₃₎ => C₃H₆
Alkyne => CₙH₂ₙ₋₂ => C₃H₂₍₃₎₋₂ => C₃H₄
Thus, C₃H₆ is an alkene
For C₆H₁₂:
n = 6
Alkane => CₙH₂ₙ₊₂ => C₆H₂₍₆₎₊₂ =>C₆H₁₄
Alkene => CₙH₂ₙ => C₆H₂₍₆₎ => C₆H₁₂
Alkyne => CₙH₂ₙ₋₂ => C₆H₂₍₆₎₋₂ => C₆H₁₀
Thus, C₆H₁₂ is an alkene
For C₈H₁₈:
n = 8
Alkane => CₙH₂ₙ₊₂ => C₈H₂₍₈₎₊₂ => C₈H₁₈
Alkene => CₙH₂ₙ => C₈H₂₍₈₎ => C₈H₁₆
Alkyne => CₙH₂ₙ₋₂ => C₈H₂₍₈₎₋₂ => C₈H₁₄
Thus, C₈H₁₈ is an alkane.
For C₇H₁₂:
n = 7
Alkane => CₙH₂ₙ₊₂ => C₇H₂₍₇₎₊₂ => C₇H₁₆
Alkene => CₙH₂ₙ => C₇H₂₍₇₎ => C₇H₁₄
Alkyne => CₙH₂ₙ₋₂ => C₇H₂₍₇₎₋₂ => C₇H₁₂
Thus, C₇H₁₂ is an alkyne.
SUMMARY:
C₃H₆ is an alkene
C₆H₁₂ is an alkene
C₈H₁₈ is an alkane
C₇H₁₂ is an alkyne
What is the empirical formula of C9H18
Answer:
CH2
Explanation:
there is a common factor for 9;18 which is 9 so u divide both numbers by it 9/9 and 18/9 giving 1:2 so 1 C to every 2 H so CH2
The empirical formula of C9H18 will be CH2.
What is the empirical formula?The empirical formula of a compound shows the ratio of atoms present in a compound. The molecular formula of the compound shows the total number of atoms present in a compound.
Here, C9H18 if we divide the number of total atoms by 9, C9/ 9, and H18/ 9. the ratio will be in the form of 1: 2. therefore, the empirical formula will be CH2.
C9H18 is the molecular formula of the compound, while CH2 is the empirical formula of the compound. The molecular formula of butane is C4H16, then its empirical formula is CH4. The molecular formula of compound is P4H10 then its empirical formula is P2H5.
Therefore, The empirical formula of C9H18 will be CH2.
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Identify the two ways that rocks are broken down into smaller pieces?
A
abrasion and erosion
B
deposition and erosion
C
physical weathering and deposition
D
physical weathering and chemical weathering
answer pleaseeeeeeeee i only have one minute
Answer:
A or C
Explanation:
Answer: It is D.
Explanation: Edge 2021
PLZ HELP ME BEING TIMED!!!!!
At what temperature a gas with volume 175 L at 15 oC and 760mmHg will occupy a volume of 198 L at a pressure 640mmHg?
Answer:
To calculate the pressure when temperature and volume has changed, we use the equation given by combined gas law. The equation follows:
\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}
T
1
P
1
V
1
=
T
2
P
2
V
2
where,
P_1,V_1\text{ and }T_1P
1
,V
1
and T
1
are the initial pressure, volume and temperature of the gas
P_2,V_2\text{ and }T_2P
2
,V
2
and T
2
are the final pressure, volume and temperature of the gas
We are given:
\begin{gathered}P_1=760mmHg\\V_1=175L\\T_1=15^oC=[15+273]K=288K\\P_2=640mmHg\\V_2=198L\\T_2=?K\end{gathered}
P
1
=760mmHg
V
1
=175L
T
1
=15
o
C=[15+273]K=288K
P
2
=640mmHg
V
2
=198L
T
2
=?K
Putting values in above equation, we get:
\begin{gathered}\frac{760mmHg\times 175L}{288K}=\frac{640mmHg\times 198L}{T_2}\\\\T_2=274K\end{gathered}
288K
760mmHg×175L
=
T
2
640mmHg×198L
T
2
=274K
Hence, the temperature when the volume and pressure has changed is 274 K
Uranium (VIII) Sulfide formula
Answer:
US₂
Explanation:
Uranium sulfide (US₂)
Uranium atomic symbol = U
Sulfur atomic symbol = S
Uranium valency = +4
Sulfur valency = -2
So;
Uranium sulfide (US₂)
Copper metal reacts with silver nitrate to produce silver metal and copper (II) nitrate.
the correct equation for this reaction is:
A: Cu + SiN—> Si + Cu2N
B: 2Cu + AgNO3–> Ag +
Cu(NO3)2
C: Cu + 2 AgNO3–> Ag + Cu(NO3)2
D:Cu + AgNO3–> Ag + CuNO3
Answer:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
Explanation:
The reactants are:
Copper metal = Cu
Silver nitrate = AgNO₃
The products are:
Silver metal = Ag
Copper (II) nitrate = Cu(NO₃)₂
So, the reaction equation is given as;
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
This is a single displacement reaction
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Which data value is most likely to be an error in the data shown?
A. The .64 in trial 2
B. The 6.4 in trial 1
O C. The 1.7 in trial 1
D. The 6.3 in trial 3
Answer:
0.64 in trial 2
Explanation:
what type of reaction is AsCl+H2S --> As2S3+HCl
Answer:
Double replacement:
Explanation:
Chemical equation:
2AsCl + 3H₂S → As₂S₃ + 6HCl
The given reaction is double displacement reaction. In this reaction arsenic trichloride and hydrogen sulfide react and produced arsenic sulfide and hydrogen chloride. In double displacement reaction both anion an cation of reactants are exchanged with each other.
Double replacement:
It is the reaction in which two compound exchange their ions and form new compounds.
General equation:
AB + CD → AD +CB
Arrange the compounds below in decreasing order of the ionic character of the bonds in them.
a. CsF
b. OF2
c. SrF2
d. F2
Answer: [tex]CsF[/tex] > [tex]SrF_2[/tex] > [tex]OF_2[/tex] > [tex]F_2[/tex]
Explanation:
The percent ionic character is used to determine if a bond is more ionic or covalent. More is the percent ionic character, the more ionic the molecule is. If the electronegativity difference between two elements is higher than 1.7 it will be considered as ionic.
The electronegativity difference for CsF is (3.98-0.79) = 3.19
The electronegativity difference for [tex]OF_2[/tex] is = (3.98-3.44) = 0.54
The electronegativity difference for [tex]SrF_2[/tex] is (3.98-0.95) = 3.0
The electronegativity difference for [tex]F_2[/tex] is 0.
Thus decreasing order of ionic character of the bonds is CsF > [tex]SrF_2[/tex] > [tex]OF_2[/tex] > [tex]F_2[/tex]