Five identical test tubes are each filled from the following five copper (11) sulfate stock solutions. Which of the following test tubes would appear the lightest blue?
a) Stock solution made form 0.200 moles of CuSO4 dissolved to a total volume of 400 ml
b) Stock solution made form 0.150 moles of CuSO4 dissolved to a total volume of 300 mL
C)Stock solution made form 0.250 moles of CuSO4 dissolved to a total volume of 500 ml
d) Stock solution made form 0.175 moles of CuSO4 dissolved to a total volume of 400 ml
e) Stock solution made form 0.125 moles of CuSO4 dissolved to a total volume of 300 ml
Answer:
deez cutz
Explanation:
did i get it right
Calculate how many grams of sodium acetate you expected to make from your starting amount of sodium bicarbonate (0.5g). This is your theoretical yield.
Equation: NaHCO3 + HC2H3O2 = NaC2H3O2 + H2O + CO2
how many moles are there in 2.20 x 10^23 molecules of Na2SO4
Answer:
Explanation:
450 grams of Na2SO4? 450 Na soullnol Na2SO4 16.02x1023 molec, Na₂SO4 = 119x1024. | 142.05g Na25041 Imol Naz
_FeCI3 + _ NaOH = _ NaCI + _Fe(OH)3 balance and strength the coefficients for each substance
Answer:
FeCl₃ + 3 NaOH ⇒ 3 NaCl + Fe(OH)₃
Explanation:
Let's consider the following unbalanced equation. This is a double displacement reaction.
FeCl₃ + NaOH ⇒ NaCl + Fe(OH)₃
We will start balancing Cl atoms by multiplying NaCl by 3.
FeCl₃ + NaOH ⇒ 3 NaCl + Fe(OH)₃
Then, we will get the balanced equation by multiplying NaOH by 3.
FeCl₃ + 3 NaOH ⇒ 3 NaCl + Fe(OH)₃
POINTSSS AND BRAINLIEST IF YOU ANSWER CORRECTLY!!! Write about the law of conservation of energy and where light energy goes. thank you :)
Answer:
The law of conservation of energy states that the total energy is constant in any process. Energy may change in form or be transferred from one system to another, but the total remains the same.
Could you please help me with the two most recent questions of mine on my page? I will give u brainliest and 20 points! :))) X
Check all that apply...helppppp
Answer:
dfgh
Explanation:
Balance the single replacement chemical reaction.
Explanation:
B) 3CuCl2+2AL..….2AlCl3+3Cu
hope it helps.
Balanced Equation:
3CuCl₂ + 2Al = 2AlCl₃ + 3Cu
100.00 mL of 0.15 M nitrous acid (HNO2) are titrated with a 0.15 M NaOH solution. (a) Calculate the pH for the initial solution. (b) Calculate the pH for the point at which 80.0 mL of the base has been added. (c) Calculate the pH for the equivalence point. (d) Calculate the pH for the point at which 105 mL of the base has been added.
Answer:
a. pH = 2.04
b. pH = 3.85
c. pH = 8.06
d. pH = 11.56
Explanation:
The nitrous acid is a weak acid (Ka = 5.6x10⁻⁴) that reacts with NaOH as follows:
HNO₂ + NaOH → NaNO₂(aq) + H₂O(l)
a. At the beginning there is just a solution of 0.12M HNO₂. As Ka is:
Ka = [H⁺] [NO₂⁻] / [HNO₂]
Where [H⁺] and [NO₂⁻] ions comes from the same equilibrium ([H⁺] = [NO₂⁻] = X):
5.6x10⁻⁴ = X² / 0.15M
8.4x10⁻⁵ = X²
X = [H⁺] = 9.165x10⁻³M
As pH = -log [H⁺]
pH = 2.04b. At this point we have HNO₂ and NaNO₂ (The weak acid and the conjugate base), a buffer. The pH of a buffer is obtained using H-H equation:
pH = pKa + log [NaNO₂] / [HNO₂]
Where pH is the pH of the buffer,
pKa is -log Ka = 3.25
And [NaNO₂] [HNO₂] could be taken as the moles of each compound.
The initial moles of HNO₂ are:
0.100L * (0.15mol / L) = 0.015moles
The moles of base added are:
0.0800L * (0.15mol / L) = 0.012moles
The moles of base added = Moles of NaNO₂ produced = 0.012moles.
And the moles of HNO₂ that remains are:
0.015moles - 0.012moles = 0.003moles
Replacing in H-H equation:
pH = 3.25 + log [0.012moles] / [0.003moles]
pH = 3.85c. At equivalence point all HNO2 reacts producing NaNO₂. The volume added of NaOH must be 100mL. That means the concentration of the NaNO₂ is:
0.15M / 2 = 0.075M
The NaNO₂ is in equilibrium with water as follows:
NaNO₂(aq) + H₂O(l) ⇄ HNO₂(aq) + OH⁻(aq) + Na⁺
The equilibrium constant, kb, is:
Kb = Kw/Ka = 1x10⁻¹⁴ / 5.6x10⁻⁴ = 1.79x10⁻¹¹ = [OH⁻] [HNO₂] / [NaNO₂]
Where [OH⁻] = [HNO₂] = x
[NaNO₂] = 0.075M
1.79x10⁻¹¹ = [X] [X] / [0.075M]
1.34x10⁻¹² = X²
X = 1.16x10⁻⁶M = [OH⁻]
pOH = -log [OH-] = 5.94
pH = 14-pOH
pH = 8.06d. At this point, 5mL of NaOH are added in excess, the moles are:
5mL = 5x10⁻³L * (0.15mol / L) =7.5x10⁻⁴moles NaOH
In 100mL + 105mL = 205mL = 0.205L. [NaOH] = 7.5x10⁻⁴moles NaOH / 0.205L =
3.66x10⁻³M = [OH⁻]
pOH = 2.44
pH = 14 - pOH
pH = 11.56What is the minimum temperature
needed to dissolve 35 grams of KCl in 100 grams of water?
Answer:
[tex]30^{\circ}\text{C}[/tex]
Explanation:
To know the temperature at which KCl dissolves in water we need to refer to the general solubility curves.
In the case of [tex]KCl[/tex], [tex]35\ \text{g}[/tex] of it will dissolve in [tex]100\ \text{g}[/tex] of water at a minimum temperature of [tex]30^{\circ}\text{C}[/tex].
So, the the minimum temperature needed to dissolve 35 grams of KCl in 100 grams of water is [tex]30^{\circ}\text{C}[/tex].
What is the maximum number of electrons that can be identified with each of following sets of quantum numbers? If there are none, enter 0.
Answer:
So, only one electron is there with n = 0, l = 0 and its quantum set is n = 0, l = 0, ml = 0, ms = -1/2. Hope, this is helping. The maximum number of electrons that can fit inside a 'n' shell is 2n^2. So it would be 1.
Explanation:
Quantum numbers are defined as the set of four numbers with the help of which we can get complete information about the electrons in an atom. Here the term 'n' represents the principal quantum number.
What is principal quantum number?The quantum number which represents the main energy level or shell in which electrons are present. It also determines the average distance of orbital or electron from the nucleus. It can have the whole number values like 1,2,3,4, ....
1. When n = 2, the maximum number of electrons present is 8. That is one 's' sub level and three 'p' sub levels. The spin of four electrons will be +1/2 and other four will be -1/2.
2. When l = 3, the possible orientations = 2l + 1 = 2(3) + 1 = 7. So the maximum number of electrons is 14.
3. The value of ml = -1 indicates only one orbital. So the maximum electrons is 2.
4. Here ml = -1, 0, 1 which shows three orbitals. So in ml = -1, there are only two electrons.
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A compound with an approximate molar mass of
65.0g/mol is made up of C, H and Cl. This same
Compound contains 55% of Cl by mass .lf 9g
of the compound contains 4.19 x 10²³ atoms,
determine the compound's:
a empirical formular and molecular formular
g Consider (12.5 A) micro-grams of a radioactive isotope with a mass number of (78 B) and a half-life of (32.6 C) million years. If energy released in each decay is 32.6 keV, determine the total energy released in joules (J) in 1 (one) year. Give your answer with three significant figures.
Answer:
Energy released = 18.985 J
Explanation:
The exponential decay of radioactive substance is given by -
N(t) = N₀ [tex]e^{-kt}[/tex]
where
N₀ = initial quantity
k = decay constant
Half life, [tex]t_{1/2} = \frac{ln 2}{k}[/tex]
⇒[tex]k = \frac{ln 2}{t_{1/2} }[/tex]
Given,
N₀ = 12.5 + 3 = 15.5 × 10⁻⁶ gm
[tex]t_{1/2}[/tex] = 32.6 + 18 = 50.6 × 10⁶ years
So,
[tex]k = \frac{ln 2}{50.6 * 10^{6} }[/tex] = 1.361 × 10⁻⁸ year⁻¹
Now,
N(1) = 15.5 × 10⁻⁶ [tex]e^{-1.361*10^{-8} *1}[/tex]
= 15.49999978904
Now,
Substance decayed = N₀ - N(t)
= 15.5 × 10⁻⁶ - 15.49999978904 × 10⁻⁶
= 21.095 × 10⁻¹⁷ kg
⇒Δm = 21.095 × 10⁻¹⁷ kg
So,
Energy released = Δmc²
= 21.095 × 10⁻¹⁷ × 3 ×10⁸ × 3 × 10⁸
= 189.855 ×10⁻¹
= 18.985 J
⇒Energy released = 18.985 J
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The pressure inside a 1.0 L balloon at 25°C was 750 mm Hg. What is the pressure (in mmHg) inside the
balloon when it is cooled to -65°C and expands to 3.3 L in volume?
mm Hg
Answer:
shhsss×<×>×××<××××
Explanation:
4×738×8<#329×
How many moles of hydrogen are needed to react with 0.234 mol oxygen according to this equation? 2H2 + O2 -> 2H2O
The number of moles of hydrogen to be 0.468.
The balanced chemical equation :
2H₂ + O₂ → 2H₂O
This implies that 2 moles of hydrogen and one mole of oxygen are required to produce 2 moles of water.
or
Thus molar ratio of ( H₂ : O₂)= 2 : 1.
So, it requires double the moles of oxygen to get the required moles of water.
Number of moles of oxygen= 0.234 mol
So following the molar ratio concept:
We will get:
The number of moles of hydrogen to be 0.468.
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Name 3 ways you can keep our community healthy?
Answer:
1. Practice healthy habits with kids in your life. ...
2. Engage in your school's efforts to encourage healthy practices. ...
3. Learn more about the decisions local officials are making that impact your environment. ...
4. Give back healthy options to your community.
Explanation:
Today, there are ____ GMO crops currently produced in the US.
A. 120
B. 10
C. 55
D. 1000
Answer: I think that is 55
Explanation: I hope I help
PlEASE HELP! 40!
A radioactive form of sodium pertechnetate is used as a brain-scanning agent in medicine. Quantitative analysis of a sample with a mass of 0.8961 g found 0.1114 g of sodium and 0.4749 g of technetium. The remainder was oxygen. Determine the empirical formula.
Answer:
moles Na = 0.1114 g / 22.9898 g/mol=0.004846
moles Tc = 0.4562g /98.9063 g/mol=0.004612
mass O = 0.8961 - ( 0.1114 + 0.4562)=03285 g
moles O = 0.3285 g/ 15.999 g/mol=0.02053
divide by the smallest
0.02053/ 0.004612 =4.45 => O
0.004846/ 0.004612 = 1.0 => Tc
to get whole numbers multiply by 2
Na2Tc2O 9
Explanation:
Hope it right hope it helps
A solution of HCl is made by dissolving .005 moles of HCl in 50 L of water. What is the pH of the solution? What is the pOH?
PH?
0.0001
4.00
11.00
2.3p
pOH?
2.00
4.00
10.00
12.00
Answer:
pH= 4; pOH= 10
Explanation:
HCl is a strong acid and therefore dissociates completely in a solution of water via HCl + H2O --> Cl- + H3O+.
Because it is a strong acid, [HCl] = [H3O+].
[HCl]= [H3O+]= (0.005 mol)/(50L)= 1.0 x 10^-4
pH= -log[H3O+]
pH= -log(1.0 x 10^-4)= 4
pH + pOH = 14
4 + pOH = 14
pOH= 10
Due today please answer! Can we make electricity in the ocean?
1: Certainly can
2: No way
3: Yes but fossil fuels will pollute the water and the air
4: Yes by grabbing on to an electric eel
Answer:
3
Explanation: good luck dude I believe in u
Make a
prediction about how a lack
of resources in an ecosystem
might impact the levels of
organization.
Answer:
Limiting factors of an ecosystem include disease, severe climate and weather changes, predator-prey relationships, commercial development, environmental pollution and more. An excess or depletion of any one of these limiting factors can degrade and even destroy a habitat.
Explanation:
The limiting factor of an ecosystem involve disease, weather change, climate change, environment pollution and more. An excess or depletion of any of these factor can destroy over habitat.
What is Ecosystem?An ecosystem is define as a community or a group of living organisms that live together and are dependent on each other.
There are two main types of ecosystem.
Terrestrial ecosystem-Terrestrial ecosystem are land based ecosystem and interaction of biotic and abiotic component in the specific area.
Example- forest, grassland desert etc.
Aquatic ecosystem-Aquatic ecosystem are ecosystem formed by surrounding water bodies. They are dependent on each other and their environment .
Example- lake, pond, river etc.
Thus ecosystem and their limiting factor have great impact on the level of organization.
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What is the atomic number of the atom
Do these two points (equivalence point and titration endpoint) in a titration occur when the same volume of titrant has been added? please Explain.
Answer:
Show a picture
Explanation:
Help hurry please !!!!!
What is the energy of an electron in a Li+ ion when an electron moves from n = 2 to n =3?
Answer:
The question wants you to determine the energy that the incoming photon must have in order to allow the electron that absorbs it to jump from
n
i
=
2
to
n
f
=
6
.
A good starting point here will be to calculate the energy of the photon emitted when the electron falls from
n
i
=
6
to
n
f
=
2
by using the Rydberg equation.
1
λ
=
R
⋅
(
1
n
2
f
−
1
n
2
i
)
Here
λ
si the wavelength of the emittted photon
R
is the Rydberg constant, equal to
1.097
⋅
10
7
m
−
1
Plug in your values to find
1
λ
=
1.097
⋅
10
7
.
m
−
1
⋅
(
1
2
2
−
1
6
2
)
1
λ
=
2.4378
⋅
10
6
.
m
−
1
This means that you have
λ
=
4.10
⋅
10
−
7
.
m
So, you know that when an electron falls from
n
i
=
6
to
n
f
=
2
, a photon of wavelength
410 nm
is emitted. This implies that in order for the electron to jump from
n
i
=
2
to
n
f
=
6
, it must absorb a photon of the same wavelength.
Do not abuse or misuse any piece of drawing instrument. ASAPPPP
What is the pressure inside a container of 3 moles of gas with a volume of 60 Liters at a temperature of 400 K?
I just need the answer not a link please :)
Plz answer the first two questions and maybe the third. I will give brainliest.
Answer:
1. 24.45 moles
2. 437.90 grams
Bonus :
0.75 grams
Explanation:
Hope it was helpful ;)
Which do you use to qualify matter?
A. Thermometer
B. Five senses
C. Balance
D. Tape measure
Answer:
c balance
Explanation:
if you weigh something, you prove it's there.
What is the reducing agent in the following reaction?
2 Br−(aq) + H2O2(aq) + 2 H+(aq) → Br2(aq) + 2 H2O(l)
Answer:
the reducing agent is Bromine
The oxidation state of an element is calculated by subtracting and the total sum of oxidation states of all the individual atom (excluding the one that has to be calculated) from total charge on the molecule. Bromine is the reducing agent in the following reaction.
What is oxidation state?Oxidation state of an element is a number that is assigned to an element in a molecule that represents the number of electron gained or lost during the formation of that molecule or compound.
The ionic equation is given as
2 Br⁻(aq) + H[tex]_2[/tex]O[tex]_2[/tex](aq) + 2 H⁺(aq) → Br[tex]_2[/tex](aq) + 2 H[tex]_2[/tex]O(l)
The oxidation state of bromine on reactant side is -1 while on product side it is 0 so, oxidation state of bromine has increased by 1 so, bromine is oxidized. If it is oxidized that means it must have reduced someone. So, bromine is acting as a reducing agent.
Therefore, bromine is the reducing agent in the given reaction.
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Q1. Consider respiration, one of the most common chemical reactions on earth occur according
to the reaction:
C6H1206 +602 = 6CO2 + 6H2O + energy
What mass of CO2 forms in the reaction of 25g of glucose with 40g of oxygen?
Answer: First we need to know how many moles of each reactant there are.
C6H12O6 : 25g/180.06g/mol=0.1388mol
O2: 40g/32g/mol=1.25mol
The equation tells us we need 6 moles of O2 for every 1 mole of Glucose.
6 x 0.1388 = 0.8328
So, we have more O2 then needed – it is in excess.
Glucose is the limiting reagent – we use this for the calculation.
The equation tells us we make 6 moles of CO2 for every 1 mole of Glucose
So, we make 0,8328 moles of Carbon Dioxide
Explanation: