Answer:
Demo Mole Quantities
58.5g NaCl(mol/58.5g)(6.02 x 1023/mol) = 6.02 x 1023 Na
+
Cl21 pre-1982 pennies (after 1982 pennies are mostly zinc with copper coating)
63.5g Cu( mol/ 63.5g)(6.02 x 1023/mol) = 6.02 x 1023 Cu
19.0g Al (mol/27.0g)(6.02 x 1023/mol) = 4.24 x 1023 Al
Explanation:
Help!!!
1.
Q: How does the distillation apparatus remove impurities from water?
Q: Why does water vapour condense in the condenser tube?
Q: As the boiling animation neared the end, what does the change in the proportion of particle types in the boiling flask indicate about the impurities?
Answer:
Q1) Distillation relies on evaporation to purify water
Explanation:
contaminated water is heated to form steam. inorganic compounds and large non-volatile organic molecules do not evaporate with the water and are left behind. The steam then cools and condenses to form purified water
The half-life of carbon-14 is 5715 years. How long would it take for 100 grams to decay to
12.5 grams
We are given:
half-life of carbon = 5715 years
Initial mass = 100 grams
Final mass = 12.5 grams
Finding the time taken:
Number of half-lives:
We know that in the relation:
[tex]\frac{Final\_mass}{Initial\_mass} = \frac{1}{2^{n}}[/tex], n is the number of half-lives taken
replacing the given values:
12.5 / 100 = 1/2ⁿ
1/8 = 1/2ⁿ
2ⁿ = 8
2ⁿ = 2³
n = 3
Hence, it took 3 half-lives to reduce the mass to 12.5 grams
Number of years:
Time taken = 3 half-lives
we know that one half-life is 5715 years, replacing that value:
Time taken = 3*(5715) years
Time taken = 17145 years
Therefore, after 17145 years, a 100 gram sample of carbon will decay and only 12.5 grams will remain
What is voltage? A. The pressure that pushes electrons to the anode; it is derived from the negative charge of electrons at the cathode. B. None of these C. The speed of the electrons flowing to the anode; it is determined by the type of metal the electrodes are made of. D. The pressure that pushes electrons to the cathode; it is derived from the negative charge of electrons at the anode.
Answer:
D
Explanation:
I think it's D but not 100% sure
The pressure that pushes electrons to the cathode is derived from the negative charge of electrons at the anode. Hence, option B is correct.
What is an electrolytic cell?An electrolytic cell is a type of electrochemical cell that undergoes non-spontaneous reactions by deriving the energy in the form of voltage from external sources.
A voltaic cell is a cell in which chemical reactions are used to produce electrical energy in form of current.
Such a cell is made up of two electrodes and their electrolytes. The electrodes are connected via a salt bridge. The salt bridge allows electrons to move between the electrodes.
In a voltaic cell, an oxidation reaction occurs in the anode. During oxidation, electrons are produced. Therefore, the Na electrode in the anode will lose an electron spontaneously. At the cathode, reduction occurs. The Iron electrode here will gain the electron produced by the oxidation reaction at the anode. The salt bridge moves the electrons from the anode to the cathode.
Hence, the pressure that pushes electrons to the cathode is derived from the negative charge of electrons at the anode.
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What is the [H+] if [OH-] = 1 x 10-5 M?
In an acid-base titration, a student uses 25.62 mL of 0.100 M HCl to reach the endpoint. How many moles of acid is this?
A)2.56 x 10-1 ml HCl
B)2.56 x 10-3 mol HCl
C)2.56 x 10-2 mol HCl
Answer:
Number of mole in HCL = 2.56 x 10⁻³ mol HCL
Explanation:
Given:
Volume of HCL = 25.62 ml
Molarity of HCL = 0.1 M
Find;
Number of mole in HCL
Computation:
Volume of HCL = 25.62 ml
Volume of HCL (in liter) = 25.62 / 1000
Volume of HCL (in liter) = 0.02562 L
Number of mole = Molarity x volume in liter
Number of mole in HCL = Volume of HCL (in liter) x Molarity of HCL
Number of mole in HCL = 0.02562 x 0.1
Number of mole in HCL = 0.002562
Number of mole in HCL = 2.56 x 10⁻³ mol HCL
What is an extinction event
You can change a subscript in an equation, but you cannot change the
coefficient.
O True
O False
Answer:
false
because you can't change a subscript ,
but you can change the coefficient.
Separation of mixtures and purification of chemical substances
Answer:
I don't understand what to do with this
State the number of protons, electrons and neutron
Answer:
You didn't show which element it is. The proton is the atomic number, the electron is the same number of protons, and the neutron is the atomic mass rounded to the nearest whole number minus the proton.
Explanation:
How can people REDUCE the amount of trash being put into landfills?
A recycle paper, glass, plastic and metal
B reuse shopping bags and food containers
compost biodegradable materials
D
all of the above
Global climate change is
a.
a politically motivated deception generated by scientists with an environmentalist agenda.
b.
hotly debated by a deeply divided scientific community.
c.
a hypothesis that is not yet well supported by scientific evidence.
d.
understood by science to be a fact, and as largely the result of human activities.
Please solve this fast pleasee i will make u the brainliest
I – FILL IN THE BLANKS:-
1. _____________plastics can be melted by heating and thereafter moulded into desired
shape.
2. Melamine and Bakelite are examples of____________________________.
3. _________________ absorbs sweat.
4. ______________are used for making toothbrush bristles.
5. _____________type of plastic is used for making grocery bags.
6. _____________type of plastic is used for making microwave cooking containers.
7. __________ fibres are obtained from plant and animals.
8. Synthetic fibres are acquired from __________ products.
9. Polythene is the polymer of __________.
10. __________ was the first artificially manufactured fibre.
11. Polyesters are extremely __________ and __________.
12. __________ is used as an alternative for expensive, warm cashmere clothes.
13. The polymer cellulose is made up of a large number of __________ units.
14. Silk fibre is obtained from __________ whereas artificial silk is obtained by chemical
treatment of __________
15. Polythene which is used to make polythene bags is an example of a __________.
16. Plastics do not react with _______________ and ____________________.
17. Plastics are generally ______________-____ than metals.
18. __________ is a special plastic on which oil and water do not stick.
19. We should always remember the 5R principle: __________, __________, __________,
1. Which of the following is a mechanical mixture?
A. shampoo
B. chocolate chip cookie dough
C. tap water
D. air
In a nuclear fission reaction, a freely moving neutron is introduced to a
nuclear fuel, such as uranium-235. What happens next?
O A. A neutron is absorbed by an atom's nucleus.
B. The neutron breaks apart.
O C. Heat is released by the neutron.
D. The nucleus becomes unstable.
The nucleus becomes unstable when a freely moving neutron is introduced to a nuclear fuel.
What is Nuclear fission?This is a reaction in which the nucleus of an atom splits into two or more smaller nuclei.
This reaction produces more neutrons and the nucleus becomes unstable when a freely moving neutron is introduced to a nuclear fuel to form fission fragments.
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pls i need help with this
Answer:
C
Explanation:
A physical change is one in which no new substance is formed. The moistening of food by saliva is purely a physical change because no new substance is formed in the process.
A chemical change leads to the formation of a new substance. The action of the enzyme converts starch into sugar which means that a new substance is formed. This is a chemical change.
What are the uses of the metal Magnesium?
Answer:
use of sterile injections for clearanti bodies
Explanation:
Answer:
Hello There!!
Explanation:
They can be used in making products that make it lightweight such as in power tools and luggages.
hope this helps,have a great day!!
~Pinky~
[H3O+] = 3.6 x 10-2 M
Answer:
Explanation:
Hello there!
In this case, since this concentration of hydronium ions is given, we infer we may calculate that of the hydroxide ions, pH and pOH because no question was specifically given. That is why we proceed as follows:
- pH: Here, we use this concentration to calculate the pH according to the negative logarithm:
[tex]pH=-log(3.6x10^{-2})=1.44[/tex]
Which means that the solution is acidic as the pH is less than 7.
- pOH: since the pH added to the pOH is 14, we can calculate the latter as follows:
[tex]pOH=14-1.44=12.56[/tex]
- Hydroxide concentration: Given the pOH, we apply the antilogarithm to calculate such concentration as shown below:
[tex][OH^-]=10^{-pOH}=10^{12.56}=2.75x10^{-13}M[/tex]
Keep in mind, this is an arbitrary solution because no question was provided.
Regards!
Why is only a small amount of the energy stored in food available to the next organism in a food web or chain?
There are more producers than consumers.
There are fewer top consumers
Primary and secondary consumers compete for their food.
Most energy is used for life or released as heat before the organism is eaten.
Answer:
There is only a small amount of energy stored in food for the next organism because the other organisms have to share their food with other animals which will limit the amount of food if that makes sense. (Basically the primary and secondary consumers competing each other for food)
Explanation:
Answer:
There is only a small amount of energy stored in food for the next organism because the other organisms have to share their food with other animals which will limit the amount of food if that makes sense. (Basically the primary and secondary consumers competing each other for food)
Explanation:
nitrogen dioxide does not rekindle a glowing splinter but support the combustion of carbon, phosphorus, lead etc, explain why given the equation of the reaction
Answer:
Nitrogen dioxide does not rekindle a glowing splinter becuase it is a not a very good oxidant. However, it will support the combustion of burning substances that are able to decompose it into nitrogen and oxygen gas.
NO₂ (g) ----> N₂ (g) + O₂
The oxygen then produced will go ahead to rekindle the glowing splinter.
Explanation:
Nitrogen dioxide isa reddish brown gas that is given when trioxiponitrate (v) salts, for example Lead (ii) trioxonitrate (v) of heavy metals are heated.
It is an mild oxidizing agent due to the presence of oxygen in the molecule of the compound.
It does not support combustion and does not burning air because of the inertnesss of the nitrogen atom. However, it will support the combustion of burning substances that are able to decompose it into nitrogen and oxygen gas.
For example, phosphorus is a very combustible material due to its low ignition temperature of 35°C. It catches fire spontaneously in air. Nitrogen dioxide is decomposed by burning phosphorus to nitrogen and oxygen. The oxygen produced supports further combustion of the burning phosphorus.
NO₂ (g) ----> N₂ (g) + O₂
Small amount of acid is added to Water during electrolysis of water . Why?
Answer:
Water doesn't have ions that are needed to pass the electricity so in order to increase the no of ions we poor acid into the water. Just increasing the no ions will increase the electricity flow faster
a gas occupies a volume of 95 mL when the pressure is 400 mmHg .what volume does the gas occupy at 1200 mmhg if the temperature
Answer:31.7ml
Explanation:
4. A student poured 50 cm^3
water into a beaker and
measured the water's
temperature. The student added
1.00 g calcium chloride to the
water, stirred the mixture and
then recorded the temperature.
The concentration of a calcium
chloride solution is 12 g/dm^3.
Calculate the volume of this
solution, in cm^3, that contains
9.0 g of calcium chloride.
Answer:
V = 750 cm³
Explanation:
The volume of the solution can be calculated by the following formula:
[tex]V = \frac{M}{C}[/tex]
where,
V = Volume of solution = ?
M = Mass of Calcium Chloride = 9 g
C = Concentration of Solution = 12 g/dm³
Therefore,
[tex]V = \frac{9\ g}{12\ g/dm^3}\\\\V = (0.75 dm^3)(\frac{1000\ cm^3}{1\ dm^3})[/tex]
V = 750 cm³
Last year Steve was shorter than his brother. This year Steve is taller than his brother. What cell process is directly responsible for Steve’s growth?
1 diffusion
2 mitosis
3. Osmosis
4 respiration
Answer:
he drank milk!!!
Explanation:
1. he told his dad to go get the milk
2. Steve's dad didn't come back until a year!
3. Steve's dad came back and gave him milk!
4. and boom, he grew!!
:)
All living organisms are capable of growing and producing offspring. All eukaryotic organisms including aquatic plants and algae grow through mitosis. Thus the correct option is 2.
What is mitosis?The mitosis is defined as the step in the cell cycle where the newly formed DNA is separated and results in the formation of two new cells which have the same number and kind of chromosomes as the parent nucleus.
It is defined as a process of asexual reproduction observed in unicellular organisms. The cell division is regarded as the driving process of reproduction at the cellular level. Mitosis is required for the growth of the cells and for the replacement of worn-out cells.
Mitosis helps organisms to grow in size and repair damaged tissue. The process of mitosis generates new cells which are genetically identical to each other.
Thus the correct option is 2.
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structure of potassium trioxalatoaluminate(iii)?
Answer:
K3[Al(C2O4)3] is the answer
State Faraday's 2nd law of electrolysis
Answer:
[tex]{\huge\red{\fbox{{Faraday's 2nd Law of Electrolysis :-}}}}[/tex]
According to the second law of electrolysis, the same quantity of electricity will produce or dissolve chemically equivalent amounts of all the substances. This quantity of electricity is called Faraday (F). One Faraday is equal to 96487 coulombs per mole of electronic charges.
Which of the following is an electrolyte?
CH4OH
O Ca(NO3)2
O C12H22011
O CH3CH2OH
Answer:
B. Ca(NO3)2
Explanation:
edg 2022
Answer:
b
Explanation:
A 81 gram solution of silver nitrate contains
16 grams of AgNO3. What is the percent by
mass of silver nitrate in this solution?
Answer in units of %.
Answer:
19.75 %
Explanation:
The percent by mass of silver nitrate in the solution can be calculated using the following formula:
% AgNO₃ = Mass of AgNO₃ / Mass of solution * 100%As all the required data is already given by the problem, we can now proceed to calculate the percent by mass:
% AgNO₃ = 16 g / 81 g * 100 %% AgNO₃ = 19.75 %A reservoir is filled with 4 billion cubic feet of polluted water that initially contains 0.4% pollutant. Every day 400 million cubic feet of pure water enters the reservoir and the well-mixed solution flows out at the same rate. When will the pollutant concentration in the lake be reduced to 0.2%
Answer:
Thus, the pollutant concentration in lake will be reduced to 0.2% after 6.931471 days
Explanation:
From the information given:
A(t) = amount of pollutant for time (t)
A 4 billion cubic ft is the same as 4000 million cubic ft:
∴
The Initial amount of pollutant is [tex]A_o = (\dfrac{0.4}{100})\times 4000[/tex]
[tex]A_o = 16 \ million \ cubic \ feet[/tex]
However;
the pollutant rate (input) = 400 × 0 = 0
the pollutant rate (output) = [tex]400( \dfrac{A(t)} {4000})[/tex]
[tex]= 1( \dfrac{A(t)} {10})[/tex]
The net rate = [tex]A'(t) = 0 - 1( \dfrac{A(t)} {10})[/tex]
[tex]\implies A'(t) = - 1( \dfrac{A(t)} {10})[/tex]
[tex]\implies \dfrac{1}{A(t)}A'(t) = -(\dfrac{1}{10})[/tex]
[tex]\implies \int (\dfrac{1}{A(t)}A'(t) ) dt = \int -(\dfrac{1}{10}) dt[/tex]
[tex]\implies In (A(t)) = -(\dfrac{1}{10})t + c[/tex]
[tex]\implies A(t) = e^{-(\dfrac{1}{10})t+c}[/tex]
[tex]\implies A(t) = Ce^{-\dfrac{1}{10}^t}[/tex]
A(0) = 16
[tex]\implies Ce^{ -(1/20)^0} = 16 \\ \\ C = 16[/tex]
[tex]\implies A(t) = 16e^{(-1/10)t}[/tex]
[tex]0.2\% \ pollutant = (\dfrac{0.2}{100})*4000 =8 \ million \ cubic \ feet[/tex]
A(t) = 8
[tex]\implies 16e^{(-1/10)t}= 8 \\ \\ \implies e^{1/10)t} = 2 \\ \\ (\dfrac{1}{10} )^t = In(2) \\ \\ t = 10\ In(2) \\ \\ \mathbf{ t = 6.931471}[/tex]
What does a group of atoms joined by chemical bonds create?
•A molecule
O A compound
O A fission reaction
O A fusion reaction
Answer:
I can say that it is not a compound because I got it wrong
Explanation:
Answer:
MoleculeExplanation:
I took the test
BONUS QUESTION
you are stuck with a problem. You need to measure pH of a solution known to be made from a metal hydroxide, but you don't have a meter or any indicators. You do happen to have some lead(II) nitrate that is soluble, and you remember that lead (II) hydroxide is insoluble. You add some to 1 liter of your own unkown solution and a precipitate forms. You add more unttil the precipitate stops forming and then a bit more just in case. After you filter and dry the precipitate, you have 3.81 grams of it. What was the approximate pH of the original solution?
*This is just a bonus question but I'm very confused on it so any help would be appreciated*
Answer:
pH = 12.5
Explanation:
The reaction that takes place is
2OH⁻(aq) + Pb⁺²(aq) → Pb(OH)₂(s)The OH⁻ species come from the metal hydroxide of the solution, and Pb(OH)₂ is the precipitate.
Now we convert 3.81 grams of Pb(OH)₂ into moles, using its molar mass:
3.81 g ÷ 241.12 g/mol = 0.0158 mol Pb(OH)₂Now we convert 0.0158 Pb(OH)₂ moles into OH⁻ moles, using the stoichiometric coefficients of the reaction:
0.0158 mol Pb(OH)₂ * [tex]\frac{2molOH^-}{1molPb(OH)_2}[/tex] = 0.0316 mol OH⁻With the given concentration (1 L), we calculate [OH⁻]:
[OH⁻] = 0.0316 mol / 1 L = 0.0316 MThen we calculate the pOH of the solution:
pOH = - log[OH⁻] = 1.5And finally we calculate the pH:
pH = 14 - pOHpH = 12.5