Answer:
Reforestation can be used to undo and rectify the effects of deforestation and improve the quality of human life by absorbing pollution and dust from the air, rebuilding natural habitats and ecosystems,reducing global warming via biosequestration of atmospheric carbon dioxide, and harvesting for resources, particularly.
Explanation:
How can you improve your ability to see the indicator color change at the endpoint of a titration?.
Answer: Place a piece of white paper under the analyte flask throughout the titration
Explanation:
The end point of titration can be made easy by the use of indicators. But we have to be keenly observe for each drop from the burette because, the colour change will be sudden for a drop.
What is titration?Titration is an analytical technique used to determine the unknown concentration using a standard reagent of known concentration. The standard reagent of known concentration is called titrant and the one to be determined is called analyte.
Usually analyte is taken in a conical flask and titrant in a burette. The end point of titration is the point at which the reaction is completed in perfect stoichiometry.
In acid-base titrations, the indicators used having different colors in different pH. Hence, the indicator in the analyte will change in color when the acidity of the medium changes. We have to observe keenly for the color change because it happens for any drop.
The adding of titrant from the burette must be dropwise and thus we can get a time to notice the sudden colour change of indicator.
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Which element has 12 protons 12 neutrons and 12 electrons
Answer:
Magnesium
Explanation:
Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure.
ΕΛΑ
1
a
C
Copper(II) nitrate decomposes on heating. The reaction is endothermic.
2Cu(NO),(s) → 2CuO(s) + 4NO2(g) + 0,(9)
Sketch a reaction pathway diagram for this reaction to include the
activation energy
[3]
b Draw an energy cycle to calculate the standard enthalpy change for
this reaction, using enthalpy changes of formation.
[3]
Calculate the enthalpy change for this reaction using the following
enthalpy changes of formation.
AH, [Cu(NO, ),(s)] = -302.9 kJ mol-'
AH, [CuO(s)] =-157.3 kJ mol-!
AH [NO,(g)] = +33.2 kJ mol-!
[3]
d Copper(II) sulfate is soluble in water. A student dissolved 25.0 g of
copper(II) sulfate in 100 cm of water in a polystyrene beaker stirring
all the time. The temperature of the water fell by 2.9 °C.
i Calculate the enthalpy change of solution of copper(II) sulfate.
(specific heat capacity of water = 4.18 Jg1 °C ; relative
molecular mass of copper(II) sulfate = 249.7 g mol-')
[3]
ii Suggest one source of error in this experiment and explain how
the error affects the results.
[2]
[Total: 14]
This problem provides information about the decomposition of copper(II) nitrate to copper(II) oxide and dinitrogen monoxide; for example, it is endothermic, the enthalpies of formation and the chemical reaction, as well as copper (II) sulfate which when dissolved in water, exhibits a temperature decrease:
[tex]2Cu(NO_3)_2(s) \rightarrow 2CuO(s) + 4NO_2(g) + O_2(g)[/tex]
First of all, we can draw the reaction pathway as shown on the attached figure, by taking into account the positive enthalpy change as it is endothermic, so that the products turn out with higher energy than the reactants, for it to be positive. In addition, keep in mind that top point is the activation energy the reaction needs to take place.
Next, we calculate the enthalpy change for this reaction by using the general formula which subtracts the enthalpy of formation of products and reactants with each species' correct stoichiometric coefficient:
[tex]\Delta H=2\Delta _fH_{CuO}+4\Delta _fH_{NO_2}+\Delta _fH_{O_2}-2\Delta _fH_{Cu(NO_3)_2}[/tex]
So we plug in the given enthalpies of formation:
[tex]\Delta H=2(-157.3)+4(33.2)+(0)-2(-302.9)=424.0 kJ/mol[/tex]
Finally, we go over the calorimetry experiment, whereby the total heat absorbed by the copper(II) sulfate is calculated via the general heat equation, which includes the heat loss from the solution of water and the salt:
[tex]Q_{rxn}=-mC_w\Delta T\\\\Q_{rxn}=-(100+25)g*4.18\frac{J}{g\°C}*-2.9\°C=1515.25J[/tex]
By dividing the previous answer by the moles of salt:
[tex]n=25.0g*\frac{1mol}{249.7g}=0.100mol[/tex]
We can obtain the enthalpy change of solution of the copper salt:
[tex]\Delta _{dissolution}H=\frac{1,515.25J}{0.100mol} \\\\\Delta _{dissolution}H=15,134J/mol=15.1kJ/mol[/tex]
To conclude, it is important to note that one possible source of error is we are assuming the solution has the same specific heat to that of water and that is not necessarily true. Also, we are neglecting any heat transfer to and from the surroundings despite the polystyrene beaker is considered a heat isolator, which means the results cannot necesarilly be accurate and the enthalpy change could have turned out higher or lower in a rigoruous experiment.
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https://brainly.com/question/15862043https://brainly.com/question/11667877What is the frequency of yellow light, which has a wavelength of 5.56 x 10^-7 m?
O A) 5.40 x 10^14 m/s
O B) 5.40 x 10^14 Hz
O C) 1.85 x 10^15 m/s
O D) 1.85 x 10^15 Hz
The frequency of yellow light, which has a wavelength of 5.56 x 10^-7 m is 5.40 x 10^14 Hz. Therefore, option B is correct.
What do you mean by wavelength ?The distance between identical points (adjacent crests) in adjacent cycles of a waveform signal propagated in space or along a wire is defined as the wavelength. This length is typically specified in wireless systems in meters (m), centimeters (cm), or millimeters (mm) (mm).
The wavelength is the distance between two wave crests, and it is also the distance between two wave troughs. The frequency is measured in cycles per second (Hz) and is the number of vibrations that pass over a given spot in one second (Hertz).
Speed is distance over time, Therefore, v = λ / T.
The frequency, f, is 1/T, so the equation relating wave speed, frequency, and wavelength is v = c / λ .
Given :
Wavelength = 5.56 x 10^-7 m
Frequency = ?
Speed (c) = 3 × 10⁸m/s
v = c / λ
By substituting given values in equation and we get,
v = 3 × 10⁸ / 5.56 x 10^-7
= 5.40 x 10^14
The frequency of yellow light is 5.40 x 10^14.
Thus, option B is correct.
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which dilute acid is used to make sodium carbonate salt
Answer:
Sulfuric acid.
The sulfuric acid can react with common salt to produce Na2SO4, and after that you add CaCO3 and carbon to get Na2CO3
what do you mean by blood pressure is 130 19 mm of HG
Answer:
Hypertension stage 1 is 130-139 mm of HG
Helium (he) has two valence electrons, and these electrons are located in the 1s subshell. Without using the periodic table, in which group and period is helium located?.
helium is in group 8 and period 1
for each compound in the table below, decide whether there would be any hydrogen-bonding force between molecules of the compound, or between molecules of the compound and molecules of water.
Hydrogen bonding occurs between water and molecules that are polar in nature.
Even though the question is incomplete, I will try to help you to the best of my ability. Hydrogen bonding is formed when hydrogen is bonded to a highly electronegative atom.
Hydrogen bonding could occur between the molecules of a compound or between the molecules of a substance and water. Hydrogen bonding occurs between the molecules of a substances such as NH3, H2O and HF.
On the other hand, hydrogen bonding occurs between water and the compound in compounds such as CH2F2, amines, etc.
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You have 505 mL of a 0.160 M HCl solution and you want to dilute it to exactly 0.100 M. How much water should you add
This problem is providing information about the volume and concentration of HCl as 505 mL and 0.160 M respectively, and it is asking for the water that have to be added to prepare a 0.100-M solution.
In such a way, we work over the assumption of constant moles in dilution processes, so that we are able to write:
[tex]M_1V_1=M_2V_2[/tex]
Which relates de volume and concentration at the beginning and end of the experiment. This means we can solve for the resulting volume of the solution as a first calculation:
[tex]V_2=\frac{M_1V_1}{M_2}\\\\V_2=\frac{0.160M*505mL}{0.100M}=808mL[/tex]
Hence, the following amount of water must be added:
[tex]V_w=808mL-505mL=303mL[/tex]
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https://brainly.com/question/5480904https://brainly.com/question/435750When a penguin gives a pebble to a potential mate, what behavior are they displaying?
A. Dance
B. Nest Building
C. Gift Giving
D. Vocalization
Answer:
Explanation:
b
How to determine intermolecular forces.
Answer:
Incase you have H and F and another H and F
The predicted yield for a reaction was 10g of product. If the percentage yield for this reaction was 50%, how much product was formed?
The quantity of the product that was formed was 5g
From the question,
We are to determine the quantity of product formed. That is, the actual yield.
Using the formula
[tex]Percentage \ yield =\frac{Actual \ yield}{Theoretical\ yield} \times 100\%[/tex]
From the given information
Theoretical yield = 10g
Percentage yield = 50%
Putting the parameters into the formula, we get
[tex]50\% = \frac{Actual\ yield}{10} \times 100\%[/tex]
Then,
[tex]50\% = Actual\ yield \times 10\%[/tex]
∴ Actual yield = [tex]\frac{50\%}{10\%}[/tex]
Actual yield = 5g
Hence, the quantity of the product that was formed was 5g
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What equation explains the relation between amperes, watts and volts?
How often a wave occurs is the wave’s
A. crest.
B. frequency.
C. wavelength.
D. amplitude
Frequency – The frequency of a wave is the number of waves that pass a given point in a certain amount of time. Frequency is measured in units called hertz (Hz), and is defined as the number of waves per second. A wave that occurs every second has a frequency of 1 wave per second (1/s) or 1 Hz.
PLEASE HELP IM DESPERATE.
Assume you are performing the calibration step of Experiment 8 and you begin with 80 g of water at 20 oC and 80 g of water at 80 oC. After adding the two portions of water into your calorimeter setup and following the procedure outlined in the experiment, you determine the temperature of the mixed portions of water to be 45 oC. What is the heat capacity of the calorimeter?
Assume room temperature is 25 oC.
Answer:
Reaction time tests can be used to assess an individual's hand-eye coordination. One test involves catching a 1 metre ruler and measuring the distance, d in metres, that the ruler travelled before being caught. The reaction time t seconds is then calculated using the formula: = √2d/9.8
What is the pH of a 0.02 M HCl solution?
O A
1.7
B.
2.0
3.7
O
D.
4.0
Answer:
2 is answer of this question
7.
Wh
6
Which Lewis electron-dot diagram is correct for
CO2?
2-m
A :0
B.
:0:0:0
0:0
:
©:
::::C::0
D. 0
:0:0:
XX
Answer:
O=c=o
Explanation:
co2is nonpolar and it has linear molecular shape
Explain how magnesium is produced at the negative electrode in experiment 1.
The liquified (/molten) MgCl₂ dissociates into Mg²⁺ and Cl⁻ ions;
The Cl⁻ ions are drawn to the positive electrode (which has a deficit of electrons) where they deposit electrons since they are negatively charged;
This yields Cl atoms (these will form Cl₂ gas by covalent bonding and bubbles will be seen as this gas rises out of the liquid and it will enter the air);
These electrons will flow from the positive electrode to the negative electrode;
The Mg²⁺ ions, conversely, will be drawn to the negative electrode or cathode (which has a surplus of electrons partly from those the Cl⁻ ions lose) where they pick up electrons since they have a positive charge;
This yields pure magnesium.
The magnesium has been produced with the application of electric current for the production of ions that accumulate at the electrodes.
The setup has been for the electrochemical process. The sample in the molten state has been applied with the electric current. The current results in the dissociation of the sample into ionic constituents.
The opposite charge attracts negative charge. Thus, the negative ion moves towards the positive electrode, and negative ion move towards the positive electrode. The accumulation of ions has been obtained from the electrodes.
The magnesium chloride under the influence of electric field has been converted into the positive Mg ions and negative Cl ions. The positive Mg ion will move towards the negative electrode, and thus Mg has been produced.
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Why is productivity greatest near the ocean’s surface
Answer:
Sunlight penetrates the top layers of the ocean, so photosynthesis occurs there.
Explanation:
If the forces are balanced...
The net force is greater than zero
The net force is zero
The net force is less than zero
Answer:
the net force us 0.............
Explanation:
please mark brain
What defines an element?
Explanation:
each of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e. the number of protons in the nuclei of its atoms.
Which of the following are required for plants to carry out photosynthesis?
Answer:
To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight
which of the following statements about this reaction is true:
CH4+2O2-->CO2+2H2O+Heat
A. The reaction releases heat.
B. heat is absorbed by the reaction.
C. the reaction consumes water.
D.The reaction releases oxygen.
Explanation:?
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
The Correct statement is ~
A. The reaction releases heatAs we can observe, there's heat in product side of the given equation that shows - In the given reaction heat is released making it an exothermic reaction ~
I hope it helps ¡
[tex]\mathrm{✌TeeNForeveR✌}[/tex]
5) When rain falls to the earth, it just doesn't sit there. Instead, the rain water starts moving. Some of the precipitation seeps into the ground to replenishing groundwater. However, most of
it flows downhill as runoff. Runoff is important in filling rivers and lakes, but it also changes the landscape by erosion and can be a powerful mover. Flowing water is a powerful force,
capable of moving boulders and carving out canyons. Runoff has an impact on streams and rivers, but it also has an impact on the ocean system. What can you infer about the impact of
runoff on Ocean life? Choose ALL that apply.
A) Runoff drops a lot of sediment in the ocean, decreasing salinity.
B) Runoff builds up the coastline, depositing sediment, disrupting habitats of marine wildlife.
Runoff can lead to overgrowth of algae that can cause oxygen deprivation and create a dead zone.
D) Runoff carries pollutants into the ocean, causing illness and death of vulnerable marine populations.
) Runoff can carry bacteria, viruses and other pathogens from pet and livestock waste that can harm shellfish and other marine organisms.
Answer: Rain evaporates and this same process happens over and over again.
Explanation:
One of the following is not a property of metals
O a
high malleability
Oь
high compressibility
Os high melting point
Od
high ductility
Answer:
O b
Explanation:
high compressibility is not the property of metal.
Will tin reduce iron?
Answer: The iron equilibrium is the more positive, and so will go in the forward direction. The tin equilibrium is less positive (more negative), and will be driven backwards. So the tin(II) ions will reduce iron(III) ions to iron(II) ions. In the process, of course, the tin(II) ions will be oxidised to tin(IV) ions.
Explanation:
How could the student obtain zinc chloride solution from the reaction mixture when all the hydrochloric acid has reacted?
Answer:
zinc oxide is only sparingly soluble in water so best option is to add zinc oxide to diluted hydrocrolic acid
When all the hydrochloric acid (HCl) has reacted, the student can obtain zinc chloride (ZnCl) solution from the reaction mixture by adding ZnO to diluted HCl.
What is a mixture?
A mixture simply refers to a combination of two (2) or more substances or chemical compounds that are present in varied proportion, and they can be visibly seen with na-ked eyes.
In this scenario, the student can obtain zinc chloride (ZnCl) solution from the reaction mixture when all the hydrochloric acid (HCl) has reacted by adding zinc oxide (ZnO) to diluted hydrochloric acid (HCl) because it's sparingly soluble in water.
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How to find the partial pressure of a gas.
Answer:
The total pressure of a mixture of gases can be defined as the sum of the pressures of each individual gas: Ptotal=P1+P2+… +Pn. + P n . The partial pressure of an individual gas is equal to the total pressure multiplied by the mole fraction of that gas.
Using diving terms, partial pressure is calculated as: partial pressure = (total absolute pressure) × (volume fraction of gas component) For the component gas "i": pi = P × F.
the Periodic Table •
Class
Key Terms
Key Terms Ch. 4
Use the clues to help you unscramble the Key Terms from the chapter. Then put the
numbered letters in order to find the answer to the riddle.
Clues
Key Terms
1. A fast-moving electron
given off by a nucleus
during radioactive decay. tbaerlpiaect
2. A term used to describe a
material that can be pounded
into shape
llbeealam
3. The process of oxygen
reacting with a metal to
form rust
4. A particle in the atomic
nucleus that carries no
charge
5. A horizontal row across the
2
rsoooiner
3
ouetnrn
periodic table
roiedp
6. Substance that can only
6
conduct electric current
under certain circumstances. otmidsceuncro
7
7. A term used to describe a
material that can be drawn
into a long wire
lecuitd
8 9
8. Radioactive isotope that can be
followed through a chemical
reaction or an industrial
process
aerrtc
9. The elements in Group 18
of the periodic table
nreti ssgea
11 12
10. The very small center core
of an atom
13
10
cuunsle
Riddle: What chart shows the repeating properties of elements?
Answer:
1 2 3 4 5 6 7 8 9 10 11 12 13
Answer:
your question too long did not read all
Explanation:
help for brainlist
More than 7,000 islands in the Philippines lack access to electricity, so after the sun goes down, light usually comes through kerosene lamps. While cheap, these fire hazards are bad for the environment and human health.
You are an entrepreneur and would like to suggest to the government of the Philippines a better solution to this problem. But to come up with the solution to this problem, you must first understand the nature of chemical bonding and factors that control the structure of compounds. You will study and understand natural materials behavior to build a very cheap and environmentally friendly lamp.
What material do you think can be a cheaper and better alternative to kerosene?
Question 2 options:
There is no better alternative to kerosene.
A material that contains ions, so it can conduct electricity.
A material that contains gas, as gases can conduct electricity.
A material having covalent boding.
Answer:
Question 1: What material do you think can be a cheaper and better alternative to kerosene?
Answer: Generic lamp oil can be used to replace kerosene in lamps. The cheaper lamp oil burns cleaner and has less odor than the more expensive kerosene.
Question 2:
Correct answer is the last option
Hope this helps!
