Answer:
25.88 g of F₂.
Explanation:
From the question given above, the following data were obtained:
Number of molecules of F₂ = 4.10×10²³ molecules
Mass of F₂ =?
From Avogadro's hypothesis,
1 mole of F₂ = 6.02×10²³ molecules
Next, we shall determine the mass of 1 mole of F₂. This can be obtained as follow:
1 mole of F₂ = 2 × 19 = 38 g
Thus,
38 g of F₂ = 6.02×10²³ molecules
Finally, we shall determine the mass of 4.10×10²³ molecules of F₂. This can be obtained as follow:
6.02×10²³ molecules = 38 g of F₂
Therefore,
4.10×10²³ molecules = 4.10×10²³ × 38 / 6.02×10²³
4.10×10²³ molecules = 25.88 g
Thus, 25.88 g of F₂ contains 4.10×10²³ molecules.
What is the subscript of Carbon in Isovaleric acid C5H10O2
The half-life of the radioactive isotope polonium-218 is 3.05 minutes.
How long will it take for the activity of a sample of polonium-218 to decrease from 2.81E4 Ci to 3.52E3 Ci?
Answer: It will take 9.13 minutes for the sample.
Explanation:
Expression for rate law for first order kinetics is given by:
[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
where,
k = rate constant
t = age of sample
a = initial amount of the reactant = [tex]2.81\times 10^4[/tex]
a - x = amount left after decay process = [tex]3.52\times 10^3[/tex]
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
[tex]t_{\frac{1}{2}}=\frac{0.693}{k}[/tex]
[tex]k=\frac{0.693}{3.05min}=0.227min^{-1}[/tex]
b) for activity to decrease from 2.81E4 Ci to 3.52E3 Ci:
[tex]t=\frac{2.303}{0.227}\log\frac{2.81\times 10^4}{3.52\times 10^3}[/tex]
[tex]t=9.13min[/tex]
Thus it will take 9.13 minutes for the sample.
[tex]t_{99.9}=40min[/tex]
The time after which 99.9% reactions gets completed is 40 minutes
If the molecules in the above illustration react to form NH3 according to the equation N2 3 H2 2 NH3 , the limiting reagent is , the number of NH3 molecules formed is , and the number of molecules in excess is
Answer:
Follows are the solution to these question:
Explanation:
Given equation:
[tex]N_2+3H_2 \longrightarrow 2NH_3[/tex]
In this equation:
[tex]1 N_2[/tex] gives [tex]= 2NH_3[/tex]
so,
[tex]3N_2[/tex] gives= [tex]2 \times 3 = 6 NH_3[/tex]
similarly:
[tex]3H_2[/tex] gives [tex]= 2NH_3[/tex]
So, [tex]6H_2[/tex] gives = [tex]\frac{2}{3}\times 6=4NH_3[/tex]
Its limited reagent is =[tex]N_2[/tex]
The amount of [tex]NH_3[/tex] molecules were formed = 4.
and the amount of [tex]H_2[/tex] excess molecules are= 1
what element is stored in the shells and skeltyons of living organisims?
Answer:
carbon
Explanation:
Many organisms use carbon to make calcium carbonate, a building material of shells and skeletons. Other chemical processes create calcium carbonate in the water. The using up of carbon by biological and chemical processes allows more carbon dioxide to enter the water from the atmosphere.
What is the molecular formula of the product formed from the oxidation of 2-methyl-2,3-pentandiol with Jones reagent (CrO3, H , H2O)
Answer:
C6H12O2
Explanation:
The Jones reagent is a reagent in organic chemistry used to convert primary alcohols to carboxylic acids and secondary alcohols to ketones. Recall that tertiary alcohols can not be oxidized.
The compound 2-methyl-2,3-pentandiol contains one secondary and one tertiary alcohol. The secondary alcohol is oxidized to a ketone while the tertiary alcohol is not oxidized.
Hence the product of the oxidation using Jones reagent is 2-Hydroxy-2-methyl-3-pentanone with the molecular formula C6H12O2.
Consider the pair of solvolysis reactions. Draw the organic products, then predict the type of substitution mechanism and compare the expected rates.
Answer:
See explanation
Explanation:
Solvolysis is a chemical reaction in which the solvent, such as water or alcohol, is one of the reagents and is present in great excess of that required for the reaction. The solvents act as or produce electron-rich atoms or groups of atoms (nucleophiles) that displace an atom or group in the substrate molecule(Encyclopedia Britannica).
For the two reactions, the organic product is the same(the product is drawn in the second image attached). The both reactions occur by SN1 mechanism since the substrate is a tertiary alkyl halide. The nucleophile is CH3OH and the rate of reaction depends on the concentration of the alkyl halide and independent of the concentration of methanol present.
Therefore, changing the volume of the solvent has no effect on the rate of reaction. The two reactions proceed at exactly the same rate since the initial concentration of the alkyl halide is the same for both reactions.
Advantages and disadvantages of Reversible Fuel Cell..
Answer:
Hydrogen fuel cells do not produce any CO2 emissions during operation, even if their production is not necessarily carbon-free. This gives them an advantage over combustion engine vehicles, which can emit small amounts of poisonous carbon monoxide and require well-ventilated rooms for indoor use.
Hi! I need some solar system facts!
Answer: I can help with that!
Explanation: 1.The tremendous growth in the U.S. solar industry is helping to pave the way to a cleaner, more sustainable energy future. Over the past few years, the cost of a solar energy system has dropped significantly -- helping to give more American families and business access to affordable, clean energy.
Through a portfolio of R&D efforts, the Energy Department remains committed to leveraging America’s abundant solar energy resources -- driving research, manufacturing and market solutions to support widespread expansion of the nation’s solar market.
2.The amount of sunlight that strikes the earth's surface in an hour and a half is enough to handle the entire world's energy consumption for a full year. Solar technologies convert sunlight into electrical energy either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation. This energy can be used to generate electricity or be stored in batteries or thermal storage.
Below, you can find resources and information on the basics of solar radiation, photovoltaic and concentrating solar-thermal power technologies, electrical grid systems integration, and the non-hardware aspects (soft costs) of solar energy. You can also learn more about how to go solar and the solar energy industry. In addition, you can dive deeper into solar energy and learn about how the U.S. Department of Energy Solar Energy Technologies Office is driving innovative research and development in these areas.
3.Solar radiation is light – also known as electromagnetic radiation – that is emitted by the sun. While every location on Earth receives some sunlight over a year, the amount of solar radiation that reaches any one spot on the Earth’s surface varies. Solar technologies capture this radiation and turn it into useful forms of energy.
Copper roofs on houses form patina (copper carbonates) over the course of years due to the reaction with oxygen, carbon dioxide and water in the air. Which of the following statements is incorrect for this process?
A) The reaction has a low activation energy.
B) The reaction has a low reaction rate.
C) The formation of patina would occur faster during the summer than the winter.
D) The formation of patina would occur slower at higher altitudes due to lower concentration of reactant. E) Adding a catalyst would increase the rate of patina formation.
Answer:
The answer is "Choice A".
Explanation:
In this question, the choice A is wrong because when the copper panels on houses produce a patina (copper oxide) through occur as a consequence of reactions from oxygen and water in the air, these reaction does not have low activation energy because lower activation energy that is stored in a faster response rate.
Why is an electron ejected when green light hits the metal?
Explanation:
If a large photon strikes the surface, that has enough strength to take out an electrode, which will then travel to the positive side since it is negative. Current is flowing at this stage. Since the reduced photons will be unable to distinguish between atoms, no power can pass.
Consider two reactants (A and B) that when mixed form a precipitate C, which can be filtered, dried, and then weighed. Carlos attempts to find the stoichiometric ratios in which A and B mix, by mixing different volumes of the same concentration of solutions of A and B (0.50 M). He records the following data:
Run Vol A (mL) Vol B (mL) Mass C (g)
1 10.0 10.0 1.17
2 20.0 10.0 2.33
3 30.0 10.0 3.50
4 40.0 10.0 3.50
Assuming that the products of the reaction are C and D, and that the stoichiometric coefficients for C and D are 1 and 2 respectively, the balanced chemical reaction will be
( ) A + ( ) B â 1 C + 2 D
Answer:
3A + B → C + 2D
Explanation:
Recall that:
[tex]\text{molarity} = \dfrac{no \ of \ moles}{volume \ of \ the \ solution}[/tex]
So;
[tex]\text{no \ of \ moles= molarity * volume \ of \ the \ solution}[/tex]
From the above table given in the question; we can have the following table:
Run moles of A moles of B Limiting reagent
1 0.5× 10⁻² 0.5× 10⁻² A and B are equal
2 1.0 0.5× 10⁻² 0.5× 10⁻² A
3. 1.5× 10⁻² 0.5× 10⁻² A
4 2.0× 10⁻² 0.5× 10⁻² B
Also, provided that the stoichiometric coefficients for C and D = 1 & 2 respectively.
Then, the stiochiometric ratio for A:B = [tex]\dfrac{1.5\times 10^{-2}}{0.5 \times 10^{-2}}[/tex]
[tex]= \dfrac{3}{1}[/tex]
Thus, the balanced equation is:
3A + B → C + 2D
Iron is a transition element. transition elements that make them different from non-transition metals
such as magnesium.
Answer:
Transition metals differ from the non-transition metals such as magnesium in the following ways;
They have variable oxidation statesFormation of complex ions.Formation of colored ions.Transition metals both in the elemental and compound forms can serve as catalysts.Explanation:
Transition elements comprise of those elements in the d-block of the periodic table and which have incompletely-filled d-orbitals.
The transition elements are all metals and has the characteristic physical properties of metals such as;
high melting and boiling points,good conductors of heat and electricity,metallic lusterhigh densitiesmalleability and ductilityHowever, their chemical properties differ from those of the non-transition metals such as magnesium in the following ways;
They have variable oxidation states - the transition metals exhibit variability in their oxidation states because of the close similarity in the energies of the 4s and 3d electrons which are available for bond formation. For example, while magnesium has only one oxidation state of +2, vanadium a transition metal can have oxidation states of +2, +3, +4 and +5.Formation of complex ions - A complex ion consists of a central metal atom or ion to which several other atoms, ions or molecules are bonded. For example, blue tetramine copper (ii) ion, [Cu(NH₃)]²⁺.Formation of colored ions - unlike non-transition metal ions, the ions of transition metals are usually colored. For example, Copper (ii) ions, Cu⁺ are blue, Chromium (ii) ions, Cr³⁺, are green, etc.Transition metals both in the elemental and compound forms can serve as catalysts. For example, finely divide nickel serves as a catalyst in the hydrogenation of vegetable oil to margarine, while vanadium (v) oxide serves as a catalyst in the contact process for the manufacture of tetraoxosulfate (i) acid.how can natural selection can cause organisms to change over generations.
Answer:
Natural selection changes how well a species can survive in an environment.
Explanation:
I'm not the best at biology, but natural selection a term we use that's describes nature's way of choosing the strongest to survive. The species with the strongest adaptations will survive while the others will die off. For example, if a school of fish was forced to live in a colder habitat than usual, over many years some fish will adapt to that environment and be able to withstand it. But, some fish won't get those adaptations and be killed off. But, future generations will be born with that ability to withstand the cold environment and it would become normal. So, natural selection changes the way a species lives. Hope this helps
Identify which trends in the diagrams below describe
atomic radius, ionization energy, electron affinity,
and electronegativity
Explanation:
the atmoc radius across the period
Atom radius as you move form left to right the atomic in the period table atomic radius decrease do to decrease the number of shell and it causes the Electron closed to nucleus. and also cause to decrease the inozation engey, electronegative andelectro affinity....... in the group the atomic radius increase as you move down the group do to increase number of shell because the Electron are far-away to the nuclear and it causes the small amount of energy to ionization so that the ionization engey , electronaffity and electronegative are increase“Sound plays an important role in our lives”. Give two points in support of this statement.
Answer:
First job out of college was in an industrial manufacturing setting. Was told by plant engineer to walk around, get used to normal sounds. He stressed anything "abnormal" is a noise more so than a sound. Report abnormalilies to supervisor immediately!! So essentially sounds are giving us warnings something is abnormal.Sounds also provide feedback. Say you are performing an experiment, requires boiling water to sanitize. Start the burner under a vessel, go on about other preparations. Sound of water boiling will trigger setting a timer for how long to let it boil.Get off work, pleasant music, nature sounds can help us decompress from a stressful day on the job.Hope some of these give you impetus to think of other bullet points, sounds good to me. !!
Explanation: