Answer:
11.25 moles of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
C₃H₈ + 5O₂ —> 3CO₂ + 4H₂O
From the balanced equation above,
1 mole of C₃H₈ reacted with 5 moles of O₂.
Finally, we shall determine the number of mole of O₂ needed to react with 2.25 moles of C₃H₈. This can be obtained as follow:
From the balanced equation above,
1 mole of C₃H₈ reacted with 5 moles of O₂.
Therefore, 2.25 moles of C₃H₈ will react with = 2.25 × 5 = 11.25 moles of O₂.
Thus, 11.25 moles of O₂ is needed for the reaction.
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.
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
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
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.What is the subscript of Carbon in Isovaleric acid C5H10O2
the electron configuration of an element in its ground state is illustrated above. which, if any, of the three principles that determine the most stable electron configuration of an element does this configuration disobey
Answer:
hello your question is incomplete attached below is missing part
answer : Pauli's exclusion principle
Explanation:
The principle that was disobeyed is Pauli's exclusion principle this is because the Pauli's exclusion principle states that no two electrons can have the same set of quantum number.
In Box A the two electrons , have the same spin which means they have the same quantum number ( disobeys Pauli's exclusion principle )
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.
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
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.