Answer:
0.0071g
Explanation:
From the question, we know that the molarity of the BaCl2 is 0.00237M. This means there are 0.00237 moles in 1dm^3 or 1000cm^3 of solution.
We also know that 35ml of the BaCl2 reacted. Here, we need to calculate the number of moles in 35.7ml of BaCl2.
This is calculated as follows;
0.00237moles are in 1000cm^3
Thus x moles will be present in 35ml ( we should note that cm^3 is same as ml)
X = (0.00237 × 35) ÷ 1000 = 0.00008295 moles.
From the reaction equation, we can see that 2 moles of BaCl2 yielded 1 mole of Ba(OH)2.
This means 0.00008295mole of BaCl2 will yield 0.00008295 ÷ 2 = 0.000041475 moles of Ba(OH)2.
To calculate the mass of Ba(OH)2 formed, we simple multiply the number of moles yielded by the molar mass of Ba(OH)2.
Molar mass of Ba(OH)2 = 137 + 2(17)
= 171g/mol
Mass = 171 × 0.000041475 = 0.007092225g
Answer:
Explanation:
Hello,
Among the options given on the attached document, since phenolic functional group is characterized by a benzene ring bonded with a hydroxyl group (C₆H₅OH) we can see that the first option correctly points out such description. Thus, answer is on the second attached picture. Other options are related with other sections found in eugenol that are not phenolic.
Best regards.
Answer
a) A solution with a hydronium molarity of 0.00045 is acidic. True
Doing the calculus of pH
![pH= -Log [H^{+}] = -Log (0.00045)](https://tex.z-dn.net/?f=pH%3D%20-Log%20%5BH%5E%7B%2B%7D%5D%20%3D%20-Log%20%280.00045%29)
b) pH is a way to express the hydronium concentration over a wide range. True
pH means –Log[H+] and this value is used to express a wide range of hydronium concentration sometimes obtaining pH minor than zero.
c) Percent K and Fe are determined by doing ion exchange then a pH titration. False
Usually, Fe is determined by redox titration with potassium permanganate due to it’s more accurate. On the other hand, K is determined usually by volumetric process which includes precipitation like potassium picrate precipitate
d) About 0.2M HCl is the reagent used for the pH titrations. False.
In order to do pH titration, it is possible to use a wide range of HCl concentrations and other acids as reagent if the analyte is a basic compound. Otherwise, if the analyte is an acid compound you should use a basic compound as reagent.
e) A Lewis base is specie that can donate a proton to an acid. False
A Lewis base is an electron pair donor.
Answer is: selenium (Se).
1) electron configuration: ₃₄Se 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp⁴.
2) ₃₃As 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp³.
3) ₃₆Kr 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp⁶.
4) ₃₁Ga 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4sp¹.
Valence electrons of selenium are 4s²4sp⁴.
Answer:
H+/H3O , H2O
Explanation:
The ability to be a proton donor is the Bronsted-Lowry definition of acids. The Lewis definition of an acid is an electron pair acceptor, which covers molecules liKE BF3
The ability to accept a pair of electrons is what is common to all acids, not the ability to be a proton donor.
All acid solutions contain hydronium ions (H3O+), hydroxide ions (OH-) and water molecules. Each different acid solution will then have an anion that is exclusive to that acid. For example, hydrochloric acid solution will contain all of the above and chloride ions (Cl-).
All acids contain the acidic substance dissolved in water. Water naturally dissociates to a small amount, creating hydronium and hydroxide ions. But most of the water remains as water molecules.
Then when we add an acid, like HCl, the oxygen on the water attracts the hydrogen from the HCl. The electrons in the covalent bond remain with the chlorine, giving it a negative charge and thus it becomes the chloride ion (Cl-). The hydrogen now has a positive charge and as said before, is attracted to the water (specifically the lone pair of electrons on the oxygen) to create hydronium ions.
This creates extra hydronium ions, making the solution acidic. But remember, there are still water molecules, hydroxide ions and the negative ion all in solution for all acids.
