The <span>henderson-hasselbalck equation is this
pH = pK + log [salt]/[acid]
We are given with
pH = 4.00
</span><span>1.50 l of 0.0200 m solution of benzoic acid
The pK for benzoic acid is
4.20
Solving for the moles of salt,
4 = 4.2 + log 1.5(0.02)/n
n = 71.62 moles
The mass is
m = 71.62 (249.2)
m = 17800 grams</span>
Answer:
The student did not have enough of the compound
Explanation:
So
As the student needs 125 g of the compound therefore the available bottle isnot enough for him.
So, the student didnot have enough of the compound
Answer:
2.56 grams of H₂S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH₃COO)₂
Explanation:
The balanced reaction is:
Pb(CH₃COO)₂ + H₂S → 2 CH₃COOH + PbS
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) they react and produce:
- Pb(CH₃COO)₂: 1 mole
- H₂S: 1 mole
- CH₃COOH: 2 moles
- PbS: 1 mole
In this case, to know how many grams of H₂S are needed to produce 18.00 g of PbS, it is first necessary to know the molar mass of the compounds H₂S and PbS and then to know how much it reacts by stoichiometry. Being:
- H: 1 g/mole
- S: 32 g/mole
- Pb: 207 g/mole
The molar mass of the compounds are:
- H₂S: 2* 1 g/mole + 32 g/mole= 34 g/mole
- PbS: 207 g/mole + 32 g/mole= 239 g/mole
So, by stoichiometry they react and are produced:
- H₂S: 1 mole* 34 g/mole= 34 g
- PbS: 1 mole* 239 g/mole= 239 g
Then the following rule of three can be applied: if 239 grams of PbS are produced by stoichiometry from 34 grams of H₂S, 18 grams of PbS from how much mass of H₂S is produced?
mass of H₂S= 2.56 grams
<u><em>2.56 grams of H₂S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH₃COO)₂</em></u>
The question is all about which among the given choices is true or properly describes the valence electron of the metallic bonds. These valence electrons of the metallic bond is shared amongst many atoms so that the metals can be bounded together. Hope this answers your qn. :)
<span>Atoms are at their most stable when their outermost energy level is either empty of electrons or filled with electrons.</span>