Answer: Please see below for answers
Explanation: Matching appropriate labels , we have
1)3/4 of the way to second equivalence point of a diprotic acid/strong base titration-- pH=pka₂
equivalence point of a weak base/strong acid titration=pH<7
equivalence point of a strong acid/strong base titration= pH=7
equivalence point of a weak acid/strong base titration=pH>7
half-way to equivalence point of a weak acid/strong base titration pH =pka
where
pH gives the measure of the amount of concentration of hydrogen ions in an aqueous solution.
pKa is known as acid dissociation constant which explains the equilibrum at which a chemical species can give out or receive proton
pka₂ is the acid dissociation constant for the second ionization energy.
Answer:
The answer is flattening
Explanation:
A physical change is generally something that affects the shape of form of the matter and a chemical change results from a chemical reaction. Flames are caused by chemical reactions, as is rust, and the process of a fruit becoming ripe. Thus, the answer is “flattening”.
Nitrogen makes up around 78% of the total atmosphere.
The given reaction is:
3Fe + 4H2O → Fe3O4 + 4H2
Given:
Mass of Fe = 354 g
Mass of H2O = 839 g
Calculation:
Step 1 : Find the limiting reagent
Molar mass of Fe = 56 g/mol
Molar mass of H2O = 18 g/mol
# moles of Fe = mass of Fe/molar mass Fe = 354/56 = 6.321 moles
# moles of H2O = mass of h2O/molar mass of H2O = 839/18 = 46.611 moles
Since moles of Fe is less than H2O; Fe is the limiting reagent.
Step 2: Calculate moles of Fe3O4 formed
As per reaction stoichiometry:
3 moles of Fe form 1 mole of Fe3O4
Therefore, 6.321 moles of Fe = 6.321 * 1/ 3 = 2.107 moles of Fe3O4
Step 4: calculate the mass of Fe3O4 formed
Molar mass of Fe3O4 = 232 g/mol
# moles = 2.107 moles
Mass of Fe3O4 = moles * molar mass
= 2.107 moles * 232 g/mol = 488.8 g (489 g approx)
