Answer:
Number of moles = 0.042 mol
Explanation:
Given data:
Number of moles = ?
Mass of calcium carbonate = ?
Solution:
Formula:
Number of moles = mass/ molar mass
now we will calculate the molar mass of calcium carbonate.
atomic mass of Ca = 40 amu
atomic mass of C = 12 amu
atomic mass of O = 16 amu
CaCO₃ = 40 + 12+ 3×16
CaCO₃ = 40 + 12+48
CaCO₃ = 100 g/mol
Now we will calculate the number of moles.
Number of moles = 4.15 g / 100 g/mol
Number of moles = 0.042 mol
A metal reacts with an acid to produce Hydrogen gas. I am sure of it
Answer:
0.99%
Explanation:
The Henderson-Hasselbalch equation relates the ratio of the ionized to the non-ionized form of an acid as follows:
pH = pKa + log([A⁻]/[HA])
Inserting the values for pH and pKa and solving gives:
7.4 = 5.2 + log([A⁻]/[HA])
2 = log([A⁻]/[HA])
[A⁻]/[HA] = 100/1
The percentage of the weak acid in non-ionized form (HA) is then calculated:
[HA]/([A⁻] + [HA]) = 1/(100+1) x 100% = 0.99&
