Answer:
0.375 L
Explanation:
We know that at neutralization, the number of mol of acid must equal the number of equivalents of base.
This is a reaction 1:1 acid to base:
HClO₄ + NaOH ⇒ NaClO₄ + H₂O
We re given the moles of the base indirectly since we know the volume and molarity. From there we can calculate the volume of HClO₄.
Moles NaOH = 0.115 L x 0.244 M = 0.115 L x 0.244 mol/L =0.028 mol
Thus we require 0.028 mol of HClO₄ in the pechloric acid solution:
Molarity = # moles / V ⇒ V = # moles / M
V = 0.028 mol / 0.0748 mol/L = 0.375 L
Note that this problem can be solved in just one step since
M(HClO₄) x V(HClO₄) = M(NaOH) x V(NaOH) ⇒
V(HClO₄) = M(NaOH) x V(NaOH) / M(HClO₄)
Answer:
C. Their properties change completely.
Explanation:
The electron configurations of the elements show a periodic variation with increasing atomic number. Consequently, there are also periodic variations in physical and chemical behavior.
When atoms interact to form a chemical bond, they combine in order to <u>achieve a more stable electron configuration.</u> As a consequence, the compounds formed exhibit completely different properties.
For example, when solid magnesium burns in air, it forms both magnesium oxide and magnesium nitride, which are gases.
You need to list the elements but remember that fluorine has the highest electronegativity out of the entire periodic table
