Answer: The molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.
Explanation:
Given:
= 43.6 mL,
= 0.125 M
= 25.0 mL,
= ?
Formula used to calculate the concentration of acid is as follows.

Substitute the values into above formula.

Thus, we can conclude that the molarity of an HCl solution is 0.218 M if 43.6 mL of a 0.125 M NaOH solution are needed to titrate a 25.0 mL sample of the acid.
Ans: Moles of Fe(OH)2 produced is 5.35 moles.
Given reaction:
Fe(s) + 2NiO(OH) (s) + 2H2O(l) → Fe(OH)2(s) + 2Ni(OH)2(aq)
Based on the reaction stoichiometry:
1 mole of Fe reacts with 2 moles of NiO(OH) to produce 1 mole of Fe(OH)2
It is given that there are:
5.35 moles of Fe
7.65 moles of NiO(OH)
Here the limiting reagent is Fe
Therefore, number of moles of Fe(OH)2 produced is 5.35 moles.
Answer: 240 cm³
Explanation:
Volume of the box = l × w × h
= (8 cm × 6 cm × 5 cm)
= 240 cm³