Calculate the volume of the solution with a mass fraction of potassium hydroxide of 44% and a density of 1.46 g / ml

Calculate the volume of the solution with a mass fraction of potassium hydroxide of 44% and a density of 1.46 g / ml for dissolving aluminum weighing 8.1 g. What volume of hydrogen (n.o.)

Decision:
The reaction equation has the form;
2Al + 2KOH + 6H2O = 2K [Al (OH) 4] + 3H2 ↑
We find the mass of KOH spent on dissolving aluminum from the proportion, we get:
8.1g: xg = (2.27): (2.26);
x = [(2. 56). 8.1] / (2.27) = 16.8g.
Find the mass of the solution, we get:
m (p-pa) = [m (KOH). 100%] / 44% = (18.6 g. 100%) / 44% = 38.18 g.
Find the volume of the KOH solution, we get:
V (KOH) = m (p-pa) / p (p-pa) = 38.18 / 1.46 = 26.15 ml.
We find the amount of hydrogen that is released during the reaction from the proportion, we get:
8.1 g g: y l = (2.27) g: (3.22.4) l;
y = [8.1g. (3 .22.4) L] / (2.27) g = 10.8L.
Answer: V (KOH) = 26.15 ml; V (H2) = 10.8 l.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.