When scandium is boiled in water, 14.8 liters of gas are collected. Determinant of the mass of scandium that has reacted.

To solve the problem, let’s compose the reaction equation:
1. 2Sc + 6H2O = 3H2 + 2Sc (OH) 3 – redox reaction, hydrogen gas is released;
2. Let’s make calculations according to the formulas:
M (Sc) = 44.9 g / mol;
M (H2) = 1 * 2 = 2 g / mol;
3. Let’s calculate the number of moles of hydrogen:
1 mol of gas at n. y – 22.4 l;
X mol (H2) -14.8 L. hence, X mol (H2) = 1 * 14.8 / 22.4 = 0.66 mol;
4. Let’s make the proportion:
0.66 mol (H2) – X mol (Sc);
-3 mol – 2 mol from here, X mol (Sc) = 0.66 * 2/3 = 0.44 mol;
5. Find the mass of scandium:
m (Sc) = Y * M = 0.44 * 44.9 = 19.75 g.
Answer: the mass of scandium reacted is 19.75 g.