Let’s implement the solution:
1. We write down the equation according to the problem statement:
X g -? m = 8.05 g;
Zn (OH) 2 + H2SO4 = ZnSO4 + 2H2O – ion exchange, zinc sulfate was obtained;
2. Calculations by formulas:
M Zn (OH) 2 = 99.3 g / mol;
M (ZnSO4) = 161.3 g / mol.
3. Determine the amount of salt, if the mass is known:
Y (ZnSO4) = m / M = 8.05 / 161.3 = 0.05 mol;
Y Zn (OH) 2 = 0.05 mol since the amount of these substances is 1 mol, which confirms the equation.
4. Find the mass of the original substance:
m Zn (OH) 2 = Y * M = 0.05 * 99.3 = 4.97 g.
Answer: to carry out the process, you will need zinc hydroxide weighing 4.97 g.
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