4. 5.

The image appears to be a page from a textbook or workbook containing a chemistry problem. Here's a summary of the problem and tasks, translated from Russian: 1. **Given**: - Mass fractions of elements in a compound (\( \text{MOH}_n \)): M = 40.1%, O = 16.4%, H = 5.0%. - Unbalanced chemical equation: \(\text{M}_x(\text{OH})_y + \text{KOH} \rightarrow \text{K}_w\text{M}_z\text{O}_t + \text{H}_2\text{O}\). 2. **Tasks**: 1. Determine which *M* and its compound correspond to given mass fractions. 2. Write and balance the chemical equation for the reaction described. 3. Calculate the ratio \( \frac{x+y}{z+t} \). 4. Name the products of the reaction, considering their structure and water molecules formed. You might need to calculate molar masses and balance the equation using stoichiometry to complete the tasks.