When salting cucumbers, 90 g of salt is taken per 1 liter of water, which is the mass fraction of salt in this solution.

1) Find the mass of 1 liter of the resulting solution for pickling cucumbers, taking into account that the mass of 1 liter of water = 1000 g:

mass of solution = mass of solvent + mass of solute = 1000 + 90 = 1090 (g).

2) Calculate the mass fraction of salt in this solution using the formula:

mass fraction of solute in solution = mass of solute: mass of solution * 100%.

Let’s substitute the initial data from the problem statement into this formula:

mass fraction of salt = mass of salt: mass of solution * 100% = 90: 1090 * 100% = 8.25%.