The empirical formula for the compound can be determined using the following steps:

1. Convert the given masses to moles:

Moles of nitrogen = 26.19 g / 28.01 g/mol = 0.935 mol

Moles of hydrogen = 7.55 g / 1.008 g/mol = 7.49 mol

Moles of chlorine = 66.26 g / 35.45 g/mol = 1.87 mol

2. Divide each number of moles by the smallest number of moles to get the simplest whole-number ratio:

0.935 mol / 0.935 mol = 1

7.49 mol / 0.935 mol ≈ 8

1.87 mol / 0.935 mol ≈ 2

3. The simplest whole-number ratio is approximately 1:8:2.

4. Multiply the subscripts of the elements by an appropriate factor to obtain whole numbers. In this case, we can multiply all subscripts by 2 to get:

2(1) = 2

2(8) = 16

2(2) = 4

Therefore, the empirical formula for the compound is NH4Cl2.