<p>A compound with molar mass 180 is acylated with&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><msub><mi>H</mi><mn>3</mn></msub><mi>C</mi><mi>O</mi><mi>C</mi><mi>l</mi></math>&nbsp;to get a compound with molar mass 390. The number of amino groups present per molecule of the former compound is:</p>