<p>How many molecule are present in 12 L of liquid&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><mi>C</mi><msub><mi>l</mi><mn>4</mn></msub></math>&nbsp;?&nbsp; The density of the liquid is 1.59 g&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>c</mi><msup><mi>m</mi><mrow><mo>-</mo><mn>3</mn></mrow></msup></math>?</p>