What mass of toluene (C6H5CH3) was added to 208.0 g of benzene (CH) if the vapor pressure of benzene became 65.4 mmHg. The vapor pressure of pure benzene
is 74.7 mmHg at 17 °C. Answer to 1 decimal place.

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?

Why is it incorrect to balance a chemical equation by changing the subscripts? explain.