Answer:
HCl- polar, soluble in water
O2- nonpolar, insoluble in water
CaCl2- ionic, soluble in water
N2- nonpolar, insoluble in water
KNO3- ionic, soluble in water
BeCl2- nonpolar, insoluble in water
BCl3- nonpolar, insoluble in water
Explanation:
Ionic and polar substances are soluble in water while nonpolar substances are not soluble in water. Solubility in water has to do with dipole interaction with hydrogen and hydroxide ions which is possible only for ionic and polar substances as shown in the answers above.