15cm³ of a gaseous hydrocarbon were exploded with 120cm³ of oxygen. After cooling, 90cm³ of gas remained. After absorption with excess potassium hydroxide solution, 45cm³of residual oxygen were left. what is the molecular formula of the hydrocarbon (all measurements are under constant room temperature and pressure).​

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.