1-13. find dry density, void ratio, and porosity: a. total mass is 101.4 g, total volume is 55.1 cm? , water content is 28.5%, and rd is 2.70 h density is 2.27 g/cm, water content is 8.5%, and rd is 2.64 .

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?