PLS HELP ASAP (no links) WILL MARK YOU

You find a ring with a mass of
13.5g. You fill a graduated
cylinder with 10 ml of water and
put the ring into the cylinder. The
water rises to 15 ml. What is the
substance?

Acommercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -35°c by rejecting waste heat to cooling water that enters the condenser at 18°c at a rate of 0.25 kg/s and leaves at 26°c. the refrigerant enters the condenser at 1.2 mpa and 50°c. if the compressor consumes 3.3 kw of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (c) the cop, and (d) the minimum power input to the compressor for the same refrigeration load.