Pure gold and silver have densities of 19,300 kg/m^3 and 10,500 kg/m^3, respectively. If a jeweler uses 0.25 cm^3 of metal to make a ring, then how much heavier (in grams) is the gold ring compared to the silver ring? Explain.

8.29 two streams containing pyridine and acetic acid at 25°c are mixed and fed into a heat exchanger. due to the heat-of-mixing effect, it is desired to reduce the temperature after mixing to 25°c using a stream of chilled ethylene glycol as indicated in the diagram. calculate the mass flow rate of ethylene glycol needed. the heat capacity of ethylene glycol at these conditions is approximately 2.8 kj/(kg k), and the enthalpy change of mixing (δmixh) is given below.