How many grams of steam at 100C must be mixed with 200g of water at 20C in order for the equilibrium temperature to be 50C?

1 answer

the sume of heats is zero...

Heat to heat water + heat or condense steam+heat to cool steam=0

200*cw*(50-20)+Hv*m + m*Cw*(50-100)=0
solve for mass m.