Asilver block, initially at 59.4 °c, is submerged into 100.0 g of water at 24.8 °c, in an insulated container. the final temperature of the mixture upon reaching thermal equilibrium is 26.2 °c.
what is the mass of the silver block?

The mass of silver block = 73.95 g

Explanation:

Given,

For water:

Mass = 100.0 g

Initial temperature = 24.8 °C

Final temperature = 26.2 °C

Specific heat of water = 4.184 J/g°C

For silver:

Mass = x g

Initial temperature = 59.4 °C

Final temperature = 26.2 °C

Specific heat of water = 0.2386 J/g°C

Heat gain by water = Heat lost by silver

Thus,  

Where, negative sign signifies heat loss

Or,  

So,  

Hence, the mass of silver block = 73.95 g

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.