Oh no! Billy forgot that his calorimeter should have 2 coffee cups to contain all the heat. If Billy dropped a 25.0 g piece of solid iron (Cs= 0.449 J/g°C) at 398 K in a coffee cup containing 25.0 mL of water at 298K and because of his mistake, 21% of the heat that should be transferredfrom the iron to the wateris lost to the atmosphere, calculate the final temperature of the iron water mixture?

Explanation:

Let the final temperature be T .

heat lost by iron = mass x specific heat x decrease in temperature

= 25 x .449 x ( 398 - T  )

Heat applied to increase the temperature of water

= 25 x .449 x ( 398- T  )  x .79  [ 21 % is lost ]

= 8.86775 ( 398 - T  )

heat gained by water = 25 x 4.2 x ( T - 298 )

Both of them are equal

8.86775 ( 398 - T  )  = 25 x 4.2 x ( T - 298 )

8.86775 ( 398 - T  )  = 105 x ( T - 298 )

105 T + 8.86775 T = 105 x 298 + 398 x 8.86775

113.86775 T = 31290 + 3529.36

113.86775 T = 34819.36

T = 305.78 K .

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

6.4 cm (max) - 25 cm (min)