6H2O + P4O10 = 4H3PO4
Coefficients: 6, 1, 4
The three beams on a triple beam balance all are different. Each beam should have a differnet unit of measurement. For example, one beam may count in 100's and the other beam may count in 10's and the last beam may count in 1's.
Answer:
7430.5 Joules (7.4*10^4 Joules)
Explanation:
Q=mc∆T
where Q is energy in Joules.
Now m=250 g
c= 0.386 J/g°C
∆T = 99 - 22 = 77 °C
plugging the values in gives
Q=250*0.386*77=7430.5 Joules
(7.4*10^4 Joules, if 2 significant figures)