Show caleulations and be mindful of significant figures for full credit. 1. A sa
ID: 587058 • Letter: S
Question
Show caleulations and be mindful of significant figures for full credit. 1. A sample of a metal with a mass of 2.74 g that might be gold was warmed to 72.1"C. It was put into a Styrofoam calorimeter where the 15.2 g of water present was initially at 24.70. At equilibrium, the final temperature was recorded to be 26.3. Answer the following questions: Mass of the metal Mass of the water Initial temperature of metal Initial temperature of water Final temperature AT waber (0.5 pt.) 2.74 g 15.2 g 72.1 C 24.7°C 26.3 ATmetal (0.5 pt.) qH20 (SH. water = 4.18 J/g°C) use equation (4 pt.) metal use equation 2 (0.5 pt.) Specific heat of metal use equation 3 (4 pt.) J/g C Is it gold? (see text table 6.4) (0.5 pt.) SH of gold Is this gold? Yes No (circle answer) Continued next page)Explanation / Answer
a)
dT = Tf- Ti = 26.3-24.7 = 1.6°C
b)
dTmetl = 26.3 - 72.1= -45.8°C
c)
Qwater = m*C*dT
qwater = 15.2*4.18*1.6
Qwater = 101.6576 J
c)
Qmetal = m*C*(Tf-Tm)
101.6576 = 2.74 * Cp * (-45.8)
d)
Cp -->
Cp = -101.6576 / (2.74 * (-45.8)) = 0.8100 J/gC
this is NOT gold, it has 0.12 J/gC which is not 0.81