Answer:
a)1661.55 J of energy is required
b) the molar heat capacity = 24.7 J /mol*°C
c) We need 1909 grams of arsenic
Step-by-step explanation:
Step 1: Data given
The specific heat capacity of arsenic is 0.33 J/g*K
Mass of As = 201.4 grams
Initial temperature = 273 K
Final temperature = 298 K
Step 2: Calculate the energy required to raise the temperature of 201.4 g As from 273 K to 298 K.
Q =m*c*ΔT
⇒with Q = the energy needed = TO BE DETERMINED
⇒with m = the mass of As = 201.4 grams
⇒with c = the specific heat capacity of Arsenic = 0.33 J/*K
⇒with ΔT = the change of temperature = 298 - 273 = 25 K
Q = 201.4 g * 0.33 J/g*K * 25 K
Q = 1661.55 J
Step 3: Calculate the energy required to raise the temperature of 1.0 mole of As by 1.0°C (called the molar heat capacity of arsenic)
Atomic mass of Arsenic = 74.9 g/mol
1 mol As has a mass of 74.9 grams
∆H = (moles * molar mass)* C* ∆T
⇒with ∆H= the molar heat capacity= TO BE DETERMINED
⇒with moles = 1.0 mol
⇒with molar mass = 74.9 g/mol
⇒with c= the specific heat capacity of arsenic = 0.33 J/g*°C
⇒with ΔT = the change of temperature = 1.0 °C
∆H = (1.0 mol * 74.9 g/mol) * (0.33J/g*°C) * 1 °C
∆H = 24.7 J /mol*°C
Step 4: It takes 1.26 kJ of energy to heat a sample of pure arsenic from 13.2°C to 15.2°C. Calculate the mass of the sample of arsenic
Q = m*c*ΔT
⇒with Q = the energy required = 1.26 kJ = 1260 J
⇒with m = the mass of arsenic = TO BE DETERMINED
⇒with c= the specific heat capacity of arsenic = 0.33 J/g°C
⇒with ΔT = the change of temperature = T2 - T1 = 15.2 °C - 13.2 °C = 2.0 °C
1260 J = m * 0.33 J/g°C * 2.0 °C
m = 1909 grams
We need 1909 grams of arsenic