Answer:
T(final) = 26.2°C (3 sig. figs.)
Explanation:
Q = m·c·ΔT
m = mass of sample of interest = 20.0g
c = specific heat of sample of interest = 0.902j·g⁻¹·C⁻¹
ΔT = Temperature change = T(final) - T(initial) = T(f) - 2.5°C
Q = 427 joules
Q = m·c·ΔT => = ΔT = Q/m·c => T(f) = Q/m·c + T(i) = (427j/20.0g·0.902j·g⁻¹·C⁻¹) + 2.5°C = 26.16962306°C (calc. ans.) ≅ 26.2°C (3 sig. figs.)