A 0.25 g sample of a pretzel is burned. The heat gives off is used to heat 50. G of water from 18 C to 42 C. What is the beefy value of the pretzel in kcal/g?

4.8 kcal/g

Explanation:

Given that:

mass of water = 50 g = 0.05 kg

specific heat capacity of water (c)= 1 kcal/K.kg

changes in temperature ΔT = 42°C - 18°C = 24°C

Since q = mcΔT

q = 0.05 × 1 × 24

q = 1.2 kcal

∴ 0.25 g sample of pretzel give 1.2 kcal of heat

as such 1 g of the sample will give out:

= 4.8 kcal/g

petroleum? coal maybe?