How much heat do you need to absorb in order to raise the temperature of 4kg water by 50 ℃? If all the energy is obtained by burning alcohol, how much alcohol do you need at least?

How much heat do you need to absorb in order to raise the temperature of 4kg water by 50 ℃? If all the energy is obtained by burning alcohol, how much alcohol do you need at least?

Q suction = cm (t-t0) = 4.2 × 10 & # 179; J / (kg ·℃) × 4kg × 50 ℃ = 8.4 × 10 ^ 5J
All this energy is obtained by burning alcohol
Q discharge = q suction
∵ q = MQ
Ψ M = q / Q = 8.4 × 10 ^ 5J / 3.0 × 10 ^ 7J / kg = 0.028kg
A: to raise the temperature of 4kg water by 50 ℃, it needs to absorb 8.4 × 10 ^ 5J heat? If all the energy is obtained by burning alcohol, it needs at least 0.028kg alcohol

How to use alcohol meter temperature conversion table

The alcohol concentration in the market is based on the alcohol meter at 20 ℃
The conversion table is too complicated to remember. It can be compared according to the empirical value. Take 20 ℃ as the standard. When the temperature increases or decreases by one degree, the alcohol content will differ by 0.3%. The alcohol content of one degree lower will increase by three points, and that of one degree higher will decrease by three points

The chemical formula of alcohol is CH3CH2OH. Try to find the mass ratio of each element in alcohol

Ethanol C2H5OH or c2h6o C: H: o = 12:3:8