Question

How much energy does it take to boil water for pasta? For a one-pound box of pasta

Answer 1

Answer:

a. 164°F

b. $91.\overline 1 \ ^{\circ} C$

c. $140.\overline 4$ kJ

Explanation:

The starting temperature of the water, T₁ = 48F

The temperature at which the water boils, T₂ = 212°F

a. The difference between the initial and the boiling water temperature, ΔT = T₂ - T₁

Therefore;

ΔT = 212°F - 48°F = 164°F

The temperature by which he temperature must be raised, ΔT = 164°F

b. 48°F = ((48 - 32)×5/9)°C = (80/9)°C = $8.\overline 8 \ ^{\circ} C$

212°F = ((212 - 32)×5/9)°C = 100°C

∴ ΔT = 100°C - $8.\overline 8 \ ^{\circ} C$ = $9.\overline 1 \ ^{\circ} C$

c. The heat capacity of the water = The heat required to increase four quartz of water by 1 °C = 15.8 kJ

∴ The heat required to raise four quartz of water by $9.\overline 1 \ ^{\circ} C$, ΔQ = 15.8 kJ/°C × $9.\overline 1 \ ^{\circ} C$ = $140.\overline 4$ kJ.