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How much energy is required to take a 15.0 g sample of ice at −15.0°C to liquid water at 45.0°C?

A) 15.0 kJ
B) 90.0 kJ
C) 45.0 kJ
D) 60.0 kJ

User Tcrosley
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1 Answer

7 votes

Final answer:

The amount of energy required to take a 15.0 g sample of ice at -15.0°C to liquid water at 45.0°C is approximately 8.3 kJ.

Step-by-step explanation:

The amount of energy required to take a 15.0 g sample of ice at -15.0°C to liquid water at 45.0°C can be calculated using the formula:

Q = mcΔT + mL

Where:

  • Q is the total energy (in joules) required
  • m is the mass of the sample (in grams)
  • c is the specific heat capacity of ice (2.09 J/g°C)
  • ΔT is the change in temperature
  • L is the latent heat of fusion (334 J/g)

First, we need to calculate the energy required to heat the ice from -15.0°C to its melting point:

Q₁ = mcΔT = (15.0g)(2.09 J/g°C)(0 - (-15.0°C)) = 468.75 J

Next, we calculate the energy required to melt the ice:

Q₂ = mL = (15.0g)(334 J/g) = 5010 J

Finally, we calculate the energy required to heat the water from its melting point to 45.0°C:

Q₃ = mcΔT = (15.0g)(4.18 J/g°C)(45.0°C - 0) = 2827.5 J

Adding all the quantities of energy together:

Q = Q₁ + Q₂ + Q₃ = 468.75 J + 5010 J + 2827.5 J = 8306.25 J ≈ 8.3 kJ

Therefore, the amount of energy required is approximately 8.3 kJ. So, the correct answer is not listed among the given options.

User Dave Cohen
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