Question

If 420 Joules are added to 20 grams of water at 30°C, what will be the final temperature of the water?

A) 35°C
B) 40°C
C) 45°C
D) 50°C

Answer 1

A) 35°C.

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Answer 2

To calculate the final temperature of the water, we can use the formula Q = mcΔT. First, convert the mass of the water to kilograms. Then, calculate the heat added and use it to find the final temperature.

Step-by-step explanation:

To calculate the final temperature of the water, we can use the formula Q = mcΔT, where Q is the heat added, m is the mass of the water, c is the specific heat capacity of water, and ΔT is the change in temperature.

First, convert the mass of the water from grams to kilograms by dividing by 1000. Then, calculate the heat added by multiplying the mass in kilograms, the specific heat capacity of water (4.184 J/g°C), and the change in temperature. Finally, use this calculated value to find the final temperature using the formula ΔT = Q / (mc).

Let's calculate:

1. Convert the mass of the water to kilograms: 20 grams = 20/1000 = 0.02 kg
2. Calculate the heat added: Q = mcΔT = (0.02 kg)(4.184 J/g°C)(30°C)
3. Calculate the final temperature: ΔT = Q / (mc)

The final temperature is approximately 35°C, so the correct answer is A) 35°C.