Question

1. Calculate the amount of heat required for 25.0 grams of water to

Answer 1

Answer:

1. 2090 J

2. 113,000J

3. 33,900J

4. -209.2 J

5. 2g

Explanation:

Note: specific heat capacity of water is 4.184 J/g°C.

1. The amount of heat can be calculated using the formula:

Q = m × c × ∆T

Q = 25 × 4.184 × (30 - 10)

Q = 104.6 × 20

Q = 2092 J

Q = 2090 J (nearest tens)

2. This question can be solved using the latent heat of vaporization of water. The latent heat of vaporization of a substance is the amount of heat required to convert a unit gram of a liquid into vapor without a change in temperature. The latent heat of vaporization of water per gram is:

2257 J/g

For 50grams of water, amount of heat that will be required will be: 50 × 2260

= 113,000J

3. For 15g of water, the amount of heat will be 15 × 2260 (latent heat of vaporization)

= 33,900J

4. Q = m × c × ∆T

Q = 5 × 4.184 × (40 - 50)

Q = 20.92 × (-10)

Q = -209.2 J

5. Q = m × c × ∆T

84 = m × 4.184 × (35 - 25)

84 = m × 4.184 × 10

84 = 41.84m

m = 84/41.84

m = 2.0076

m = 2g