Question
Numerical Response (1 mark) 1. The minimum amount of heat energy required to completely evaporate 150 g of water expressed in scientific notation , is btimes 10^ast J. If the heat of fusion of water is 6.01kJ/mol and water's heat of vaporization is 40.65kJ/mol, what is the value of b correct to three significant digits? (Record your answer in the box on the right).
Solution
Expert Verified
4.7(325 Voting)
SilasExpert · Tutor for 3 years
Answer
Here's how to solve this problem:<br /><br />1. **Calculate the moles of water:**<br /> * The molar mass of water (H₂O) is approximately 18.015 g/mol.<br /> * Moles of water = mass / molar mass = 150 g / 18.015 g/mol ≈ 8.326 mol<br /><br />2. **Calculate the energy required for vaporization:**<br /> * Energy = moles × heat of vaporization <br /> * Energy = 8.326 mol × 40.65 kJ/mol = 338.3 kJ<br /><br />3. **Convert to joules and scientific notation:**<br /> * Energy = 338.3 kJ × 1000 J/kJ = 338300 J<br /> * In scientific notation, this is 3.383 × 10⁵ J<br /><br />4. **Identify the value of b:**<br /> * The question asks for the value of *b* in the expression *b* × 10^* J.<br /> * Therefore, *b* = 3.38 (rounded to three significant figures).<br /><br />**Final Answer:** 3.38<br />
Click to rate: