Explanation and Answer:
An endothermic change is a process that absorbs heat from the surroundings and cools the surroundings.
For example: the physical endothermic change of the melting process of a ice cube. The ice cube will absorb heat to melt and convert into liquid water.
1. mol = 77.56/100 = 0.7756 mol
2. mol = 2.55 × 10^24/6.02 × 10^23 = 4.236 mol mass = 4.236 × 74.5 = 315.582 g
3. mass = 0.0931 × 208.3 = 19.393 g
4. mol = 1.55 × 10^22/6.02 × 10^23 = 0.0257 mol
5. molecules = 0.664 × 6.02 × 10^23 = 3.997 × 10^23 molecules
6. mol = 86/242 = 0.355 mol
7. mol = 7.88 × 10^23/6.02 × 10^23 = 1.309 mol mass = 1.309 × 44 = 57.596 g
8. mass = 7.56 × 62 = 468.72 g
9. mol = 7.56/84 = 0.09 mol
10. mol = 8.55 × 10^21/6.02 × 10^23 = 0.014 mol mass = 0.014 × 58.5 = 0.819 g
recheck to ensure all answers are correct
