<span>a large amount of energy is released when water dissociates into oppositely charged ions.</span>
Answer:
See Explanation
Explanation:
The rate of a chemical reaction depends on certain factors. Some of these factors include; surface area, temperature, nature of reactants etc.
The trial that exhibits the slowest rate of dissolution of CuSO4 crystals is trial 2 because the crystals have a small surface area since the crystals were large. Also, the solution was not agitated or stirred to increase the rate of collision between the water and the CuSO4 crystals.
Increase in temperature, agitation of the reaction solution and high surface area increases the rate of collision between the water and CuSO4 crystals leading to a faster rate of dissolution. This occurs in trial 3.
Answer: Fe2O3
Explanation:
5.60 g Iron Oxide
- 3.92 g Iron
===========
= 1.68 g Oxygen
Convert Fe and O to moles:
3.92 g Iron/55.85 = 0.0702 moles Fe
1.68 g Oxygen/16 = 0.105 moles O
The ratio of O to Fe is 1.50. There are 3/2 O for each Fe. Multiply by 2 to get whole numbers: 2Fe for every 3O: Fe2O3
5L O2 x 1 mol O2/ 22.4L O2 x 2 mol H20/ 1 mol O2 x 22.4L H20/ 1 mol H20 = 10 L H2O
For future reference though, since its at STP that means that the coefficient are in proportion. Since oxygen has a coefficient of 1 and water has a coefficient of 2 for every 1 liter of oxygen there is 2 liters of water. Hence you started with 5 liters and ended with 10
Answer: B. A chemical Change
Explanation:
The Burning of paper changes the paper into a new substance (ash). So the ashes cannot be reversed into paper, therefore it is a chemical change.
