Answer:
1200 J/K
Explanation:
The formula for the entropy associated with a reversible phase change is
1. Calculate q
For a reversible phase change like melting,
2. Calculate ΔS
Answer:
A. 0.31 mol NaNO2
Explanation:
Buffer solutions are the solutions that resist changes in pH on addition of small amount of acid or base.
Buffer solutions usually contain the mixture of a weak acid and its salt, or a weak base and its salt.
Among the options listed in the question, only NaNO2 is the salt formed from the nitrous acid.
Answer:
The mole fraction of ethanol is 0.6. A 10 mL volumetric pipette must be used for to measure the 10 mL of ethanol. The vessel should be clean and purged.
Explanation:
For calculating mole fraction of ethanol, the amount of moles ethanol must be calculated. Using ethanol density (0.778 g/mL), 10 mL of ethanol equals to 7.89 g of ethanol and in turn 0.17 moles of ethanol. The same way for calculate the amount of water moles (ethanol density=0.997 g/mL). 2 mL of water correspond to 0.11. The total moles are: 0.17+0.11=0.28. Mole fraction alcohol is: 0.17/0.28=0.6
