The Second Law of Thermodynamics<span> says that processes that involve the transfer or conversion of heat energy are irreversible.</span><span> ... The First </span>Law of Thermodynamics<span> states that energy cannot be created or destroyed; the total quantity of energy in the universe stays the same.</span>
Answer:
sodium hydroxide is the limiting reactant
Explanation:
The first step is usually to put down the balanced reaction equation. This is the first thing to do when solving any problem related to stoichiometry. The balanced reaction equation serves as a guide during the solution.
2NBr3 + 3NaOH = N2 + 3NaBr + 3HOBr
Let us pick nitrogen gas as our product of interest. Any of the reactants that gives a lower number of moles of nitrogen gas is the limiting reactant.
For nitrogen tribromide
From the balanced reaction equation;
2 moles of nitrogen tribromide yields 1 mole of nitrogen gas
4.3 moles of nitrogen tribromide will yield 4.3 ×1/ 2 = 2.15 moles of nitrogen gas
For sodium hydroxide;
3 moles of sodium hydroxide yields 1 mole of nitrogen gas
5.9 moles of sodium hydroxide yields 5.9 × 1/ 3= 1.97 moles of nitrogen gas
Therefore, sodium hydroxide is the limiting reactant.
Answer: The answer is C. A mercury thermometer is better to measure very small changes in temperature.
Explanation:
i took this quiz and this is the answer .
A) A mercury thermometer can measure the freezing point of a liquid that freezes at −80 °C.
B) An alcohol thermometer can measure the boiling point of a liquid that boils at 80 °C.
C) A mercury thermometer is better to measure very small changes in temperature.
D) An alcohol thermometer is better to measure the boiling points of colorless liquids.
Percentage recovery gives us an idea of the amount of pure substance recovered after the chemical reaction. Percentage recovery can be more than 100 % or less than 100 %. Usually, in any experiment performed the weight percentage recovery will be less than 100. Percent recovery values greater than 100 show that the recovered compound is contaminated.
Amount of acetaminophen initially taken = 350 mg
Amount of acetaminophen obtained after recovery =185 mg
= 
= 52.9%
Answer:
Use the Bromotriflouride catalyst, BF₃
Explanation:
The BF₃ is most likely to yield less desired side products. The effect lies in the reaction mechanism.
BF₃ is a Lewis acid. Its role is to promote the ionization of the HF. This is achieved through the electrophilic mechanism. The reaction mechanism is as follows:
2 - methylpropene + H-F-BF₃ → H-F + H₃C + benzene
butylbenzene + F-BF₃ → tert-butylbenzene + H-F + BF₃ (regenerated catalyst)
