Answer:
Option 3. The catalyst does not affect the enthalpy change (
) of a reaction.
Explanation:
As its name suggests, the enthalpy change of a reaction () is the difference between the enthalpy of the products and the reactants.
On the other hand, a catalyst speeds up a reaction because it provides an alternative reaction pathway from the reactants to the products.
In effect, a catalyst reduces the activation energy of the reaction in both directions. The reactants and products of the reaction won't change. As a result, the difference in their enthalpies won't change, either. That's the same as saying that the enthalpy change of the reaction would stay the same.
Refer to an energy profile diagram. Enthalpy change of the reaction measures the difference between the two horizontal sections. Indeed, the catalyst lowered the height of the peak. However, that did not change the height of each horizontal section or the difference between them. Hence, the enthalpy change of the reaction stayed the same.
<span>1. A scientific hypothesis can become a theory if the hypothesis is tested extensively and competing hypothesis are eliminated. A scientific hypothesis is a proposed explanation made on the basis of reasoning without any assumption. For hypothesis to be termed a scientific hypothesis, it has to be something that can be supported or refuted through carefully crafted experimentation or observation.
2. A preliminary untested explanation that tries to explain how or why thing happen in the manner observed is a scientific hypothesis. A primary trait of a hypothesis is that something can be tested and that those tests can be replicated. A hypothesis is often examined by multiples scientists to ensure the integrity and veracity of the experiment. The process can take years, and in many cases hypothesis do not go any further in the scientific method as it is difficult to gather sufficient supporting evidence. </span>
Answer:
an increase of acceleration or decrease of acceleration
Explanation:
Molar mass NaOH = 40.0 g/mol
Volume in liters of solution :
5 mL / 1000 => 0.005 L
number of moles :
4 / 40 => 0.1 moles
M = n / V
M = 0.1 / 0.005
= 20 mol/L or 20 M
hope this helps!
a b c d no a no b yes c no d ok
