I think this the the list of choices relating to the above question.
reaction rate
<span>activation energy </span>
<span>collision theory </span>
<span>spontaneous reaction
</span>
The term that best relate to ben's observation is REACTION RATE.
Reaction rate is defined as the speed at which the chemical reaction proceeds. It either is the amount of concentration of a product in a given unit of time or the concentration of the reactant that is being consumed in a unit of time.
Answer: 250 kJ
Explanation: According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to Hess’s law, the chemical equation can be treated as algebraic expressions and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
(1)
(2)
Net chemical equation:
(3)
Adding 1 and 2 we get,
(4)
Now dividing equation (4) by 4, we get
(4)
We determine the percent by mass of water in the compound by dividing the mass of water by the total mass. The total mass of Na2SO4.10H2O is equal to 322 g. The mass of water is 180 g.
percent by mass of water = (180 / 322)*(100 %) = 55.9%