That's the set up. We're going to run the reactants, the reaction. The reactants are going to turn into products.
这就是我们的装置,我们要进行反应,让反应物变成生成物。
And we haven't talked about reactions at all yet, so you don't need to worry about the specifics of that exactly, but just that if you have this negative change in energy, you have a more stable product than you do reactant.
当然我们还没有开始讨论反应,所以你不用担心它的细节是怎么样的,你只需要知道,如果能量的变化是负值,那么你将得到一个比反应物更稳定的生成物。
That's the important message, delta H of formation of the products, minus delta H of formation of the reactants.
去反应物的生成焓,这,是个重要的信息,生成物的生成焓,减去反应物的生成焓。
The whole thing's going to come to some new equilibrium temperature between the products and the oil or whatever's around it, and we're going to measure that.
生成物和周围的油或,别的什么东西之间,达到某种新的平衡态,我们要测量的就是这个。
I didn't even need to know that heat capacity of the product, right. Because it's effect the thermal mass of the product is negligible compared to the thermal mass of the calorimeter.
我甚至不需要知道生成物的,热容是多少,因为生成物的,热质量的作用相比于,量热计的热质量是可以忽略的。
So we're just subtracting, in effect, zero, right, from the enthalpy of the product, but of course it's important have that established because the heat of formation is something you could measure, right?
所以从效果上说,我们只是,从生成物的焓中减去了零,但,是确立这一点很重要,因为生成热是,你能测量的东西,对吧?
So we don't really need to put in a certain amount of heat and change the temperature of the products and the calorimeter and so on.
所以我们实际上并不需要输入,一定的热量,改变生成物,和量热计的温度之类。
How many moles of gas are there in each case, in reactants and products? If that changes, of course you know that the pressure in there is going to change at constant volume if the amount of gas in there is changing.
在反应物和生成物中,各有多少摩尔的气体?,如果它发生了变化,当然在等体条件下,如果气体的总量,发生了变化,压强也会发生变化。
It's a state function. If we know the enthalpy of the products minus the enthalpy of the reactants, right. It's a state function.
如果我们知道生成物的焓减,去反应物的焓的值,它是个态函数,原则上我们可以做到。
In other words, I've got reactants, and I've got products. What's delta H of reaction?
换句话说,我有了反应物,我有了生成物?
In other words, we choose a convention for the zero of entropy, so that then we can write entropies of products and reactants always referring to the same standard state.
换句话说,我们选择了一个,焓零点的约定,这样我们,就可以总是相对于同样的标准,状态写出生成物和反应物的焓。
There is some mixture of them.
实际情况是生成物与反应物的混合。
We can tabulate them. We can know them, and then when we have reactions that inter-convert different compounds, we can calculate the heat of reaction is just the difference between the heat of formation of the reactants, and the heat of formation of the products, right.
种化合物的生成热,可以把它们列成表,可以认知它们,而当我们要处理,在不同化合物间转变的反应时,我们只要计算反应物和,生成物的生成热之间的不同,就能计算出反应热。
When delta G is zero, you know, it doesn't mean that you've got all of one side, all reactants and zero products or all products and zero reactants.
当dG等于零的时候,化学反应并不处在任何一边,例如全部都是反应物没有生成物,或者全部都是生成物而没有反应物。
It's delta H of formation of the products minus delta H of formation of the reactants.
反应的△H是多少?,它就是生成物的生成焓减。
Fewer products and calorimeter at T1, right.
以及T1下的生成物和量热计,对吧?
So what we'll end up with is boron plus, 1 s 2 2 s 2 1 s 2, 2 s 2, E and what we say is the delta energy or the change in energy as the same thing as saying the energy of the products minus the energy of our reactant here, that's how much energy we have to put into the system to eject an electron.
所以结果应该是正一价的硼,电子排布为,我们说,Δ,也就是,E,的变化量,等于生成物的能量,减去反应物的能量,这就是我们从这个系统中,打出一个电子所需要的能量。
Right? In other words I've got the stoichiometric coefficients in there and the values, and I'm subtracting the reactants from products -1652kJ/mol wind up with minus 1652 kilojoules per mole.
对吧?换句话说这里我用了化学,计量系数和生成热的值,从生成物中减去反应物,最后得到。
Of course, the cyclic steps that we've taken to do this apply not just for breaking down reactants and product into the elements in their standards states, but of course we could also look at whole sets of reactions and write cycles as well, right.
当然,我们这里用的循环的,步骤不仅仅在把生成物,和反应物拆成其标准状态下,的元素时有效,我们也可以研究整个一系列,反应并写出相应循环。
It's just how much heat is involved when we change the temperature. Now, the products have some heat capacity associated with them right, it takes a certain amount of heat if we make their temperature change, to either put it in or take it away, depending on which direction the temperature is changing.
问题就是当我们改变温度时,有多少热量发生了转移,生成物具有一定的热容,如果我们改变,它们的温度,就要输入或,提取一定的热量,这取决于温度改变的方向。
So here, I'm going to have delta H, is just the sum for all the products of delta heat of formation right? Here I'm going to put together all the products. So this is a positive heat of formation.
所以这里△H就是所有生成物的,生成热的和,对吧?这里,我要把元素组合成所有这些,生成物,所以这里是正的生成热。
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