00:01
In stationometry, we relate the quantities of the species that are involved in a certain reaction.
00:06
In this problem, zinc reacts with hydrochloric acid to form zinc chloride and hydrogen gas.
00:12
1 .35 grams of zinc reacts with 60 ml of 0 .7 .5 molar h .gel solution.
00:19
It is found out that the heat that is evolved is 3 .14 kilojoules.
00:24
We want to find the enthalpy change of the reaction in kilojoules per mole of zinc that reacts.
00:30
So first is that let's find which of the reactant is limiting.
00:35
So to know that, we have to take the ratio of their most by their coefficients in the balanced reaction.
00:44
So for example, for zinc, we have most of zinc divided by its coefficient.
00:50
A coefficient is one.
00:51
We don't see any number in front of zinc, but it's understood that its coefficient is one.
00:56
The most of zinc is obtained by dividing its mass, which is 1.
01:00
34 by its molar mass which is 65 .4.
01:06
So solving this gives us 0 .0205 divided by 1 or let's still 0 .0205...