00:01
Okay, for this problem we are given 4 .36 grams of an unknown alkali metal hydroxide, which i'm referring to as xoh, and we are trying to find the identity of x.
00:12
For this problem, we are told that we titrated this alkali metal hydroxide.
00:19
Okay, alkali metals are in group one, so that means there will be one of those per one oh.
00:26
That's an important thing to understand.
00:28
But when we titrate that with the hydrochloric acid, it took 17 milliliters to reach the equivalence point.
00:36
So we need to find how many moles of hydrochloric acid were used, because at the equivalence point, moles of acid equal moles of base, and we are first trying to find molar mass.
00:47
Molar mass is equal to moles per liter.
00:52
Sorry, that's molarity.
00:56
Molar mass is equal to grams per mole.
00:59
We know how many grams we have.
01:01
We have 4 .36 grams of xoh.
01:04
So if we could figure out how many moles of xoh we have, then we could find our molar mass.
01:11
So we will take this information right here.
01:15
We will, to find moles, it is your molarity times your liters.
01:21
So molarity is 2 .50 times 0 .017 liters...