00:03
Hey there, in this question we are given this equation and we're told that we have 3 .474 grams of the naf reacting.
00:19
And we want to know how many grams of the fluorine gas will be produced.
00:26
Well we see that we have a mass of one thing in the equation, we're trying to find the mass of another.
00:30
Making this a mass to mass stoichiometry problem.
00:42
Okay, and in a mass to mass stoichiometry problem the first thing we need is a balanced equation.
00:47
So you should always check an equation that's given to you to make sure it's balanced.
00:51
And this one is not.
00:53
Because we see that yes there's one sodium on each side, but there's only one fluorine on the reactant side and two on the product side.
01:00
So we need a coefficient of two in front of naf.
01:03
That gives us two sodium on the left, so we need a two in front of nacl to give us two sodium on the right.
01:09
That then gives us two chlorine on each side.
01:12
So now this equation is balanced.
01:15
And since it's a mass to mass stoichiometry there are three basic steps that we need to follow.
01:21
The first step will be to convert to moles of the given substance by using its molar mass in grams.
01:29
We get the molar mass from the periodic table, it's the mass of one mole of a substance.
01:34
So we add together the mass of na plus the mass of f.
01:38
Alright, then we'll be at moles.
01:41
So we can convert from moles of naf to moles of f2.
01:46
And we do this by using the mole ratio.
01:49
The mole ratio comes to us from the coefficients in the balanced equation.
01:54
So that's why we needed these coefficients.
01:57
We needed to balance it first.
01:59
Well there's nothing written in front of fluorine, so that's understood to be a one...