I really need help with this stoich problem please :*(?

Question

The reaction of Na2SO4 with BaCl2 is a double displacement reaction. If the solutions containing exactly one gram of each reactant are mixed, how many grams of BaSO4 are produced?

Answer 1

Na2SO4 + BaCl2 ----> BaSO4 + 2NaCl

First of all you have to find the limiting regent, This is the regent that controls the man amount of BaSO4 produced.

You find this by working out the no of moles each regent has and then which one has the lowest amount that can fully be reacted.

No. of Moles of compound = weight used (1 g in this case)/ molecular weight of compound.

Now as one mole of Na2SO4 reacts with one mole of BaCl2
it is a reactive ratio of 1:1

So if the no. of moles of Na2SO4 is greater then the No. of Moles of BaCl2 when the no. of moles of BaCl2 is the limiting regent, else it is the no. of moles of NaSO4.

Now as each regent reacts with the other one to produce 1 mole of BaSO4 the product ratio is 1:1.

So in this case the no. of moles of BaSO4 produced = the no. of moles of the limiting regent x 1.

Now you have to convert back into grams using the formula below.

No. of grams of BaSO4 produced = No. of moles of BaSO4 produced x the molecular weight of BaSO4

Answer 2

Moles of Na2SO4 = 1/(46+96) = 1/142

Moles of BaCl2 = 1/(137+71) = 1/208

Thus mass of BaSO4 = 233/208 = 1.12 g

Answer 3

its not too difficult.

find the mole of sodium sulphate and barium chloride used.
mol = mass / molar mass.

next find out which one is the limiting reactant.

from there, compare the ratio of moles of the limiting reactant and barium sulphate.

use mol = mass/molar mass to get the mass produced.

really not that difficult. :)