Question

When reacting 5.00 g of MgCl2 with 15.0 g of AgNO3 , what is the limiting reagent based on the following equation?MgCl2 (aq) + 2 AgNO3(aq) --> 2 AgCl (s) + Mg(NO3)2 (aq)

Answer 1

`AgNO_3\text{ is the limiting reagent}`

Step-by-step explanation:

Here, we want to get the limiting reactant

The limiting reactant is the reactant that would produce less amount of the solid precipitate

Firstly, we need to get the number of moles of each of the reactants

To get this, we divide their masses by the molar masses

The molar mass of magnesium chloride is 95 g/mol

The number of moles would be:

`(5)/(95)\text{ = 0.053 mol}`

Now, from the equation of reaction, 1 mole of MgCl2 produced 2 moles of AgCl

Then: 0.053 mole of MgCl2 will produce 2 * 0.053 mol = 0.106 mol AgCl

For AgNO3, the molar mass is 170 g/mol

The number of moles would be:

`(15)/(170)\text{ = 0.088 mol}`

Now, looking at the equation of reaction:

2 moles of AgNO3 produce 2 moles of AgCl

0.088 mol AgNO3 will also produce 0.088 mol AgNO3

Now, looking at the values of the number of moles of AgCl produced, we can see that AgNO3 produces less of the product

This means that AgNO3 is the limiting reactant