What is the concentration of the solution formed when zinc metal is reacted with 950.0 cm3 of 1.25 M hydrochloric acid? What is the volume of hydrogen gas (at stp) that is evolved in the same reaction?
How much Zn metal?
It doesn't say how much zinc metal that's why I am having problems trying to figure it out
To find the concentration of the solution formed when zinc metal reacts with hydrochloric acid, we can use the concept of stoichiometry and the balanced chemical equation for the reaction:
Zn(s) + 2HCl(aq) â ZnCl2(aq) + H2(g)
The balanced equation tells us that one mole of zinc reacts with two moles of hydrochloric acid to form one mole of zinc chloride and one mole of hydrogen gas.
Step 1: Calculate the moles of hydrochloric acid.
Given that the volume of the hydrochloric acid solution is 950.0 cm^3 (cubic centimeters) and the concentration is 1.25 M (molar), we can use the equation:
moles = volume (in liters) x concentration
First, convert the volume from cm^3 to liters:
950.0 cm^3 = 950.0/1000 = 0.95 L
Now, calculate the moles of hydrochloric acid:
moles of HCl = 0.95 L x 1.25 M = 1.1875 moles
Step 2: Calculate the moles of zinc.
From the balanced equation, we see that the stoichiometric ratio between hydrochloric acid and zinc is 2:1. This means that for every 2 moles of hydrochloric acid, you need 1 mole of zinc.
Since we have 1.1875 moles of hydrochloric acid, we can calculate the moles of zinc:
moles of Zn = 1.1875 moles HCl / 2 = 0.59375 moles
Step 3: Calculate the concentration of the solution.
The concentration can be determined by dividing the moles of zinc chloride formed by the volume of the solution in liters:
Concentration = moles of ZnCl2 / volume of solution (in liters)
Since the balanced equation shows that 1 mole of zinc forms 1 mole of zinc chloride, the moles of zinc chloride formed in this reaction are the same as the moles of zinc:
Concentration = 0.59375 moles / 0.95 L = 0.625 M
Therefore, the concentration of the solution formed is 0.625 M.
Now let's calculate the volume of hydrogen gas (at STP) that is evolved in the same reaction.
Step 1: Calculate the moles of hydrogen gas.
From the balanced equation, we know that the stoichiometric ratio between zinc and hydrogen gas is 1:1. This means that 1 mole of zinc metal produces 1 mole of hydrogen gas.
Since we calculated earlier that we have 0.59375 moles of zinc, we also have 0.59375 moles of hydrogen gas.
Step 2: Calculate the volume of hydrogen gas at STP.
At STP (Standard Temperature and Pressure), the volume occupied by 1 mole of any gas is 22.4 liters.
Therefore, the volume of hydrogen gas evolved in this reaction is 0.59375 moles x 22.4 L/mol = 13.3 L.
So, the volume of hydrogen gas (at STP) that is evolved in this reaction is 13.3 liters.