A 35 mL solution of HCl, reacts completely with 20 mL of 0.25 M KBr. What is the molarity of the HCl solution?
What reaction? HCl is an acid, and KBr is a salt. There is no reaction that I see.
I need a passing grade in chemistry. Our mid term is tomarow it is not realy a class it is for G.T. We have to make a modle of an atom. HELP.
To find the molarity of the HCl solution, we need to use the concept of stoichiometry.
Stoichiometry relates the amounts of reactants and products in a chemical reaction. In this case, the reaction is between HCl and KBr, and it is given that they react completely.
The balanced equation for the reaction is:
HCl + KBr -> HBr + KCl
From the equation, we can see that 1 mole of HCl reacts with 1 mole of KBr to form 1 mole of HBr and 1 mole of KCl.
Given that the volume of the HCl solution is 35 mL, we need to convert this to moles. To do this, we use the formula:
moles = volume (in liters) x molarity
The volume of the HCl solution is 35 mL, which is equivalent to 0.035 L. However, the molarity of the HCl solution is unknown, so we'll label it as "x M" for now.
Using the given information about the reaction between HCl and KBr, we can set up a ratio based on stoichiometry:
1 mole HCl / 1 mole KBr = 0.035 L HCl / 0.020 L KBr
Now, we need to calculate the moles of KBr using its molarity and volume:
moles of KBr = molarity x volume (in liters)
= 0.25 M x 0.020 L
= 0.005 moles KBr
Since the reaction is balanced in a 1:1 ratio for HCl and KBr, the moles of HCl will also be 0.005 moles.
Now we can use the calculated moles of HCl (0.005 moles) and the volume of the HCl solution (0.035 L) to find its molarity:
Molarity of HCl = moles / volume (in liters)
= 0.005 moles / 0.035 L
= 0.143 M
Therefore, the molarity of the HCl solution is 0.143 M.