Hello, please I need help with this excersice of chemical equilibrum. I really don't get what "1:6" means and how can I use that proportion". The excercise says:
"0,014" moles of HCl are dissolved in water in a proportion of 1:6 (1 mole of HCl per 6 moles of H2O). What is the pH of the solution?
so the concentration of H⁺ from the HCl is ... 1 mole in 6 moles of water
pH is based on moles of H⁺ per liter of solution
water's volume is 18 mL per mole (based on the molar mass)
so 6 moles is 108 mL
so, [H⁺] = 1 mole / .108 L
pH is the negative log of [H⁺]
Hello, thanks to answer my question. .. I was thinking about the answer because it give me a negative pH ... Is that posible? And Does the initial moles of HCl the problem (0,014) interact in something?
I don't think this problem has a simple answer. You can estimate an answer only, I think.
6 mols H2O, as Scott writes, is 108 grams and if we assume the density of H2O is 1.00 g/mL, this then is 108 mL or 0.108 L. However, if we add 0.014 mols HCl to that we don't know the final volume. If we assume adding 0.014 mol HCl doesn't change the volume, then (H^+) = mols/L and that is 0.014/0.108 = approx 0.13
Then pH = -log(0.13) = approx -(-0.9) = 0.9
To understand what "1:6" means in the context of the exercise, it is a proportion that specifies the ratio of moles of HCl to moles of water. In this case, it means that for every 1 mole of HCl, there are 6 moles of water present in the solution.
To find the pH of the solution, we need to consider the dissociation of HCl in water. HCl is a strong acid that completely dissociates into H+ (hydrogen ions) and Cl- (chloride ions). The concentration of H+ ions determines the acidity or pH of the solution.
Given that we have 0.014 moles of HCl, we can use the stoichiometry of the proportion to calculate the moles of water.
1 mole of HCl: 6 moles of H2O
0.014 moles of HCl: x moles of H2O
Using the proportion, we can calculate:
(0.014 moles of HCl) / (1 mole of HCl) = (x moles of H2O) / (6 moles of H2O)
Simplifying this equation gives:
x = (0.014 moles of HCl) / (1 mole of HCl) * (6 moles of H2O) = 0.084 moles of H2O
Now that we know the moles of HCl and H2O in the solution, we can calculate the moles of H+ ions. Since HCl is a strong acid, it completely dissociates into H+ and Cl- ions. Therefore, the concentration of H+ ions will be equal to the moles of HCl.
Concentration of H+ ions = Moles of HCl / Volume of Solution
Unfortunately, the volume of solution is not given in the exercise, so we cannot directly calculate the concentration of H+ ions and the pH. We need the volume of the solution to determine the concentration.
Therefore, without the volume of the solution, we cannot calculate the exact pH of the solution. The concentration of H+ ions and the pH depend on the volume of the solution.