100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. Calculate final molarity of h2s04 solution if final density is 1.25g/ml.
50ml of 20.8% bacl2 and 100ml of 938% h2s04 solutions are mixed. Molarity of cl ions in the resulting solutions is at. wt of ba =137
Who helps me solve two questions
Thank a lot
1. Assuming the volumes are additive; i.e., 100 + 400 = 500 mL, then
M H2SO4 = 1 M x (100/500) = ?
2.
I don't know how to deal with 938% H2SO4; however, that never enters into the problem. I assume that 20.8% BaCl2 is w/v and that means 20.8 g BaCl2/100 mL. Therefore, in 50 mL there must be just half that or 10.4g BaCl2.
mols BaCl2 in 10.4g BaCl2 = 10.4g/molar mass BaCl2 = approx 0.05. mols Cl^- is twice that = or approx 0.1 mol and that in 50 mL is M = mols/L = 0.1 mol/0.05L = approx 2 M.
That is diluted from 50 to 150 mL so 2M x (50/150 mL) = approx ?
I can help you solve both of the questions. Let's solve them one by one:
Question 1:
We are given:
Initial volume of H2SO4 solution (V1) = 100 ml
Initial molarity of H2SO4 solution (M1) = 1 M
Initial density of H2SO4 solution (D1) = 1.5 g/ml
Water added (V2) = 400 ml
Final density of the solution (D2) = 1.25 g/ml
Now, let's calculate the final molarity of the H2SO4 solution.
Step 1: Calculate the mass of H2SO4 in the initial solution.
Mass = Volume * Density = 100 ml * 1.5 g/ml = 150 g
Step 2: Calculate the moles of H2SO4.
Moles = Mass / Molar mass (Molar mass of H2SO4 = 98.09 g/mol)
Moles = 150 g / 98.09 g/mol = 1.53 mol
Step 3: Calculate the volume of the final solution.
Volume = V1 + V2 = 100 ml + 400 ml = 500 ml
Step 4: Calculate the final molarity of H2SO4.
Molarity (M2) = Moles / Volume = 1.53 mol / 500 ml
But we need to convert the volume to liters as molarity is expressed in moles per liter.
Molarity (M2) = 1.53 mol / 0.5 L = 3.06 M
Therefore, the final molarity of the H2SO4 solution is 3.06 M.
Question 2:
We are given:
Volume of BaCl2 solution (V1) = 50 ml
Concentration of BaCl2 solution (C1) = 20.8%
Volume of H2SO4 solution (V2) = 100 ml
Concentration of H2SO4 solution (C2) = 938%
Atomic weight of Ba (At. wt.) = 137
We need to find the molarity of Cl ions in the resulting solution.
Step 1: Calculate the moles of BaCl2.
Moles of BaCl2 = Volume * Concentration / 100
Moles of BaCl2 = 50 ml * 20.8% / 100
Now, let's calculate the moles of BaCl2 using the atomic weight of Ba.
Moles of BaCl2 = Moles of Ba * (2 moles of Cl / 1 mole of Ba)
Step 2: Calculate the moles of Cl ions in the resulting solution.
Moles of Cl ions = Moles of BaCl2 * 2 moles of Cl
Step 3: Calculate the volume of the resulting solution.
Volume = V1 + V2 = 50 ml + 100 ml = 150 ml
Step 4: Calculate the molarity of Cl ions.
Molarity = Moles of Cl ions / Volume
But we need to convert the volume to liters as molarity is expressed in moles per liter.
Molarity = Moles of Cl ions / 0.15 L
Therefore, the molarity of Cl ions in the resulting solution is (Moles of Cl ions / 0.15 L).