Answer:
The molarity of the final solutions if these two solutions are mixed is 27.14 
Explanation:
Yo know:
- Solution-1: 25M, 400mL
- Solution-2: 30M, 300 mL
Molarity being the number of moles of solute per liter of solution, expressed by:

You can determine the number of moles that are mixed from each solution as:
Number of moles= Molarity*Volume
So, being 1 L=1000 mL, for each solution you get:
- Solution-1: being 0.400 L=400 mL ⇒ 25 M* 0.400 L= 10 moles
- Solution-2: being 0.300 L=300 mL ⇒ 30 M* 0.300 L= 9 moles
When mixing both solutions, it is obtained that the volume is the sum of both solutions:
Total volume= volume solution-1 + volume solution-2
and the number of total moles will be the sum of the moles of solution-1 and solution-2:
Total moles= moles of solution-1 + moles of solution-2
So the molarity of the final solution is:

In this case, you have:
- moles of solution-1: 10 moles
- moles of solution-2: 9 moles
- volume solution-1: 0.400 L
- volume solution-2: 0.300 L
Replacing:

Solving:

Molarity= 27.14 
<u><em>The molarity of the final solutions if these two solutions are mixed is 27.14 </em></u>
<u><em></em></u>
Answer:
Explanation:
Cubic decimeter is the same unit as liter; so, mole per cubic decimeter is mole per liter, and that is the unit of concentration of molarity. Thus, what is asked is the molarity of the solution. This is how you find it.
1. <u>Take a basis</u>: 1 dm³ = 1 liter = 1,000 ml
2. <u>Calculate the mass of 1 lite</u>r (1,000 ml) of solution:
- density = mass / volume ⇒ mass = density × volume
Here, the density is given through the specific gravity
Scpecific gravity = density of acid / density of water
Take density of water as 1.00 g/ml.
- density of solution = 1.25 g/ml
- mass solution = 1.25 g/ml × 1,000 ml = 1,250 g
3. <u>Calculate the mass of solute</u> (pure acid)
- % m/m = (mass of solute / mass of solution) × 100
- 56 = mass of solute / 1,250 g × 100
- mass of solute = 56 × 1,250g / 100 = 700 g
4. <u>Calculate the number of moles of solute</u>:
- moles = mass in grams / molar mass = 700 g / 70 g/mol = 10 mol
5. <u>Calculate molarity (mol / dm³)</u>
- M = number of moles of solute / liter of solution = 10 mol / 1 liter = 10 mol/liter.
Answer:

Explanation:
Potassium nitrate is a soluble salt which readily dissolves in a polar solvent, such as water. When solid potassium nitrate is dissolved in water, it dissociates into potassium cations and nitrate anions.
Due to the resultant ionic charges, the polar water molecules attract the resultant ions and potassium nitrate ions become hydrated, that is, surrounded by water molecules.
Nitrate, our anion, attracts the partially positive ends of water molecules by attracting them via hydrogen atom.
Potassium, the cation, attracts the partially negative end of water molecules by attracting via oxygen atom.
Answer:
-1,103.39KJ/mol
Explanation:
We use the subtract the standard enthalphies of formation of the reactants from that of the products. It must be taken into consideration that the enthalpy of formation of elements and their molecules alone are not taken into consideration. Hence, what we would be considering are the standard enthalpies of formation of H2S, H2O and SO2.
In places where we have more than one mole, we multiply by the number of moles as seen in the balanced chemical equations.
The standard enthalpies of the molecules above are as follows:
H2S = -20.63KJ/mol
H2O = -285.8KJ/mol
SO2 = -296.84KJ/mol
O2 = 0KJ/mol
ΔrH⦵ = [2ΔfH⦵(H2O) + 2 ΔfH⦵(SO2)] − [ΔfH⦵(H2S) + 3
ΔfH⦵(O2)]
ΔrH⦵ =[(2 × -285.8) + (2 × -296.84)]
-[ 3 × -20.63)]
= (-571.6 - 593.68 + 61.89) = -1,103.39KJ/mol
Answer:
D
Explanation:
D. V1P1 / T1=V2P2 / T2 is correct