Question

Помогите пожалуйста с задачей по химии,заранее благодарю.Рассчитайте молярную концентрацию раствора, содержащего 90 г КОН в 800 мл раствора.​

Answer 1

1) Находим массу 1 моля КОН:

М(КОН) = 39 + 16 + 1 = 56 г/моль

2) Молярную концентрацию рассчитывают по формуле:

См = m / (M * V)

где: m  - масса растворённого вещества, г

        V - объём раствора, л

См = 90/(56*0,8) ≈ 2 моль/л

Answer 2

Molar Concentration Calculation

To calculate the molar concentration of a solution, we can use the formula:

Molar concentration (M) = moles of solute / volume of solution in liters

First, we need to convert the given mass of solute (90 g KOH) to moles, and then we can use the volume of the solution (800 ml) to calculate the molar concentration.

Conversion of Mass to Moles

The molar mass of KOH (potassium hydroxide) is approximately 56.11 g/mol. We can use this to convert the mass of KOH to moles.

Moles of KOH = Mass of KOH / Molar mass of KOH

Moles of KOH = 90 g / 56.11 g/mol

Moles of KOH ≈ 1.604 moles

Calculation of Molar Concentration

Now that we have the moles of KOH, we can use the given volume of the solution (800 ml) to calculate the molar concentration.

Volume of solution = 800 ml = 0.8 L

Molar concentration (M) = 1.604 moles / 0.8 L

Molar concentration (M) ≈ 2.005 M

So, the molar concentration of the solution containing 90 g of KOH in 800 ml of solution is approximately 2.005 M.