Question

I mess up every time while solving problems related to density, molality and molality.

Please explain in the simplest way possible (Step wise) that how I'm supposed to solve them without messing them up.

​

Answer 1

Answer:

The formula for molality is m = moles of solute / kilograms of solvent. In problem solving involving molality, we sometimes need to use additional formulas to get to the final answer. One formula we need to be aware of is the formula for density, which is d = m / v, where d is density, m is mass and v is volume.Molarity and density are different ways of expressing essentially the same thing. Whereas density is the mass of a solid, liquid or gas divided by its volume, molarity is the number of moles of solute per liter of solution.Solutions in volumetric glassware

Solutions in volumetric glassware|Shutterstock

PHYSICAL SCIENCE

Molarity, Molality, or Normality? (A Quick Review)

Looking for a way to reinforce your students’ understanding of these concepts? Try this quick review.

Molarity and Molality

Molarity (M) is defined as the number of moles of solute per liter of solution.molarity = moles of solute/liters of solution

Molality (m) is defined as the number of moles of solute per kilogram of solvent.molality = moles of solute/kilograms of solvent

Although their spellings are similar, molarity and molality cannot be interchanged. Molarity is a measurement of the moles in the total volume of the solution, whereas molality is a measurement of the moles in relationship to the mass of the solvent.

When water is the solvent and the concentration of the solution is low, these differences can be negligible (d = 1.00 g/mL). However, when the density of the solvent is significantly different than 1 or the concentration of the solution is high, these changes become much more evident.

Example:Compare the molar and molal volumes of 1 mol of a solute dissolved in CCl4 (d = 1.59/mL).

For a 1 Molar solution, 1 mol of solute is dissolved in CCl4 until the final volume of solution is 1 L.

For a 1 molal solution, 1 mol of solute is dissolved in 1 kg of CCl4.1 kg of CCl4 × (1,000 g/1 kg) × (mL/1.59 g) = 629 mL CCl4

Normality

Normality (N) is defined as the number of mole equivalents per liter of solution:normality = number of mole equivalents/1 L of solution

Like molarity, normality relates the amount of solute to the total volume of solution; however, normality is specifically used for acids and bases.

How to calculate normality from molarity

The mole equivalents of an acid or base are calculated by determining the number of H+ or OH- ions per molecule: N = n × M (where n is an integer)

For an acid solution, n is the number of H+ ions provided by a formula unit of acid.Example: A 3 M H2SO4 solution is the same as a 6 N H2SO4 solution.

For a basic solution, n is the number of OH- ions provided by a formula unit of base.Example: A 1 M Ca(OH)2 solution is the same as a 2 N Ca(OH)2 solution.

Note: The normality of a solution is NEVER less than its molarity

Answer 2

Hey mate,

Loops not allowed ✅✅.

Use only one variable ✅✅

I am not sure about which program u are asking, I have done both of them.

For the first question, I have created array of objects and one integer array, so, total number of variable=1.

For the second question,I have calculated by using formula.

Have a great day.

Kya hua?