Question

2. Calculate the molar (Cm) and the normal (CN) concentration of phosphoric acid solution with a mass
fraction of 14.6% (the density of solution (p) is equal to 1.08 g/ml)​

Answer 1

Answer:

The molar concentration unit [mol/ L (M)] is a conventionally widely used as concentration method. It is the number of moles of target substance (solute) dissolved in 1 liter of solution. Here is how to calculate the concentration.

(Weight of 1 liter solution) x (purity) ÷ molecular weight

[Specific gravity of solution (g/mL) x 1,000 (mL) x Purity (w/w%) /100 ÷ Molecular weight]

For example, let's calculate the molar concentration of 2-mercaptoethanol (HSCH2CH2OH). The necessary information is as follows.

Specific gravity (or density) = 1.114 g/mL

Purity (or content) = 100 w/w% (assumed)

Molecular weight = 78.13

By calculating this value by applying this value to the above equation, you can know the molar concentration.

1.114 g/mL x 1,000mL x 100w/w%/100 ÷ 78.13 = 14.26mol/L

In order to caluculate the concentration like above, it is necessary to know three points of "specific gravity (or density)", "purity (or content)" and "molecular weight". The table below is a quick reference chart of common acid and base concentrations. In acid and alkali, there is a use for "neutralization titration", "normality (N)" is often