Solution b was made by dissolving 40g of sodium carbonate in water and made up to 1 liter find the strength of solution b and percentage of pure sodium carbonate . show me caculation .
or answer me this.
is this right ,mol of solute =mass of solute /molar mass of solution ?

What is avogadro’s number, and why is it useful

What happened to the amount of carbon dioxide in the atmosphere from 2010–2017?

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.