If a solution contains 33 percent calcium chloride, is this by weight, volume or a combination of the two? And so, how many grams of calcium chloride would there be in a liter of the solution?
There’s no real way to tell if it isn’t explicitly stated. Conventions vary by industry, so you might be able to guess from context.
To actually answer the question, it would be 330 g/L if it’s 33% w/v or 326 g/L if it’s 33% w/w. The effect on volume is so small that it probably doesn’t matter for your purposes.
Apparently this is on the label:
Calcium chloride content : > 33% (w/w) / > 430 g/l
How do you get to 326 grams per liter?
Grams or grains?
That checks out. I must have fat-fingered something.