Weight PercentAnother similar way of expressing the concentration of a solution is to express it in weight percent (or mass percent, if you prefer).

Weight percent = weight of solute weight of solution x 100%

You've done this kind of calculation earlier - last term in the lesson on composition. You may already be prepared to answer the questions in exercise 2 in your workbook. If so, do that and check your answers at the bottom of the page. If not, read on.

As an example, let's consider a 12% by weight sodium chloride solution. Such a solution would have 12 grams of sodium chloride for every 100 grams of solution. To make such a solution, you could weigh out 12 grams of sodium chloride, and then add 88 grams of water, so that the total mass for the solution is 100 grams. Since mass (unlike volume) is conserved, the masses of the components of the solution, the solute and the solvent, will add up to the total mass of the solution.	12 % NaCl solution =	12 g NaCl    100 g solution
	12 g NaCl            (12 g NaCl + 88 g water)	= 12% NaCl solution

To calculate the mass percent or weight percent of a solution, you must divide the mass of the solute by the mass of the solution (both the solute and the solvent together) and then multiply by 100 to change it into percent.

若能收集到该词条相关资料的跟帖者给予奖励，根据收集资料的水平给予5～100不等的论坛币，当然也可以谈谈自己的看法、应用，上传资料等等都可以。

请大家尽量不要复制一些搜索引擎很容易收集到的资料。

     我每天都会发送不等数量的词条，所以诚邀不同统计背景的各路大侠给予评论。

     欢迎大家多多跟帖！要数量也要质量哟