The substances which are formed during chemical reaction differ from each other in many properties, including solubility. Both well soluble substances, and slightly soluble, and even almost insoluble, like chloride silver can be products of reaction. In the latter case substance immediately drops out in a deposit. Sometimes there is a need to calculate its weight.
Instruction
1. The first and most natural way: to weigh this deposit. Certainly, at first it needs to be taken from solution and to dry up. It becomes by filtering. It is possible to use a usual glass funnel with the paper filter. If there is a wish to filter quicker a deposit and to achieve fuller extraction it from solution, it is better to use Byukhner's funnel.
2. After the deposit is separated from liquid, it should be dried up carefully (when using a funnel of Byukhner, the deposit already turns out rather dry therefore process of drying will take a little time) and to weigh. Certainly, than we will have more exact scales, especially you receive the exact answer.
3. Whether it is possible to solve a problem, without resorting to filtering, drying and weighing? Of course, it is possible. Only to write exact the equation of chemical reaction is necessary to you and to know amount of initial substances. For example, in interaction of 10 grams of chloride sodium and 4 grams of nitrate silver the white deposit of chloride of silver was formed. It is required to calculate its weight. Write the reaction equation: NaCl + AgNO3 = NaNO3 + AgCl
4. Count the molar mass of initial substances. 23 + 35.5 = 58.5 grams/mol – the molar mass of chloride sodium, 10/58.5 = 0.171 mol – such its quantity were before reaction. 108 + 14 + 48 = 170 grams/mol – the molar mass of nitrate silver, 4/170 = 0.024 asking – such amount of this salt was before reaction.
5. You see that chloride sodium is in big surplus. It follows from this that all nitrate silver (all 4 grams) reacted, having connected also 0.024 asking chloride sodium. So how many as a result it was formed chloride silver? Count its molar weight. 108 + 35.5 = 143.5 grams/mol. Now we will make calculations: 4 * 143.5/170 = 3.376 grams of chloride silver. Or, considering in round figures, 3.38 grams. The task is solved.