A small amount of silver metal is dispersed in a porous ceramic material. The sa
ID: 840067 • Letter: A
Question
A small amount of silver metal is dispersed in a porous ceramic material. The sample of silver and ceramic has a mass of 871.6 grams. When the sample is treated with concentrated nitric acid, the silver will dissolve but the ceramic is inert. The balanced equation for the reaction is:
3 Ag(s) + 4 HNO3(aq) -----> 3 AgNO3(aq) + NO(g) + 2 H2O(l)
If 327.2 mL of the nitric acid was required to just dissolve the silver, how many grams of silver were in the ceramic and what was the percent of silver in the original sample? The acid solution is 40.0% by weight HNO3 and the density is 1.249 g/mL.
Explanation / Answer
mass of HNO3 required = 0.4*327.2*1.249
=163.469 grams.
so moles of HNO3 = 163.469/63
=2.59 moles
so moles of Ag present = 2.59*(3/4)
=1.946 moles
so mass of Ag=1.946*108
=210.168 gams
si percentage of silver = 210.168*100/871.6
=24.1129 %