Four beakers containing potassium nitrate dissolved in water are allowed to evaporate to dryness. beakers 1 through 4 contain 2.3, 1.91, 5.985, and 0.52 g of dry potassium nitrate respectively. how many moles of potassium nitrate were recovered after the water evaporated?

Explanation:

Molar mass of potassium nitrate will be calculated as follows.

   Molar mass = molar mass of K + molar mass of N + 3 × molar mass of O

                             = 39.098 g/mol + 14.006 g/mol + 3 × 15.999 g/mol

                             = 102.102 g/mol

Now, adding the given amount of potassium nitrate present in each beaker as follows.

               (2.3 + 1.91 + 5.985 + 0.52) g

               = 10.715 g

Therefore, calculate number of moles as follows.

                   No. of moles =

                                         =

                                         = 0.105 mol

Thus, we can conclude that 0.105 moles of potassium nitrate were recovered after the water evaporated.

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3