152k views
3 votes
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?

User Phylis
by
8.7k points

1 Answer

6 votes

Step-by-step explanation:

Molar mass of potassium nitrate will be calculated as follows.

Molar mass
KNO_(3) = 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 =
\frac{mass}{\text{molar mass}}

=
(10.715 g)/(102.102 g/mol)

= 0.105 mol

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

User Itsanewabstract
by
7.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.