Question

1. A student tried to solve the following problem by selecting the tile as shown. What, if anything, did the student do wrong?

Answer 1

Answer:

B. The student chose the correct tile, but needs to flip the tile to make the units cancel

Explanation:

Based on the reaction:

2AgNO₃(aq) + Cu(s) → 2Ag(s) + Cu(NO₃)₂ (aq)

2 moles of AgNO₃ react per mole of Cu producing 2 moles of Ag and 1 mole of Cu(NO₃)₂

Thus, if you want to produce 6.75moles of Cu(NO₃)₂ you need:

$6.75moles of Cu(NO_3)_2 \frac{2 mol AgNO_3 }{1 mol Cu(NO_3)_2}$ = 13.50 moles of AgNO₃ are needed

Thus, if you analize the tile shown by the student:

B. The student chose the correct tile, but needs to flip the tile to make the units cancel