Answer:
6.1 M
Step-by-step explanation:
Step 1: Calculate the moles of HNO₃ in the initial solution
A student has 475 mL (0.475 L) of a 4.5 M HNO₃ (4.5 mol HNO₃/ L) solution.
0.475 L × 4.5 mol HNO₃/ L = 2.1 mol HNO₃
He leaves the top of the container open, so water will evaporate, but the moles of HNO₃ will remain the same.
Step 2: Calculate the final concentration of the solution
2.1 moles of HNO₃ are in 347 mL (0.347 L) of solution.
[HNO₃] = 2.1 mol / 0.347 L = 6.1 M