Answer:
The percentage concentration (w/v) of phenylephrine in the injection is 1 %.
Step-by-step explanation:
The percentage concentration in w/v of the phenylephrine hydrochloride can be calculated as follows:

Where:
m: is the mass of the solute in grams
V: is the volume of the solution in milliliters
The concentration of the phenylephrine hydrochloride is 10 mg/mL, so the percentage concentration is:



Therefore, the percentage concentration (w/v) of phenylephrine in the injection is 1 %.
I hope it helps you!