Question

what quantity in moles of hcl is there in 75.0 ml of 0.455 m hcl?

Explanation:

Step1: Convert volume to liters

The volume is given as 75.0 mL. Since 1 L = 1000 mL, we convert it as $V=75.0\ mL\times\frac{1\ L}{1000\ mL}=0.0750\ L$.

Step2: Use the molarity formula

The molarity formula is $M = \frac{n}{V}$, where $M$ is molarity, $n$ is the number of moles, and $V$ is volume in liters. We want to find $n$, so we can re - arrange the formula to $n = M\times V$. Given $M = 0.455\ M$ and $V=0.0750\ L$, then $n=0.455\ mol/L\times0.0750\ L$.

Step3: Calculate the number of moles

$n = 0.455\times0.0750\ mol=0.034125\ mol$.

Answer:

$0.0341\ mol$ (rounded to three significant figures)