Which solution is the most concentrated?

A. [tex]$2.0 \, \text{mL}$[/tex] of [tex]$10 \, M \, H_2SO_4$[/tex], where [tex]$H_2SO_4$[/tex] has a molar mass of [tex]$98 \, \text{g/mol}$[/tex]

B. [tex]$5.0 \, \text{mL}$[/tex] of [tex]$1.0 \, M \, PbSO_4$[/tex], where [tex]$PbSO_4$[/tex] has a molar mass of [tex]$303 \, \text{g/mol}$[/tex]

C. [tex]$2.0 \, \text{mL}$[/tex] of [tex]$10.5 \, M \, H_2O_2$[/tex], where [tex]$H_2O_2$[/tex] has a molar mass of [tex]$34 \, \text{g/mol}$[/tex]

D. [tex]$100 \, \text{mL}$[/tex] of [tex]$10 \, M \, NaCl$[/tex], where [tex]$NaCl$[/tex] has a molar mass of [tex]$58 \, \text{g/mol}$[/tex]



Answer :

To determine the most concentrated solution among the given options, we need to compare the molarities (concentrations in moles per liter) of each solution. Let's list the given solutions with their respective concentrations:

1. [tex]\( 2.0 \, \text{mL} \)[/tex] of [tex]\( 10 \, M \, \text{H}_2\text{SO}_4 \)[/tex]
2. [tex]\( 5.0 \, \text{mL} \)[/tex] of [tex]\( 1.0 \, M \, \text{PbSO}_4 \)[/tex]
3. [tex]\( 2.0 \, \text{mL} \)[/tex] of [tex]\( 10.5 \, M \, \text{H}_2\text{O}_2 \)[/tex]
4. [tex]\( 100.0 \, \text{mL} \)[/tex] of [tex]\( 10 \, M \, \text{NaCl} \)[/tex]

The concentration of a solution is typically measured in molarity (M), which represents the number of moles of solute per liter of solution. Since the molarity values are already given, we can directly compare these values to find the most concentrated solution without needing to consider the volume or the molar mass of the solutes.

Let's list the molarities for each solution again:

1. [tex]\(\text{H}_2\text{SO}_4\)[/tex] has a concentration of [tex]\(10 \, M\)[/tex]
2. [tex]\(\text{PbSO}_4\)[/tex] has a concentration of [tex]\(1.0 \, M\)[/tex]
3. [tex]\(\text{H}_2\text{O}_2\)[/tex] has a concentration of [tex]\(10.5 \, M\)[/tex]
4. [tex]\(\text{NaCl}\)[/tex] has a concentration of [tex]\(10 \, M\)[/tex]

From these values, it's clear that the highest molarity among the solutions is [tex]\(10.5 \, M\)[/tex].

Therefore, the most concentrated solution is [tex]\( \text{H}_2\text{O}_2 \)[/tex] with a molarity of [tex]\( 10.5 \, M \)[/tex].