Which solution is the most concentrated?
2.0 ml of 10 m h2so4, where h2so4 has a molar mass of 98 g/mol
5.0 ml of 1.0 m pbso4, where pbso4 has a molar mass of 303 g/mol
2.0 ml of 10.5 m h2o2, where h2o2 has a molar mass of 34 g/mol
100 ml of 10 m nacl, where nacl has a molar mass of 58 g/mol

100 mL of 10 M NaCl, where NaCl has a molar mass of 58 g/mol

Explanation:

Concentration refers to the amount of substance in moles present in a solution. Number of moles is obtained from; number of moles= concentration*volume

For our chosen answer, 100/1000 * 10=1 mole. If we follow this procedure to calculate the amount of other solutions stated in the question, we will realize that 100ml of 10M NaCl has the highest number of moles present. Since concentration has to do with the number of moles present in a solution, this is the most concentrated solution.

2.0 mL of 10.5 M H2O2, where H2O2 has a molar mass of 34 g/mol.

Explanation:

It is most concentrated because it contains 10.5 M of Hydrogen peroxide.