THE NO. OF H3O+ IONS PRESENT IN 10ML OF WATER AT 25 DEGREE CENTEGRATE

To determine the number of H3O+ ions present in 10 mL of water at 25 degrees Celsius, we first need to understand the concept of pH and the dissociation of water. At this temperature, pure water has a neutral pH of 7, which corresponds to a concentration of H3O+ ions of 1 x 10^-7 moles per liter.

Calculating H3O+ Ion Concentration

In pure water, the concentration of H3O+ ions is equal to the concentration of OH- ions due to the self-ionization of water:

• H2O ⇌ H3O+ + OH-

At 25 degrees Celsius, the concentration of H3O+ ions is:

• [H3O+] = 1 x 10^-7 moles/L

Volume Conversion

Next, we need to convert the volume of water from milliliters to liters because the concentration is given in moles per liter. Since there are 1000 mL in a liter, we can convert 10 mL to liters:

• 10 mL = 10/1000 L = 0.01 L

Calculating the Number of H3O+ Ions

Now that we have the concentration and the volume, we can calculate the number of moles of H3O+ ions in 10 mL of water:

• Number of moles = Concentration × Volume
• Number of moles = (1 x 10^-7 moles/L) × (0.01 L) = 1 x 10^-9 moles

Converting Moles to Number of Ions

To find the actual number of H3O+ ions, we can use Avogadro's number, which is approximately 6.022 x 10^23 particles per mole:

• Number of H3O+ ions = Number of moles × Avogadro's number
• Number of H3O+ ions = (1 x 10^-9 moles) × (6.022 x 10^23 ions/mole)
• Number of H3O+ ions ≈ 6.022 x 10^14 ions

Final Result

In summary, in 10 mL of water at 25 degrees Celsius, there are approximately 6.022 x 10^14 H3O+ ions present. This illustrates the vast number of ions that exist even in a small volume of water, highlighting the microscopic nature of chemical species in solutions.