How many total moles of ions are released when the following sample dissolves completely in water:
5.15x10^-3 g Ca(NO3)2
To determine the total moles of ions released when Ca(NO3)2 dissolves completely in water, we need to calculate the number of moles of calcium ions (Ca2+) and nitrate ions (NO3-) in the given sample.
First, let's calculate the moles of Ca(NO3)2:
Molar mass of Ca(NO3)2 = atomic mass of Ca + 2 * (atomic mass of N + 3 * atomic mass of O)
Molar mass of Ca(NO3)2 = 40.08 g/mol + 2 * (14.01 g/mol + 3 * 16.00 g/mol)
Molar mass of Ca(NO3)2 = 40.08 g/mol + 2 * (14.01 g/mol + 48.00 g/mol)
Molar mass of Ca(NO3)2 = 40.08 g/mol + 2 * 62.01 g/mol
Molar mass of Ca(NO3)2 = 40.08 g/mol + 124.02 g/mol
Molar mass of Ca(NO3)2 = 164.10 g/mol
Now, let's calculate the moles of Ca(NO3)2:
moles of Ca(NO3)2 = mass of Ca(NO3)2 / molar mass of Ca(NO3)2
moles of Ca(NO3)2 = 5.15x10^-3 g / 164.10 g/mol
moles of Ca(NO3)2 ≈ 3.138x10^-5 mol
Since Ca(NO3)2 dissociates into one calcium ion (Ca2+) and two nitrate ions (2NO3-), the total moles of ions released would be three times the moles of Ca(NO3)2:
total moles of ions = 3 * moles of Ca(NO3)2
total moles of ions = 3 * 3.138x10^-5 mol
total moles of ions ≈ 9.414x10^-5 mol
Therefore, when the given sample of Ca(NO3)2 dissolves completely in water, approximately 9.414x10^-5 moles of ions are released.
To determine the total moles of ions released when a compound dissolves completely in water, we need to first calculate the number of moles of the given compound.
The molar mass of Ca(NO3)2 can be calculated by adding up the atomic masses of its constituent elements:
Ca: 40.08 g/mol
N: 14.01 g/mol
O: 16.00 g/mol (x3 for three oxygen atoms)
Molar mass of Ca(NO3)2 = (40.08 g/mol) + (14.01 g/mol) + (16.00 g/mol x 3) = 164.09 g/mol
Now we can calculate the number of moles of Ca(NO3)2:
Number of moles = mass of compound / molar mass
Number of moles = 5.15x10^-3 g / 164.09 g/mol
Remember to convert grams to moles by dividing by the molar mass.
Number of moles = 3.14x10^-5 mol
Since Ca(NO3)2 dissociates into three ions when it dissolves, we multiply the number of moles by 3 to find the total moles of ions released:
Total moles of ions = 3 x Number of moles
Total moles of ions = 3 x 3.14x10^-5 mol
Finally, we can simplify the expression:
Total moles of ions = 9.42x10^-5 mol
Therefore, when 5.15x10^-3 g of Ca(NO3)2 dissolves completely in water, a total of 9.42x10^-5 mol of ions are released.
8.55*10^19
Convert 5.15 x 10^-3 to moles. How many molecules will that be? moles x 6.022 x 10^23 x moles = # molecules.
Then Ca(NO3)2 provides 3 ions/molecule so multiply # molecules above by 3.