Question

Be sure to answer all parts.

How many total moles of ions are released when the following sample dissolves completely in water? Enter your answer in scientific notation.

7.72 × 10^-4 g of Ca(NO3)2: ___ × 10^_____mol

Answer 1

Ca(NO₃)₂ $\rightarrow$ Ca²⁺ + 2NO₃^-

moles of Ca(NO₃)₂ = $\frac{7.72× 10^{-4}}{164.08}$

moles of Ca(NO₃)₂ = 4.7× 10^-6 moles

Total number of ions = 3

so according to stoichiometry total concentration of ions = 3 × 4.7× 10^-6 moles

which is equal to 14.1× 10^-6 moles