Answer to Question #98783 in Chemistry for Lesly Coss

Question

Consider the reaction 3CaCl2(aq) + 2Na3PO4(aq) --> Ca3(PO4)2(s) + 6 NaCl(aq) (molar mass of calcium phosphate is 310.18 g/mol)

What volume of 0.500 M Na3PO4 solution is needed to react with 275 mL of 0.150 M CaCl2? _____ mL (Give answer to correct sig figs in units of mL)

Answer 1

Answer on Question #98783 – Chemistry – Other

Task:

Consider the reaction 3CaCl₂(aq) + 2Na₃PO₄(aq) --> Ca₃(PO₄)₂(s) + 6NaCl(aq) (molar mass of calcium phosphate is 310.18 g/mol)

What volume of 0.500 M Na₃PO₄ solution is needed to react with 275 mL of 0.150 M CaCl₂? _____ mL (Give answer to correct sig figs in units of mL).

Solution:

Balanced equation:

3CaCl₂ + 2Na₃PO₄ --> Ca₃(PO₄)₂ + 6NaCl

According to the reaction equation: n(CaCl₂) / 3 = n(Na₃PO₄) / 2;

2*n(CaCl₂) = 3*n(Na₃PO₄);

n = C*V, then:

2 * C(CaCl₂) * V(CaCl₂) = 3 * C(Na₃PO₄) * V(Na₃PO₄);

2 * 0.150 M * 275 mL = 3 * 0.500 M * V(Na₃PO₄);

82.5 = 1.5 * V(Na₃PO₄);

V(Na₃PO₄) = 82.5 / 1.5 = 55 mL

V(Na₃PO₄) = 55.0 mL.

Answer: V(Na₃PO₄) = 55.0 mL.