What mass of Na 2 SO 4 is needed to make 3.2 L of 2.5 M solution? | General Chemistry 2

Molarity vs. molality - 1 | Chemical Calculations

Chapter 2 - Chemical Calculations

What mass of Na₂SO₄ is needed to make 3.2 L of 2.5 M solution?

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Solution

n_Na2SO4 = M_sol x V_sol and n_Na2SO4 =

\frac{m_{Na 2 SO 4}}{M_{Na 2 SO 4}}

⇒ $\frac{m_{Na 2 SO 4}}{M_{Na 2 SO 4}}$ = M_sol x V_sol

⇒m_Na2SO4 = M_sol x V_solx M_Na2SO4

⇒m_Na2SO4 = 2.5 x 3.2 x (23 x 2 + 32 + 4 x 16) = 1.1 x 10³ g = 1.1 kg