Question
48
Identify the ions that exist in each aqueous solution, and specify the concentration of each ion. (a) 0.25 M (NH_4)_2 SO_4 (b) 0.123 M Na_2 CO_3 (c) 0.056 M HNo_3 Identify the ions that exist in each aqueous solution and specify the concentration of each ion. (a) 0.12 M BaCI_2 (b) 0.0125 M CuSO_4 (c) 0.500 M K_2 Cr_2 O_7 An experiment in your laboratory requires 500. ml, of a 0.0200 M solution of Na_2 CO_3. You are given solid Na_2 CO_3, distilled water, and a 500 -mL volumetric flask. Describe how to prepare the required solution. What mass of oxalic acid, H_2 C_2 O_4, is required to prepare 250 mL of a solution that has a concentration of 0.15 M H_2 C_2 O_4? If you dilute 25.0 mL of 1.50 M hydrochloric acid to 500.mL, what is the concentration of the dilute acid? If 4.00 mL of 0.0250 M CuSO_4 is diluted to 10.0 mL with pure water, what is the molar concentration of copper(II) sulfate in the diluted solution? Which of the following methods would you use to prepare 1.00 L of 0.125 M H_2 SO_4? (a) Dilute 20.8 mL of 6.00 M H_2 SO_4 to a volume of 1.00 L (b) Add 950 mL of water to 50.0 mL of 3.00 M H_2 SO_4.
Explanation / Answer
48)
Molarity of oxalic acid H2C2O4 = 0.15 M
volume = 250 mL = 0.250 L
Molarity = moles / volume
0.15 = moles / 0.250
moles = 0.0375
moles = mass / molar mass
0.0375 = mass / 90
mass of oxalic acid = 3.38 g