Question

1. Write the nettonic equation for the following reaction: CaCl2(aq) + K2SO4(aq) → CaSO4(s) + 2KCl(aq) 2. What volume is needed dissolve 100.0g of NaBr to create a 0.20M solution?

Answer 1

ANSWER 1 Molecular equation: CaCl2 (aq) K2SO4(aq) = CaSO4 () + 2KCI (aq) Total ionic equation: Ca2+ (aq) + 2Cl(aq) + 2K+ + SO ? (aq) = CaSO4(s) + 2K+ (aq) + 2CT (aq) Net ionic equation (neglecting the spectator ions): Ca²+ (aq) + so ? (aq) = CaSO4(s) ANSWER 2 MW of NaBr is 102.894 So, 1 mole NaBr = 102.894 g NaBr or 1 g NaBr = 1/102.894 mole NaBr or. 100 g NaBr=100/102.894 mole = 0.972 mole NaBr 1000 ml of 1 M NaBr solution contain 1 mole NaBr Or, 1 mole of NaBr is present in 1M solution whose volume is 1000 mL or, 0.972 mole of NaBr is present in 1 M of NaBr solution whose volume is 1000 x 0.97 mL or, 0.972 mole of NaBr is present in 0.2 M of NaBr solution whose volume is (1000 x 0.972 )/0.2 mL = 4860 ml 4860 mL volume is needed to dissolve 100 g of NaBr to create a 0.2 M solution