Question

17) When 200, mL of water are added to 100. mL of 12 % KCl solution the final concentration of KCI is (Assume the volumes add.) A) 12% B) 4.0% C) 36%. D) 6.0% E) 8.0% 18) What is the molarity of a solution containing 5.0 moles of KCI in 2.0 L of solution? A) 2.5 M B) 1.0 M C) 5.0 M C) 10. M E) 2.0 M 19) What is the molarity of a solution which contains 58.5 g of sodium chloride dissolved in 0.500 L of solution? C) 1.50 M E) 4.00 M A) 0.500 M B) 1.00 M D) 2.00 M 20) How many moles of CaCl2 are in 250 mL of a 3.0 M of CaCl2 solution? B)1.3 moles E) 3.0 moles D) 0.75 mole C) 83 moles A) 750 moles
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Answer 1

17) When 200. mL of water are added to 100. mL of 12 % KCI solution the final concentration of KCI is (Assume the volumes add.) A) 12 %. B) 4.0%. C) 36%. D) 6.0% E) 8.0% 18) What is the molarity of a solution containing 5.0 moles of KCI in 2.0L of solution? A) 2.5 M B) 1.0 M C) 5.0 M C) 10. M E) 2.0 M 19) What is the molarity of a solution which contains 58,5g of sodium chloride dissolved in 0.500 L of solution? C) 1.50 M E) 4.00 M D) 2.00 M A) 0.500 M B) 1.00 M 20) How many moles of CaCl2 are in 250 mL of a 3.0 M of CaCl2 solution? B)1.3 moles E) 3.0 moles C) 83 moles D) 0.75 mole A) 750 moles 17) 12 % KCI means 12 g of KCI in 100 mL Mass of KCI = 12g volume of solution after adding 200 mL water 300 mL Final concentration (12/ 300) x 100 = 4 % 18) Molarity No. of moles of solute volume of solution in liter (5 mol) / (2.0 L) =2.5 M 19) moles of NaCl = (58.5 g) / (58.44 g/mol) 1 mol volume 0.5 L Molarity (1 mol) / (0.5 L) 2 M 20) moles of CaCl2 = (3.0 M) X (0.25 L) 0.75 mol