Question

1. A l64-g sample of HF is dissolved in water to give 2.0 x 10' ml of solution. The concentration of solution is: A) 0.82 M B) 0.16 M C) 0.08 M D) 4.1 M E) 8.2 M 2. You have 75.0 mL of a 2.50 M solution of Na,CrO(ag). You also have 125 mL of a 2.01 M solution of AgNOs(ag), Calculate the concentration of Cro. after the two solutions are mixed together. A) 0.00 M B) 0.309 M C) 0.938 M D) 0.251 M E) 2.50 M 3. A 74.28-g sample of Ba(OH) is dissolved in enough water to make 2.450 liters of solution. How many mL of this solution must be diluted with water in order to make 1.000 L of 0.100 M Ba(OH)2? A) 565 mL B) 177 mlL C) 17.7 mL D) 4.34 mL E) 231 mL A 1.59-g sample of a metal chloride, MClh, is dissolved in water and treated with excess aqueous silver nitrate. The silver chloride that formed weighed 3.60 g Calculate the molar mass of M. A) 70.9 g/mol B) 28 g/mol C) 55.9 g/mol D) 63 g/mol E 72.4 g/mol Consider an aqueous solution of calcium nitrate added to an aqueous solution of sodium phosphate. Write and balance the equation for this reaction to answer the following question. What is the sum of the coefficients when the molecular equation is balanced in A) 4 B) 5 C) 7 D) 11 standard form? E) 12

Answer 1

16.4 g HF has (16.4/20)= 0.82 mol of HF.

Now, 200 mL solution contains 0.82 mol HF

So, 1000 mL solution contains [(0.82 /200) * 1000] = 4.1 mol of HF.

Therefore, concentration of the solution is 4.1 M.

So the correct answer is 4.1M (D)