Question

2M, 2L aqueous HCl solution is mixed with 3L H20, the molarity of resultant solution is[NCERT Pg. 23] (A) 1.34 M (B) 0.4 M (C) 0.8 M (D) 1 M

Answer 1

Upon diluting a 2M, 2L solution of HCl with 3L of water, the final molarity is calculated as 0.8 M by dividing the total moles of HCl by the total volume of the solution.

Step-by-step explanation:

The question involves calculating the molarity of an aquatic solution after dilution. When 2M, 2L hydrochloric acid (HCl) solution is mixed with 3L of water (H2O), the molarity of the resultant solution can be determined by using the concept of molarity and volume. Molarity (M) is defined as the number of moles of solute per liter of solution. The initial number of moles of HCl is given by the initial molarity multiplied by the initial volume (2 M × 2 L = 4 moles of HCl). After adding 3 liters of water, the total volume becomes 5 liters (2 L + 3 L).

Next, we'll use these values to calculate the final molarity (Mf) of the solution:

Final molarity (Mf) = Total moles of HCl / Total volume of solution
= 4 moles / 5 liters
= 0.8 M.

Therefore, the molarity of the resultant solution is 0.8 M, which corresponds to option (C).

Answer 2

By calculating the total moles of HCl in the initial solution and then dividing by the new total volume after dilution, the molarity of the resultant solution is found to be 0.8M.

Step-by-step explanation:

To find the molarity of the resultant solution when a 2M, 2L aqueous HCl solution is mixed with 3L H2O, we can use the concept of dilution. The molarity (M) of a solution is defined as the number of moles of solute (n) divided by the volume of solution in liters (V). Initially, we have a 2M solution of HCl, meaning there are 2 moles of HCl per liter.

First, calculate the total moles of HCl in the initial 2L solution:

• Moles of HCl = Molarity × Volume = 2M × 2L = 4 moles HCl

After mixing with 3L of water, the total volume of the new solution becomes:

• Total volume = Initial volume + Volume of water added = 2L + 3L = 5L

Now, calculate the molarity of the new solution:

• New Molarity = Moles of HCl / Total volume = 4 moles HCl / 5L
• New Molarity = 0.8M

Therefore, the molarity of the resultant solution is 0.8M, which corresponds to option (C).