To how much water should 50mL of 12M hydrochloric acid be added to produce a 4M solution?

50 mL of 12M HCl should be added into 100 mL of water to produce a 4M solution.

Explanation:

According to law of dilution-

where and are initial concentration, final concentration, initial volume and final volume respectively.

Here, , ,

So, = = 150 mL

Hence, final volume of HCl solution should be 150 mL.

So, volume of water needed = (150-50) mL = 100 mL

Therefore 50 mL of 12M HCl should be added into 100 mL of water to produce a 4M solution.

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