1.how to prepare
a)200ml of a 4MHCl?
b)100ml of a 1.5NaOH?
4 mols HCl
= 4 * (1+35.5) = 146 grams of HCl per liter
so either mix a liter that way and pour out .2 liter
or
put .2*146 = 29.2 grams of HCl in .2 liter of water
Of course that is easier said than done because how do you get 29.2 grams of the acid HCl ? It is not a solid that you can weigh on a scale. It is either available as a standard solution which you can dilute or it exists as a gas. So you would do it by diluting in real life.
CAUTION!! If working to dilute manufactured concentrate of any acid, be sure to add HCl concentrate to ~ half of final volume needed for solution. Adding water onto 146gms of HCl (~172-ml of concentrated acid) will ionize so fast and give off sufficient heat that the liquid acid might explode. Wear protective clothing and safety goggles for sure.
To prepare the desired solutions, you would need to calculate the amount of solute (HCl for a) and NaOH for b)) needed to achieve the desired molarity (M). Here's how you can calculate it:
a) To prepare 200ml of 4MHCl:
Step 1: Determine the molecular weight of HCl (hydrochloric acid). The molecular weight of HCl is 36.46 g/mol.
Step 2: Multiply the desired molarity (4M) by the desired volume (0.2 L or 200 ml) to obtain the number of moles required:
Moles = Molarity × Volume
= 4M × 0.2 L
= 0.8 moles
Step 3: Calculate the mass of HCl needed using the equation:
Mass = Moles × Molecular Weight
= 0.8 moles × 36.46 g/mol
≈ 29.168 grams
So, to prepare 200ml of 4MHCl, you would need approximately 29.168 grams of HCl. Dissolve this amount of HCl in water and then make up the final volume to 200ml.
b) To prepare 100ml of 1.5M NaOH:
Step 1: Determine the molecular weight of NaOH (sodium hydroxide). The molecular weight of NaOH is 39.997 g/mol.
Step 2: Multiply the desired molarity (1.5M) by the desired volume (0.1 L or 100 ml) to obtain the number of moles required:
Moles = Molarity × Volume
= 1.5M × 0.1 L
= 0.15 moles
Step 3: Calculate the mass of NaOH needed using the equation:
Mass = Moles × Molecular Weight
= 0.15 moles × 39.997 g/mol
≈ 5.9995 grams
So, to prepare 100ml of 1.5M NaOH, you would need approximately 5.9995 grams of NaOH. Dissolve this amount of NaOH in water and then make up the final volume to 100ml.
Remember to always handle concentrated acids and bases with care and follow proper safety protocols, such as using protective equipment and working in a well-ventilated area.