how to make 400 ml of 5% w/w h2so4
5% w/w H2SO4 means 5 g H2SO4/100 g solution.
So you want 5g H2SO4 and 95 g H2O BUT be sure you add the H2SO4 to the H2O and not the other way around. That gives you 100 g solution. To make 400 mL just multiply everything by 4.
To make a solution of 400 mL of 5% (w/w) H2SO4, you need to know the concentration and density of the concentrated sulfuric acid you are starting with.
First, let's understand what 'w/w' means. It stands for weight/weight and represents a percentage concentration by weight. For this case, it means that 5% of the total weight of the solution will be sulfuric acid.
To calculate the amount of sulfuric acid needed, you'll need to know its density (g/mL) and its percentage purity. Let's assume you have a concentrated sulfuric acid with a density of 1.84 g/mL and a purity of 98%.
Here's how you can calculate the required amount:
1. Calculate the total weight of the desired solution:
400 mL x 1 g/mL (assuming the density of water as 1 g/mL) = 400 g
2. Calculate the weight of sulfuric acid required:
5% * 400 g = 20 g
3. Determine the volume of concentrated sulfuric acid needed:
Weight of sulfuric acid / Density of sulfuric acid = Volume of sulfuric acid
20 g / 1.84 g/mL = 10.87 mL
Remember to handle concentrated sulfuric acid with extreme caution as it is highly corrosive and can cause severe burns. Always work in a well-ventilated area and wear appropriate protective equipment.
To prepare the solution:
1. Measure 10.87 mL of concentrated sulfuric acid using a calibrated pipette or another reliable measuring device.
2. Transfer the measured sulfuric acid into a container, preferably made of glass due to its resistance to chemical reactions.
3. Gradually add deionized water to the container while stirring gently.
4. Once the sulfuric acid is thoroughly mixed, add water up to the final volume of 400 mL.
5. Stir the solution or use a magnetic stirrer to ensure complete homogeneity.
Please note that this procedure assumes ideal 100% mixing efficiency and neglects any heat effects that might occur during dilution. Always exercise caution and follow proper lab safety protocols when working with hazardous chemicals.