How do you make 5% ammonium oxalate? I know the mass is 142.11g.
Is that 5% w/w or 5% w/v? I assume w/v. How do you know 142.11 grams? Doesn't it depend upon how much you want to make. And you don't show that in your post.
To make a 5% solution of ammonium oxalate, you will need to know the concentration in terms of percentage weight/volume (% w/v).
The term "5% solution" means that there is 5 grams of solute (ammonium oxalate) dissolved in every 100 milliliters of solution. To calculate the mass of ammonium oxalate needed, you can use the formula:
Mass (g) = (Percentage / 100) * Volume (ml)
For a 5% solution of ammonium oxalate with a mass of 142.11 grams:
Percentage = 5%
Volume = 100 ml
Mass (g) = (5 / 100) * 100 = 5 grams
Therefore, you will need 5 grams of ammonium oxalate to make a 5% solution.
Make sure to measure the mass accurately using a balance and dissolve the ammonium oxalate in the desired volume of solvent, such as distilled water, while stirring to ensure proper dissolution.