Concentrated phosphoric acid,H3PO4 was added slowly into some water to produce 5.0dm^3 of a dilute acid solution.100g of the pure phosphoric acid,H3PO4 was present in the solution.Find the concentration of the acid,in g dm^-3.
Wouldn't that be 100g/5 dm^3 = 20g/dm^3
To find the concentration of the dilute acid solution in grams per decimeter cubed (g dm^-3), you need to calculate the number of moles of the acid and then divide it by the volume of the solution.
Here's how you can do it step by step:
1. Calculate the number of moles of phosphoric acid (H3PO4) present in the solution.
- Convert the mass of the phosphoric acid from grams to moles using its molar mass.
- The molar mass of H3PO4 is 98 g/mol.
- Number of moles of H3PO4 = mass of H3PO4 / molar mass of H3PO4.
In this case, the mass of the H3PO4 is given as 100 g:
Number of moles of H3PO4 = 100 g / 98 g/mol.
2. Determine the volume of the solution in decimeters cubed (dm^3).
- The volume of the dilute acid solution is given as 5.0 dm^3.
3. Calculate the concentration of the acid in g dm^-3.
- Concentration (in g dm^-3) = Number of moles / Volume of solution.
Substituting the values, we get:
Concentration = (100 g / 98 g/mol) / 5.0 dm^3.
Calculate the division to find the concentration of the acid in grams per decimeter cubed (g dm^-3).
Note: It's important to be consistent with units during calculations. Make sure the units for mass and volume are compatible, and convert them if necessary.