How to calculate moles in a sample
1 mole is 6.022 * 10^23
what is your question? is there an equation that u need to solve?
I was doing a lab experiment on the reaction of copper(II) sulphate and aluminum:
1) I measured 2.02g of copper(II) sulphate pentahydrate
2) I dissolved the copper(II) sulphate pentahydrate in 10mL of distilled water
3) I added 2.0mL of concentrated HCl to the solution and mixed well
4) I added 0.25g on Aluminun foil to the solution.
5) After 5 minutes, i added an additional 5mL of concentrated HCl
6) After all the aluminum foil has reacted, i decanted the solution from the solid (leaving copper behind).
7) The mass of copper product after drying it was 0.69g.
Now we have:
-Mass of CuSO4*5H2O = 2.02g
-Mass of Aluminuim foil = 0.25g
-Mass of copper metal product = 0.69g
The questions are:
1) Calculate moles of Al used.
2) Calculate the moles of CuSO4*5H2O used.
3) Calculate the moles of copper product based on moles of Al.
4) Calculate the moles of copper product based on moles of CuSO4*5H2O.
5) Whats the limiting reactant.
6) Whats the grams of copper product based on the limiting reactant (theoretical yiel).
7) Calculate the percent yield of Copper.
To calculate the number of moles in a sample, you need to know the mass of the sample and the molar mass of the substance.
Here's the step-by-step process:
1. Determine the mass of the substance: Measure or find the mass of the sample in grams. This value is usually given in a problem or can be measured using a scale.
2. Identify the molar mass: Find the molar mass of the substance. This is the mass of one mole of the substance and is expressed in grams per mole (g/mol). You can usually find the molar mass on the periodic table or by adding up the atomic masses of the elements in the compound.
3. Set up a ratio: Divide the mass of the sample by the molar mass. This will give you the number of moles in the sample. The equation looks like this:
Moles = Mass (in grams) / Molar mass (in g/mol)
For example, if you have 20 grams of a substance with a molar mass of 40 g/mol, the calculation would be:
Moles = 20 g / 40 g/mol = 0.5 mol
So, the sample contains 0.5 moles of the substance.
Remember to always make sure your units are consistent throughout the calculation. This method allows you to convert mass into moles, which is a fundamental unit for quantifying substances in chemistry.