Chemistry Moles, Molecular Weight

[Dooga Blackrazor]

Homework Statement

I did an experiment and found the weight of CaC(2)O(4)H(2)0 to be 31.4966 subtracted by the weight of a crucible which is 31.2612.

I put this for my weight of CaC204H20 (as I can't think of any other weight that it would be requested). I followed the next question calculating molecular weight. 146.112. After that I calculated the moles of CaC204H20 to be 1.6 x 10^-3 (not sure on this).

I now need the moles of Ca(2+ charge). There are 27.42% Ca(2+) mass percentage of it.

I don't know what to do from there. Same goes for the concentration of Ca(2+)

Homework Equations

The Attempt at a Solution

If I had to guess, I would say the moles of Ca2+ are 0.2742 times 146.112, but I am not sure.

Concentration, I have no clue. I have been looking through my online notes on this for hours now. Thanks for any help.

 

[Ygggdrasil]

Your calculation of the moles of CaC₂O₄*H₂O is correct. According to the formula of the compound, how many moles of Ca²⁺ does one mole of the compound contain?

 

[Blueshift5]

I can provide some guidance and suggestions for your experiment and calculations.

First, it is important to clearly state your objective and hypothesis for the experiment. What were you trying to determine or measure? This will help guide your calculations and make sure they are relevant to your experiment.

Next, it is important to accurately record and report your data. In this case, it seems like you have found the weight of CaC2O4H2O and the weight of the crucible. It would be helpful to include the units for these measurements (grams, milligrams, etc.) to ensure accuracy.

To calculate the molecular weight of CaC2O4H2O, you can use the formula weight = mass/ moles. You have already calculated the mass and have an estimate for the moles (1.6 x 10^-3). Make sure to use the correct units for mass and moles (grams and moles, respectively) in order to get the correct answer for molecular weight.

To determine the moles of Ca2+, you can use the mole ratio of Ca2+ to CaC2O4H2O. From the given information, it seems like there is a 27.42% mass percentage of Ca2+ in CaC2O4H2O. This means that for every 100 grams of CaC2O4H2O, there is 27.42 grams of Ca2+. Using this ratio, you can calculate the moles of Ca2+ in your sample.

For concentration, you can use the formula concentration = moles/ volume. It is important to know the volume of your sample in order to accurately calculate the concentration. Also, make sure to use the correct units for moles and volume (moles and liters, respectively) in order to get the correct units for concentration (moles per liter).

I hope this helps guide you in your calculations. Remember to always double check your units and make sure they are consistent throughout your calculations. Good luck!