Can anyone help with this looking for step-step info: I have some calculations for this process.
Empirical Formula of a Hydrate
In this experiment you will determine the empirical formula of a hydrate. What is a hydrate? The hydrate is an ionic compound that contains water. You can remove the water by simply heating the hydrate. Once the water is removed from the compound, we call this “anhydrous” which means it is dry (It does not contain water). The hydrate formula is usually written as ionic compound*XH2O. For example, copper (II) nitrate trihydrate is written as Cu(NO3)2*3H2O. What does this mean? It means one mol of copper (II) nitrate contains three molecules of water. (Note: * does not mean multiplication, it means the compound contains water). What happens when you heat Cu(NO3)2*3H2O? The copper (II) nitrate trihydrate will decompose and water and anhydrous copper (II) nitrate (pure salt) will be produced. The chemical equation for decomposition of copper (II) nitrate trihydrate can be written as:
Cu(NO3)2*3H2O Cu(NO3)2 + 3 H2O
In this experiment, the hydrates are written with X in front of water. That’s because you will determine the number of water molecules in the hydrate.
Experiment 1
1. Record the following masses:
a mass of the crucible (g) 88.000(g)
b mass of the crucible and hydrate (g) 93.000(g)
c mass of the crucible and pure salt (g) 91.196(g)
2. Calculate the following:
Make sure to include your work for the following calculations.
Helpful hints: 2(b). To calculate the number of moles of water in the sample, you have to convert mass of water from 2(a) to moles of water. Remember, you have to use the following conversion factor to convert grams to moles:
1 mol of substance = atomic mass of that substance (g)
In this case, the substance would be the water.
2(d). To calculate the number of moles of salt in the sample, you have to convert mass of pure salt from 2(c) to moles of salt. Remember, you have to use the following conversion factor to convert grams to moles:
1 mol of substance = atomic mass of that substance (g)
In this case, the substance would be the pure salt.
2(e). To get the molar ratio of water to salt in the sample, you need to get moles of water from 2(b) and moles of salt from 2(d) and compare them. For example, I got 2 moles of water from 2(b) and 0.5 moles of salt from 2(d), the molar ratio of water to salt in the sample is 4:1 (Note: This is NOT the actual value I recorded from the lab, I just made them up).
a mass of water in the hydrate sample (g)
b number of moles of water in the sample
c mass of pure salt in the sample (g)
d number of moles of salt in the sample
e molar ratio of water to salt in the sample