Question

Chem Lab prelab
1. In an experiment, a student dehydrated an unknown hydrate and found that the mass of the hydrate was initially 1.2067g. After heating, mass of residue was 0.7592
a) calculate mass of water in hydrate
b) calculate mass percent of water in the hydrate
2. What is the formula of copper (II) nitrate pentahydrate? what is the percentage by mass of copper in copper (II) nitrate pentahydrate?
3. A student takes 1.1705g of an unknown copper compound. Following isolation by displacement by Mg, 0.6382g of copper metal was recovered.
a) percentage by mass of copper?
b) molar mass of the compound given that there is only 1 mole of copper of the compound

Answer 1

need person to back up calculations if they're right

Answer 2

a) simple 1.2067g-0.7592g=grams of water in the hydrate correct?
b) mass % h20=mass of h20/total mass (which is 1.2067g) times 100

Answer 3

2. Cu(NO3)2 * 5H2O

Answer 4

mass of cu/mass of overall *100=percentage of mass

Answer 5

@vocaloid hi chem queen

Answer 6

3a) 0.6382g/1.1705g *100?
b)idk lol

Answer 7

Is the rest correct?

Answer 8

Looks good

I’d have to think more about 3b) given the lack of info