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Hydrated salts equation

A nickel compound has the formula Ni(NO3)2 .xH2O and a molar mass of 290.7 g mol^-1. calculate the value of x.

help please

Reply 1

miszanjz

so you know the whole Mr is 290.7. If you work out the Mr of the Ni(NO3)2 it's 182.7. Therefore the Mr of the water in the formula must be 290.7-182.7=108. We also know that the Mr of one water molecule is 18. So how many waters must we have to have a Mr of 108? 108/18 = 6. x = 6.
i was stuck on this too but i figured it out after a while :smile:

Reply 2

_it.t1

Original post by miszanjz

so you know the whole mr is 290.7. If you work out the mr of the ni(no3)2 it's 182.7. Therefore the mr of the water in the formula must be 290.7-182.7=108. We also know that the mr of one water molecule is 18. So how many waters must we have to have a mr of 108? 108/18 = 6. X = 6.
I was stuck on this too but i figured it out after a while :smile:

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