Sam records the mass of his evaporating dish as 6.251 g.

he records the mass of the evaporating dish and the sample of hydrate as 16.864 g.

after heating the sample in the evaporating dish to constant weight, the mass of them combined is 11.13 g.

how many moles of water were removed from the sample by the heating process?

report your answer with three digits after the decimal.

Explanation:

1. Mass of water removed

This amount must be rounded to two decimals, because the least precise measure (11.13 g) contains two decimals.

2. Moles of water removed from the sample by the heating process

You must use the molar mass of water to convert 5.73 g of water to number of moles.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles