You are given the data for the following reaction which involves the heating of magnesium sulfate heptahydrate (MgSO4•7H2O) to remove the waters of hydration and form the anhydrous salt magnesium sulfate (MgSO4):

MgSO4•7H2O (s) → MgSO4 (s) + 7H2O (g)

initial weight of salt (hydrate) 0.5282 g
final weight of salt (anhydrous) 0.2579 g
total weight of waters lost 0.2703 g

Which answer represents the total moles of anhydrous salt?

Question

You are given the data for the following reaction which involves the heating of magnesium sulfate heptahydrate (MgSO4•7H2O) to remove the waters of hydration and form the anhydrous salt magnesium sulfate (MgSO4):

MgSO4•7H2O (s) → MgSO4 (s) + 7H2O (g)

initial weight of salt (hydrate) 0.5282 g
final weight of salt (anhydrous) 0.2579 g
total weight of waters lost 0.2703 g

Which answer represents the total moles of anhydrous salt?

Vocaloid · Answer

hm. well my first instinct, convert g of water (0.2703g) lost to moles and divide by 7.

Vocaloid · Answer

it's been a while since i've done this though.

zarkam21 · Answer

2.325x10^22

Vocaloid · Answer

is there a list of choices?

zarkam21 · Answer

0.008372

0.002143

0.001072

0.004186

Vocaloid · Answer

convert 0.2703g to moles, not molecules

Vocaloid · Answer

divide by the molar mass of water

zarkam21 · Answer

0.2703 divided by avogadros number

Vocaloid · Answer

$\color{#0cbb34}{\text{Originally Posted by}}$ @Vocaloid
divide by the molar mass of water
$\color{#0cbb34}{\text{End of Quote}}$

zarkam21 · Answer

I mean to convert it to molecules would I use avogradros

Vocaloid · Answer

moles are not the same thing as molecules

Vocaloid · Answer

you would convert 0.2703g to moles by dividing by the molar mass of water

zarkam21 · Answer

I got 24.0052 for the molar mass of water

zarkam21 · Answer

wait nvm hold on

zarkam21 · Answer

molar mass of water is 18.0158

zarkam21 · Answer

so 0.2703/18.0158=.0150034...

Vocaloid · Answer

good, that gives total moles of water.

MgSO4•7H2O

tells us that there are 7 moles of water for every 1 mole of compound so

.0150034/7 = 0.002143 is my best attempt

zarkam21 · Answer

You are given the data for the following reaction which involves the heating of magnesium sulfate heptahydrate (MgSO4•7H2O) to remove the waters of hydration and form the anhydrous salt magnesium sulfate (MgSO4):

MgSO4•7H2O (s) → MgSO4 (s) + 7H2O (g)

initial weight of salt (hydrate)	0.5282 g
final weight of salt (anhydrous)	0.2579 g
total weight of waters lost	0.2703 g

Which answer represents the total moles of water lost?

zarkam21 · Answer

would I just subtract

zarkam21 · Answer

0.03000

0.01500

0.06000

0.04500

zarkam21 · Answer

These are the answer choices

Vocaloid · Answer

we already calculated that 0.2703 g is about 0.01500 moles so 0.01500 would be your solution

zarkam21 · Answer

Which answer represents the simplest whole number molar ratio (moles of water lost/moles of anhydrous salt)?

zarkam21 · Answer

7:1?

Vocaloid · Answer

yeah that's what i think too