How many milliliters of an aqueous solution of 0.157 M magnesium nitrate is needed to obtain 17.4 grams of the salt?

747mL of the 0.157mL are needed

Explanation:

To find the grams of salt we need to convert these grams to moles using molar mass of magnesium nitrate (148.3g/mol). Then, with the molar concentration we can convert the moles to liters and, as last, to milliliters, as follows:

Moles Mg(NO₃)₂:

17.4g * (1mol / 148.3g) = 0.117 moles of magnesium nitrate

Volume:

0.117 moles * (1L / 0.157moles) = 0.747L

= 747mL of the 0.157mL are needed

In a 0.157M solution there are 0.157 moles per liter of solution

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

the awnser is group 12