In a coffee-cup calorimeter experiment, 10.00 g of a soluble ionic compound was added to the calorimeter containing 75.0 g h2o initially at 23.2°c. the final temperature of the solution was 31.8°c. what was the change in enthalpy for the dissolution of this compound? give your answer in units of joules per gram of compound. assume that the specific heat of the solution is the same as that of pure water, 4.18 j ⁄ g ⋅ °c. a) 2.7 x 10^2 j/g b) -3.1 x 10^3 j/g c) -3.1 x 10^2 j/g d) 3.1 x 10^2 j/g

Given:

Mass of the ionic compound  = 10.00 g

Mass of water = 75.0 g

Initial temperature of water T1= 23.2 C

Final temperature of water T2 = 31.8 C

Specific heat of water c = 4.18 J/gC

To determine:

Enthalpy of dissolution of the ionic compound

Explanation:

Heat gained by water is given as:

Q = mcΔT

m = mass of water

c = specific heat

ΔT = change in temp of water = T2-T1

Q = 75.0 g * 4.18 J/gC * (31.8-23.2)C = 2696 J

Now,

Heat gained by water = heat lost by the ionic compound (i.e. heat of dissolution)

Thus, q(ionic) = 2696 J

ΔH = q(ionic)/mass of ionic compound = 2696 J/10.00 g = 2.7 *10² J/g

Ans: A) enthalpy change = 2.7*10² J/g

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

2b2t

explanation:

2b2t