Calculate the molarity of 32.9 g32.9 g of MgS MgS in 971 mL 971 mL of solution.

0.60 M

Explanation:

Given data:

Mass of MgS = 32.9 g

Volume of solution = 971 mL (0.971 L)

Solution:

Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.

Formula:

Molarity = number of moles of solute / L of solution

Number of moles of MgS:

Number of moles = mass/molar mass

Number of moles = 32.9 g/ 56.38 g/mol

Number of moles = 0.58 mol

Molarity of solution:

M = 0.58 mol/ 0.971L

M = 0.60 M

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.