Question

please answer asap! worth 35 points!

Given the change in the temperature from adding 3.00 grams of lithium chloride to 100.00 mL of water, calculate the enthalpy of solution for lithium chloride in units of kJ/mol. the change in temp was 6.09

Answer 1

Answer:

The enthalpy of the solution is -35.9 kJ/mol

Explanation:

Step 1: Data given

Mass of lithiumchloride = 3.00 grams

Volume of water = 100 mL

Change in temperature = 6.09 °C

Step 2: Calculate mass of water

Mass of water = 1g/mL * 100 mL = 100 grams

Step 3: Calculate heat

q = m*c*ΔT

with m = the mass of water = 100 grams

with c = the heat capacity = 4.184 J/g°C

with ΔT = the chgange in temperature = 6.09 °C

q = 100 grams * 4.184 J/g°C * 6.09 °C

q =2548.1 J

Step 4: Calculate moles lithiumchloride

Moles LiCl = mass LiCl / Molar mass LiCl

Moles LiCl = 3 grams / 42.394 g/mol

Moles LiCl = 0.071 moles

Step 5: Calculate enthalpy of solution

ΔH = 2548.1 J /0.071 moles

ΔH = 35888.7 J/mol = 35.9 kJ/mol (negative because it's exothermic)

The enthalpy of the solution is -35.9 kJ/mol

Answer 2

The enthalpy of solution is -37.4 kJ/mol.

What is enthalpy?

This is the energy evolved  or absorbed in a reaction. We know from the question that;

Mass of water = 100 g

Mass of LiCl = 3 g

Total mass present = 103 g

Number of moles of LiCl = 3 g/42 g/mol = 0.07 moles

Temperature change = 6.09°C

Given that;

q = mcdT

q = 103 g * 4.18 J/g/°C * 6.09°C =2.62 kJ

Enthalpt of solution in kJ/mol = -(2.62 kJ/ 0.07 moles)  = -37.4 kJ/mol

Learn more about enthalpy of solution: https://brainly.com/question/2697602