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Buffy carries out a neutralization reaction in her styrofoam cup calorimeter, with a heat capacity of 41 J/C. She mixes 25.0mL of 3.0M acid solution and 25.0mL of 3.0M base solution at 22.3 degree C. The temperature rose to 36.5 C. D=1.03 g/ml and Heat Capacity= 4.05 J/g*C

-Calculate heat energy absorbed by solution (qsolution)

-Calculate heat energy absorbed by the calorimeter (qcalorimeter)

-Calculate q reaction

-calculate number of moles of acid reacting

-calculate delta H neut. of the reaction in joules/mole

Answer 1

Buffy carries out a neutralization reaction in her styrofoam cup calorimeter, with a heat capacity of 41 J/C. She mixes 25.0mL of 3.0M acid solution and 25.0mL of 3.0M base solution at 22.3 degree C. The temperature rose to 36.5 C.

Heat capacity of Styrofoam cup calorimeter = 41 J/C

Initial T = 22.3 deg C , Volume of acid solution = 25.0 mL and molarity = 3.0 M , molarity of base = 3.0 M and volume is 25.0 mL

Final T = 36.5 deg C

Calculate heat energy absorbed by solution (qsolution)

Step 1) Calculation of mass of solution

Mass of solution = Volume of solution * density

= (25+25 )mL * 1.0 g/mL          (density of water = 1.0 g / mL )

= 50.0 g

q = c m delta T

= 4.18 J / g Deg C * 50.0 g * ( 36.5- 22.3 ) deg C

= 2967.8 J

-Calculate heat energy absorbed by the calorimeter (qcalorimeter)

q = sp heat of Calorimeter * T change

= 41 J/ deg C * ( 36.5- 22.3 ) deg C

= 582.0 J

-Calculate q reaction

q = Heat absorbed by solution+ heat absorbed by calorimeter

= 2967.8 J + 582.0 J = 3.55 E 3 J

-calculate number of moles of acid reacting

We calculate number of moles of acid present in the solution by using molarity and volume in L

Number of moles = volume in L * molarity

= 0.025 L * 0.30 M

= 0.0075 mol

Number of moles of base = 0.025 L * 0.3 M = 0.0075 mol

So equal moles of base and acid so 0.0075 mol of acid is reacted

calculate delta H neut. of the reaction in joules/mol

Number of moles of acid = 0.0075 mol

Delta H = - q * n =- 3.55 E 3 J / 0.0075 mol

= - 4.73 E 5 J per mol