2.00 l of 0.500 m h2so4 (density = 1.030 g/ml) at 25.000°c is mixed with 200. g of a naoh solution, also at 25.000°c. after stirring, the temperature of the solution is 36.820°c. calculate q for the reaction. (assume the specific heat capacity of each solution is 4.184 j/g°c. ) is the reaction exothermic or endothermic?

Q = 111.8 kJ;

The reaction is endothermic.

Explanation:

The heat of the mixture can be calculated by the equation:

Q = m*c*ΔT

Where Q is the heat, m is the mass of the solution, c is the specific heat, and ΔT is the variation in the temperature (fina - initial).

The mass of H₂SO₄ is the volume multiplied by its density:

mH₂SO₄ = 2000 mL * 1.030 g/mL = 2060 g

Then the total mass is:

m = 2060 + 200

m = 2260 g

Q = 2260*4.184*(36.820 - 25.000)

Q = 111,468.03 J

Q = 111.8 kJ

The reaction is endothermic because the solution is absorbing heat (Q > 0), which can be noticed by the increase in the temperature. When the reaction loses heat, it is exothermic and the temperature decreases.

tracks, burrows, eggshells, nests, tooth marks, or gastroliths

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol