Astudent mixes a 10.0 ml sample of 1.0 m naoh(aq) with a 10.0 ml sample of 1.0 m hcl(aq) in a polystyrene container. the temperature of the solutions before mixing was 20.0°c. if the final temperature of the mixture is 26.0°c, what is the experimental value of dhrxn 

The value of for the experiment will be 19.278 J.

can be defined as the change in enthalpy of product and reactant in the chemical reaction.

The value of can be given as:

= msT

m = mass of reactant

s = specific heat = 4.2 g/mol

T = change in temperature = 26 - 20   = 6  

moles = Molarity Volume (L)

Moles of NaOH = 1 M 0.01

Moles of NaOH = 0.01 mol

Moles of HCl =  1 M 0.01

Moles of HCl = 0.01 mol

Mass of 0.01 mol HCl = 0.01 36.5 grams

Mass of 0.01 mol HCl = 0.365 grams

Mass of 0.01 mol NaOH = 0.01 40

Mass of NaOH = 0.4 grams

The total mass of reactants = 0.365 + 0.4

Mass of reactants = 0.765 grams

= 0.765 4.2 6

= 19.278 J

The value of for the experiment will be 19.278 J.

For more information about enthalpy, refer to the link:

link

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm

58750.08068 is the answer i think