During an exothermic reaction, H for the reactants was 890 kJ/mol. Which of the following statements is correct about the H for the products and the comparison of the energy in bonds? Select one:
a. It is less than 890 kJ/mol, and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
b. It is less than 890 kJ/mol, and the amount of energy required to break bonds is less than the amount of energy released in forming bonds.
c. It is greater than 890 kJ/mol, and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
d. It is greater than 890 kJ/mol, and the amount of energy required to break bonds is less than the amount of energy released in forming bonds.

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >