For a particular catalyzed reaction, the change in enthalpy is 26kJmole and the activation energy is 67kJmole. Which can be the change in enthalpy and the activation energy for the uncatalyzed reaction

26kJmole,84kJmole

Explanation:

A catalyst lowers the activation energy between reactants and products. Once this energy barrier is lowered, reactants are converted into products faster.

However, the enthalpy change of a reaction is constant both in the catalysed and uncatalysed reaction.

The activation energy of the uncatalysed reaction must be higher than the activation energy of the catalysed reaction. Hence the answer above.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.