1. The dissociating constant of butyric acid C3H, COOH is 1.5x 10 Calculate the degree of its dissociation in a 0.005 M solution.
2. What is the hydrogen ion concentration [H*) in an aqueous solution of formic
acid if a = 0.03?
3. Calculate the concentration of acetate ions in 0.1 M solution of acetic acid in
presence of 0.01 M HCl.
4. Calculate the ionic strength and the activities of the ions in a solution containing
0.01 mole. l' of Ca(NO3)2 and 0.01 mol/l of CaCl2

They can measure  the amount of energy gained or lost

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

Where are the following questions

Must be negative.substance increases