A) In an experiment, a student needed to use a 0.25 M NaOH solution as standard solution. He prepared 250 mL of the working solution from a stock solution labeled as 50% NaOH. Despite knowing the concentration of the stock and working solutions, the student still needs to standardize the working solution. Give one property of NaOH that explains why the student is still required to standardize the working solution despite knowing he was preparing 0.25 M NaOH solution from the stock solution. Justify your answer. (2 marks)

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. 

Idon’t know what the answer is i wish i could