The manufacture of aluminum includes the production of cryolite (na3alf6) from the following reaction: 6hf+3naalo2=na3alf6+3h2o+al2o3 how much naalo2 (sodium aluminate) is required to produce 3.47 kg of na3alf6?

6HF  +  3  NaAlO2  =  Na3AlF6  +3H2O  +Al203
calculate  moles  of  Na3AlF6   formed

moles  =mass/molar  mass
molar  mass  of  Na3AlF6  =209.94  g/mol
convert 3.47Kg  to  grams  ,  that  is  3.47  x1000=  3470  grams
moles  is  therefore= 3470  g/ 209.94  g/mol  =  16.53  moles

by  use  of  mole  ratio  between  NaAlO2  to  Na3AlF6  which  is    3:1  therefore  the   moles  of  NaAlO2   is  (16.53  x3)/ 1=  49.59  moles
mass  of  NaAlO2 is  =moles  of  NaAlO2  x  molar  mass  NaAlO2

that   is  49.59  mole  x  81.97 g/mol =  4064.89 grams  or  4.065  Kg

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.