The overall chemical equation is C(s)+H2O(g)->CO(g)+H2(g). To calculate the final enthalpy of the overall chemical equation, which step must occur?

a)Reverse the first equation, and change the sign of the enthalpy. Then, add.

b)Reverse the second equation, and change the sign of the enthalpy. Then, add.

c)Multiply the first equation by three, and triple the enthalpy. Then, add.

d)Divide the third equation by two, and double the enthalpy. Then, add.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.

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.