The complete oxidation of one mole of a sugar produces carbon dioxide and water. 2000 kj of heat is transferred from the system to the surroundings. the rearrangement of bonds as 0.5 moles of the sugar are oxidized generates heat in an open test tube (101 j•l–1 pressure and 300 k temperature). what is the change in internal energy of the system (δu)? what is the change in enthalpy of the system(δh)?

Explanation:

According to the first law of thermodynamics,

When there is no work done then, w = 0.

As, 0.5 mole of sugar generates heat (q) = -2000 kJ

So, amount of heat (q) generated by 1 mole of sugar will be calculated as follows.

                    = -1000 kJ

So, putting the values into the above formula as follows.

                                  = -1000 kJ + 0

                                  = -1000 kJ

Also, according to the definition of enthalpy the relation between enthalpy and internal energy is as follows.

As change in volume is 0.

Hence,

                         = -1000 kJ

Thus, we can conclude that the change in enthalpy of the system() is -1000 kJ.

no

explanation:

go away, people want answers, not to hook up

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms