Answer:
Mass is a measure of the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg), but smaller masses may be measured in grams (g).
Enthalpy of formation is defined as the heat change that is needed for formation of one mole of substance from its constituent elements in pure state.
In present case, Heat of formation of one mole of C2H6 at <span>101.3 kpa and 298 k is -84 kJ/mol. Negative sign indicates that, heat is evolved from the system.
Thus, for two mole of ethane, heat of formation will be 2 X (-84) = -168 kJ/mol.
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Answer:
I think it's c I hope this helps
<span>A molecule consists of two or more atoms that are chemically bonded. together. Atoms ... In a nuclear change new materials are formed by changes ... In one isotope called Deuterion the nucleus contains a proton and a neutron. ... It has 3 protons and 4 neutrons in its nucleus and 3 electrons. Two of .... Yttrium 39 2 8 18 9 2.</span><span>
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