For which of the following reactions is î"hârxn equal to î"hâf of the product(s)?

you do not need to look up any values to answer this question.

check all that apply.

1. 2na(s)+cl2(g)→2nacl(s)
2. na(s)+12cl2(l)→nacl(s)
3. c(s)+o2(g)→co2(g)
4. na(s)+12cl2(g)→nacl(s)
5. caco3(g)→cao+co2(g)
6. co(g)+12o2(g)→co2(g)

1, 2, 3 and 4.

Explanation:

Hello,

Standard enthalpy of reaction is defined by the difference between the products whole enthalpy and the reagents whole enthalpy. It is known that an element's (by itself or as a diatomic gas) enthalpy of formation is 0, turning out into an equality between the enthalpy of formation and the products whole enthapy. Thus, the reactions that accomplish the given questions are 1, 2, 3 and 4, since the reagents are just the elements sodium, chlorine, carbon and oxygen.

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c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current