Which of the following chemical equations corresponds to the standard molar enthalpy of formation of Na_2CO_3(s)? a. 2 NA(s) + C(s) + 3 O(g) > Na_2CO_3(s)
b. Na_2O(s) + CO_2(g) >Na_2CO_3 (s)
c. Na_2(s) + C(s) + 3 O(g) > Na_2CO_3 (s)
d. Na_2O(s) + CO(g) > Na_2CO_3(s)
e. 2 Na(s)+ C(s) + 3/2 O_2(g) > Na_2CO_3(s)

2 Na(s) + C(s) + 3/2 O₂(g) → Na₂CO₃(s)

Explanation:

The molar enthalpy of formation of a chemical is defined as the change in enthalpy during the formation of 1 mole of the substance from its constituent elements (Constituent elements are pure elements you have in the periodic table)

For Na₂CO₃ constituent elements are Na(s), C(s) and O₂(g) and the chemical equation that represents the molar enthalpy is:

Puberty stage include different types of changes including cognitive (emotional), physical (voice, pubic hair, genitalia, etc.) and physiological (synthesis of sex steroid hormones) modifications

Explanation:

Physical puberty changes in girls occur from ages 10  to 14 and they are associated with the growth of pubic and underarm hair, breast development, and the first menstrual period (known as menarche). In boys, puberty occurs from ages 10 to 20, being this period associated with the growth of the testicles, the growth of pubic hair, changes in the voice, presence of sperms in the seminal fluid, etc.

Puberty hormones:  

     - Boys and girls: gonadotrophin-releasing hormone (GnRH) required for the production of Follicle Stimulating (FSH) and Luteinizing (LH) hormones

     -Boys: testosterone  

     -Girls: estrogen