Choose the reaction that represents Delta H^ _f for Ca(NO_2) 2. A) Ca(s) + N_2 (
ID: 532769 • Letter: C
Question
Choose the reaction that represents Delta H^ _f for Ca(NO_2) 2. A) Ca(s) + N_2 (g) + 3O_2 (g) rightarrow Ca(NO_3)_2 (s) B) Ca^2+ (aq) + 2 NO^-_3 (aq) rightarrow Ca(NO_3)_2 (aq) C) Ca(s) + 2 N(g) + 6O(g) rightarrow Ca (NO_3)_2 (s) D) Ca(NO_3)_2 (aq) rightarrow Ca^2 (aq) + 2 NO^-_3 (aq) E) Ca (NO_3)_2 (s) rightarrow Ca(s) + N_2 (g) + 3O_2 (g) Use the Delta H^ _f and Delta H^ _rxn information provided to calculate Delta H^ _f for if: IF_7 (g) + I_2 (g) rightarrow IF_ (g) + 2 IF(g) Delta H^ _rxn = - 89 kJ/mol A) 101 kJ/mol B) -146 kJ/mol C) - 190. kJ/mol D) -95 kJ/mol E) 24 kJ/mol Calculate the frequency of the red light emitted by a neon sign with a wavelength of 659.9 nm. A) 2.20 times 10 ^ s^-1 B) 1.98 times 10^ s^-1 C) 4.55 times 10^ s^-1 D) 5.05 times 10^ s^- E) 3.32 times 10^ s^-1 Which of the following visible colors of light have the largest frequency? A) green B) red C) blue D) yellow E) orangeExplanation / Answer
Ans 26. A) Ca(s) + N2(g) + 3O2(g) = Ca(NO3)2
The enthalpy of formation of Ca(NO3)2 can be calculated from the reaction that involves the use of reactants in its most standard forms.
So the reaction A hold good for calculating this enthalpy change