Answer:
Please re do your question I not able to understand what is your problem asking.
1- Yo haría mi tarea esta noche pero no se como hacerla.
2- Yo compraría un coche nuevo pero yo no tengo bastante dinero.
3- Yo comería el almuerzo esta tarde pero ya no tengo hambre porque acabo de comer.
4- Yo Iría a Costa Rica pero yo no tengo bastante tiempo para ir de vacaciones.
The correct demonstrative adjective for this sentences would be "este".
* Este niño en la foto es mi primo Francisco". Because "ESTE" refers to a singular male subject. If it would have been a girl, the correct option would have been "ESTA". For plurals we need to use "estos" and "esa" when it is a singular, female and we point the subject at a certain distance. "Esa es mi prima" --> That is my cousin (over there)
Write equations (balanced) for the reaction of nitric acid with each of the following.
(i) sodium
(ii) magnesium oxide
(iii) ammonia