Idon't get it how the question says select all that apply and only give us one answer don't you think its common sense that there is more than one answer

Un cierto gas tiene un volumen de 800ml a 80°c y 600ml a 80°c y 600mmhg de presión. ¿cual será el volumen del gas a condiciones normales? sí el gas es oxígeno, ¿cuál será su peso? y ¿cuántas moléculas están presentes en el sistema?

200. ml of 3.00 m nacl solution is diluted to a final volume of 500. ml. what is the molarity of the final solution?

Suppose that during that icy hot lab 65,000 j of energy were transferred to 450 g of water at 20°c what would have have been the final temperature of the water