Suppose you are working with a NaOH stock solution but you need a solution with a lower concentration for your experiment. Calculate the volume (in mL ) of the 1.400 M stock NaOH solution needed to prepare 250.0 mL of 0.1476 M dilute NaOH solution. Type answer:

You need to calculate the enthalpy change \( \left(\Delta H^{0}\right) \) of the reaction \( \mathrm{A}+\frac{1}{2} \mathrm{~B} \rightarrow \mathrm{C} \). How can the enthalpies given for the reaction steps below be combined to give the overall change in enthalpy? \[ \mathrm{A}+\mathrm{B} \rightarrow \mathrm{D} \]

At what temperatures is an exothermic reaction spontaneous? A. At higher temperatures when the change in entropy is negative B. At no temperatures C. At all temperatures all the time D. At all temperatures when the change in entropy is positive

The electronic configuration of one element is \(1s^ 2 2s^ 2 2p^ 6 3s^ 2 3p^ 6 3d^ { 10} 4s^ 1\). What is same group which is recently discovered?

Tenga en cuenta la ley de los gases para resolver los siguientes ejercicios ( 1.0 puntos). Un gas se encuentra en un recipiente cilíndrico con diámetro 160 cm y 0.9 m de alto a una presión de 950 mmHg y \( 220^{\circ} \mathrm{F} \). ¿Qué presión se debe ejercer para ocupar un volumen de \( 1,9 \mathrm{~m}^{3} \) a \( 320^{\circ} \mathrm{C} \) ? ( 0.7 puntos). Si en un recipiente con \( 1 \mathrm{~m}^{3} \) de volumen a 1.4 atm y 80 K , se encuentra Oxigeno \( \left(\mathrm{O}_{2}\right) \) ¿Cuántos kilogramos del gas contendrá dicho recipiente?.

The half-life of the radioactive element unobtanium- 47 is 10 seconds. If 80 grams of unobtanium- 47 are initially present, how many grams are present after 10 seconds? 20 seconds? 30 seconds? 40 seconds? 50 seconds?