Una muestra de agua de 100 mL con pH inicial de 9,5 se titulo con Ácido Sulfúrico 0,02 N, la muestra consumió 8 mL del ácido para llegar a un pH de 8,3, luego se necesito de 13 mL adicionales del mismo ácido para llegar a un pH de 4,5. Teniendo en cuenta lo anterior, calcule en ppm de Carbonato de Calcio: a) La alcalinidad debida a los iones hidróxido

b) La alcalinidad debida a los iones bicarbonato

c) La alcalinidad debida a los iones carbonatos

d) La alcalinidad total

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

#20 which type of bond is formed when bases pair in dna? ionic bond covalent bond coordinate bond hydrogen bond

Which fossil fuel is mainly used for heating and cooking? a. electricity b. coal c. petroleum d. natural gas