1. Cierta muestra fue diluida así: 1 mL MP se agrega 4mL de agua, luego se extrae 0,5 mL y se lleva a 5 mL y de esta última se obtiene 0,2 y se añade 1,3 de diluyente. Calcule la dilución total.

1/375

Explanation:

Primero se debe calcular el factor de dilución para cada dilución seriada. Para ello, se divide el volumen de muestra entre el volumen final de la solución diluida.

1) 1 mL  en 1 mL + 4 mL = 5 mL

D1 = 1 mL/5 mL = 1/5

2) 0,5 mL en 5 mL

D2 = 0,5 mL/5 mL = 1/10

3) 0,2 mL en 0,2 mL + 1,3 mL = 1,5 mL

D3 = 0,2 mL/1,5 mL = 2/15

La dilución total se calcula como el producto de las diluciones seriadas realizadas:

DT = D1 x D2 x D3 = 1/5 x 1/10 x 2/15 = 1/375

b) mutualism

hope this : )

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.