Hannah does an experiment. She has two colorless chemicals that she mixes together in a beaker. Which of the following indicates that a chemical change occurs when she mixes the two chemicals together? I. The chemicals change color from colorless to purple.

II. A yellow gas form.

III. A brown solid forms in the bottom of the beaker.

IV. The temperature of the chemicals rises 15°C.

need answer asap

am i too late?

explanation:

wher is the rest of the question

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.

un recipient conține 6,4 moli de gaz. gazul hidrogen reprezintă 25% din totalul kilometrilor din container. în cazul în care presiunea totală este de 1.24 atm ceea ce este