Mr. Abersold informed his class that, under normal conditions, water boils at 100°C. He wanted to demonstrate that if the conditions change, water can boil at a lower temperature. Mr. Abersold used a hot plate to warm a beaker of water to 43°C. In step 1, he used a syringe to pull water out of the beaker. He made sure that the syringe was sealed and no air was inside. In step 2, he pulled up on the syringe plunger, which increased the space inside the syringe. When he did this, the water began to boil at 43°C, as shown in the image below. What caused the water in the syringe to boil at 43°C? A. The thermal energy of the water increased. B. The pressure on the water decreased. C. The air around the water started moving. D. The water was put into motion by his hand.

Explanation:

Mr. Abersold informed his class that, under normal conditions, water boils at 100°C. He wanted to demonstrate that if the conditions change, water can boil at a lower temperature. Mr. Abersold used a hot plate to warm a beaker of water to 43°C. In step 1, he used a syringe to pull water out of the beaker. He made sure that the syringe was sealed and no air was inside. In step 2, he pulled up on the syringe plunger, which increased the space inside the syringe. When he did this, the water began to boil at 43°C, as shown in the image below. What caused the water in the syringe to boil at 43°C? A. The thermal energy of the water increased. B. The pressure on the water decreased. C. The air around the water started moving. D. The water was put into motion by his hand.

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.