Sarah gets ready for work every morning. When she gets up, she brushes her teeth, washes her face, and combs her hair. She folds her pajamas and makes her bed. For breakfast, she boils water to make tea and eats toast with peanut butter. She drives to work in her car, and when the sun shines brightly, she unfolds her sunglasses and puts them on. On this winter morning, she needs to turn on the defroster in her car to clear the windshield of ice. She crumples a piece of paper and throws it in a plastic bag she keeps in the car. As she parks her car at work and gets out of her car, she notices that it’s cold enough to see her breath. She hurries to the building to get out of the cold. 1. Based on the text above, list the instances of physical and chemical changes described.

2. Write your own scenario and include at least three instances of physical changes and three instances of chemical changes.

answer; protein;

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :

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.