General chemistry questions Flashcards
State what is meant by the term IONIC BOND.
Electrostatic attraction between positive and negative ions, which hold cations and anions together forming an ionic bond.
Compare the electrical conductivities of solid and aqueous barium chloride.
Explain your answer in terms of the particles involved.
Barium chloride does not conduct electricity when solid and because it has ions which are fixed in position so are unable to move and carry a charge.
Barium chloride conducts electricity when in aqueous solution and because it has mobile ions which are able to transport charge.
Describe the use of aqueous barium chloride in qualitative analysis.
It is used to test for barium sulfate ions (SO4^2-). A white precipitate forms (when barium chloride solution is mixed with a solution containing sulfate ions) which are insoluble in barium, sulfate BaSO4
The calculated value of the complete combustion for hexane from this experiment is different from the databook value.
Suggest two reasons for this difference.
The heat released to the surroundings other than water.
Incomplete combustion is a different reaction to complete combustion hence has different enthalpy values.
Non-standard conditions used in the experiment would contrast with the databook value which is a standard value.
The first step in the reaction mechanism involves hemolytic fission of a chlorine molecule to form two chlorine radicals.
Why is this step an example of homolytic fission?
One electron from the bonded pairs goes to each atom leaving each atom with a single unpaired electron.
What are the conditions needed and reagent to carry out a dehydration reaction?
H2SO4 and 170 degrees
