4 This question is about rusting.
(a) When iron rusts, it-reacts with oxygen in the air.
A student uses the rusting of iron to find the percentage of oxygen in a sample of air.
The diagram shows the apparatus.
100 80 60 40 20
cm
air
gas syringe
conical flask
wet iron
filings
These are the student's results.
volume of air in conical flask and connecting tube = 265 cm
volume of air in gas syringe at start = 100 cm
volume of air in gas syringe at end = 25 cm
Calculate the percentage of oxygen in the sample of air using the student's results.
(3)​

What would most likely be the transmittance of a 0.70 m solution of solute a?

In an exothermic reaction the bonding energy of the product is: less than the reactants same as the reactants greater than the reactants dependent upon the presence of a catalyst

Many reactions take place in aqueous solution. when potential reactants are mixed, a reaction will occur if there is some driving force that favors the formation of products. it is often convenient to categorize reactions in terms of these driving forces: precipitate formation, in which an insoluble solid is formed, weak electrolyte formation, as in a neutralization reaction involving water, or transfer of electrons, as in a redox reaction. these reactions can be represented by full molecular equations, which contain all species in the reaction mixture, or by net ionic equations, which show only the species that actually undergo a change. the latter does not contain the spectator ions, which do not undergo a net change or do not take part in the reaction. part a when the following two solutions are mixed: k2co3(aq)+fe(no3)3(aq) the mixture contains the ions listed below. sort these species into spectator ions and ions that react. drag the appropriate items to their respective bins. view available hint(s) spectator ions ions that react part b what is the correct net ionic equation, including all coefficients, charges, and phases, for the following set of reactants? assume that the contribution of protons from h2so4 is near 100 %.ba(oh)2(aq)+h2so4(aq)→ express your answer as a chemical equation. view available hint(s) nothing provide feedback