What does the letter r symbolize in a structural formula, such as rcooh?

Achemist is studying the following equilibirum, which has the given equilibrium constant at a certain temperature: 2 no(g) + cl2(g) < => 2 nocl(g) kp = 2 x 10^(-6)he fills a reaction vessel at this temperature with 13. atm of nitrogen monoxide gas and 12. atm of chlorine gas. use this data to answer the questions: a. can you predict the equilibrium pressure of noci, using only the tools available to you within aleks? y/nb. if you said yes, then enter the equilibrium pressure of nocl at right. round your answer to 1 significant digit.