It's tough even for geezers who've been investing forever to blurt out the name of a more recognized company than ExxonMobil (NYSE: XOM).

Following its year-ago $35 billion acquisition of natural gas producer XTO Energy, Exxon became an active operator in unconventional natural gas plays, moving ahead of Chesapeake (NYSE: CHK) as the nation's top gas producer. But despite the importance of diversification for both companies and investors, Exxon's status as the world's second-largest chemicals manufacturer -- behind Germany's BASF -- often goes unnoticed.

ExxonMobil Chemical, which chalked up operating income of $1.52 billion in the most recent quarter, is in the process of spending billions of dollars to expand its production facility in Singapore. The enlargement will increase by 11% the company's capacity to turn out plastics and other products made from petrochemicals. In the process, the Singapore operation will surpass Exxon's big Baytown, Texas, facility as its largest petrochemical-refining operation.

Exxon began the Singapore expansion with an eye toward China's increasing demand for chemical products. Indeed, Exxon's management expects petrochemical demand to realize compounded annual growth of 5% through 2020, with half of the hike likely emanating from China. Once completed, the Singapore facility will be able to produce significantly more feedstocks than it currently can.

This isn't to indicate that Exxon's chemical segment is the only member of its industry that is on the go, or even that China is the sole source of chemical demand. For instance, BASF has multiple projects in Brazil on the drawing board. And Dow Chemical (NYSE: DOW) may construct a large plant near the Gulf of Mexico coast, a project also being considered by Chevron (NYSE: CVX) and ConocoPhillips (NYSE: COP), which together operate Chevron Phillips Chemical Co.

Along with the chemical industry's announced new ventures, an active merger and acquisition climate portends ongoing strength for the group. For instance, last month DuPont (NYSE: DD) completed a $6 billion purchase of Danisco, a Danish maker of food ingredients. At the same time, Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B) is forking over $9 billion for Lubrizol.

Despite ExxonMobil's underappreciated chemicals unit, the company continues to achieve upstream oil and gas successes. On Thursday, for instance, it received an award at Houston's annual Offshore Technology Conference for successfully completing deepwater projects in Angola that have delivered peak production of 700,000 barrels of oil per day.

Given that the market recently has begun to wobble somewhat, I feel strongly that Fools would be wise to monitor sizable companies that demonstrate across-the-board strength. ExxonMobil obviously fits that bill nicely. Why not add the big company to your watchlist?