There are health concerns around cooking with gas, since burning natural gas in air produces some nitrogen oxides $(N{O}_x),$ which are air pollutants, as a byproduct.

a$.$ This research article measured the rate of $N{O}_x$ emission from a residential stove burner. In the Abstract and again in the Results and Discussion section, it reported an average value for combined nitrogen oxides $(N{O}_x)$ in terms of $ng$ of $N{O}_x$ per $J$ of heat released. Report that value.

b$.$ Based on that value, what is the rate of $N{O}_x$ generation in $m\frac{g}{h}r$ for a burner producing $7000BT\frac{U}{h}r$ of heat?

c$.$ Suppose someone ignites a $7000-$BTU burner to begin cooking in a kitchen with a volume of $71m^3,$ with decent ventilation at $4\mathrm{.}2$ turnovers per hour. $N{O}_x$ is believed to be harmful above concentrations of about $0\mathrm{.}120m\frac{g}{m^3}.$ At the generation rate you calculated in $($b$),$ how long would it take for the $N{O}_x$ concentration to reach the harmful level? Assume that outdoor air contains no $N{O}_x$ and that the $N{O}_x$ does not undergo reactions after being emitted from the burner.