Nitrogen dioxide is a gas that can be generated by emissions from vehicles and factories. It can also be generated by natural sources, such as forest fires, lightning, and microbial activity in soil. The equation for producing nitrogen dioxide is shown below. 2NO + O2 1 2NO2 Colorless Colorless Gass Gas 48.7g ? Brown Gas 67.21g Which of the following best represents the amount of Oxygen gas needed for this reaction to follow the Law of Conservation of Mass? Record your answer and fill in the bubbles on your answer document. Be sure to use the correct place value. aliokrina the bubbles