Consider the following gas phase reaction: 2NO(g) + O2(g) --> 2NO2(g)

400. mL of NO at STP is reacted with 500. mL of O2 at STP. Calculate the volume of the reaction mixture at STP after the reaction goes to completion.

A.700 mL
B.800 mL
C.900 mL
D.1300 mL
E.100 mL

The answer is A. 700 mL, can someone please explain how they arrived at that answer.

Which statement describes how phase changes can be diagrammed as a substance is heated? the phase is on the y-axis and the temperature is on the x-axis. the temperature is on the y-axis and the phase is on the x-axis. the time is on the y-axis and the temperature is on the x-axis. the temperature is on the y-axis and the time is on the x-axis.

The reaction q+r2=r2q is found to be first order in r2 and

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.