A student is testing a solid material to determine whether it is a pure substance or a mixture. Which observation would MOST likely indicate that the material is a mixture?
The material has crystals of two different colors.
The material does not dissolve completely in water.
The material does not melt when it is heated over a burner.
The material reacts with an acid solution to form bubbles of gas.

Base your answer on the information below and on your knowledge of chemistry. nitrogen dioxide, no2, is a dark brown gas that is used to make nitric acid and to bleach flour. nitrogen dioxide has a boiling point of 294 k at 101.3 kpa. in a rigid cylinder with a movable piston, nitrogen dioxide can be in equilibrium with colorless dinitrogen tetroxide, n2o4. this equilibrium is represented by the equation below. 2no2(g) n2o4(g) + 58kj at standard pressure, compare the strength of intermolecular forces in no2(g) to the strength of intermolecular forces in n2(g).

Match term definition ellipse a) diagonal cross section of a cylinder circle b) diagonal cross section through the widest part of a sphere sphere c) cross section parallel to the base of a cone great circle d) shape created when a semi-circle is rotated around the y-axis triangle e) perpendicular cross section of a cone

How can one make a supersaturated solution? (apex)