Nitric acid+sodium=>sodium nitrate+hydrogen

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

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).