Give an example of a purely physical change and an example of a chemical change

Which of the following is NOT considered a branch of Chemistry? Organic Chemistry Biochemistry Analytical Chemistry Inorganic Chemistry Physical Chemistry Pure Chemistry How many significant digits are in the number 0.0001305? 3 4 7 8

Given the balanced equation: 2 KI + F2 - -> 2 KI + I2 Which type of chemical reaction does this equation represent?

The OH - ion concentration is greater than the H3o + ion concentration in a water solution of A) HCl B) CH3OH C) H2SO4 D) Ba (OH) 2

Which of the following polyatomic ions will form an ionic compound with two sodium ions? CO32- HCO31- NO21- NO31-

Atoms of which element have the greatest tendency to gain electrons? (1) bromine (3) fluorine (2) chlorine (4) iodine

Suppose that a solution is tested for NO2 ion by adding 3M H2SO4 and heating, repeating this process until no further reaction occurs.

Is pepperoni pizza an element?

What is the molarity of a 31% (w/v) glucose solution? the chemical formula for glucose is c6h12o6.?

What is diffusion and osmosis?

Why are H2S, mercaptans, sulphur compounds and salt removed from the crude oils?