The percentage by mass of oxygen in a compound containing potassium, chlorine, and oxygen was determined experimentally. The technique used follows. solid (KClo compound is weighed. Then it is heated in a crucible. The The solid decomposes to produce oxygen gas and a salt. Because the oxygen escaping, mass of the original solid decreases. From the mass of oxygen lost and mass is the the percentage by mass of oxygen in of the original the original compound is determined. KClyo. (s) salt (s) O (g A student performs five trials and determines the following by mass of oxygen in the compound (KCLO) by mass of oxygen Trial in the compound 38.933 38,940 38,892 38.900 a. Determine the average experimental percentage oxygen in the compound. by mass of 30.933
b. If the actual value of the percentage by mass ofoxygen in this compound is 39.13 determine the percentage error.

See explanation

Explanation:

The percentage by mass of oxygen is defined as;

Mass of oxygen/ molar mass of the compound * 100/1

The average percentage by mass of oxygen = 38.933 + 38.940 + 38.871 + 38.892 + 38.900/5

The average percentage by mass of oxygen = 38.907

Percentage Error  = (|accepted value – experimental value| \ accepted value) x 100%

Percentage Error  = 39.13 - 38.907 / 39.13 * 100

Percentage Error  = 0.57%

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3