The percent by mass is the ratio of the mass of each element to the total mass of the compound expressed as a percentage. Attached is the formula. What is the percent by mass of Oxygen in 10 grams of H20 given the mass by analysis of oxygen in that sample is 8 grams. (Answer should be given with a %. i. e. if the answer were 23% you answer in the textbox would be 23%) Percent by mass = mass of solute mass of solution x 100
help me please:((

The percent by mass of Oxygen : 80%

According to Proust: the mass percentage of the constituent elements of a compound is constant⇒compounds have a constant composition of elements

Given

mass of Oxygen (solute)= 8 grams

mass of H₂O(solution)=10 grams

Required

Percent by mass

Solution

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.